Sign in to follow this  
Followers 0

Having trouble tuning your suspension with a lowering link?


motoinmoab

The longer your links are, the more they lower your seat, and the more they affect your suspension: The rear end gets too soft.

Lowering links increase the leverage, or compressive force, applied to the shock as it travels thru the stroke. The different components that make up the rear suspension linkage are very well engineered and balanced by the factories. Changing any one piece affects the overall function. The lowering link introduces a longer lever arm into the heart of the linkage mechanism, applying greater force to the spring and compression damping circuits. They make the ride more plush initially, and much softer near the end of the stroke.

The links that drop the seat more than 1” usually work good for someone who doesn't ride really hard, like a dual sported bike that sees dirt roads and trails at moderate speeds. But when you turn up the speed, or hit rougher trails, these links will soften the rear end too much. If you are frequently bottoming your suspension, you’ve got too long of a link for these conditions. Now the fun part begins: Tuning. The longer links are a fairly aggressive modification to your suspension’s design, you’ll have to spend some more time and money to make it ride right again. Although this is one of the easiest ways to get your feet closer to the ground, the suspension action is greatly compromised.

For more aggressive trail riders, the links that lower 1” or less will usually work OK, without softening your effective spring rate too much. With the links that lower more than that, the ride gets too soft for you: The bike will most likely bottom out hard on your bigger hits, especially when jumping, and in deep compression G-outs like crossing a wash. If you’re having these problems with one of the shorter links, the following suggestions should help get your butt bouncing back under control. Any lowering link for heavy riders, or race speeds, can easily overpower the shock and it will blow through the travel.

The rear end really needs to be stiffened up. The easy adjustments that you can make are somewhat limited:

Adding Preload to the spring doesn't change the overall strength of the spring, it only affects the initial stiffness, and can seriously affect steering. Preload is the “Race Sag” adjustment, and not the proper way to correct for the lowering link effects. And the “Free Sag” measurement, for determining proper spring rate, can’t be used with a link. It will measure out that you need a softer spring when you really need a stiffer one.

A Stiffer Spring may help, at least it sounds right in theory. But the increase in force applied to the spring isn’t necessarily linear, it varies with different bike models, and the force can increase through the compression stroke. As I said before, you’re messing with the heart of the design. While a new spring alone isn’t guaranteed to get your good ride back, it can help a lot. Another important point: Have you checked to make sure that you have the correct springs for your weight? Springs that are too soft initially will compound the link issues. Check out the RaceTech Spring Rate Calculator, and figure you will need to add at least a couple of steps heavier. (I tried a 1 1/4” lowering link on my Suzuki, went up from the stock 5.3kg to a 5.7kg, it wasn’t enough.) The link only affects the rear spring, you don’t need to get stiffer fork springs to match if they’re good now.

Adjusting your Compression Damping will help, but you are limited by the range of the adjusters, which might not be enough. Turn in your compression adjusters a lot, high and low speed if your shock has both. These adjusters really affect the ride, so you will probably need to play with them a few times until you find an adjustment that you like. If you need help understanding how to tune your suspension, the ThumperTalk store sells a good DVD on the subject. Too much compression damping and a weak spring will make your bike ride terrible.

Another option is to ship your shock off to a tuner, who will take it apart and change the internal damping shims to a stiffer moto or SX like ride. I've spoken with a couple of tuners about this, they didn’t like tuning for lowering links, they prefer to shorten the shock stroke to lower the seat height. That service is more expensive than a simple link modification, and you will lose some travel. Many riders that have tried both methods preferred shortening the shock and forks, and resold their links.

The factory designers aren’t idiots, they’ve designed a good working suspension, and the linkage components are balanced to each other. The real problem is just that they are all too tall. If they had short legs like us, we’d get a good fitting bike off the showroom floor. Anything we do to lower the seat height, afterwards, will have an effect on the quality of the ride. If you can’t make your bike ride right with the lowering link, you do have some other options you can try. Read this article about Lowering your seat height for more ideas. :thumbsup:


Sign in to follow this  
Followers 0


User Feedback


Motocross Action said that using a slightly longer link on the 2014 2015 yz450f stiffens the initial part of the travel by putting  the shock deeper into the rising rate.

Share this comment


Link to comment
Share on other sites

i use a kouba lowering link i think if i have lost an inch that would be the most i have lost ! my problem is even though i have a 32 inch inside leg i am still stretching to touch the floor but i also feel i am sitting in the bike rather than on it !If i fitted a higher seat foam i would be happy easy fix!! but then i will be even higher from the floor ,should i shorten the forks and shock ?

Share this comment


Link to comment
Share on other sites

I used a lowering link on a 2010 crf250r. It lowered the seat 34 mm. A little over a inch. Then I raised the forks in the triple clamps about 10mm from the top of the fork or 5 mom from the standard mark. It worked really great. I ran more than normal sag also because Honda had made some significant changes that year. Now I have been testing Race Tech shock spacers to shorten the shock on a 2096 rm250. I have it shortened about 1 1/2 inches. Recally all it is doing is not letting the shock use the last 1 1/2 of the sag. You should sag a little over 4 inches so when you are on the bike you just notice the rear does not come up as high when you hit a bump makes it fill like it sticks to the ground.

Share this comment


Link to comment
Share on other sites


Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


  • Similar Content

    • By InAquaVeritas
      I've searched the forum for info on this, but can't find anything except for a shock in the TT shop.
      I'm in the process of rebuilding my 2005 SM, front to back. After running the engine into the ground, too little oil and stupidity, I have ordered a big bore kit. As I'm doing that, I want to get the suspension redone as well, but all the rebuilders over here refuse to service the OEM Showa rear shock, as it "will always be a poor quality shock".

      What are good replacement options?
      What is the OEM shock length eye-to-eye?
      Are there progressive springs for the forks?
      Thanks a lot!
    • By mebgardner
      Stainless Steel Heavy Duty Rear Shock Preload Collar for KTM 690 (non-2008).
      From here: https://superplushsuspension.com/
      It accepts KTM adjustment tools, or generic "pin type" (BMW) adjustment tools, both on the same collar. Or, beat it with a screwdriver and hammer will work too.
    • By vbuffalini
      What's up all?
      I recently bought a 2009 yz450f and I have a few questions about sag and spring rate.  The rear felt super stiff before I adjusted anything.  After setting my race sag to 100mm and free sag to 25mm (which denotes a correct spring rate) my rear was super soft and washy.  I jacked up the high and low speed compression, but it didn't help.  Rebound is slightly slower than stock and feels good.  I added pre-load and now i'm not sure what the race sag is because i have no one to help me measure it, but the free sag is set to 20mm and its somewhat better but honestly, I liked how the bike handled when it was super stiff.  Should I get a stiffer spring? (maybe this one is worn out) Is it reasonable to ride with about 90 something mm of race sag and 20mm of free sag? Or maybe I just don't know how to ride. Any help is appreciated.
    • By wachterxc
      Just got my first paycheck from my first formal job. So... if you had 800 bucks, what would you get for your 2015 KTM 300 XC-W?
      (I studied finance so dont tell me to save for my retirement or invest! that shit is #boring)
      Regards from Mexico!
    • By wachterxc
      I would like to get my forks moving faster in order to respond to the smallbump-slowspeed chatter that bothers my ride. My valving is spot on (Race Tech Gold Valve), SKF seals are pretty fresh, and oil is at a good height. Ive come to the conclusion that im probably dealing with some stiction issues. Any tips on how to reduce this? Trying to find some low-budget solutions... (PLEASE dont suggest some kashima coating /ti-nitride fancy pantsy coating because im pennyless)
      Ive read some folks "polish" the inside of their fork tubes to reduce stiction. How do you polish these? Any special tools or technique?