XT Front Mech Rub vertical not horizontal... Help?

Mat100

Hi All

Tried searching this but I haven't found the answer.

I have a Whyte T129 Works. It uses an XT Mech on the front. When in the smallest chain ring the chain rubs on the derailleur cage. Not on either side, the cable tension, limit screws etc. are correct. But it drags on the bottom of the cage (when in the lower gears/smaller sprockets on the rear cassette).

Ideally if I could change the angle of the cage this wouldn't happen, but there is no adjustment for this. I can't lower the cage any further as it will hit the teeth of the large chain ring.

Is there an adjustment you can make to the angle of the cage I am missing?

Thanks in advance if anyone has the know how

Cheers Mat

Chunkers1980

You need it at the correct height. About a 2p coin between the outer cog and the cage - that should then set the lower height if you're within the capibility of the mech with the ring sizes you have.

Mat100

Hi Ok, thanks for the tip...

... but like I said the height adjustment is as low as I can take it without hitting the large chain ring. My bad though, it's a SLX mech. I'll post the photo

Mat100

Photo

cooldad

So don't use the small ring and small cogs - no need to. Same ratios on large ring with bigger cogs.

jimothy78

Mat100 wrote:

the height adjustment is as low as I can take it without hitting the large chain ring. My bad though, it's a SLX mech. I'll post the photo

What model number is that mech, and what sizes are your chainrings?

Chunkers1980

Looks like direct mount. And you're at the bottom, move it up and see what happens.

Mat100

Hi

So the Mech is: Shimano SLX, High Direct Mount, 10 Speed

and the chain rings: Shimano XT, 38-24 29er Ratio, Compact Double, 10 Speed, Black

I can try moving the mount up, but won't that just make the problem worse?

(I take onboard that I can get round the problem in the way I use the gears but having it occur with half the cogs on the cassette using the smallest chain ring is not great)

cooldad

Adjust the angle so the rear part is lower.

Mat100

Exactly Cooldad! But that's my question, is that possible with a direct mount front mech?

I can't find any adjustment on it for angle.

Chunkers1980

Is any of this stuff new to this setup?

cooldad

If not this ^^^^^^^
Then the gap looks larger at the back than the top. Maybe a bit of judicious bending.

Mat100

Other than I put a new chain on it's all the factory kit. It did rub a little from the get go, just seems more noticeable now. So judicious bending it may well be

Cheers Guys

bbpuffer

I have the same issue. Looks like the reason is the frame alignment for the direct mount front deraileur not match with the Shimano.

I put my favour to the biggest cog and smallest chain ring so it rub on smallest cog and smallest chain ring.

Currently my front cage is not aligned properly. Looks like the tail (left) is a bit up (ie. not horizontal) than the front (right side). May need to tailor the front mech rail by sticking tape close to the top of it so that after installation the cage drop a bit to compensate for the frame rail vertical alignment error.

photonic69

Can you slacken off mounting bolt and twist anti clockwise? There might be enough wiggle room otherwise filing a bit off the front mech to clear the welds around the mount point? You could even file a little indent in the mount slot to enable more twist if req. All sounds a little bit sus. Don't file any part of frame though.

The Rookie

There is some scope on DM, to tweak it, so just loosen and tilt and retighten....