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weird tire deal

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Ok so there's no obvious section to put this in so I'll try here.

140lbs rider, '04 crf250r bike with 19" rear wheel. Tire is Michelin MS3 which I inherited from some wheelset I had. I've been testing various tire pressures and lo and behold, I get the best results with NO AIR AT ALL!!! ***??? There's a super heavy duty tube in there but if I bleed it out entirely, it hooks up best and actually doesn't look deflated at all, looks just about right actually flex-wise. It spit all the rim strip out when I ran it for a day with no air and the tire seems to sit a bit crooked on the rim but it hooks up awesome. Granted most of my riding is 2-3rd gear and sometimes 1st, intermediate pace.

Not sure what to think about this, old tire in cold conditions or I just need to find the softest sidewall tire there is since most are outside of design envelope for how light the bike and rider are?

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of COURSE it gets good traction and all but will eventually ( soon actually) disintegrate. just run a trials tire here in the northwest and you will get better traction and be amazed. Shinko makes a 19" one now.

Joe

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Don't want to run tirals tire... Know what it is but the way it works is just not aligned with my goals now, need progressive wheelspin at good lean angles.

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You could try a tubliss. Even when the outer chamber is "flat" the inner bladder with be holding the wheel on the rim like a giant rimlock. I'm not sure how well the tire will hold up though... Be careful about hitting sharp rocks hard, too!

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So help me understand this.. Normally the tire shape is supported by carcass and the air in the tube. To get a desired tire flex normally both play a role.

Now if for my desired tire flex only the tire carcass is sufficient to get desired flex, does this mean the cacrass of the tire is too stiff and I need to find a tire with more flexible sidewalls?

I see a few ways to go from here: find that more flexible tire, put a second rim lock and run something like mousse just to fill up the space like Pumpkin450 suggests, or tubliss. First seems to be the most straightforward?

Will switching to 18" wheel help with getting the right tire flex?

Also, for trials tire I was thinking of getting MT43 later on but now I'm second guessing that as well, it's supposed to be less flexible than competition trials tires so will it even work for me?

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Of course it hooks up good. Hit a hard jump landing, rock, or step-up ledge, and you will be replacing the rear rim if you are lucky. If you are not lucky, it will be the rim, spokes, hub, brake caliper, and possibly rear swingarm when everything explodes. The air in the tire is the cushion between the metal and the ground. With dirtbikes, it is a constant give and take with how low can you run the tire pressures and still protect the wheel.

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Keep in mind that a full sized so bike is a good 75 pounds heavier than a trials bike so what may be a crap tire for trials competition may be just what you need for riding down trails. I also believe I read somewhere that you can run the MT43 flat. Although I'm not sure if that is indefinitely or just limp home mode.

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Keep in mind that a full sized so bike is a good 75 pounds heavier than a trials bike so what may be a crap tire for trials competition may be just what you need for riding down trails. I also believe I read somewhere that you can run the MT43 flat. Although I'm not sure if that is indefinitely or just limp home mode.

MT43 will not run flat, not like a knobby will

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Got it, thank you! The bike hardly ever is more than 2 feet off the ground and a root or a rock will probably be doing damage to the front wheel first, but I got the idea of the balance between traction and resisting hits. Hopefully I'll get fast enough that this will be a real possibility at some point :bonk: If I get my 210lbs buddy on my bike with no air in the tire, it's obviously unrideable. With me on it it squishes down just barely in a static situation.

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Dmitry- The MS3 is a soft terrain tire, therefore the carcass is very stiff. You had to run it with no air to get it to hook up in medium conditions, but if you ran it in mud or sand it would do fine with air in the tube. I would say that if you got a Michelin M12 that you could run 7-9 psi and get great performance. Wet and slippery is not "soft" terrain. It's just that, wet and slippery muck over hard packed earth. You need a tire that flexes, and the MS3 won't do that with air pressure and your skinny butt. Find a good medium terrain tire and try that. I get what you are saying about needing a knobby vs a trials tire, I have both tires mounted (one on each bike) and can tell the difference. The YZ likes the knobby, and the gasgas likes the trials tire.

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Thanks Phil, that makes good sense! I didn't have this problem on my ktm so yea shopping for a different tire now. Let's go for a trail ride someday.

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Since it's a 250, you're probably running a 100 size tire.maybe try getting a fatter, more aggressive knobbie and run it low?

Well, I just happen to have an 18x2.15 wheel that'll fit this bike too just don't have a tire to throw on it. If somebody has reco's for a tire that'll do well in wet roots and rocks with a light bike and even lighter rider on, i'm all ears! I've got an IRC trials tire that I can always throw on there and it works awesome but I want a knobbie :/

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MX 51, MX 31, Maxxcross SI. Even though the MX31 an Maxxcross SI are both soft terrain tires, they do great in rocks and the open spacing between the knobs gives you good traction on exposed roots. JMHO

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the m12 is not a very desireable tire, and the MS3 is a medium-soft tire, the S12 is the soft terrain. Are there softer sidewall tires out there? maybe, i don't know.. I run 13.5PSI or i get flats in the woods at an A pace.. would love to run less. As some suggest, get the TUBLISS system, about $100 per rim and you can run 7-8psi .. THAT will feel squishy, even for a 140lb rider.

I prefer the michelin Ms3 rear and S12xc front (i go through a few every few months) and this talk of "no air" is just silly and amazing to me.. Your head is spinning like the "excorsist" chick analysing different tires, different size rims, etc. Just PUT SOME AIR in there, and soften your SUSPENSION if you like a soft ride. Your going to ruin the tire, pinch a tube (even though your not presently utilising it), and at some point BREAK a RIM.

:bonk:

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Thanks Phil, that makes good sense! I didn't have this problem on my ktm so yea shopping for a different tire now. Let's go for a trail ride someday.

If I can get my reeds sorted I will take the GasGas out Tuesday the 27th to Walker Valley. It has a trials rear and Michelin HC4 front. If not, I'll take the YZ with the M12. The M12 comes well recommended for our conditions (packed dirt and wet stuff), so if I bring both bikes you can go back-to-back. Also the Motoz tire is mentioned a lot, I have a front that seems to work well and the rear is supposed to be just as good. PM "Ride" (Kelly) on this board for Motoz tires. He's local and can get you squared away. If you want a good tire for a good price talk to Tom Young (WMRRA Pirelli guy). I can get you his email if you want. He is in Oregon so the tire could conceivably be shipped up here by Monday.

Just remember that "Soft" tires have a hard carcass to pierce the dirt, and "hard" tires have a soft carcass to conform to the terrain. Medium tires are a combination of both, but a softer carcass is recommended for Northwest terrain. Look for the tire thread in the NW section, lots of good recommendations for tire combinations.

Regarding your last comment about the KTM, what tire did you have? Do you still have that tire?

I am heading to Walker Tuesday at about 8 AM and I need to be home by 3, so it will be a short day on the trails. If you want to go, send me an email and we'll figure out how to carpool.

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Good to go for Tue, I'll get in touch. KTM had S12 I think, gone with the bike.

I'm gonna suffer the MS3 until it's done and then get something else.

Greg, here's to give you an idea of my riding. This is pretty much all of it. Nowhere near A pace. 2-3rd gear all the time, hardly ever any jumps. Getting good traction is way more important for me than worrying about breaking a rim or something. That just won't happen.

I'm not trying to overanalyze anything, just surprised at my "testing" results.

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.. sweet trail actually! but you really think running zero air is helping?? put some air in your tires (even 8psi), soften up your suspension (if you never played with it it is likely set up for mx and WAY too stiff for the trails your riding). You will be amazed, but you will likely have better "feel", more control (vs having the tires rolling around on your rims as you steer, brake,accelerate).. that is if the tubes don't have 15 holes in em..

I know you think you found something with the "zero air works better" , but soften the suspension up. if you don't know how, find someone that does.

you say "suffer the ms3" .. you do realise that is a VERY popular tire.. you have a problem with your bike, your not solving the problem correctly.

As someone tried to point out earlier, the "SOFT TERRAIN" tires will likely have a STIFFER SIDEWALL and stiffer knobs so they don't bend in the soft stuff. The MS3 and harder terrain tires have SOFTER rubber/knobs so they dont chunk.. see ?

PS: mount the camera to your helmet. Watching video of dirt biking with the camera mounted to the front of the bike is ..well.. not easy.

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Yea suspension has MX valving but at least springs are correct for me and valving matches the springs. I run compression all the way out, need to lower oil level and it'll probably be somewhat tolerable.

Looks to me the issue is I expect to feel some tire flex on roots and rocks and with 8psi in this tire I feel none, with no air it feels "normal" to me. And yea feels like that purely for getting forward motion out of it, that works better too.

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