Just An Inch Lower

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Nov 25, 2000
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#1
Jeremy W. or Anybody:
I have a 2001 YZ250 and would like to lower the seat height an inch or so. Right now I have adjusted the rear shock ring out by 3 turns and that helped the seat height a bit. I know there is a range to work within. If I change the rear shock ring to the highst length--less spring preload. What will I need to do to the front to keep it balanced. Is this an acceptable way to lower the seat height without cutting the seat foam. Also, anybody fooled with the subframe. It really isnt that bad I can tip-toe it now with a 30" inseam and 170lb frame. Just got back into riding since the 1970's so you can imagine the seat height change---but what a hoot, the plush suspension is just amazing. thanks
 

_SOLO_

Pro Champ
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Jan 15, 2000
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#2
Might want to try doing a search. I knw there have been some posts about this lately.
 
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#3
dperyman:

When you remove all the preload the bike rides down in the steeper rate portion of the linkage "curve". This causes your bike to kick and buck you over the bars when hitting sharper objects like braking bumps, rocks, roots and such. It can be quite scarry.

I can guarantee that you'll be unhappy with your suspension set up like that. You'd be much better off learning to deal with the higher seat/ride height that is appropriate for your weight (about 95 to 100mm of sag in the back with all your gear on).

Like _solo_ said, read up on buying a real lowering kit for the rear linkage. I think RC is running about 1" less rear travel than anyone else out there. He can flat foot his KX250 and he's only about 5'3" tall. I saw it yesterday in person at the Salt Lake SX.

Good luck with it.
 
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#4
thanks Hammer:

Do you know who makes the lowering kit for the rear linkage? That makes sense. Thanks
 

Jeremy Wilkey

Owner, MX-Tech
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#6
DPM,
I would very much disageree with some of the advice given. It is quite posible to lower your suspension and achieve good results. I don't think the linkage is the right way to do it all. The problems Hammer talked about can easily be addressed in the valving.
Regards,
Jer
 
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#8
Jeremy:

A couple of questions:

1. How do you deal with the upward travel from 125mm of sag? Is there rebound valving work that needs to be done as well? Maybe a top out spring in side the shock?

2. Isn't the middle of the linkage curve a little flat to get firm low speed damping without the high speed spike at the end when sitting down an extra inch or so?

I had a nightmare of a time with my "flat to steep" linkage curve last winter (94 YZ250). The new linkage I make from the Devol print completely solved my problem without the need for any valving work. What you're proposing seems as though it would only use the concave part of the linkage curve, effectively. That is exactly what the newer linkages for standard bikes have all gone away from. They are now all set up with a convex looking curve in the first 3" or so of travel, then flatter, then ever so slightly concave toward the end. It seems quite difficult to work around that with just valving.

Trade secrets aside, what's your concept there?
 

Jeremy Wilkey

Owner, MX-Tech
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#9
c3Hammer,
I actually run less sag.. We lower overall shaft travel, proportinal to linkage ratio. This gives us a sag number of 3 2/3.. We use a machined AL spacer working with the topout..

As for the valving it's propritary but its not that big a deal. Most of the time riders are in things range anyway.. Think about it you rail out of a corner and your weight is transfeered to the rear. Where are you at?

The older bikes where designed for the longer whooped sections of the track that create a need to lightly pack.

Regards,
Jer