I’ve got some issues with gear upshifts to 1 specific cog, and with my alignment tool I can confirm that the hanger is misaligned on the vertical axis. Closer to the wheel at the bottom, that it is at the top. I haven’t measured but it’s probably ~4mm difference.

But I can’t identify any signs of a bend in the hanger. Lying it against everything flat I can find, it seems perfectly straight. And now I’ve just replaced with a brand new hanger which leaves exactly the same symptoms.

When I removed and refitted the hanger I cleaned up the mount area, so I’m reaching the conclusion that my frame must be skewed. Anything else to check?
If the frame was out of alignment, surely the bearings would have died off in no time.

It’s done this ever since I upgraded to 12 speed at the end of last year. I suspect it’s been like that for a long time, but the looser tolerances of the old 10 speed meant it didn’t actually cause a problem.

The photo below shows the setup:
hoop smileys

Don’t know what to suggest about the frame alignment, but the top jockey wheel should be way closer to the cassette than that.

The frame might be out a little but you just “adjust” the hanger to compensate.

12 speed is a bit picky with alignment. As above, check the B screw adjustment too.

Hmm, I agree that the gap looks pretty large there. It might just be the angle of the photo though, as just yesterday I re-checked the B screw position, and it was already spot-on with the largest tooth on the smallest gear lining up with the line printed on the XT mech.

It may not be clear, but it’s a mix and match setup – I’ve got an Eagle cassette with Shimano mech & shifter (thank you very much, Microspline licensing) and whilst people acknowledge that it’s not quite as crisp as a full Shimano lineup, it should at least work in all gears. This guy here has set it up in exactly the same way and can hit all gears: https://www.youtube.com/watch?v=g4l_O1qtJ8I

When you fit a new mech hanger you check the alignment, and align it to the frame if required, unfortunately tolerances/fit are not that good on many bikes. You would normally get away with it on 8/9s, not on 11/12s.

This is interesting as I’m still a luddite on 1*10 and hadn’t appreciated that my next step was going to be so sensitive. I’ve got my first hanger alignment tool on route (the kids seem to bend them by looking at them!).
It seems funny to me that any system that’s quite so finicky around a component that’s easily slightly bent on a mountain bike ride is a bit nuts. I guess there are loads of people out there on 1*11 and 12 now happily enjoying it so maybe I’m over thinking it. I know I’m going to have to buy into it at some point so at least now prepared.

It’s always worth checking hanger alignment, i’d guess that about 80% of new bikes are out of line and need straightening before they’re passed on to the the customer/sent out heavily packed to resist the courier’s best efforts at misaligning them again.

When you fit a new mech hanger you check the alignment, and align it to the frame if required, unfortunately tolerances/fit are not that good on many bikes.

Appears that bending the hanger to compensate might be the the only option. I did have a go at bending it when I first suspected it was the source of the problem, but with what felt like a bloody large amount of force, it still wouldn’t budge. I can try harder next time, but would be mindful of damaging the frame.

I guess applying heat may help? Or is that a waste of time on aluminium?

SRAM? Could be B-Bolt wear, they’re spring loaded / floating, my seized and wore, now there’s a decent amount of play in it.

Just bend it using the alignment tool. It doesn’t matter what the frame is doing, align it to the wheel as that’s what the cassette is mounted on.

Just pulled an old Kona out and rebuilt it, it’s been singlespeed for a while, the alignment tool showed 40mm of variation at the rim!

looking at that photo the dropout appears tweeked inwards a bit

This is interesting as I’m still a luddite on 1*10 and hadn’t appreciated that my next step was going to be so sensitive. I’ve got my first hanger alignment tool on route (the kids seem to bend them by looking at them!).
It seems funny to me that any system that’s quite so finicky around a component that’s easily slightly bent on a mountain bike ride is a bit nuts. I guess there are loads of people out there on 1*11 and 12 now happily enjoying it so maybe I’m over thinking it. I know I’m going to have to buy into it at some point so at least now prepared.

It’s not so much the spacing as the size of the gears.

Extreme example an eagle 50t is twice the size of a 25t road cassette so you need the hanger alignment to be half the tolerance. Trouble is the hanger is generally bolted to a painted frame so it’ll never be perfect.

Appears that bending the hanger to compensate might be the the only option.

That’s what the alignment tool is for afterall.

Hi,the shimano docs say that the teeth of the largest sprocket should line up with the white line on the cage,not the smallest.That is how i have my b screw set up.

2mm at the rim is less than half a degree, I’d be surprised if you could get it better..

The gap to the sprocket looks big.

I spent a day trying to fix a similar issue. The problem was the clutch. Basically it was too stiff to get the mech in a clean position. Even with the clutch off, it was still too hard so I have to clean and grease the clutch mechanism .

Hi,the shimano docs say that the teeth of the largest sprocket should line up with the white line on the cage,not the smallest.That is how i have my b screw set up.

Ah yes of course, when I said smallest I actually meant lowest!

That’s what the alignment tool is for afterall.

Very true I suppose. I’ve only used it on steel dropouts or on hangers I’ve been trying to fix without replacing. I’d always (wrongly) assumed that fitting a new one “reset” to an aligned position, which evidently isn’t true. Though it might have been close enough in the days before we were cramming 11 or 12 gears into a cassette.

Get yourself an alignment tool, one of the best bits of kit I’ve got. It’s surprising how much some of mine were out….