Lowering a CR500 rear end ? **UPDATE**

[SoCalDesertRider]

Hi guys. It's been a loooooong time since I've been on the board here (and somehow I'm missing an 'r' on the end of my name now too...?).

Anyways, I have this '89 CR500 that I want to lower down a little so the seat is not so high. I've already adjusted the rear shock spring adjuster nuts almost as far up the shock body as they will go, there are only 4 threads left, and the spring is at full-length, according to the Chilton manual (11 inches at full drop). There is still pre-load on the spring, but I don't think there will be enough if I raise the adjuster nuts any more than they are, so I don't think I have any more adjustment there. I need to bring the bike down another inch or two.

Is it possible to use a shorter spring on the rear shock? I'm thinking a CR250 might have a shorter spring, since my friend's '88 CR250 has the same size tires as my bike but his bike sits lower than mine and his shock still has some adjustment left in it. The bikes seem almost identical in all respects, except height and obviously engine size, and alot of parts seem like they would interchange.

I also looked at possibly cutting down the existing spring, but it appears to have flattened ends on it and cutting it would eliminate those formed ends and the spring might not mount correctly in the shock.

Any ideas are welcome. Thanks.

[WMX500_RACER]

hi as for the cr250 spring i think there the same length as i lowered my 84 CR250 for hill climbing but also wanted to jump with it so i put a CR500 shock on it cause the 500 shock is stifferthen the 250 but is the same lengh if you put the 250 shock linkage on the 500 im pretty sure it will lower it quit a bit thats pretty much what i did with mine i put a 87 CR500 complete rear setup on mine to modifi it to rear disc and the linkage was shorter and that lowered it so it will probly do the same in your case hope this help anthony

[SoCalDesertRider]

Thanks, I'll park the 250 and the 500 next to eachother and compare the linkages and see if that may do the trick. Thanks for your help.

[WMX500_RACER]

i hope it helps i know that it's alot easier to control a bike with alot of power when it's closer to the ground so good luck

[SoCalDesertRider]

...alot easier to kick it over too! I should be able to find out this weekend, since both bikes will be going riding with us.

[yater]

If you like the way it handles, don't change linkages (if it's even possible). A longer link will alter the frame geometry and you'll definately "push" in corners. If you know anyone who machines, a spacer can be made so the shock doesn't extend all the way. A riding buddy of mine did it to a drz400 and wr450--no problems with geometry changes and it costs <$10. You should check out dirtrider.net or thumpertalk.com (I know it's a smoker but they don't care)

[TrikeKid]

Have you looked into shaving the seat? you can useually get an inch or 2 lower depending on you're seat.

[yater]

The kouba link definately changes the handling. I've dealt with several bikes and kouba links (always #1s) and the change is in the angle of the shock (not the sag in the rear). Even with the fork pulled up, it's a different bike. If you'll carefully read the instructions on a kouba link, you'll see that the sag should be set to compensate for the lower rear--meaning the only purpose of the link is to change the geometry, not the seat height. This is a positive change on poor handling bikes like the dr350 (rear kicks everywhere)

[TrikeKid]

Kouba them selves markets them as lowering links.

[yater]

Yeah I should have been more clear on that. The #1 is not meant to lower the bike. It WILL lower 3/4" if you don't adjust sag. The #2 and #3 will lower up to 2 3/4 inches!

[SoCalDesertRider]

Here's an update and a few questions.

I checked out the linkages on the two bikes this weekend and they didn't appear to be much different from eachother. The lower shock bushing centers are about the same distance below the bottom of the swingarms on both bikes, so I don't think it would be worth tracking down a CR250 linkage to experiment with.

I have heard about shaving the seat. It's not real thick now, but maybe it can be made a little thinner. I don't know how to do it to make it come out even though and I'm not sure I want to ruin a good seat foam. Maybe I will find someone who knows how and have it done.

I'm happy with the bike's handling, so I wouldn't want to change that, just the ride height and the stiffness of the spring. A little lower and softer would be good.

What is this kouba link? Is it the whole linkage setup or is this a replacement piece? Am I clear in thinking that the #1 link would not be right for me but the #2 or 3 could be ok (not change geometry but lower the bike)?

The spacer that was referred to, where does it go and what does it do?

Thanks again.

[yater]

All of the kouba links will change the geometry. The #1 will just do it the least. I wouldn't mess with that on a good handling bike like the cr500--You'll end up pogo-ing all over the place...trust me. You can machine spacers for the fork and shock. Go to www.thumpertalk.com and search for "shock spacer" and something should come up. This will allow you to lower the bike without changing handling characteristics

[SoCalDesertRider]

Vater, I checked out Thumper Talk. There was ALOT of discussion on lowering all sorts of bikes and everyone there seemed to have a completely different idea of how to do it and how not to do it. Alot of info, but I think I left with more questions than answers....

I'm going to investigate chopping a short section of tube out of each of the lower legs of the rear subframe and welding it back together as a method of lowering the seat without messing with the susupension. It looks like I might be able to chop out up to a half inch of tube possibly. Not sure how much that will lower the seat, but I will do some measuring and see if it may be worth it. Maybe that together with shaving the seat foam and raising the forks a little in the tripple trees will give enough change in height to make the bike more comfortable to ride and easier to start. I really should have a lighter spring put on the shock and have the shock spacer put in it, but that sounds like it would cost big bucks to have the shock built, which I would rather not spend on the bike since I have so much money into it already.

Thanks for the help so far! Any other ideas or thoughts are certainly welcome .

[yater]

One more thing....I'm 5'7" 140lbs with a 29" inseam and ride my bikes stock--no problems (at least not because of seat height). The only bikes I shave the seat on are my dual sports. I don't want to put myself in an awkward situation in traffic where I can't get a foot down. Otherwise, I manage just fine in the woods. I'm assuming you have some experience since you're riding an open class 2stroke? I understand that they take a hefty kick but you might be able to deal with that? It would be a shame to chop up that bike

[SoCalDesertRider]

I'm 5'6, 150. I have trouble kicking it hard enough to start it when I'm standing over it. If I was taller and heavier, it' wouldn't be a problem starting it. I usually put the kickstand down and stand on the left footpeg so I can jump on the kicker with the other foot and start it. The bike takes a few HARD kicks to get going. When I stop in sand, the kickstand is useless since it sinks into the sand. I try to avoid stopping anywhere where it will be difficult to start it again, but sometimes stuff happens...

As far as riding it, I'm fine with the height. I ride open desert and don't need to put my foot down all that much. I would like it if I could get it to the same height as my friend's 88 CR250. I start that one fine in one kick standing over it. His bike is about 2 or 3 inches shorter than mine and still has some adjustment left in the rear spring too. Mine is as low as it can go right now.

I have two desert seasons riding experience on 2 wheels, started with a YZ80, got comfortable on it, decided a full size bike and more power were needed, intended to buy a CR250 and ended up with the 500. So yeah, I'm not the greatest dirtbike rider, but I'm getting better . I'm happy with the bike (other than the overheating) and like riding it, love the torquey motor, it's just the starting that's difficult because of the height . I always do manage to start it, but it would be alot nicer if it was lower.

If I chop the rear subframe, I can always cut it and weld more tube back in if I want it stock again, as long as I take measurements before I cut it. It will look nice when Im done with it, not all buggerd up, I have lots of welding and fabricating experience .

It looks to me like cutting down the subframe will bring the back end of the seat down noticeably, but may not do much for the center of it, since it will pivot about the upper mounting location, which is just about below the lowest point on the seat right now. I guess my question is, do you think I will be able to get enough drop out of this modification or will I be doing alot of work for not much difference in seat height?

Thanks again for your help!