Etap troubleshooting help

[madsciencenow]

Here's the problem: on occasion (and by this I mean fairly frequently), when I have my chain on the small ring (36 teeth) in front and on one of the smaller/smallest sprockets in back (I'm running an 11/-28 cassette), my chain pulls across the lower pulley in such a way as to nearly jump off the pulley, making a racket. This can be remedied by shifting the rear derailleur onto a larger sprocket. I had the bike into my LBS at one point and I thought they fixed it but the problem is back again and it's fairly annoying as it eliminates a number of gears from use when on the smaller ring.

I should mention that I'm running an etap front and rear derailleur, sram red chain, ultegra 11-28 cassette, and DA 9100 52/36 crankset.

I'm wondering about a couple of things.

1. What's the fix?
2. Is it possible that the 9100 crankset (small chainring being inset .4mm) is the issue here (don't think so b/c my LBS was able to dial away this issue temporarily and I can't be the only one running this combination)

Disclaimer: there may be a really simple solution as I'm not the worlds best wrench (in fact it's an insult to a real mechanic to even call myself a wrench).

Anyway, if you've dealt with this issue or think you might know how to fix it I'd be grateful for your input.

[VTR1000SP2]

What make/model bike?
Cast or CNC derailleur hanger?
Chainstay length?

[madsciencenow]

it's a moots vamoots rsl (2016 I think) size 52 w/ standard geo except chain stays were extended by 2 mm to fit 28 mm tires. If my math is correct the chain stay length should be 40.9 cm.

[VTR1000SP2]

I'd look at the derailleur hanger first. It could be slightly off.

[oldpotatoe]

I'd look at the derailleur hanger first. It could be slightly off.

I agree or perhaps the der cage is bent some..needs to be 'out' a wee bit.

[madsciencenow]

how likely would it be for a titanium derailleur hanger to be bent or off on a bike that's never been wrecked or even fallen over onto its side? I should also add that I previously had an ultegra 6800 groupo on the bike and I didn't have any issues like this.

If it turns out that others feel the derailleur hanger could be bent I can have it checked but this doesn't strike me as the problem given the 6800 groupo not having issues and the fact that for a few months after the LBS adjustment I didn't have this problem.

[oldpotatoe]

how likely would it be for a titanium derailleur hanger to be bent or off on a bike that's never been wrecked or even fallen over onto its side? I should also add that I previously had an ultegra 6800 groupo on the bike and I didn't have any issues like this.

If it turns out that others feel the derailleur hanger could be bent I can have it checked but this doesn't strike me as the problem given the 6800 groupo not having issues and the fact that for a few months after the LBS adjustment I didn't have this problem.

Pretty sure it's an aluminum replaceable type.

On the ones I have seen, the der cage is 'bent', in that, when chain is that angle, small ring, smallish cogs, the chain floats off the lower pulley..Also, has the cage been taken off? Is it upside down?

[-dustin]

how old is the RD?

i remember SRAM RDs used to do this a lot. hadn't seen it in a while, though.

[madsciencenow]

I think the groupo has a few 1000 miles on it, possibly as many as 5k. I'm not the first owner so I don't know for certain that the cage hasn't been taken off but I know that I've not taken it off and I'm pretty certain it's on correctly.

[oldpotatoe]

I think the groupo has a few 1000 miles on it, possibly as many as 5k. I'm not the first owner so I don't know for certain that the cage hasn't been taken off but I know that I've not taken it off and I'm pretty certain it's on correctly.

Can you dupe this in the stand? I'd try to do that then gently, big pliers around lower pulley bolt, bent ever so slightly outboard to align cage better with chainline/upper pulley.

[stien]

Been there. Not with Etap but with di2. Lbs said soft hanger. Realign and if it never happens again, mozel. If it comes back, new RD. That’s what fixed it for me.

[VTR1000SP2]

To check the derailleur hanger, if you don't have an alignment tool, take it to a lbs and ask them to just check that alone. Easy to do.

[madsciencenow]

I'll have my LBS check the hanger but I'm pretty sure it's fully integrated (I may have this confused with my Legend).

[FlashUNC]

It's the hanger I'd bet.

[loxx0050]

I can tell you when swapping my road bike (SS Evo) from 6800 mechanical to Di2 I rechecked the derailleur hanger alignment since I already had it apart. It was slightly off and I remedied that before putting on my Di2 parts.

The 6800 shifted just fine prior to removal and was running for about 1800ish or so miles on it. I did notice my RD cable coating was down to bare metal for inside the shifter though. This is Jagwire teflon coated stuff with the Elite Link housing. But it still shifted through all the gears just fine.

[madsciencenow]

so, ... I'm not at home right now and I called Moots and they confirmed that my bike has the integrated hanger. Assuming this is not bent (I can/will still have this checked) what other thoughts do people have? Old spud's idea that the cage may be bent or I'm just an idiot and haven't set things up properly are the two best options I've heard beyond the hanger itself being bent.

[guru]

Friend of mine had a similar problem with his mechanical DA. When he installed the rear derailleur he didn’t have the B-screw tab properly seated in the the derailleur hanger

[madsciencenow]

I put the bike on the stand last night and tried to replicate the problem and couldn't. I'm gonna head to my LBS today to see what they can find. stay tuned...

[madsciencenow]

looks like maybe the chain was too long by one link. I've not had an opportunity to take a ride since the extra link was removed but this is the preliminary diagnosis (embarrassing but will chock this up to experience and move on).