Anyone here ever lowered an MX bike before?

LuckyStar64

LuckyStar64

PR Addict
What's up gang! If you know me, then you KNOW why I'm asking this question! Hahaha! Yep-- I'm only 5'5 with a 30 inch inseam! I generally love thrashing on play bikes, but I raced at Meadowlarks a few weeks ago, and I really liked the track. I've been tossing around the idea of becoming a member there. I like fun and easy tracks, and I feel like I have Smith Rd., the Cabin, and Meadowlarks all a stones throw away, so I'm thinking that it'd be worth building an inexpensive 125 so I can ride the tracks close by.

Before ya suggest a 150RB-- know that I've had a coupla them before, and they ARE a hoot to ride. but not really as your only bike. I love riding a 125, even though I could prolly go faster on a 250F. I don't think I wanna throw down enough cash that it'd take to get and maintain a 250F, so I'm thinking a 125'd be fine.

I CAN ride a 125 as they come height wise, but the size was uncomfortable when I was 25, and even more uncomfortable now that 50 is closing in. Been reading a bit about what they did to Ricky Carmicheal's 450 for him, and alot of those things can be done to a random 125.

MX bikes generally come with 36 inch seat heights, and my goal would be 33 inches. Here are some of the ideas I have so far, and many were done to RC's bike.
- Suspension lowered an inch with internal spacers, and the travel limited as well.
- Fork tubes slid up in the clamps
- Very slightly shorter dog bone links in the linkage.
- 18 inch rear and 20 inch front rim. (RC ran a 19 inch rear with a short tire and a 20 inch front rim)
- 1/4 inch cut out of the bottom of the sub frame should equal about 3/4 of an inch of seat height.

Any other ideas? I wouldn't likely do the Kouba link out back as it choppers the stance. I think I could do those mods without comprimising the ride or ergos? Cutting the suspension travel shouldn't be a huge issue for me because I'm not a huge jumper. Anybody have any experience with any of these mods? --L*64
 
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When I worked for F&S, we regularly used Tech Care to shorten suspension. I remember a 125 we had shortened by 3 - 4 inches at the seat with reduced travel and shaved seat foam. The bike looked odd sitting next to a stock one, but the rider loved it.

Good luck finding a 20" front rim. Those were rare birds in 2000 - 2001; time has not made them more available. 18" rear tire has almost the same outer diameter as a 19" too.
 
Yep, Tech Care. I THINK the 20 inch front is more common in Europe, and I haven't inquired about the 18 inch rear yet, but I know the KTM Free Ride uses one. I think PR2 can do a dog bone link 5-10 mm longer which would lower the rear an inch, and I could compensate by moving the fork tubes up in the clamps slightly.
 
Bob Harrington at pro action of northern ohio. 99% sure he lowered a guys suspension a while back. Not sure what he did or how he did it but I'm pretty sure he made it work.
 
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My dad does it on most of his bikes. He rides a 14 FE KTM 450. I think one issue is that some places lower the bike, but don't account for the suspension in effect riding 25% down in the stroke from the start and making the bike feel harsh.
 
Try and get a pic of tour dad's bike from the side and post it up. I want to see how it looks. If the suspension has 12 inches of travel, then we're only talking about 8% down in the stroke if I take an inch out at both ends. Should be OK. Looking to take another inch with slightly smaller wheels if possible, then another inch with the linkage mod/fork tubes slid up in the clamps. I think I'd be good with a 33 inch seat height. --L*64
 
What about frankenbootzs
 

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Lowering link for the back and forks adjusted to match? A good suspension guy should be able to make suggestions. Changing wheel size could be a difficult task. But it's easier when you're older to stand from a taller seat. I've used a tall seat for years to be comfortable. The stock seat height might do that for you?
 
One of my bikes is Michael Willards 2008 YZ250F practice bike from when he raced the US outdoors for Cycra/K&C Cycle and it has a shaved sub frame and it sits waaaay low. Like I'm 6'4 in boots and I can straddle the bike, stand flat footed, and still have 5 inches between me and the seat.

You might be asking why I bought a super short bike when I'm 6'4 and the answer is because I can lay that bad boy over and rip some ruts. I'll never sell it!
 
I have a 150XCW that is lowered just over 1". My wife rides it and is 5' 2". Jamie Reed from JRP suspension in Covington OH can do it for you and is very reasonable on price. IM me if you would like his contact info.

As far as the other things like shaving seats and stuff, I know people who have done that and it seriously alters the bike ergo's and makes them uncomfortable to ride.
 
Damn! Looks like there are a few riders besides me that aren't exactly thoroughbreds? That KTM150 is definitely a bike I'd be interested in. is the engine the same in the XC as the MX bike? I was thinking that Care Tech had the most experience with lowering because I was thinking that they'd done alot of supermoto bikes? --L*64
 
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LuckyStar64 said:
Try and get a pic of tour dad's bike from the side and post it up. I want to see how it looks. If the suspension has 12 inches of travel, then we're only talking about 8% down in the stroke if I take an inch out at both ends. Should be OK. Looking to take another inch with slightly smaller wheels if possible, then another inch with the linkage mod/fork tubes slid up in the clamps. I think I'd be good with a 33 inch seat height. --L*64
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I'll get you a photo tonight.

The XCW is the same engine as the SX but has a different ignition and a heavier flywheel. It also has electric start! It is a super fun bike.
 
Sharc-- That's not your JWRP bike is it? Gorgeous!! That KTM Doesn't look horrible, but I wouldn't want to take a quarter of the suspension stroke. Seems like it'd do something strange handling wise. I'd do an inch of suspension, and the rest with linkage and sliding the fork tubes up in the clamps. I've called ProWheel about wheels, and they can do 18/20's on most bikes. They do it in Europe, but they said the rear 18 isn't going to save that much because the tires are taller than the low pro tires available for the 19 inch rims. That's what RC ran. --L*64
 
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