Front wheel installation ... 2mm between fork and spacer?

[Jay12]

Hi,

I just got finished changing the front tire on my 250 XC and installed / torqued down the front axle and tightened the front pinch bolts per the manual. When I was finished, I noticed a 2mm space between the right fork and the wheel spacer. I had not noticed in before I took the wheel off. Is this pace supposed to be there or have I made an error installing the wheel?

Thanks,
J

 

[KevinAnderson]

Hi J,

A 2mm space seems about right. When you had the front axle out you can see that the right fork side of the axle is wider. The right fork sits on the wider part, while the smaller diameter to the bolt is used to compress the wheel bearings to the left fork.

This is the (tightening) sequence I use when putting my front tire back on. This assumes everything is already together, but the pinch bolts for both forks are loose and the axle nut is loose too. 1) tighten the axle nut to the shop manual torque value. 2) Tighten the left for pinch bolts to the shop manual torque value. 3) Compress the front forks ~4 times (since the right fork pinch bolts are not tightened the fork can slide left and right on the axle), this lets the forks align. 4) Tighten the right fork pinch bolts to the shop manual torque value.

I wanted to add the sequence of tightening the axle and fork pinch bolts. Cause if both pinch bolts are tightened but the forks are not aligned to each other, it will bind and the forks will not function optimally.

 

[rackatttack]

on your xc you will have to make sure your axle is push all the way in on the right fork leg (sitting on the bike) the snug down the pinch bolts (right side only) before tightening the axle then loosen the pinch bolts this is when you will see the forks spring out or in and centre them selfs then spin the wheel and hit the brake a couple of time now tight the pinch bolts again to spec you should be centred and have no clearance between axle and spacer
side note your rotor should be centered in the caliper

 

[zedro]

Another way that assures the forks are aligned is you should be able to move the RHS fork leg back and forth slightly (float), it's easy to feel when the forks are parallel. As you tighten it you should only be able to move it 1mm back and forth, then you know you're centered.

I have way more space on my 2012 xc btw, essentially the outside of the axle is aligned with the foot.

 

[Jay12]

Hi All,

I'm still having some problems getting rid of the space (unless it is supposed to be there based on fork alignment ... but wouldn't a space like that cause the front wheel to move side to side on the axle?). Here are a couple of pics. I actually measured the gap with a caliper and it was 2.92mm.

https://www.bikepics.com/pictures/2807340/2012-ktm-xc

T

 

[zedro]

Don't think you understood, you are not supposed to get ride of the space, there should be 2-10mm depending on the bike and wheel combo. Your fork is definitely bound up now.

Caliper side: no space (the axle bolt makes that happen)
Right hand side: there's a gap. You should be able to wiggle the fork leg back and forth before tightening. The axle is stepped and pulls the wheel towards the caliper side, that's what keeps the side play from happening.

Will you be at the novice camp on Saturday? We can show you how to do it properly, or check out some videos on YouTube.

 

[Jay12]

OK, so the space is supposed to be there (unlike road bikes). In that case I think I'm fine. I'll just loosten the right side pinch bolts apply the brake and compress the forks a few times and re-tighten. I think I should be good from there?

Unfortunately by the time I tried to get on the course today, it was already full. Thanks though for offering to help me out with this.

J

 

[rackatttack]

after looking at the picture that space should not be there! loosen up all your pinch bolts and axle bolt slide (by hand the axle in as far as possible) now snug down pinch bolts on left fork (looking at it) then check to see if the rotor is sitting centre of the caliper hanger if it is tighten the axle bolt and check alignment again if all good loosen pinch bolt and spin the front wheel hit the brakes a couple of times and then tighten pinch bolts to spec
if the space is still there then I would check your fork alignment (any hard crashes or hit last year?)