Anyone out there who really knows their drivetrain onions?

I think I have got myself in a pickle and don’t want this to end with (another) integral mech hanger bent out of shape.

I am running 1×10 with a raceface thick thin 32 tooth ring on a 11-36 cassette. Zee short cage mech. I lost the chain three times yesterday on a ride and this has been increasing in frequency for a little while. I have been progressively tightening the clutch. However, I have now taken a link out of the chain and am worried for a couple of reasons. In the largest cog, the mech is still not quite at full stretch, so I think I ought to be alright, but a couple of things are nagging at me.

The lower jockey wheel is gouged (ie the plastic wheel part around the bearing is being worn away and rubbing a bit). This seems to have happened with all my mechs. Assuming I was running the chain too long, why has this happened inside three months?

Should I have just left the chain as it was? The thing being that I thought narrow wide and clutch mech was virtual insurance against chain drop, but to lose it three times in one ride was a bit much.

Please help, I don’t want the mech jamming and going into the rear wheel like last time!

When you say the lower wheel is gouged, you mean the chain has been running across it at an angle?

This suggests to me chain too short and hanger bent because of it. Did that to my Zesty last Autumn with an inadvised Zee/11-36 2×10 and too-short chain nightmare… And yes, I felt silly after.

Bent mech hanger putting it out of alignment? Is this set up on a hard tail or full suss? The worn jockey wheel was probably responsible in entirety!

Bent mech hanger IME. Stick the gears in the big rings, deflate the shock, if there’s Still a bit of slack in the chain, you’re fine. You’ll be surprised the grief a slightly bent hanger can cause!

You are running the FR not DH Zee aren’t you? Is this on a full-sus with chain stretch to consider? Very odd that you’ve been losing chains or had to tighten the clutch!

Steel hardtail with a previously mangled hanger that I have straightened. The hanger seems ok. I think the lower jockey wheel is knackered and on the verge of jamming the chain between itself and the cage. This could cause chain drop now I think about it. If I have moved the pedals backward even slightly and the jockey has made the mech pull slightly, it would create enough slack for the chain to jump off.

Jockey wheels and new chain ordered (hope I have ordered correct jockey wheels). I think this is going to solve the issue, I do hope so! I can’t be bothered with another slow and protracted drivetrain death.

It does seem to be the mech thats misaligned.

If the hanger isn’t bent then check the dropout – that could have bent inwards also. Stand the bike up straight and check the mech cage is perfectly vertical (perpendicular to the ground). If its bent inwards at all then grab that mo-fo and bend it back out. Steel frame so this wont fatigue it……much.

Mech cage is fine (I spent a lot of time straightening it and using a dowel through the hole to line it up as best I could). I think that slightly shit chain line combined with cheap original jockey wheel and loads of mud and grit has just worn the jockey wheel to the point where it is dragging.

I hope new jockey wheel will sort it. Thanks for the advice on here.

My money is still on the rear mech hanger being bent. You need to get it straightened properly by someone with the right tool.

Also worth checking the rear axle isn’t broken, there is no play in the cranks, the chainring is straight, the rear mech is straight, the transmission is not excessively worn.

If it was all straight you wouldn’t have the problem. The jockey wheel is a distraction and symptom rather than the cause.

You are running the FR not DH Zee aren’t you?

You need to answer this question too…if you don’t understand the question, maybe you’re not running the right mech. There are 2 flavours of zee, only one will take a 36t properly.

Danny, I live in Loughborough and have the correct tool. Drop me an email (in profile) and I can take a look at it for you if you’d like?

If you didn’t use a gauge when you straightened it, the hanger is still out.

schmiken – email sent if the offer is still open I’d like to sort this properly (this week if poss)!

In response to some of the other questions above, I am definitely running the version of the Zee that can cope with the wider ratio cassette (FR).

Definitely no play in the cranks, rear axle has been examined in the last month and no problems there. Rest of drivetrain is probably not worn (the whole thing is around 500 miles old) – but I agree a bit of checking wouldn’t go amiss.

Anyway, with a bit of help from STW it looks like I can get this sorted by someone who knows what they are doing (cheers schmiken).

Update – the very nice mr schmiken fixed my bike for me yesterday.
Using the proper tool rather than a big spanner and lots of squinting and going “that looks about right”.

Turns out the mech hanger was slightly bent again – so sorry to anyone who postulated this and was dismissed by me 😳

Also stuck new jockey wheels in and a new chain (the old one was the wrong side of 0.75% worn) – so hopefully all is now well in the drivetrain department.

Thanks to the STW collective again for advice and practical help – the good side of the forum on display again.