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Showing content with the highest reputation since 07/12/2020 in Articles

  1. 7 points
    We know this is technically 'Thumper'Talk, but we also know a lot of you have 2-strokes in your garage. We want to share some tips we put together that will help you prevent and diagnose potential problems with your 2-stroke engine. Bookmark this maintenance guide to help keep your bike on the track or trail and off the bench! Article by Paul Olesen. Two-stroke engines have a storied history of being finicky beasts. If you’ve been around two-strokes for any length of time, you’ve probably heard stories that start and end to this effect: “It was running amazing...then the next thing you know - it blew”. We find these stories interesting, and empathize with the unfortunate owners or riders who tell them. At the same time, however, it is often wondered if there were any signs that could have predicted the fateful date with destruction. Photo: Steve Cox We're going to discuss and share a number of observations and diagnostic tests that can be performed to help identify whether or not your engine is going to leave you in the unfortunate role of the broken engine storyteller. While many operators are insistent that their engine gave up without warning, this is often not the case. We’ll start by going over observations that can be made with the engine running, and progress into diagnostic tests that can be routinely made to assess engine health. Recognizing Symptoms Startability Does the engine struggle to start when kicked, but is more prone to coming to life when the electric start is used or when the machine is bump started? Poor starting under normal conditions is not an inclusive sign that the engine is doomed to a spectacular failure, but it is a sign that something is amiss. Carburetion or injection issues are possible, but the bigger potential issue to be aware of resides within the cylinder. Worn piston rings can cause incomplete sealing, resulting in lower compression and more difficulty in starting. Worn piston rings or reed valves that are no longer sealing properly may be the cause of the poor startability characteristic. When the piston rings don’t seal properly, the engine doesn’t build good compression, so when kicked, the engine struggles to come to life. Similarly, if the reed petals are damaged or broken, less air will be trapped in the cylinder. Push the machine or use electric start, and the compression event is shortened via faster rotational speeds, which may be just enough to bring the engine to life. Damaged or worn out reed petals will allow air to leak out, creating less cylinder pressure and starting/running difficulties. Inconsistent Performance Does the engine struggle to hold a tune, or seem like the jetting constantly needs attention, despite relatively stable atmospheric conditions? Sporadic running is not always a death sentence, but should be investigated further. A dirty carburetor or worn spark plug can contribute to this behavior, but the problems that can lead to catastrophe are worn engine seals or gaskets. Stator side crank seals, leaking base gaskets, or intake manifold gaskets are all examples of seals that will result in air leaks which can lean out the air fuel ratio. Lean air/fuel ratios when running at full power can result in excessive combustion temperatures, which can melt a hole in the piston or seize them in the cylinder bore. Ignoring the possibility of a bad gasket or seal isn't worth the potential damage, especially with the affordability of OEM quality gasket kits from ProX. Gearbox Oil Consumption Loss of gearbox oil is abnormal, and in all cases should be able to be traced back to leaking seals or gaskets. In the unlikely event the bike tipped over or cartwheeled, gearbox oil can occasionally exit via the gearbox/crankcase breather. If the gearbox is losing oil but the leak path cannot be identified externally, there is a good chance the drive side crankshaft seal is leaking and allowing the gearbox oil to migrate into the crankcase. During the scavenging process the oil is transferred up into the combustion chamber and burned. Tracking down a leak like this and finding you need new crankshaft seals will commonly turn into a bottom end rebuild job. If you're going to tear into the bottom end to replace seals, that same amount of wear the seal experienced could be evident in other components as well, including your crankshaft and bearings. Not only does ProX make it easier to tackle a bottom end rebuild with our rebuild guide (10 Tips for a Dirt Bike Bottom End Rebuild), but one of the most recent additions to the OEM-quality replacements parts lineup are complete crankshafts. Dropping in a complete ProX crankshaft paired with a main bearing and seal kit is an affordable option for reliable performance. ProX crankshafts are assembled with double-forged, Japanese steel connecting rods, as well as Japanese big-end bearings, crank pins, and thrust washers, all manufactured by OEM suppliers. Excessive Smoke After Warm Up Since the engine is burning pre-mix oil we have to be careful here, because blueish-white smoke is a normal occurrence of two-stroke engine operation. However, excessive smoke after warm up can be an indicator of a couple problems. Blue smoke exiting the exhaust pipe after the engine has warmed may be a sign that gearbox oil is burning in the combustion chamber. While I would never encouraging sniffing your exhaust, combusted gearbox oil will have a different odor than the normal pre-mix oil the engine is using. White smoke exiting the exhaust pipe after the engine has warmed may be a sign that coolant is burning in the combustion chamber. The root of this problem is typically a leaking cylinder head gasket or o-rings. Excessive Coolant Exiting the Overflow Tube While it is common for coolant to exit the overflow tube when the bike has been tipped over or when it has overheated, it should not occur regularly. Coolant blowing out the overflow tube is another good indicator of a leaking head gasket. Note where your coolant overflow line runs, so you can keep an eye out for overheating issues. Coolant Weepage Dribbles of coolant exiting the engine around the coolant pump are indicative of a faulty water pump seal. If left unattended, the entire cooling system will eventually empty, causing overheating and an incredible amount of damage. Excessive Top End Noise Isolating top end noise in a two-stroke is easy since the only moving component is the piston assembly. Discerning what is normal takes a trained ear and familiarity with the particular engine in question. However, audible cues often present themselves when components wear or clearances loosen up. The most common noise associated with a two-stroke top end is a “metallic slap”. This is commonly referred to as piston slap, and is a result of the piston rocking back and forth in the cylinder bore as it reciprocates. This phenomena is normal, but the intensity of the slap will increase as the piston skirt and cylinder bore wear. Left unattended, excessive piston slap can result in failure of the piston skirt. Check out our complete 2-stroke top end rebuild guide here. Excessive piston slap can cause damage to the piston and weaken the skirts. It's important to check piston-to-wall clearance when installing a new piston to ensure a long operating life. 2-Stroke pistons fitted with skirt coatings also help reduce friction and operating noise. Diagnostic Checks & Tests Engine Coolant Coolant contaminated with black specks can often be traced back to a leaking head gasket or o-rings. Combustion byproducts are forced into the coolant system due to the high pressures in the combustion chamber during the combustion event. These black specks will often float and show themselves as soon as the radiator cap is removed. Gearbox Oil The composition of the gearbox oil can provide a lot of clues as to what is happening within the engine. For starters, what color is it and what is in it? Oil that appears milky is a good indicator that moisture is finding its way into the gearbox oil. The most common culprit is a faulty oil side water pump seal. A keen eye can spot various metallic particles within the oil itself. Aluminum will appear silvery gray. Bronze particles will have a gold shine. Ferrous particles will be dull and are often more discernable by dragging a magnet through the oil. Accumulation of all of these aforementioned particles will be normal in small quantities, but excessive amounts of any of them could be cause for concern. Fortunately, since gearbox and power cylinder lubrication are separate the number of causes for problems is limited and more easily pinpointed. Other than changing your gearbox oil regularly, keep an eye out for metallic particles, as those can be a sign of accelerated wear on internal parts. Cylinder Leak Down Testing While less commonly prescribed on two-stroke engines, performing a cylinder leak down test is by far one of the most definitive diagnostic procedures that can be performed to determine the health of the piston rings, cylinder bore, and cylinder head seal, whether gasket or o-rings. If any of the previously mentioned symptoms are observed, a leak down test is almost always a great next step. A leak down test pressurizes the engine’s combustion chamber and compares the amount of pressure going into the combustion chamber to the pressure that is retained. Pressurized air is administered via the spark plug hole and two pressure gauges are used to make the comparison. The piston is positioned at top dead center. Air exiting the combustion chamber can then be traced back to the piston rings or cylinder head seal. Compression Testing A compression test can be an tell-tale indicator of the health of your top end components. Be sure to compare your reading the manufacturer's recommended compression measurment. A compression test aims to quantify how much pressure builds during the compression event. A compression tester which is connected to the spark plug hole consists of a pressure gauge and a one way check valve. The engine is kicked repeatedly or turned over a number of times using the starter. The resulting pressure that is recorded can then be used to assess the health of the cylinder bore. Low pressure readings can then be attributed to problematic piston rings or leaking cylinder head seals. Crankcase Leak Down Testing A crankcase leak down test is utilized in order to assess the sealing integrity of the crankcase and cylinder. Personally, this is one of my favorite tests to perform because of its ability to isolate a number of potentially problematic seals and gaskets all at once. Components such as crank seals, base gasket, and power valve seals can all be checked to determine if they’re leaking. In summary, a crankcase leak down test is performed by sealing the intake manifold, exhaust outlet, and any power valve breathers. Then the crankcase is pressurized under low pressure. Typically, the goal is to retain the pressure in the crankcase over a set length of time. Loss of pressure is indicative of leaks, which can then be traced to their cause. Preemptively replacing components before the engine suffers a major failure is both safer and more affordable than dealing with the problem after the engine has stopped working entirely. Most problems that can occur within the two-stroke engine can be mitigated by servicing components such as pistons, rods, rings, bearings, seals, and crankshafts. Many riders dread the thought of having to service these items due to the excessively high costs associated with OEM or premium aftermarket parts. Fortunately, brands such as ProX offer a comprehensive lineup of OEM-quality components at reasonable prices, many of which are produced by OEM suppliers. Depending on what you need to service, components such as piston kits, connecting rods, crankshafts, bearings, gaskets, and seals can all be found in the ProX catalog. Replacing components as part of preventative maintenance can save time and money, especially with the availability of affordable, OEM quality parts. Find ProX parts for your machine here. Discussing specific time intervals in regards to when things should be replaced is futile. The reason is simple: different engines, maintenance practices, and applications will all have different intervals. Installing an hour meter on your engine so that you can log the number of hours the engine has run can be one of the most insightful ways to establish maintenance and replacement intervals specific to your engine, riding, and maintenance habits.
  2. 2 points
    Paper and mesh filters take a fundamentally different approach to filtering. Mesh filters filter down to a certain size, and for practical purposes, no smaller than that. They do, however, only require a single pass to filter to that level. They work by simply having a very strictly controlled mesh size, through which a spherical object larger than that size cannot pass. They are rated in "absolute" terms, as with the Scotts (35μm "absolute"). This rating tells you that nothing larger than 35μm (35 microns) will pass through it. (1 micron, or micrometer more correctly, is 1/1,000,000 of a meter, or 0.001 mm, or 0.000039") Mesh filters are able to achieve this level of filtration with remarkably low resistance to fluid flow as well, which in the case of the Scotts means that the bypass valve will not open on cold starts, and there will be no appreciable pressure loss across the filter. Scotts Performance Stainless Steel Oil Filter "Paper" filters are different. They can stop even finer debris than mesh filters, but they also allow some larger debris to pass. They filter somewhat the same way a thick shrub catches objects thrown into it. Most tennis balls get stuck, but not all. An occasional golf ball gets caught, but an occasional soccer ball passes through to balance that out. HiFlo Filtro Paper Oil Filter The random arrangement and density of the fibers in the element create odd and irregular gaps through which debris can pass. This creates little crotches of sorts that enable the filter to catch extremely small debris, but also creates gaps that allow it to pass ridiculously large material at other times. The paper element media is also three dimensional to a degree, whereas mesh is essentially two dimensional; if something passes through one opening in the mesh, it's through, which isn't necessarily the case with fiber media. Fiber, or paper, filters can stop debris as fine as 20 microns, or even less. But, they won't stop it all on the first pass. Worse yet, they won't stop all of the debris even as large as 90 microns or more on the first pass, and some particles occasionally come free of the filter to re-enter the oil stream. They are considered multi-pass filters, which carries the expectation that the same debris will pass through the system multiple times before being intercepted. They will be given "Beta" ratings like "80/25", which tells you that it will stop 80% of all 25 micron particles on the first pass. However, they will rarely publish the fact that they may very well also test at 85/35 or 85/40, and certainly will not mention that they tested at only 95/60 (95% of 60 micron debris). Additionally, paper filters resist oil flow, particularly when cold, a great deal more than does mesh, and cold starts often cause a paper filter to bypass. In the Scotts filter, a one inch square of the mesh media they use will flow 1.9 gallons of cold 90 weight gear oil per minute at only 1 psi pump pressure (70 degrees F). The YZ filter contains about 15 sq/in of mesh, which means that the media itself has the ability to flow over 28 GPM of cold 90 weight at 1 psi. The pump at the corner gas station is less than half that fast on a good day. That figure is also far beyond the delivery capabilities of the engine oil pump in any case. That basically means that unless you run half a shop rag through your engine, the Scotts filter will never bypass under any conceivable circumstance, and will filter at full capacity regardless of temperature. This is often not the case with "paper" filters, which commonly open the bypass valve during warmup operation. So, it isn't a black and white, indisputable, one's better than the other kind of choice, but in my opinion, the 35 micron stainless mesh is the way to go, and Scotts makes the best example of that type of filter. Let me also point out that there is a huge difference between the medical grade stainless steel mesh used in Scotts filters and the OEM brass screen filters used in YZF's up until '03. The brass filters will filter no finer than 70-80 microns absolute, which is not nearly acceptable, IMO. Paper filters are vastly preferred by race teams because stainless filters do not capture water, but paper filters do catch water. Water is the number one engine lube problem and always condenses into the oil as it cools down and from storage. The issues with water vapor condensing are much harder on an engine, than a short filter bypass in very cold weather start up conditions. Paper filters should be changed at every oil change, not because of solid debris, but because of the collected water that they absorb. What's been your experience using either of these types of filters? Are you firmly in one camp or another and if so, why? Does your experience conflict with anything I've written? Please do hit me up in the comments section below!
  3. 1 point
    At Ride Engineering, we pay close attention to handlebar position and bar mount height. You’d be surprised just how much a few millimeters from stock can make to improve your body position and overall control. Keeping the bars neutral is another important aspect. By this we mean keeping the bars parallel to the forks within a few degrees. Drastically changing them by raising the bars 25mm+ or moving them forward that much can have a totally adverse effect. This article’s main focus is to explain where the “sweet spot” is for maximum control reinforcing the proper riding position on track or trail. Handlebars that are rotated too far out of parallel alignment with the forks can create adverse handling issues The first thing that you want to do is pick a handlebar bend that you are comfortable with. Typically, a lower bar will allow you to “muscle” the bike more, but it should still be relative to your height. For example, at my 5’6” stature I like the lowest bends. Currently, my favorite handlebar is the Husqvarna bend Pro Taper Evo. It's 80mm in height at the ends and a little less sweep that my old favorite, the Pro Taper Carmichael. If you’re a bit taller, you may like the SX Race bend with a height of 87mm. Those over 6’, may like the stock Honda bars at 97mm tall (Renthal 971). Since each bike is different, your favorite bar may still need further adjustment. For example, I love the Husky bar on a Husky or KTM with the stock bar height, but on the 2017 CRF450R, I preferred it 5mm lower. On my current 2018 RM-Z450, I prefer them 5mm higher. I tried the SX Race bend with the stock bar mount height, but they felt too tall for me, even though the net difference was only 2mm more. Also, due to my short arms, in every case I run the bar mounts in the back position. This gives me a good head over the bars posture and maximum control of the bike. Incidentally, the forward holes that come on a stock KX-F and YZ-F triple clamps are too far forward for most riders. Before you start shaking your head and tell me that the OEMs wouldn’t design it that way if that were true, let me explain further. Because they use a rubber mounting design, which I agree is way better than the old metal on metal system, they have no choice but to put the forward holes 25-30mm out. The rubber cones are over an inch in diameter, so it’s not physically possible to provide a second mounting position any closer than that. Remember, KTM used to have two positions. But back then it was only a 10mm bolt hole, so it was possible to add a second hole 15mm away. Then by using an offset bar mount you could make changes in 5mm increments. Now that they also offer a rubber cone system, they have eliminated the forward position all together. Ride Engineering bar mounts are typically made the same height as stock (except YZ bar mounts which are the same as the 2017 & older stock mounts and 5mm lower than the 2018) with plus or minus 3mm of adjustability forward or back. We also offer 5mm and 10mm spacer kits to raise our mounts (Ride bar mounts come with posts that unscrew to allow for a height adjustment or to replace in the event they are bent in a crash). Aftermarket bar mounts that are 20 or more millimeters higher that stock are going to put the rider in a less than ideal riding position. Neutrally mounted handlebars Many steering dampers also have this adverse effect. They mount over the stem nut and under the handlebar, so often raising the bar is the only way to make clearance (Ride Eng. offers a damper kit that mounts behind the front number plate, allowing one to keep the bar height standard). Some riders like to go on mellow trail rides for a couple of hours and have found really tall handlebars add comfort. The problem lies when you come across a rider heading in your direction or an unforeseen obstacle that needs an instantaneous reaction. A poor riding posture can contribute to a crash and getting injured. If that happens, any added comfort will be the last thing on your mind. Handlebar mounts w/ spacers Read Dirt Bike Handlebar Reviews Here’s how a few fast guys with a lot of riding experience set up their riding position: Sean Lipanovich Pro 5’5” - 150lb - 27 yrs old Years riding from 12 yrs old to present Slmxschool.com Current ride: 2017 KTM450sxf Sean has raced professional supercross and motorcross, finished in the top 25 at the 2016 USGP, won the 25+ class at the 2017 Vet World championships and now trains young riders for SL MX School. He’s always couching riders to “put your head over the bars, squeeze the bike with your knees and be on the balls of your feet.” “I run the stock KTM handlebars (78mm tall) in the back position (bar mounts rotated back) with the Ride Eng. bar mount that is the same height as stock with the bars neutral (not rotated forward or back) to the forks. I feel this gives me the most control of the bike to get on the gas harder.” Kris Keefer Pro 6’ – 170lbs – 40 yrs old Years riding from 9 yrs old to present Keeferinctesting.com Favorite bike: 2018 YZ450F At 24 years old, Kris started his testing career with Yamaha Motor Corporation which led him to a position at Dirt Rider magazine as associate editor, then eventually to Senior Test editor. Today he’s doing his own testing and pod casts as a new business owner for keeferinctesting.com. Throughout his career he’s raced professional motocross and supercross, the Canadian nationals, Vet World and Loretta Lynn’s. “I use the SX Race bend on my YZ450F with last year’s bar mounts (5mm lower) in the back hole with the mounts rotated forward. I like to keep the bars fairly neutral and coach others to do the same. If you have your bars rotated too far back, it’s harder to get your weight forward on the bike when entering corners. If you have them rotated too far forward where the ends are pointing up, you don’t have the right leverage to initiate the turn.” Ted Campbell Pro 6’ – 210lbs – 42 yrs old Years riding from 12yrs old to present Current bike: 2017 CRF450R Ted has traveled the world racing professional supercross and motorcross and has made many lifelong friends because of dirt bikes. He obtained his first pro national number in 1999 and kept a top 100 number for 6-7 years of his professional racing career. “I use the Mika Metal’s RC bend (this is a tall bar at 105mm), and like to set up my bike with my bars just behind the forks (bar mounts rotated back) in the neutral position so I can get over the front of the bike. I feel I have more control turning and it puts me more in the attack position. I run my bars back further than most being 6’ tall but it gives me the ability to really feel comfortable turning and leaning the bike over as I’m on top of the bars more.” Ted added a set of Ride Eng. CRf triple clamps which did lower the bar position 5mm and moved it 3mm forward from stock. Cody Webb Pro 6’ 3” – 185lbs – 29 yrs old Years riding from 3yrs old to present https://www.facebook.com/codywebb247/ Current bike: 2017 350EXC Cody is the 2010 AMA National Trials champion, 2014 and 2017 AMA Endurocross champion and has finished on the podium or won numerous other off-road races like the 2017 Erzberg Rodeo where he finished in 3rd place. “I run the PHDS bar mount system (these have +/- 5mm of adjustability) with the Renthal 996 handlebars (93mm tall) on Neken triple clamps with no added bar risers although sometimes I hit my knees on the bars. We place the bar mount in the forward hole (these have two 10mm holes for adjustment) with the bar mounts rotated back. If I have the stock clamps on my practice bike, I run the mounts in the forward position. I also like the bars just a hair rolled back from the neutral position.” Cody’s race results speak for themselves and his “average Joe” set up works great even for a guy 6’3” tall (he only raised his bars 15mm from the stock height). I hope this helps everyone understand regardless of your stature, you shouldn’t increase your bar height or move the bars forward too drastically. Small increments of 5mm is ideal. In many cases such as mine lowering the bars will be far more beneficial in reinforcing proper riding posture, getting your head over the bars and maintaining optimal control of your dirt bike. Happy riding. Adrian Ciomo President Ride-engineering.com Vet Int. 5’6” - 150lb - 53 yrs old Years riding from 14 yrs old to present Current ride: 2018 RMZ450 About Ride Engineering Ride Engineering Inc designs and manufactures the highest quality billet aluminum accessories to improve the performance of motocross and off-road motorcycles specializing in handling and braking components. The company combines hands on testing with feedback from past and present professional race teams to bring products to the average customer that are typically not available for sale. Located in Southern California, all Ride Engineering products are made in the USA.
  4. 1 point
    In my last blog post I covered how to lace up a wheel assembly with new spokes. This week I’ll discuss how to properly true the rim. Truing the rim is actually not too difficult. Once you understand the interaction between the spokes and rim, you will make quick work of the job. To get started a truing stand of sorts needs to be set up. This doesn’t have to be anything special and I used a bench vice, adjuster block, rear axle, spacers, a series of old bearings and washers, and the axle nut. The reason I went to the trouble of clamping the hub in place was to eliminate any possibility of the hub sliding back and forth on the rim, which would make my truing efforts difficult. This is by no means the only way to create temporary truing stand and you can use your imagination to come up with alternatives. Temporarily installing the wheel back into the swingarm may work equally well if you don’t have a bench vice. Next, some sort of gauge will be needed so the amount of runout can be seen. I used a dial indicator attached to a magnetic base, however more simple solutions could easily be fabricated. It isn’t absolutely necessary to measure runout, especially right away when major adjustments may need to be made. Instead you only need to see how the gap between the end of the pointer and rim changes as the wheel rotates. A coat hanger, piece of welding rod, or even a pencil could all be used to the same effect as the indicator shown. Axial (side to side) runout will be corrected first. Here you can see there is a noticeable difference in gap size between the rim and pointer through a full revolution of the rim. The goal is to tweak the tension in the spokes so that the gap between the rim and pointer is even as the rim is rotated. To do this the gap can either be increased or decreased depending on which spokes are tightened or loosened. To decrease the gap, tighten the spokes originating on the side of the rim where you want the gap to decrease. In the previous photo I’m tightening the right side spokes, and in doing so I am pulling the rim to the right. An ⅛ to ¼ turn of the nipple is enough to induce a change. For the given area of the rim that must be pulled over, evenly tighten at least three of the surrounding spokes on the side being pulled. If the rim needs to shift a lot, loosen the opposite side spokes the same amount you have tightened the pull side spokes. This will help keep even tension on all spokes and help to shift the rim. The process of tightening and loosening the spokes to pull the rim from side to side can be performed at all the high and low points surrounding the rim. Continue to turn and rotate the rim around until the gap between the rim and pointer evens out. Some areas may require tightening the spokes and pulling the rim one way while other areas may need to be loosened to allow the rim to move back the opposite way. Take your time and make small changes as you go. As I mentioned before, it doesn’t take much to see a significant change in rim location as the spokes are tensioned. As the rim is fine tuned for side to side runout, the pointer can be moved closer to reduce the gap. Reducing the gap as the rim is trued will make it easier to see smaller differences in runout. To really fine tune things I like to use a dial indicator, setting the contact point up on the outer edge of the rim. Again, this isn’t absolutely necessary and similar accuracy could be achieved with a simple pointer. Here I’ve snapped photos of the high and low points on the rim. The total runout is the difference between the high and low points. In the left picture the needle is 0.0075” (0.19mm) to the left of my zeroed point. In the right hand picture the needle is 0.008” (0.20mm) to the right of the zero. This gives me a total runout of 0.0155” (0.39mm). Most service manuals suggest a max runout of 0.079” (2mm) so I’m well within spec! Quite frankly I was very pleased to get the rim to 0.0155” since the rim is old and slightly dinged up. The rim I was working on is centered on the hub. Some rims will be offset and it will be more important to pay attention to the relationship between the edge of the rim and a feature on the hub (usually the brake disc machined surface or the machined surface for the sprocket). Your service manual will provide specs for measurement points and specify how much offset should be present. Setting the offset correctly is important because if the offset is off, the front or rear wheel will not be inline with the other wheel. This can make the bike's handling very interesting! I don’t think a little misalignment is too noticeable on dirt, but it is definitely a problem on asphalt. A straightedge can be used to measure from the indicated surface, outer edge of the sprocket, or brake disc to the edge of the rim. If measuring off the sprocket or brake disc, you’ll need to subtract the thickness of the sprocket or disc from your measurement. If the rim is not quite positioned right after all the side to side runout has been corrected, it can be shifted at this time. To pull the rim one way or the other, simply evenly tighten all the spokes on the side you are trying to pull the rim to. The opposite side spokes can also be loosened to help allow the rim to shift over. Once the rim is set where it needs to be, half the battle is over! Next, the radial runout must be corrected. To do this move the pointer so that it sits past the outer edge of the rim. The gap between the pointer and outer edge of the rim will be monitored and tweaked to achieve evenness throughout the rotation of the rim. This time to induce change in runout, all the surrounding spokes in the area will either be tightened or loosened evenly in unison. To increase the gap, as I’m doing in the following photo, all the spokes are tightened which pulls the rim inward, enlarging the gap between the pointer and edge of the rim. To decrease the gap in a specific area all the spokes in that area can be loosened allowing the rim to expand outward towards the pointer. Just like with side to side runout corrections, the nipples only need to be turned an ⅛ to a ¼ turn to make noticeable changes in the gap. As long as all spokes in the affected area are tightened or loosened evenly, the side to side runout will not be affected. Slowly rotate the rim and make the necessary tweaks until the gap between the edge of the rim and pointer is close to the same as the rim rotates around. The pointer can be moved closer and closer to refine the roundness of the rim. The surface of my rim was too beat up to take accurate measurements so I simply relied on eyeballing the gap to set its roundness. Once the rim has been trued both axially and radially, the spokes will still be relatively loose. The spokes will all need to be tightened gradually and evenly so that all the efforts of truing the rim are not wasted. Since the majority of rims are either 32 or 36 spoke rims every 4th spoke around the rim can be tightened. This results in an even 8 or 9 step pattern which is repeated four times to tighten all the spokes. First all the red spokes are tightened, then the greens, yellows, and finally blues. Tighten each spoke ¼ turn at a time. Alternatively, forum member @ballisticexchris suggested a pattern where every third spoke is tightened. This would allow the tensioning of both sides of the rim within the same revolution of the wheel. I've always had good results with the pattern I've outlined but believe his suggested pattern will work equally well and is another option for you to use. As the spokes are tightened, not surprisingly, the nipples will become harder and harder to turn. The evenness of the spoke tension can be checked by tapping the end of the spoke wrench against the center of the spoke. The spokes will emit a ringing sound and the pitch will be different for spokes which aren’t the same tightness. Continue to work your way around the rim gradually tightening the nipples until all the spokes are similarly tensioned. Next, use your hand to squeeze the spokes which are parallel to each other together. Squeeze all the spokes evenly around the rim. Squeezing the spokes will help gauge the tension, ensure the heads are fully seated, and help relieve stress built up in the spokes. After squeezing the spokes together, check the tension in the spokes one final time. Most spokes should only be tightened up to 6Nm and the rim I was working on called for 2.2Nm of torque. A spoke torque wrench is the appropriate tool to use to set the final torque of all the spokes, however I didn’t have one on hand and some of you may not either. Instead I based the final spoke tension on how the new spokes felt in relation to a previously laced rim. This method worked okay, but it is always best to use the right tool for the job. After you’ve finished tightening all the spokes it is never a bad idea to check runout both axially and radially one final time to confirm the rim hasn’t shifted. As long as the spokes were tightened evenly, changes in runout should not be an issue. Once you have checked runout one last time you are all set to install a new rim strip and put on the tire. I hope you enjoyed this two part series on building and truing rims. Now that you have the info to feel confident building your own wheels from here on out, and are able to save some cash in doing so, go for it! If you have tips and tricks pertaining to wheel building, I’d enjoy hearing them. Please leave a comment below! Paul Olesen DIY Moto Fix - Empowering And Educating Riders From Garage To Trail
  5. 1 point
    At their core, backpack-style hydration systems have remained relatively unchanged for some time. Fill the bladder, bite a valve and suck to drink. This design is simple, cost effective and functional, but is this as far as performance-oriented moto hydration systems can go? Is there still room for meaningful improvement? The folks at LiquidAider certainly thought so when they designed and perfected the world’s first push-button wireless hydration system. How’s LiquidAider work? Who’s LiquidAider for? What are LiquidAider’s benefits? We caught up with Matt Steele, inventor & CEO of Arapaho Technologies to answer these questions and more. TT: Matt, push-button hydration is self-explanatory. What is the rest of the story? LiquidAider: The idea behind LiquidAider is that we do not see hydration bladders as a complete solution to hydration. Dangling suck tubes are no good when the going gets tough. And when you are simply exhausted, sucking water sucks! Drinking less at a time but constantly to match exertion is the concept here and by doing that, you will pee less, retain focus and maintain your hydration level. TT: So what is LiquidAider? LiquidAider: It’s simple: Push button. Drink water. We provide a small wireless button that mounts next to your grip and a small pump that plugs into any hydration pack’s quick connect port. There is a magnetic disconnect that connects the pump tube to the helmet tube. A small adjustable nozzle mounts inside the front of your helmet. As you ride, and I mean in any situation or terrain or speed, you can drink water by hitting the thumb button. No reaching for a tube, and no bite valve. And we add only 8 ounces to your pack, as much weight as a cup of water. TT: That’s actually pretty significant. Look at the pictures of any group of trail riders or race photos and even the top pros have a dangling tube not being used. And nobody wants a lot of weight added to their already heavy packs. LiquidAider: Exactly true. Staying hydrated is why we all wear hydration bladders. And no matter how good you are, there are times where you need to drink but cannot take your hands off the controls. The harder the exertion, the harder it is to hydrate with a suck tube. LiquidAider pairs with that partial solution and makes it a total solution. Even if you like a bite valve, you can power the bite valve with LiquidAider and not have to suck water. TT: So is this only for pros? LiquidAider: No, not at all. Our customer base spans all ages and the entire spectrum of casual trail riders, to adventure bikers, road racers, and all forms of 4-wheel off-roaders. I think trials and motocross are the only 2 market segments where LiquidAider is not present. TT: What are some of the features? LiquidAider: We engineered some very cool features into it. Burst Mode can be set as you ride and it changes the operation to a 2, 3, or 4 second burst of water with a single quick press of the button. You can pair the button to any number of pumps so imagine a team race like the Baja 1000. One rider gets off and another gets on the bike. The second rider has his own LiquidAider pump and helmet nozzle and he can use the button to hydrate. A magnet disconnect pulls apart to separates the backpack from the helmet. Take off your helmet and it disconnects. Then lay your pack on the ground and water will not run out your pack. With the disconnect separated, pushing the button will not pump water. And we will replace any broken part for 50% of the online price. I recall we have had 2 cases where something broke, and it wasn’t the button or pump. In both cases I just sent the parts for free. I was impressed they managed to break something! I know one Canadian rider cartwheeled his bike down a 200 foot whoop section and even without using the supplied button guard, the button was intact and undamaged. TT: Battery powered? LiquidAider: Yes. The LiquidAider button is about 10mm wide, and inside of it is a coin cell battery that you can replace. But even though the button never turns off, always is running, that the internal battery will last all riding season if not the year. The pump battery is rechargeable. It will pump somewhere up to 40 liters before needing a charge. LiquidAider can be used with virtually any hydration bladder, even children's. TT: Care to drop some notable customer names? LiquidAider: (Laughing) Ha! Well, we have shipped LiquidAider all over the world. We have a lot of talent trusting our product to give them a major advantage over guys with suck tubes. Certainly not a complete list, but Jackson Davis (factory Sherco racer), Ron Ribolzi (7x ISDE), David Knight (5x FIM World Enduro Champ) all use it. Cody Webb has been extremely generous to us by using it and testing early versions, and we designed the button to fit his available bar space. At the Mint 400, Damon Bradshaw picked up a kit and then brought a friend over to buy one. Then Damon, as nice a guy as you’ll ever meet, stood at my vendor tent for about 45 minutes demonstrating LiquidAider to desert racers who probably didn’t know who he was! Mason Klein who I met at the Parker 250 race this year is 18 years old and finished 3rd in all stages of the 2020 Sonoran Rally except the first one. This means he finished behind Ricky Brabec and Skyler Howes but ahead of a stellar cast of racers and he credits LiquidAider for contributing to his amazing performance. Mason gave us a video of his thoughts about LiquidAider and it’s on our website and YouTube channel. We do not pay anyone to use LiquidAider, so if you look over and see our button on the handlebars next to you, it’s because they bought a key advantage to beating you and they know it! Factory Sherco rider Jackson Davis hydrates in the heat of battle with LiquidAider. TT: Is it difficult to install? LiquidAider: No, it’s actually easy when you realize all you are doing is installing a nozzle inside your helmet, plugging in our pump, and connecting the tubes with the magnetic disconnect. I highly recommend watching our YouTube videos because it makes everything really easy to understand. Our included written instructions are over the top in detail for anyone wanting that. Handlebar control switch is easy to reach and takes up very little space. TT: And what is the future for LiquidAider? LiquidAider: We are aware of other applications including military, bicycles, etc. and we are pursuing them. Ricky Johnson helped another entity with a similar concept, probably focused on Trophy Truck racing, but I heard they had issues and are not to market. The technology involved for such a simple concept is very advanced and challenging to implement. We’d welcome conversations with anyone about partnerships or applications. As a side note, I gave Ricky a kit when I met him at King of the Hammers in February and he seemed genuinely blown away at the product quality and packaging and I think it caught him by surprise that this existed in a final production form. I hope he uses it and gets back to us. TT: Closing thoughts Matt? LiquidAider: Think about this. We have done everything to our bikes and spent a ton of money to upgrade and give us an advantage over the next guy or just be able to ride better. Suspension tunes, anti-vibration additions, pivot pegs, steering dampers, billet everything. Then a guy goes riding/racing and hopes his body can do what he asks and comes back to the pits with half a bladder of water and is wiped out for a day of recovery. The bike is perfect. The body is shouting “Hey! What about me?!”. LiquidAider is the one thing that you can do for your body, right now, and have an immediate advantage over anyone with a suck tube. All things being equal, the rider with LiquidAider will win every time. And it’s not expensive. Why would you not want that major advantage? TT: Thanks for taking the time Matt! LiquidAider is available at https://liquidaider.com. Use coupon code : TT20 for $20.00 off & free shipping (US orders). You can follow LiquidAider on Instagram and like them on Facebook @LiquidAider. YouTube videos make the installation and operation very simple to understand.
  6. 1 point
    They say necessity is the mother of all invention, I agree. I decided to build this flywheel holder because I am unemployed and dont have the money to be throwing around on over priced tools. The other methods some of you may use to remove the crankshaft nut did not work for me. I tried an impact wrench, oil strap, and putting it in gear while holding the brake down. I also did not like the idea of the jamming something in the clutch basket method. If you have also tried these methods and had no luck than building this tool is the way to go. Its like the saying " The right tool for the right job" and this is one case where it where it applies extremely well. I built this flywheel holder for about $5.50. I have seen this sort of tool go for $30+ dollars online. The price for you will vary by a dollar or so depending on what you already have laying around. I already had some nuts and bolts around so I only needed the steel bar and 4 nuts. I built this for a 06 YZ250F so you may need to change the bolt size according to you bike. For my bike a 5/16 bolt fit perfectly. I think this tool is simple enough to build for anyone just by looking at the pictures but i will try to detail what i did in each step. Parts List 3/16 x 3/4 x 3ft steel strip two 5/16 x 1 1/2" bolts four 5/16 nuts one 3/16 x 3/4" bolt one 3/16 nut one washer First, cut the steel strip into one 14" strip and one 6 1/2" strip. You can use a hacksaw, a cutoff wheel, or what ever else you have that can cut steel. Second, drill a hole using a 5/16(or what every size you need for your bike) drill bit into one end of each steel strip. I used a drill press for this step. If you dont have one a hand drill should work just fine but you will have to work a little more. Put a piece of scrap wood under the steel strip so as not to drill into you work surface. Next, lay the smaller piece of steel strip on the larger strip with the two 5/16 hole aligned. Place one of the 5/16 bolts through both of the holes to secure the strips for the next step. Both strips should be parallel and squared to each other. Now drill a hole at the other end of the small piece straight threw both pieces. Use a 3/16 drill bit for this step. This hole will be for the pivot screw. You may want to clean up the drill holes and cut ends strip for sharp spots using a file. Place the 3/16 bolt with a washer through the pivot hole and secure it with the nut on the other side. Take the two 5/16 bolts and thread a nut to the end of each bolt. The purpose of two nuts on each bolt is to secure the bolt into the tool and to adjust the depth of the bolts into the flywheel. Now place each bolt into the 5/16 hole and secure it with a nut. Thats it, your done. Simple eh.
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