I changed from 11-42 on a 32t to a 10-42 on a 30t (oval).

I have lost 3 teeth so the chain is never taut even in this max configuration.

Seems to work OK but perhaps a little noisier than before on the 42t. Would it be because the chain is too long ? Or due to the oval ring ? Or neither ? Or both ?

I have a SRAM powerlink so do I simply open it with thin nose plier and remove 2 links (the minimum presumably) ?

Thanks for any guidance.

A 30t oval at its maximum eccentricity will be the same as a 32t, your rear is still a 42t so it should remain the same. Ensure your checking with the oval ring at its greatest radius.

I’d say so looking at that, is it really slack in the 10? If not then I’d just leave it.

A 30t oval at its maximum eccentricity will be the same as a 32t

You do realise the chain is wrapped around half the ring so a 30 is two teeth less than a 32 regardless of roundness?

How does the mech look on the smallest cog?

I found the oval nw superstar chainring I had was quite a bit noisier than the round nw race face chainring I had. After a month or so of riding the oval quietened down a bit – although in really sloppy mud I found it dropped the chain far easier than the round one.

I’m back to a round chainring now and don’t plan to swap back to an oval.

I always thought the mech should be in that sort of position, or maybe a tad back when in the highest gear?

Thx everyone – here is the chain when in the 10t:

It’s almost resting on the chainstay is there is no pedalling tension.

I personally would be happy losing a link or so from that (depending whether it’s a hardtail or not) and bringing the mech upwards a little when in the biggest cog.

This photo is from a Pinkbike article that shows it about right imho. Obviously whether or not it’s a suspension bike is a factor.

Pinkbike article

I would take a link out without hesitation.

What about deviation or repetition?

Unless you think you’re likely to go up a chainring size I’d take a link out probably. Or not, it’s not that bad.

yeh too long, surprised it’s not rubbing on the mech in the smallest cog (looks like it must be close).

I would take a link out without deviation. If not sufficient, I would take a link out with repetition.

Thanks a lot – it’s a hardtail.

What’s deviation / repetition please ?

Link out & some B screw winding in to stop the noise on the 42. This is of course accepting that the low stop screw is adjusted correctly?

What’s deviation / repetition please ?

Someone will give you the answer in just a minute

Shimano tech manual link (I think it’s the correct model)
Break the chain and put it around the large ring/large sprocket, sixty seconds tops, don’t hesitate

Can i claim my bonus point that rocketdog has actually used repetition?

Rocketdog gets a bash on the head like this. Or like this.

Update – I removed 6 links in the end to make it more or less instruction compliant (max + 2 links)! It makes rear mech adjustment easier and has improved shifting significantly. Still poor compared to old XT-10 speed of course but at least it kinda works for now.

I basically removed twice the length that the loss of 3 teeth equated to so the chain was too long to start with (thanks LBS…).

caught my wife ‘mirin another dudes chain. Its been frosty since.