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Effects of suspension lowering

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I have a Honda CRF250x that I'm planning on lowering a fair bit. I plan on getting a 1.5" lowering link ( http://www.crfsonly.com/catalog/product_info.php/cPath/26_131/products_id/577) for the rear. I know I'll have to use bar risers to clear the fork tubes, but I'm more interested in understanding the effects of sliding the tubes in the clamps a bit more or less than the 1.5" to match the rear. I know it's a bunch of geometry change. I want to understand what effects it will have.

 

Thanks for any information.

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I have found the front drop only needs to be half the rear drop

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By doing it that way you still have 12" of travel; but you don't have 12" of clearance.  So when you bottom out, your tire will be packing into your fender and will at best buck you very hard.  At worst, you crack your subframe, rip off a fender, etc.  BTW, I doubt you can raise your forks more than 1/2" or so because the tubes start to taper after that.

 

The proper way to lower (front and rear the SAME amount) is to have someone install internal spacers and sometimes shorter springs.  Talk to a suspension shop, it should be done right, especially if you're going to lower it as much as you say.  

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I invite you to read my recent experience with a lowering link on my YZ125,

the design of the Yamalink and Kouba are different but it's probable that the Kouba will also affect the leverage ratio.

 

Last post in this thread :

http://www.thumpertalk.com/topic/1157506-does-suspension-seem-low/

 

As bikedude987 mentionned above, if you insist on lowering the bike do it properly with internal spacers.

Edited by mlatour

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So i got my girlfriend an 08 wr250f. Along with all the other mods i threw on a yamalink to accomplish 2 things.

1: it lowered the rear of the bike by about 1.5 inches.

2: it changed the lever ratio making the stock spring correct for her weight.

I tried sliding up the tubes in the clamps and it worked. but she had an absolutly terrible time turning. I chalked this up to her being new and inexperienced.

Fast forward a year later i decided to do things proper, seeing she was still having issues. I called up racetech and 200$ later i had shorter springs and spacers. I shortened the forks 32mm and WOW what a difference. The bike was finally in balance. It was like bolt on confidence. She was very happy with the results. Even i could feel a massive difference with the handeling. I wish i wouldve done this in the begenning.

In conclusion, balance your bike. In my case a lowering link made the rear softer and also brought her spring rate in spec. With that said i had to lower the front to match.

If youre going to lower the bike consider the effects of a lowering link vs having it internally lowered. Regardless what you do with the rear you will want to have the forks internally lowered to match.

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By lower internally, you mean take it directly off the travel, instead of keeping the travel and changing the linkage and sliding the tubes?

So if he had 12" travel front and rear and wanted to lower it 1.5, he would end up with 10.5" travel front and rear?

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By lower internally, you mean take it directly off the travel, instead of keeping the travel and changing the linkage and sliding the tubes?

So if he had 12" travel front and rear and wanted to lower it 1.5, he would end up with 10.5" travel front and rear?

Yes, sorta? What you are really doing is eliminated the free sag, but basing your decision on available travel length after lowering is somewhat irrelevant. Lowering a bike 1.5in is A LOT when it's actually lowered. My wife is 5'5 and we only went a 1".

A lowering link along with sliding the forks is a poor man's way and negatively effects the overall balance of the bike. A lower linkage changes how the shock acts, and sliding the forks up brings the motor closer to the front wheel putting more weight on the front end. I'm sure with much trial and error you can achieve a decent balance but it would never be "as" good. Now of you are one of those guys who says that you don't care, don't mind or doesn't believe it's worth it to lower it internally, then I ask why do it at all?

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My riding buddy is old, short, and has hip joint problems. I feel sorry for him. I am always going for more trials type technical riding and he hates it because he can't touch the ground when he gets off balance.  He is too hard-headed to get a bike with low travel. He gets full moto and suffers. A couple years ago he got a Husky 310 and we talked him into having the shop lower it. They did it with 3/4" lowering link and forks 1/2" up in the tubes. It didn't seem to help much. He still couldn't touch and wrecked all the time from legs too short to reach the ground. His latest bike is the KTM 250 freeride with unaltered suspension. Still way too tall for him but better than the Husky.  I am 6'1" have no problems so it frustrates me. I wish they made a short mans bike with good balance, power, and suspension I could get him to try. If that KTM Freeride were 2" lower it would be a good start.

 

It is too tall for him to get his leg over, so he gets on it like a bicycle; standing at the side with a foot on the peg and then slips the clutch and gets the bike moving then stands and puts the leg over.

Edited by wielywilly-g
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My riding buddy is old, short, and has hip joint problems. I feel sorry for him. I am always going for more trials type technical riding and he hates it because he can't touch the ground when he gets off balance. He is too hard-headed to get a bike with low travel. He gets full moto and suffers. A couple years ago he got a Husky 310 and we talked him into having the shop lower it. They did it with 3/4" lowering link and forks 1/2" up in the tubes. It didn't seem to help much. He still couldn't touch and wrecked all the time from legs too short to reach the ground. His latest bike is the KTM 250 freeride with unaltered suspension. Still way too tall for him but better than the Husky. I am 6'1" have no problems so it frustrates me. I wish they made a short mans bike with good balance, power, and suspension I could get him to try. If that KTM Freeride were 2" lower it would be a good start.

It is too tall for him to get his leg over, so he gets on it like a bicycle; standing at the side with a foot on the peg and then slips the clutch and gets the bike moving then stands and puts the leg over.

A Beta Xtrainer

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I had my 08 CRF250R lowered 1" internally via spacers and then shaved the seat about 1" and the bike looks stock and handles perfect. Along with proper springs and valving, I have never had an issue and am an intermediate B class rider. My girl now rides the bike and it works great for her as well.

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It is too tall for him to get his leg over, so he gets on it like a bicycle; standing at the side with a foot on the peg and then slips the clutch and gets the bike moving then stands and puts the leg over.

I'll have to try that method.  I usually start my day standing on my trailer but obviously, there isn't always something to stand on.

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The 3 of the 4 bikes my wife has owned all were lowered internally. Works great. The loss of travel doesn't slow her down and when other people who are shorter try her bikes they like them. The only down side is the pegs and frame drag easier. Ktm's are short from footpeg to seat so cutting the seat would only make it worse.

Also the shop we use cuts springs and revalves when lowering so the bike is fully set up when we get it back.

Lowering by sliding the forks makes the front wheel move closer to the fender ant full travel, potentially causing run issues.

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The 3 of the 4 bikes my wife has owned all were lowered internally. Works great. The loss of travel doesn't slow her down and when other people who are shorter try her bikes they like them. The only down side is the pegs and frame drag easier. Ktm's are short from footpeg to seat so cutting the seat would only make it worse.

Also the shop we use cuts springs and revalves when lowering so the bike is fully set up when we get it back.

Lowering by sliding the forks makes the front wheel move closer to the fender ant full travel, potentially causing run issues.

Yes, the pegs and frame drag easier.  Less ground clearance.  Kinda like the 50 million bikes sold in the 60's, 70's and 80's.  I don't remember it ever being a problem or even noticeable.  Of course, I didn't cross that many logs.  I think it's more important to be able to touch the ground and if that gives up a little clearance, I'D gladly make that trade-off.

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The 3 of the 4 bikes my wife has owned all were lowered internally. Works great. The loss of travel doesn't slow her down and when other people who are shorter try her bikes they like them. The only down side is the pegs and frame drag easier. Ktm's are short from footpeg to seat so cutting the seat would only make it worse.

Also the shop we use cuts springs and revalves when lowering so the bike is fully set up when we get it back.

Lowering by sliding the forks makes the front wheel move closer to the fender ant full travel, potentially causing run issues.

I have never cut springs to lower a bike and don't understand why you would?

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I have never cut springs to lower a bike and don't understand why you would?

When adding a spacer to the damping rod to limit the length you need to have a shorter spring to accomodate or move the spring perch the same amount as the spacer. Moving the perch isnt always a possability. Neither is finding a shorter spring. So a custom length has to be ordered or made.

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When adding a spacer to the damping rod to limit the length you need to have a shorter spring to accomodate or move the spring perch the same amount as the spacer. Moving the perch isnt always a possability. Neither is finding a shorter spring. So a custom length has to be ordered or made.

I've had 4 bikes lowered, 2 KTMs, 2 Yamahas, never had custom springs or such. All your doing is compressing the suspension, nothing more...

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I've had 4 bikes lowered, 2 KTMs, 2 Yamahas, never had custom springs or such. All your doing is compressing the suspension, nothing more...

Depending on the forks you may not need to. But take for example some OC kybs. I had a 30mm spacer made and installed it on the damping rod. By doing so my fork now extends 30mm less than previously. If i were to leave the spring the stock length then i would have an extra 30mm of preload! No bueno. So to get the preload back into spec a shorter spring is needed or they need to be shortened, which ever is more practical.

On a lot of twin chamber forks you can simply make a new groove in the cartridge, for the circlip that holds the spring perch, and move it farther up the cart accordingly. Some forks dont have the ability to move the spring perch so other methods such as shorter springs are required.

Edited by Dadee

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"On a lot of twin chamber forks you can simply make a new groove in the cartridge, for the circlip that holds the spring perch, and move it farther up the cart accordingly. Some forks dont have the ability to move the spring perch so other methods such as shorter springs are required. "

 

Dadee can you tell me more. I have a KTM 450 sxf 08 with Closed Chamber

Or is it not the same as twin chamber?

Edited by skorpan777

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"On a lot of twin chamber forks you can simply make a new groove in the cartridge, for the circlip that holds the spring perch, and move it farther up the cart accordingly. Some forks dont have the ability to move the spring perch so other methods such as shorter springs are required. "

Dadee can you tell me more. I have a KTM 450 sxf 08 with Closed Chamber

Or is it not the same as twin chamber?

Closed chamber is a twin chamber. Are you comfortable taking the forks apart? If so remove the cartridge from the fork. The spring perch sits against a circlip. The circlip is seated in a groove. Simply machine a new groove farther up the cart equal to the spacer you install underneath the mid valve piston.

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