OzVMX Forum
Clubroom => Tech Talk => Topic started by: YZAT252 on March 14, 2014, 08:38:58 pm
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Hi all, can anyone suggest a good suspension guy in Brisbane to adjust tune my suspension in YZ250G? Just spent plenty on Racetech gear front and rear and not happy at all, seems way too stiff and just trying to hang on is main problem, any thoughts?
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Did you ever consider that the YZ just has too much power!
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Lol, that is probably the problem, the thing has some wick! But surely it should be better to ride than before with 34 year old suspension that I suspect never been touched?
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Dave from Suspension Matters is very good, and seems to be a more-than-decent bloke too.
Be interested to know what sort of spring rates (and your weight).
My old G with YZ-H forks ended up with stock front springs from a TTR250 (0.42, IIRC).
On the rear it had the stock spring from an 06 YZ125, with an unknown helper spring. I simply jammed a '93 CR125 valve piston in there.
It wasn't a perfect setup, but it was very good - miles better than stock. I'd fully expected to take a few goes at revalving the shock, but it was remarkably close straight away - close enough that my skill as a rider couldn't pick any specific fault.
Also, I've previously bought a modern bike that supposedly had been professionally set up for someone of my weight with Gold Valves and re-sprung. In reality, it was massively over sprung and just as badly overvalved... The revalving process basically involved throwing away about a third of the shims.
Sounds similar to your complaint - makes me wonder if there's an easy way to screw up the RT recommendations. I've done a few bikes to RT specs, and have been very happy with all of them.
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Yes Nathan, Racetech website reckons the original springs both front and rear were "way too soft!" However everything I have ever ridden has been old school soft and mushy, probably why I am struggling with firm, modern like damping, probably should have left it way it was...
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I am curious as I have just brought springs & emulators for my YZ465 forks but have not fitted them yet,
Did you use there spring calculator on the racetech website? are you using emulators? what weight fork oil?etc etc :)
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Yes Smed, and as I am an average rider and wanted softer set up, I asked for novice rider, over 45 yrs old, enduro /trail rather than mx etc. it was all set up for me by experienced guy in dealership, he has backed off the preload etc as far as he can, set static sag etc, we used 10w oil, can still play with adjustments on emulators etc, but even the rear seems to bounce around a lot, in saying that I am 54 yrs old, only weigh 72 kg, so maybe it just too much power for me?
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Hmm I hope my springs are Ok then,the calculator recommended 0.431, Mine are the triple rate springs,one long & 2 short,put all 3 in together for the softest & 1 only for the hardest ;)
1 long & 1 short is 0.43 so that is my starting point, I am a jockey also ;D 70ish KG
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Front springs are 43 also, the fitter adjusted sag etc and said he can't make softer unless we change from 10w oil to 5 and play with emulators etc. rear though feels really bouncy too, probably too much bike for me, should be on 125's lol
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My old 250H used go pogo in the read very badly particularly under heavy braking into corners. I could not successfully tune that out if the bike
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One thing I've noticed on the RT website, is that the recommendations don't change much for anything other than rider weight.
Enduro vs MX, old vs young, blah blah all make no (or very minimal) difference.
It does sound like your spring rates (and probably valving) are more set up for someone who is fit and aggressive. To put my spring rates into context, I'm 90kg.
I don't think you can get rid of the 'Yamahop" with the stock valve piston.
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Isn't spring rate more or less dependent of your weight (and the bikes), not your racing type, unless you are a very fast rider?
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if the rear is still to "bouncy", suggests to me that the compression damping is still too hard and the rebound a bit soft so 1 your not getting the full travel on compression and then it springs back too quick. your wheel hits a bump and gets hit up in the air too easily as the shock wont absorb it fast enough.. note also that too soft front end will also assist this feeling. I would try some stiffer damping in the forks.
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Isn't spring rate more or less dependent of your weight (and the bikes), not your racing type, unless you are a very fast rider?
Yeah, that's my understanding too. Just seems a bit odd that they ask for so many parameters that are apparently irrelevant.