www.DaveMossTuning.com What's the difference between progressive and linear (straight rate) springs? Almost every bike sold today is fitted with progressive springs. www.DaveMossTuning.com
Watched a few of your videos. Your information and the way you put it across is superb. It flows very well not a single pause. It really shows it’s ultra clear in your mind. Like it 👍🏻
How do you set sag with a progressive spring? I bought a set of öhlins for my triumph and it came with progressive springs 18-27NM/mm. Should I buy a set of linear instead?
Set 2 fixed points between rear axle and bodywork. Fuly extend and measure, set the bike under its own weight and measure, then have someone measure you.Record the numbers and do the maths. Then see how much actual shock travel you use via the shock shaft to see what you need (text book vs real world) davemosstuning.com/?s=setting+sag
I have a question. I recently got a new 2023 GSX-R1000 and the spring looks like the one depicted at 2:00 -- at the top where the end of the spring touches the coil, I am seeing wear on the coil from the spring end rubbing against the coil, causing paint to rub off, etc. Is this normal? Is it a sign the spring isn't properly adjusted? Manufacturing defect?
Thanks for your question. It is very unusual to have paint chip or rub off a spring from riding and to have debris you can see. I would ask the dealer for a review of the rear shock paint debris.
Hi Dave. I wish there was more info on progressive springs and setting sag. I've found the subject to be quite confusing. To my understanding, after a shock has been compressed by weight, adding preload doesn't shorten the spring but instead it pushes the bike up. Wouldn't this mean that adding or removing preload gives you the same spring rate characteristics as before, as the spring is still in the same position (but the bike is now lower or higher)? I've got Hyperpro progressive springs on my SV1000 2003. I've found that none of the instructions found on the internet or even the Hyperpro Manual make any sense. Even with max preload there is still 40-45mm sag. One would say the spring is way too soft, but with my weight the bike only drops another 9mm, and even with zero preload and compression damping it never bottoms out. I'm guessing this is due to the progressive nature. Weirdly enough, the bike feel by far the best when I don't put in any preload at all, but it gives huge sag numbers (45-50mm).
What about bikes with linear springs but then fitted with a progressive linkage? I have a monster S4 that has a linkage and a monster 1200 R that doesn’t. The R is harsh over the bumps in the road and I want to soften it off. I’m struggling to work out if a progressive spring would help or if the high speed damping is too hard and it’s hydraulically locking up. Thanks
For the R, check shock travel used first. A little grease on the shock shaft can reveal a great deal. 2. Soften preload and make sure you set rebound correctly with hot oil. 3. Ride normally for 40 minutes and review shock travel. Ideal is 2-3mm above the bumper.
If you have the $$, linear is preferred for the forks and it will take some time to find the right rate. Same is true of the shocks. BUT, you have to be good enough to overpower the OEM springs first.
@@catalystreactionsbw thanks for the reply. So if one does put in the effort to find the right rate then linear as I understood? Would make sense, a progressive spring one the other hand would be a better one fits all solution I guess.
@@Max-yy3lz Very well said and accurate. Do you want the right spring for you or one that kind of works? So, it depends on $$ and types of use as to what will have the best return on investment.
What are some reasons why my motorcyle would sit lower? I would typically be tip-toed, but now i'm able to plant my feet on the ground. No adjustments have been made. Would it be wear & tear on the rear shock?
1. Progressive springs are much softer and generally sag more, so if you reduce spring tension, you get much bigger sag numbers. 2. Oil in the forks and shock ages over time to become less viscous so the resting point drops a few millimeters. 3. The seat wears in and foam is more compressed so your feet are closer to the ground.
Maybe you finally hit puberty? Just kidding, one thing is your getting more confident in your riding where you used to feel barely in control you think of it as on tiptoe and now better planted but it is unlikely your bike is sagging 5 or 6 inches lower than before even with all the ideas that Dave brought up.
Set sag at 35-40mm front and 30-35mm rear. Ride and monitor fork and shock travel used and optimize it appropriately (separate videos on fork and shock travel). Once testing is completed, remeasure and sag and find what was ideal for you and your motorcycle. Repeat the process for every motorcycle you own. It is worth a a couple of hours of work!
Hi Dave thanks to share this. Question for a travel bike with electronic suspension like ktm 1290 super adventure to travel heavy loaded two persons + luggage like 230kg of load , you recommend progressive suspension or linear? I have the possibility to buy a ktech linear 210n/mm or hyperpro progresive 170n/mm - 230n/mm currently my stock ktm is using 160n/mm i think linear.
Service the oil? Are you kidding me? I would have to take half the bike apart just to get my my hand on the rear shock. I would rather just put up with it then service it every 7000 miles. All I want is a spring that does not bottom out. On rough roads, I will live with the fact I just need to slow down since the rebound does not match the road surface. Bike manufactures need to stop screwing around and build bikes we can service. I should not have to take 20 screws, bolts and panels off just to change oil in a shock. I understand people who race need to do all this but 99 percent of us doe not race. I buy a 15 - 25 thousand dollars bike and the first thing I have to is replace the fork springs and the rear spring. That's BS.
When you build a bike that is sold worldwide, I guess 30+% are going to be disappointed given the weight range and loading up for touring with a passenger. Thankfully the aftermarket helps substantially outside of "bling". Point taken on the time it takes to get shocks out. Some are a couple of minutes, others are 30 minutes or more.
@@catalystreactionsbw That is why it needs to serviceable. A bike which can be purchased by a 120 pound woman or a 250 pound man needs to be adjust at the time of sale and the process needs to be easy. In stead we take springs out and throw them away. AND I had a friend fide my 800GS and do some quick stop. She is 140 pounds and she too bottomed out the front springs. I'm 6 foot 4 220 and ride with people much bigger than I am.
Hi Dave. I wish there was more info on progressive springs and setting sag. I've found the subject to be quite confusing. To my understanding, after a shock has been compressed by weight, adding preload doesn't shorten the spring but instead it pushes the bike up. Wouldn't this mean that adding or removing preload gives you the same spring rate characteristics as before, as the spring is still in the same position (but the bike is now lower or higher)? I've got Hyperpro progressive springs on my SV1000 2003. I've found that none of the instructions found on the internet or even the Hyperpro Manual make any sense. My bike feel by far the best when I don't put in any preload at all, but it gives huge sag numbers (45-50mm). One would say the spring is way too soft, but with my weight the bike only drops another 9mm, and even with zero preload and compression damping it never bottoms out. I'm guessing this is due to the progressive nature.
You are correct in your assessment of sag vs travel used. Progressive springs will generally have 40-60mm of sag depending on bike and rider weight combined. As the spring travels it stiffens up, so the rule of thumb is to start at 40mm and ride. If you have plenty of shock travel left as seen on the shock shaft, you can soften installed preload (or compression) to give more comfort via more travel. Ideal is 2-3mm of dirt on the shock shaft. To all intents and purposes, setting travel used is the go to factor.
@@catalystreactionsbw Thanks for replying. I used a tie-wrap and max travel from manual to find out if it's bottoming out. With 0 preload and very little compression damping on the forks I've still got about 23mm of travel left (97mm used). I'm not sure if it's handling better because of the preload setting or simply because the front is lower. The SV1000 seems to love lower front-end. I already 'raised' the forks by 5mm but it seems to want more. Surprisingly the bike doesn't get unstable at all. Your 2-clicks-out video's helped me out a ton on setting compression/rebound. Bike has been transformed! Thanks
Hi Dave. I wish there was more info on progressive springs and setting sag. I've found the subject to be quite confusing. To my understanding, after a shock has been compressed by weight, adding preload doesn't shorten the spring but instead it pushes the bike up. Wouldn't this mean that adding or removing preload gives you the same spring rate characteristics as before, as the spring is still in the same position (but the bike is now lower or higher)? I've got Hyperpro progressive springs on my SV1000 2003. I've found that none of the instructions found on the internet or even the Hyperpro Manual make any sense. My bike feel by far the best when I don't put in any preload at all, but it gives huge sag numbers (45-50mm). One would say the spring is way too soft, but with my weight the bike only drops another 9mm, and even with zero preload and compression damping it never bottoms out. I'm guessing this is due to the progressive nature.
