Spanners, springs, valve shims (and cockups!)
Sorry that we’ve been a bit quiet of late on the Xtrainer posts… it’s due to us having a bit of a falling out (and off) with the forks on the bike and ending up with two broken ribs and a couple of months off the bike 🙁
We were riding at speed on rocky terrain when the forks suddenly completely compressed and spat us off. Although the bike has been great in low speed technical riding, in it’s factory trim it just cannot handle fast Enduro style riding… time to get the spanners, springs and valve shims out!
So after a lot research online we though we would put it all together in this handy blog post…
The Xtrainer only has a spring in one fork leg and the valving in the other. We sourced a new spring from Steve Plain Motorcycles in the UK. There is a spring rate chart available online – popular opinion seems to agree that you need to go up two spring weights higher than the chart states, so we went from standard 8.0KG to 8.4KG.
First things first… how to get the fork open?
Once you remove the fork cap there is another cap holding the spring in the stanchion. You can’t use a pin wrench on the cap as even with the fork fully collapsed you can’t get to the cap without a special tool (which we didn’t have). So we separated the fork outer and stanchion (pull down dust seal, remove locking clip with a screwdriver and pull apart).
You can now get to the cap with a pin wrench, but we still couldn’t undo the cap as someone at the Ollé factory had gone nuts with the loctite, so much so, that even using a lot of heat we couldn’t remove it.
After a lot of sweating and swearing something had to give! Rather than the cap coming undone, the axle holder unscrewed instead. No problem, you still get access to the spring.
The new spring is only tapered at one end compared to both on the factory spring.
The tapered end goes to the top and holds the ‘rod thingy’ (as you can probably tell we’re not suspension experts) 😉
And that’s it, screw the axle holder back onto the stanchion and you’re good to go.
Muchos respect needs to go to Clod Martin on the Facebook Beta Xtrainer Group for coming up with this valving modification… his original post and instructions can be found here and we recommend following his instructions rather than our poor excuse for technical know-how.
First step is to part with some hard-earned and order the above shims from your friendly neighbourhood KTM dealer – just don’t tell them it’s for a Beta or the deal will be off! ;). You need 1x 48600213, 1x 43570120 and 2x 48600214. From memory it was about £10 with delivery (ouch).
EDIT: Don’t do what we did and cockup Clod’s mod by adding the shims to the compression valve (as above)! Make sure you’re adding them to the rebound valve… (Sorry no picture – see Clod’s instructions).
Insert your KTM shims into the rebound stack (as per Clod Martin’s instructions), put it all back together and you should have much improved forks.
We tried to use a lighter 7.5w oil but it didn’t feel as nice as the 15w we were using so we’ve gone back to that. Overall the forks are much better than they were… less bouncy and more firm.
EDIT: Even though we added the shims to the compression valve by mistake, the fork still feels much better… we’ll swap the shims to the rebound valve in a few weeks and report back on the difference