Tyre Rubbing Forks when Turning?

iLukeKendall

I've started to notice recently, that when I turn corners, occasionally my front tyre will rub against the forks, creating sound and reducing speed. I'm riding a 2013 Trek Mamba 29er, with the standard RockShox XC-32 forks, and Bontrager AT-850 wheelset (QR) with Bontrager 29-2 tyres.

What would be causing this to happen and is there a way to prevent it? I'm not sure whether it's the axle that flexes, or perhaps the rim itself?

DCR00

Sounds like your QR isnt done up tightly enough

Chunkers1980

Cones may be loose.

Qr loose.

Sloppy wheel build.

Tyre just too big.

Fork flex - could be bushes.

Options- tighten loose things. Get a narrower tyre. Don't ride hippy flexey 29ers

iLukeKendall

DCR00 wrote:

Sounds like your QR isnt done up tightly enough

I'll double check, but I'm pretty sure it's fully tightened. When it happened a few months ago, I noticed my wheel had a lot of movement in the dropouts when it was loosened - I had to hold the wheel straight within the dropouts before tightening the QR, otherwise it would lean more to one side when tightened without any persuasion.

Chunkers1980 wrote:

Cones may be loose.

Qr loose.

Sloppy wheel build.

Tyre just too big.

Fork flex - could be bushes.

Options- tighten loose things. Get a narrower tyre. Don't ride hippy flexey 29ers

Thanks, I'll double check the cones. The wheel build should be fine - they're factory built and I had them trued the other day whilst I had my bike in for a new freehub body. The tyres are 2.2's, and are what came with the bike, so I'd hope they'd be suitable. The tyre's I've been looking at upgrading to are 2.3's, but maybe that's not such a good idea now. The fork is a pile of crap to be honest, but I wouldn't imagine that flexes - it's far too stiff.

DCR00

Chunkers1980 wrote:

Cones may be loose.

Qr loose.

Sloppy wheel build.

Tyre just too big.

Fork flex - could be bushes.

Options- tighten loose things. Get a narrower tyre. Don't ride hippy flexey 29ers

Not sure fork bushes would do this. The wheel is attached to the lowers, so if the lowers move, so does the wheel

Cqc

The cones I would say. To get that much flex from the axle or wheels would be more than slightly worrying...

iLukeKendall

Okay, so I took a closer look this afternoon.

The front tyre appears to be sitting off to one side between the forks. I've checked the QR is tight, and the cones, which are all as they should be, however it still sits to one side when placed into the dropouts.

The only thing I have noticed, is that I have to force the forks apart slightly to get the QR to sit in place - could this be part of the issue?

I've attached a few pictures below. They're not the clearest, but hopefully they show what I'm trying to explain!

oxocube1

Looks as though your wheel has not been dished correctly or that or one of the lowers legs is bent slightly inwards. Could be the reason why you have to pull them apart to install the wheel.

DCR00

What size are the tyres? Not much space either side

Are you 100% that your wheel is sat in the drop out properly?

Does the distance between tyre and lower change as the wheel rotates?

iLukeKendall

oxocube1 wrote:

Looks as though your wheel has not been dished correctly or that or one of the lowers legs is bent slightly inwards. Could be the reason why you have to pull them apart to install the wheel.

I think the wheel is fine, as when I flip the wheel in the dropouts, it still pulls to the same side, so I'd assume the problem is the fork lowers; I have the force them about 2mm apart to get the wheel to drop in.

DCR00 wrote:

What size are the tyres? Not much space either side

Are you 100% that your wheel is sat in the drop out properly?

Does the distance between tyre and lower change as the wheel rotates?

The tyres are 2.2's, inflated to 40psi that came as stock. The distance remains constant.

I've just gone and double checked the QR, and it was tight. However, I've managed to straighten the wheel up by holding it in a visibly central position and then tightening the QR, therefore not relying on the bottom of the dropout. When looking at the dropout side on, it appears to be seated all the way in, but if I was to loosen the QR it would drop a little further, putting the wheel off centre again. The wheel still spins evenly, except for some very minor off-true wobble. Could the dropouts on my forks be uneven perhaps?

Slightly off the main topic, but whilst my bike was flipped, I noticed the back tyre sits awfully close to the frame as well, and also slightly off-centre. Seems they've made this frame super-tight.

DCR00

iLukeKendall wrote:

oxocube1 wrote:

Looks as though your wheel has not been dished correctly or that or one of the lowers legs is bent slightly inwards. Could be the reason why you have to pull them apart to install the wheel.

I think the wheel is fine, as when I flip the wheel in the dropouts, it still pulls to the same side, so I'd assume the problem is the fork lowers; I have the force them about 2mm apart to get the wheel to drop in.

DCR00 wrote:

What size are the tyres? Not much space either side

Are you 100% that your wheel is sat in the drop out properly?

Does the distance between tyre and lower change as the wheel rotates?

The tyres are 2.2's, inflated to 40psi that came as stock. The distance remains constant.

I've just gone and double checked the QR, and it was tight. However, I've managed to straighten the wheel up by holding it in a visibly central position and then tightening the QR, therefore not relying on the bottom of the dropout. When looking at the dropout side on, it appears to be seated all the way in, but if I was to loosen the QR it would drop a little further, putting the wheel off centre again. The wheel still spins evenly, except for some very minor off-true wobble. Could the dropouts on my forks be uneven perhaps?

Slightly off the main topic, but whilst my bike was flipped, I noticed the back tyre sits awfully close to the frame as well, and also slightly off-centre. Seems they've made this frame super-tight.

So you can solve the front issue by seating the front wheel manually?

If so then problem solved. As long as the wheel is secure. TBH I've lost count of the amount of bikes I've built that had to have some manual adjustment to the front wheel to get it to run true. As for the back, I'm led to believe that 29 er are indeed a little tight for space, but that's your fault for having a 29er....

iLukeKendall

It seems that way. I'm going to go a try the trails again tomorrow with the tyre in this position, and I'll report back if I still hear any rubbing.

Problem is, I was about to order new tyres which are 2.3's, but that's probably not a good idea now after realising how tight I am on space! I don't have any come back for that 29er comment, other than the fact that's what I bought as my first half-decent bike, and I find it much faster and efficient to ride than my previous/Dad's 26ers!

DCR00

I was taking the piss

Ride whatever you want mate

apple eater

I have a 2014 trek excaliber, when i tried to fit a 2.3 tyre on the rear i had numerous issues getting it to fit but mainly due to the tyre being malformed.

The size was also way to tight for my liking in the rear triangle. I have 2.25 nobbly nics now and they seem to be about as big as i will put on them.