20mm Piston Kit

[SP2rider]

Been considering a 20mm Ktech or Ohlins Piston kit for the front end anybody else done the same mod ????

I find the front end harsh on anything but smooth tarmac but dives heavily on the brakes and if you adjust with the comp damping the ride becomes worse with the front feeling nervous and chatter on the brakes.

[steve p]

Agree, got K-Tech to rework mine with springs to my weight and valves etc. Total transformation well worth it.

[Dmac]

HI SP2rider, I just have standard forks with 5W oil so I can't comment on the upgrade kit - wouldn't mind trying it out though

I find the front end harsh on anything but smooth tarmac but dives heavily on the brakes and if you adjust with the comp damping the ride becomes worse with the front feeling nervous and chatter on the brakes.

I think we all know what you are saying here, I am not a suspension expert - but in my opinion and limited experience I have found,

1 I think the standard springs are quite soft - and have too much static sag - limiting travel. Increasing preload will lift the front of the bike giving you more suspension travel. This can let the springs do the work and then back off the compression damping.

2 If you have too much rebound the forks do not have enough time to re-extend after hitting a bump - then when it hits the next bump there isn't enough travel left to absorb the second bump and that can lead to the harsh feeling. I back the rebound way off the add as needed.

3 Tyre pressures - it is worth checking out the thread on this here - can make a big change to comfort.

I copied this on another forum - they were discussing suspension set up and this made alot of sense to me - not my words - credit goes to a guy from Greece.

"Assuming you can not alter the springs strengh, only preload, you start with the preload settings to set a good starting sag. Then I would say you can sacrifice a bit on the recommended sag setting to alter the bikes geometry more to your liking.

Compression needs to be soft. As soft as possible not to allow the suspension to bottom out. If springs were strong enough, no compression damping would be required, try to remember this and you will end up with a nicely set up compression damping. Both comfy and stable. Also remember your throtle is also your realtime compression damping adjuster. The more throtle the more compression damping the bike, especially the rear, appears to have...

Rebound. That is a difficult one to call. Basically again start light and go harder one at a time until feels it stable. Not planted to the road but stable.

If you go too hard on either of the of the damping settings the bike will slide around. It will feel stable but slide. If too soft the bike will wallow(ship like)...

Sometimes if springs are too soft, you might end up giving extra preload to achieve good rider sag, and then you need extra rebound damping to avoid botomming up(maxing up) the suspension... That a better compromise than a very large rider sag that will leave almost no suspension travel... Remember if the suspension bottoms down and/or up, thats an instand slide...

Suspension need to be able to work. Not locked solid by damping."

Let us know how you get on

[SP2rider]

Cheers for the help

Totally agree the static sag is too much and even at 11.5 stone I m struggling to set it up correctly so might try stiffer springs. I reckon the low speed comp is too little and the high speed too much and as they can't be adjusted independently I m stuck with a a poor performing stock front end which hopefully a good piston kit will cute.

[Sppete]

I fitted a Hyperpro spring kit in the front on the recomendation of a local mechanic who race preps bikes. The rebound and compression is more than adequate in the SP2 for these kits and I've been well pleased with mine. £116 from cal sports and has everything you need in the kit
http://www.calsport.co.uk/photos-prods/ ... 2256a5.jpg

Pete

[Dmac]

They look just the job Pete

I would love to try them out when I have some spare cash/win Euro millions, whichever comes sooner

Can you rember Pete if they are just firmer or are they longer than standard too?

[Sppete]

Never thought to compare them to be honest
They are definately harder than std when fully compressed but they are also softer than std when not under load. It's a progressive spring which gets harder the further you squish it. Some folk argue they arn't as good as linear springs but I've always found them better for on the road because they can handle a wider range of situations- pot holes, two up riding, braking into dips ect. If I was into racing I would probably have a linear spring and then be able to set it up more consistantly through out it's length of travel. All suspension is a bit of a compromise depending on the situation, I've found I just don't have to compromise quite so much with the Hyper-pro kit

Pete

[Dmac]

Spot on Pete, Thanks