Hyperpro spring review for the S10

[kjetil4455]

Hi guys

I bought a hyperpro spring kit for my XT660 and it turned out beatifully, also added an emulator kit in the front. Because of this, although I had read some bad reviews here, I decided to go with the same kit for the S10. I will leave this here for anyone else contemplating the same:

The shock spring is still undersprung, but works pretty well. I needed to add 50% preload when weighing just 220 lb. It is an OK deal for the price, but I think a thicker caliber spring is better. Because below 220, changing the spring won't be necessary anyway. The fork spring, however, is extremely stiff, and the kit comes with 15W oil which makes the bike handle like dogshit. I decreased it to 5W (stock) and reduced preload to zero, but it is still extremely stiff. I will probably be changing back to stock springs and keep the hyperpro shock spring.

For those of you who are considering buying this kit, I recommend buying only the rear spring and choosing another provider for the front spring or sticking with the stock and simply increasing compression dampening. The forks spring seems to be designed on bad specs.

I will probably be changing the rear shock for a TFX one that is fully customizeable. The fork didn't really need any work, at least for me, to being with. It just needed more compression dampening.

 

[kjetil4455]

Updating this post. It took me a lot of money and a lot of time to find something that would work well for my use.

There's nothing wrong with the hyperpro spring upfront; the problem is that 1. the 20W oil that comes with it is absolutely inappropriate as it's a 70ish centistoke (viscosity) oil and the OEM valving on the S10 is for 15 centistoke oil. It hydrolocks and feels like shit. I noticed, to my initial perplexion, that hitting a smaller obstacle at speed would cause a hard impact upfront, and it took me quite a while to realize that this was due to the OEM valving and using the 20W oil that came with the kit. As I went down (15W, 10W, 5W) this kept happening until I realized I needed a 15 (ish) centistoke oil. And, 2., as the springs get harder the "margin of error" for poor valve settings become narrower, and you need to know what you're doing. If you don't, as I didn't, it's easy to go ahead and blame the springs when the real problem is the valving. To be fair, though, the instructions that came with the fork springs are pure rubbish.

If you choose to go with the hyperpro front spring, go with the OEM oil thickness and gradually increase compression dampening until you're just barely not "falling" into the corners when leaning over (let the fork oil warm up first). If you feel that you're falling into the corner, compression dampening is too low. If you reach max comp dampening and still have this happen to you then either preload is too low or the oil thickness is too low. If you're comfortable going into the lean, but it's slow to get back up, then the spring preload is too low (OEM spring, unlikely with hyperpro spring) or rebound is too slow (very unlikely with OEM valving, as OEM fork rebound is quite quick)

The compression dampening orifice in the compression valve piston is very thin and it will hydrolock on high-speed movement with certain 5W oils and certainly at a 10W oil. Go by centistoke, not W.

I chose to go with the Stoltech revalve option as it was recommended here. I was and am very happy with the compression dampening valve he provided, but quite unsatisfied with the rebound dampening as it was extremely overdampened. He also provided me with a spring tension that was way lower than what I needed. If the reader wants to revalve, I'd recommend just going with a new compression piston and NOT doing the rebound as it's way overdampened. I ended up having to take out a staggering 5 shims from the rebound stack to get the bike to come out of corners properly. I also went back to the hyperpro spring.

I went with a TFX shock rear but the hyperpro rear spring is a fine and lower cost option for those with lesser demands. The OEM shock is pretty well dampened other than being somewhat low on rebound dampening (this gets more obvious once the harder spring is placed). 3 out from max rebound works OK (max will affect compression too much).