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Posted: Aug 22, 2021 at 17:10 Quote
joshhuber2 wrote:
It's actually really plush. I don't have many jumps or drops to ride. The trails I ride are fast with lots of small bumps. I am running a longer stroke spring but with less weight rating. I had to make a special tool for my press to get it installed. I should run a 600 lb but can get 25% sag with a 450 lb and zero turns of preload. The result is a softer spring rate throughout with little high speed compression and no bottom out. THIS IS NOT A RECOMENDATION as it only fits my particular riding style.

How much travel does running a longer stroke get you?

Posted: Aug 22, 2021 at 17:23 Quote
kilo11 wrote:
joshhuber2 wrote:
It's actually really plush. I don't have many jumps or drops to ride. The trails I ride are fast with lots of small bumps. I am running a longer stroke spring but with less weight rating. I had to make a special tool for my press to get it installed. I should run a 600 lb but can get 25% sag with a 450 lb and zero turns of preload. The result is a softer spring rate throughout with little high speed compression and no bottom out. THIS IS NOT A RECOMENDATION as it only fits my particular riding style.

How much travel does running a longer stroke get you?

I don’t think his travel changes because the shock stroke is still the same just with a longer spring.

Posted: Aug 22, 2021 at 17:29 Quote
Same travel just that the overall spring length is greater so it is compressed before I even get on it. If I needed a 600 lb spring and say 1/2" of sag, the 600lb spring would exert 300lbs of force. For the same sag but a 450lb spring preloaded 1/4", the force exerted would be about 330lbs. If I used the correct length spring but preloaded ot 1/4", i would risk exceeding the spring compression range. My bike is softer throughout the travel, but I suspect it will bottom out if I hit large drops. I came from a dirtbike background exclusively; no bikes up until 6 months ago. I always felt off when I do jump with the air spring. It just feel right for my style and level of riding. I'm a middle aged balding guy with a wife and kids; I'm never going to be K.O.M...

Posted: Aug 22, 2021 at 17:33 Quote
gnarcissistictendency wrote:
kilo11 wrote:
joshhuber2 wrote:
It's actually really plush. I don't have many jumps or drops to ride. The trails I ride are fast with lots of small bumps. I am running a longer stroke spring but with less weight rating. I had to make a special tool for my press to get it installed. I should run a 600 lb but can get 25% sag with a 450 lb and zero turns of preload. The result is a softer spring rate throughout with little high speed compression and no bottom out. THIS IS NOT A RECOMENDATION as it only fits my particular riding style.

How much travel does running a longer stroke get you?

I don’t think his travel changes because the shock stroke is still the same just with a longer spring.

Ah yeah, I read that wrong. My bad lol

Posted: Aug 22, 2021 at 17:38 Quote
doesn't change anything.

Running a spring too long for the preload adjustor/clip will kill the shock eventually.

That is, If the spring free length is longer than what the preload ring to spring clip is.

However, if the spring fits inside fine, there is no issue. I run 2.9 springs in a 65mm stroke shock purely because they are slightly cheaper.

You don't get any additional travel, that is mandated by shock stroke.

Posted: Aug 22, 2021 at 17:41 Quote
its my understanding that running a slightly longer spring length allows for less preload to achieve same sag value and more sensitive beginning of stroke. I tested this on my 65mm shock with a 450lb 2.9” spring and a 450lb 2.6” spring, and the 2.9” felt more plush over le bumps

Posted: Aug 22, 2021 at 18:54 Quote
Isn’t preload just to keep the coil held firm while the spring rate determines the sag? Adding extra preload just increases the force required to move the spring, so ideally 0 preload is the goal right?

Posted: Aug 22, 2021 at 18:56 Quote
twonsarelli wrote:
Isn’t preload just to keep the coil held firm while the spring rate determines the sag? Adding extra preload just increases the force required to move the spring, so ideally 0 preload is the goal right?

Not necessarily. Depends on the compression tune and kinematics of the bike. For example, my shock requires 3 turns of preload in order to reach the ideal setup for my tuned shock.

Posted: Aug 22, 2021 at 19:17 Quote
Mntneer wrote:
twonsarelli wrote:
Isn’t preload just to keep the coil held firm while the spring rate determines the sag? Adding extra preload just increases the force required to move the spring, so ideally 0 preload is the goal right?

Not necessarily. Depends on the compression tune and kinematics of the bike. For example, my shock requires 3 turns of preload in order to reach the ideal setup for my tuned shock.

Ok that’s interesting. Perhaps I have been misinformed but I was told that you want minimum preload, otherwise a bump first has to overcome that force applied to the spring before it can compress further. That would mean any bump resulting in a smaller force than already applied to the spring will just go straight to the rider.

Posted: Aug 22, 2021 at 19:33 Quote
I'm not claiming to be an expert. The way I thought of it is; no matter what spring rate (k) you use, the force to hold you at 30% sag will be the same. Where (k) is the amount of force to compress the spring 1". The preload increase the initial force to that point. More turns for lower spring rate(k), less turns for higher spring rate(k). What I did only works for my specific trails and preferences. The spring can only maintain (k) to a certain level of compression; after that it becomes erratic because it deforms. That's why you can only turn the preload screw so far or you risk forcing the spring into the deformed state under full travel. In my case, in order to use a 450lb spring my preload would be at 40% sag. I think..

Posted: Aug 22, 2021 at 20:10 Quote
preload maximums are because the shock itself will fail due to excessive top out force. Or in rare circumstances where you are on the limits of the spring free stroke you get coil bind, which will also kill the shock.

The phenomenon of feeling a more supple feel to the same lb/in spring isn't placebo, the tolerances on some brands are terrible, verified using an intercomp spring tester. Cane creek VALT and Fox SLS are very close to listed in/lb, rockshox steel and especially fox steel springs are all over the place, the higher the rate the wilder the variance.

Best solution IMO, minimum preload as possible and a variable rate spring (springdex)

Posted: Aug 22, 2021 at 20:34 Quote
Brasher wrote:
preload maximums are because the shock itself will fail due to excessive top out force. Or in rare circumstances where you are on the limits of the spring free stroke you get coil bind, which will also kill the shock.

The phenomenon of feeling a more supple feel to the same lb/in spring isn't placebo, the tolerances on some brands are terrible, verified using an intercomp spring tester. Cane creek VALT and Fox SLS are very close to listed in/lb, rockshox steel and especially fox steel springs are all over the place, the higher the rate the wilder the variance.

Best solution IMO, minimum preload as possible and a variable rate spring (springdex)

Cool. I’m running minimum preload and sprindex. Bob’s your uncle.

Posted: Aug 22, 2021 at 20:57 Quote
I didn't consider top out forces, so I may need to revisit when the shock fails. I got it for $150.00 from a shop overseas so I'm not out full tilt. I also bought a used spring for $20.00 because the spring calculators I used were all over the map, so I didn't want to spend a lot. I read on the form that fox steel springs run short so go the next size up. It was more accidental that I came up with this setup. I did recently have to increase my high speed compression when I switched the pike ultamate for the fox performance because I was able to carry more speed through the really choppy area of a particular trail I ride. I usually had to brake because my bars would shake violently. I keep a glob of grease on the bumper to moniter bottom out.

Posted: Aug 23, 2021 at 3:29 Quote
twonsarelli wrote:
Isn’t preload just to keep the coil held firm while the spring rate determines the sag? Adding extra preload just increases the force required to move the spring, so ideally 0 preload is the goal right?

Yep this is 100% correct, running a longer spring with loads of preload is just wrong. All you are doing is loosing all the nice small bump you get from a coil setup, adding extra weight from the bigger spring and potentially damaging your shock as the spring tries to ram the spring collar off.

You’re not changing the kinematics of the bike or the shock by doing this. If the spring is already compressed you are just starting the compression stroke further up the graph with no change of the angle of the force line.

Run the correct length spring for the sag you want to achieve.

Posted: Aug 23, 2021 at 6:23 Quote
I completely misunderstood the system. Thanks for setting me straight. Now to find the correct spring in a post apocalyptic covid industry.


 
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