Hello everyone,

A few months ago I bought a Canyon Sender with a Fox 40 Factory (model 2016). Recently, I realized that the fork has very little sensitivity: when I slowly put weight on it, the fork compresses slightly, then it gets stuck, then it moves again, then it gets stuck, and so on. In short, instead of moving continuously in a smooth way, the fork moving keeps stopping until more weight is loaded.

I have some experience in servicing forks and I know that usually this problems means that oil is missing in the open bath; therefore I opened the fork (there was plenty of oil as it is new) and I changed the oil. I also checked the air chamber and made sure there was sufficient oil there. Having put the fork back together, I tried to compress the stanchions individually: no problem! They both compress really smoothly.

Finally, I put the fork back on the bike, and for some reason that I can’t understand, the problem was still there. I don’t understand how this is possible, as the stanchions were moving perfectly when I was trying them individually. The only explanation that I can think of is that there is an imperfection in the geometry of the lower leg: this makes the stanchion move at an angle instead of parallel, therefore creating this friction which makes the fork getting stuck.

Has this ever happened to anyone? What’s the problem? Can you suggest a way to fix it?
The fork is brand new. It was used about 5-6 times. It shouldn’t have this kind of issue, not for that price!
Also you should know that the high and low speed compression valves were fully open the whole time.

Where in the travel range are we talking? Below the sag point? How much extra force are you having to add to get it to start compressing again?

Have you checked the crowns are properly lined up? If they’re off they be bending everything out of line

This happens after the sag point has been reached usually. Imagine to slowly put your body mass on the fork, until you have all of your weight on it. As you do that, the fork gets stuck at least 4-5 times.

I believe that the crowns are lined up, because I removed the stanchions from it (and put them back on it) without any problems. They slid out easily.

Hmm I know very little about suspension but did have a similar issue with my 34’s. Basically after one really rough downhill they lost all their small bump sensitivity and made a weird sucking noise for the first 20mm of travel with no damping for this first 20mm. This continued for a few weeks. I tried depressurising the air and the zip tie trick, dropped the lowers etc and had them booked in for a warranty. Then I got stuck on a chairlift for 30mins with bike upside down and when I got to top they were cured.

Is it noticeable when you are riding it? Properly, not just round a car park?

IME 40s always feel harsh until you get them well up to speed

Personally, I do not notice it while I ride. However, i think that my hands notice it. Nevertheless, it’s a brand new super expensive fork; it really bothers me that it is not as smooth as my 8 year-old 140 mm Rockshox Pike.

Send it in for warranty

Canyon

warranty

Ha

I think I will. However I have opened the fork to change the oil. Will they accept it for warranty? I have only changed the oil, nothing else.

Don’t tell them about that bit. Go direct to canyon, they’ll probably tell you to send them/the bike back to Germany or wherever. Do the slider bushings still need to bed in?

I don’t think so. I have in some bike park in the alps about 5-6 times already.
Anyway, I am afraid that if I don’t say anything about the oil change they will think: “the oil needs to be changed”. They will change it and send it back to me with the same problem.

I don’t understand how this is possible, as the stanchions were moving perfectly when I was trying them individually.

When you were trying them individually I bet the stanchions were sliding up and down with all the force going directly along the angle of the stanchion. On the bike if you push down on the handlebars the forces aren’t acting in exactly the same way, you’re pushing down but the forks wants to slide at an angle (because the head angle isn’t 90 degrees). This will be worse On a DH bike with a slack head angle. The forces will bind the stanchions against the bushings more causing more stiction than just sliding the stanchions up and down individually. Did you try removing the fork and compressing it vertically with everything installed?

When you were trying them individually I bet the stanchions were sliding up and down with all the force going directly along the angle of the stanchion. On the bike if you push down on the handlebars the forces aren’t acting in exactly the same way, you’re pushing down but the forks wants to slide at an angle (because the head angle isn’t 90 degrees). This will be worse On a DH bike with a slack head angle. The forces will bind the stanchions against the bushings more causing more stiction than just sliding the stanchions up and down individually. Did you try removing the fork and compressing it vertically with everything installed?

My money would be here too

as above, but also add some fork grease to the bushings..

Fair enough! You are right, I will try that.

Already added grease to the bushings. Did not help

5 – 6 rides is not really enough for them to fully bed in. I dont have any Fox forks but both my Pikes and Yaris needed several long rides to become more sensitive. I also notices after servicing my forks (lower leg service) they needed another few rides to bed in again. So maybe they need time for the grease to move around a bit.

As mentioned above you’re describing binding; some years ago triple clamp forks used to come with fairly rigorous & involved instruction on alignment and the order in which to tighten things etc. My last set came with virtually nothing about this so it may be worth taking some advice on realigning it all, especially as you’ve already had them apart.

I’ve got some year old Fox 34’s. Never been happy with their small bump sensitivity. Have changed the oil. Fiddled around with air volume spacers and air pressures. Added compression damping to keep them higher up the travel.

Still get sore hands and wrists – never had this problem with two pairs of Revelations. I recall that 2017 Fox forks have a lighter rebound tune which might make a difference but would need to send back to Mojo to be retuned, which his not cheap.