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unequal rate fork springs-OK to do?

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Posted by: clw---------------------

Yeah I know I'm cheap, but is it OK to buy just one fork spring to alter the overall rate?

Say, is a .43 and a .41 the same as two .42's

Thanks



Posted by: WhiPit---------------------

It is okay to mix different rate springs....the result is the average rate of the two combined springs.
I'm not sure who's going to sell you just one spring, though!



Posted by: clw---------------------

Thanks

Yamaha sells their optional rate springs separately, not as pairs. So, at my cost of $22/spring it's a quick way to experiment with a different spring rate.



Posted by: WhiPit---------------------

I did not know that........



Posted by: Vic---------------------

Quote:
Originally posted by WhiPit:
I did not know that........


Me neither, but you can be sure I'm gonna remember it! http://dirtrider.net/ubb2/smile.gif





Posted by: yamadawg---------------------

Yes you can mix spring rates.You will come up with odd rates,ex. 43 and 42 would be 42.5 overall 43 and 45 would be 44.To figure this out add the two rates together and divide by 2,that will give you the spring rate that you would have.

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it dont hurt till the bone shows.

2001 YZ 250



Posted by: MoO_coW---------------------

In one of the mags they did that with the 2001 KTM's and they said it worked great.



Posted by: mxneagle---------------------

KTM's came with White power (I believe) forks a while back that had compression damping on one side and rebound damping on the other. So I doubt springs of differnt rates is a problem at all. I do it frequently when testing.



Posted by: texaspro---------------------

One thing to consider is that there is such a thing as manufacturing tolerances. They are 5% for most OEM's. So a .42kg might not be a .42 by direct test. If you want to be sure you have to test each spring.



Posted by: motor86---------------------

Wouldn't this put extra stress on the tubes?

What would happen if your compression adjusters or rebound adjusters where not set to the same position on each fork?

I was always told that you are supposed to adjust your clickers on each fork equally. If this is true, then putting a different spring in each would be a problem also due to the twisting.

Thanks

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motor86
85' KDX200(mine-for sale) 96' CR250R(mine)**81' YZ125(Dad's)**81' CM400 (my street bike)
Motor86's home page



Posted by: DKT735---------------------

I don't think it would be a problem. A few years ago KTM had bikes where on fork did the damping and the other had the spring.

Try it and let us know if you can feel any difference.



Posted by: clw---------------------

OK, a follow up to my one spring change.

After a 70 mile Enduro yesterday I can attest that what I felt was better compliance on the small stuff, with a slight loss of whoop stability (wants to hobby horse).

I put one .40 in with the stock .43 for an average rate of .415. Much easier to pick lines into turns. If there is twisting, unequal flex, etc. I can't feel it.

Any suggestions to stop the hobby horsing? Guess I need to recheck the sag (may be high as a consequence of lowering the front with the softer spring rate) and maybe slow the rear rebound a tad as it feels too active. At a reset I tried more front compression but then my wrists took a pounding and it resisted turning in as well. Didn't have time to soften the rear compression, but would I soften hi or low to level out the bike? Too many questions.




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