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Frontend Wobble…Almost

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Hey All, I revalved my Stock spring suspension per Borynack’s Site as ‘Desert Racer’ a while back and the bike rode great, Much Improvement over stock. With fork Compression 16 clicks and rebound 12 clicks. (And the shock settings per his website as well)

After a month or two I then got stiffer springs to match my weight with gear. (4.5 kg front and 10kg rear)

A ride or two later I had motor trouble AGAIN and just now get the motor back from being rebuilt by a DIFFERENT Shop. Point being I never really got to adjust my suspension settings to the new springs. I’ve been out trying to put some break-in miles on it and found that the front end is really squirrelly and doesn’t feel stable in real loose ground. I use to be able to tear up loose gravel stable as a tank at all speeds and in the corners. Now I get the feeling that if I am much over putting along its not planted on the front and loose which will hinder on loose single track turns.

I’m going to check my Sag this evening but I have a big ride this weekend and would like to have it in the ball-park so I can fine tune it then. Should I raise the forks in the Triples as well? Or just soften the compression and rebound a click or two front and rear? Or would the sag off a 10-20mm be enough to cause this?

What should help stabilize the front?

Thanks in Advance!

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My sag was at 90mm...I adjusted it to 110mm. Is that enough to make the front end that sloppy?

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My sag was at 90mm...I adjusted it to 110mm. Is that enough to make the front end that sloppy?

as may have expected this didn't help and possibly made it worse though I didn't have any loose gravel roads to test on this evening. So I went back to a sag of 90-100mm and I did raise my forks from 3mm to 5 mm. I'm starting to wonder if maybe my springs are too stiff? I'm 180 without gear but I tested the sag with my Boots and helmet and Tool fanny pack on so I know I'm probably at 195-200 loaded. So I expect the fork spring rate of 4.5 and shock rate of 10 would be proper.

Well unless someone can tell me I'm not doing something right or its obviously set up wrong I will give this a go this weekend.

Any and all ideas are appreciated!

JT

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J_T,

It doesn't look like you have had any replies to your original post, so I'll put in my 2¢.

More sag should have resulted in more front end stability, but as you indicated, you did not get into any gravel to test it properly, so I'm not sure why you feel that you did not gain stability from the change. Suspension is a bit of a "black art" to most people, but there are some simple tricks to sort out some basics before you head off too far in the wrong direction. First is to set the sag to the factory recommended height (I think that 80mm ~ 100mm is correct for a XR650L, but you did not say what bike you were trying to adjust). Set the front forks so that about 1/2" is above the top of the triple clamps (just a starting point). Then set all your compression/rebound clickers to the factory recommended locations. Make sure there is no extra air in the forks (release the pressure if there is any). Then stand up on the pegs and bounce (compress the suspension) once or twice while a buddy stands off to the side and watches what the compression and rebound does at both ends of the bike. I do this next to a wall so I can balance over the center of the bike by steadying myself with one hand on the wall. Your suspension should compress and rebound equally front and back. If it does not, adjust the dampening clickers so it does (write down your settings!). Once it is set to this "neutral" condition, then go out for a ride on a controlled course and push it as hard as you can. Only you can decide what you like regarding how your bike handles. Some people like a setup where the rear end comes around way before the front end looses grip, and some people like a setup where the front end bites and plows through the turns without the rear end stepping out. That can be achieved fairly easily by moving the forks up or down in the triple clamps (flush with the clamps makes the bike more stable but it will not turn as easily). Setting the sag to something more than the factory setting (100mm ~ 120mm) will also make it more stable, but at the cost of usable compression travel at the rear (it may bottom out on the jumps). Make some adjustments and go back to the same controlled course and see if it feels better or worse. Don't start messing with the dampening settings until you get the steering geometry close to the way you like it! Once the geometry is close, you can start messing with the dampening settings. Again, everybody likes things a little different then the next guy. I find that the riding conditions dictate how I set my dampening adjusters more than anything else. Choppy conditions with small jumps (whoop's and single track trails) get less compression dampening and more rebound dampening. Bigger jumps and higher speeds (desert or fire roads) get more compression dampening and less rebound dampening. I almost never have to mess with my spring settings any more (air in the forks or rear spring), because I no longer race, and if I'm pushing it hard enough to bottom out both the front and back end, then I'm going way too fast on a 350 pound motorcycle anyway! A lot of guys find their suspension somewhat "lacking" and just go out and buy stiffer springs and spend money on valving without first getting the geometry right (though you may need stiffer fork springs or heaver fork oil to make it past the "bounce check"). I think it is far more efficient to figure out what needs to be changed (hitting the end of an adjustment) before spending time and money on parts that may not resolve the underlying issue. My rule is,,, If you don't hit bottom once during a hard ride, then you are not using all of the available suspension and therefore something is set too tight (typically springs). I paid good money for the suspension travel designed into the bike, so If I'm not using all of it (suspension) I'm either not riding hard enough, or my setup is wrong!

So that is my 2¢ for what it is worth :busted:

Sorry, I just noticed that you are adjusting the "R", not the "L" so the sag "guesses" I made may not be right. But hey,,, at least you have rebound dampening adjustments on the front. Dang,,, I wish I had those!

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Thanks Randy for responding. I set it up as you recommended last night and will give it a go on the dirt this weekend instead of paved roads. It is a new place to ride so I doubt I'll be making any changes based on it I just didn't want to be fighting it either after traveling to a new ride out-of town.

I didn't think someone could tell me how to set up my bike for sure...I was wondering if there was a rule-of-thumb...like if going a stage stiffer on springs would mean I could back off the settings by 1 or 2 clicks from what I knew worked before?

Thanks again!

JT

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at ~200lbs u shud be run'n...

...0.45kg in the forks and 10.0kg on the shock.

set ur rear race sag to ~4.5", get the fork tubes back in the stock position and set ur compression/rebound to BWB suggested start'n point...

...ride it a get back to us :thumbsup:

:busted:

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Thanks Randy for responding. I set it up as you recommended last night and will give it a go on the dirt this weekend instead of paved roads. It is a new place to ride so I doubt I'll be making any changes based on it I just didn't want to be fighting it either after traveling to a new ride out-of town.

I didn't think someone could tell me how to set up my bike for sure...I was wondering if there was a rule-of-thumb...like if going a stage stiffer on springs would mean I could back off the settings by 1 or 2 clicks from what I knew worked before?

Thanks again!

JT

Rules of thumb would be great, but the variables creep in and make those very "hit and miss". Example: what fork oil weight and level are you using? How close to the limits of travel (and dampening adjustments) are you using? Are you running toward the low or high end on your tire pressure? All of those variables will (and do) have a significant impact on the "feel" of the bike in different conditions. Example: If your geometry and dampening settings were perfect, but you were running say 30PSI in the front tire in gravel,,, that puppy just ain't gona turn! Back that front tire pressure down to 15 ~ 18 PSI and that puppy will carve through turns like it was on rails (all else being perfect). Drop down to about 12 ~ 15PSI in the rear, and it will bite coming on to the throttle enough to snap you up out of a turn so fast you will need to slide forward on the seat to keep the front end on the ground! Make small adjustments and document the changes. Log books can make your rides so much more enjoyable because you will be able to make small tweaks on the trail based on previous combination's that you know work in varied conditions. Than can make the difference between a punishing outing and an AWESOME ride! Hammer the suspension, not your body!:busted:

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there's alot of gud info in this thread...most of the links r from Bruce's site(BWB)... :thumbsup:

http://www.thumpertalk.com/forum/showthread.php?t=610767&highlight=suspension

w/ ur proper spring rates i doubt the forks shud be raised more than 2-4mm and wud start with the stock height...raising them will improve turning BUT will make the front less stable...there's always a trade-off.

:busted:

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I have a bunch of options now Thanks everyone:

  1. My tires were inflated for road last weekend when I really noticed it at 25psi where I usually run 12-15 on the trail. So that will help some letting some air out.
  2. I revalved my suspension per BWB's site and used his recommended settings but about 4 months ago I stiffened it a little for a dual sport ride and my motor went down soon afterwards so its just now getting back going and I forgot I did so. So I can reset the clickers back.
  3. My sag was at 90mm (3.5in) instead of 110 (4.3in) which I'll fix again

So this ought to really clear up the wobble and help with stability correct?

Thanks Ya'll

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I have a bunch of options now Thanks everyone:

  1. My tires were inflated for road last weekend when I really noticed it at 25psi where I usually run 12-15 on the trail. So that will help some letting some air out.
  2. I revalved my suspension per BWB's site and used his recommended settings but about 4 months ago I stiffened it a little for a dual sport ride and my motor went down soon afterwards so its just now getting back going and I forgot I did so. So I can reset the clickers back.
  3. My sag was at 90mm (3.5in) instead of 110 (4.3in) which I'll fix again

So this ought to really clear up the wobble and help with stability correct?

Thanks Ya'll

if u get ur fork tubes back where they shud be(stock position) :busted:

Bruce(BWB) reccomends get'n more front sag if needed by adjusting the rear sag(cranking up rear preload) rather than moving ur tubes up :banana:

if u have the proper spring rates which it appears that u do...set the rear sag ~110-115(~4.5") and ur forks/front sag shud be fine in the stock position.

from ur described previous settings u musta been really biased to the front wheel...great for turning but very twitchy and unstable in a straight line :banana:

:thumbsup:

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Thanks...I forgot I moved my forks to 5mm from top. I'll put it back to 2-3mm.

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