So, built up 1 x 10 flat bar road bike for my wife.

40t chainring and 11>36 cassette.

Works fine until I try to change into 36t at rear….then drops chain off chainring.

Looks like the chainring needs spacing back towards the bb as the angle is a bit extreme.

So, I could get a shorter axle bb (square taper) or use chainring spacers to achieve the same.

However, they are mostly very expensive or out of stock.

Anyone point me in the right direction please?

Ps I have fitted a Pauls chainkeeper….which stops the chain dropping but think I still need to space the chainring….

Is the ring on the inner position?

Yes, ring is on inner side of tabs.

Hmmm, must have a fair length b/b axle on it then as should run well with 40 inner ring. You can get DH bolt kits that may have some spacers and long bolts to suit….

I fitted a 118mm octalink bb to a ht that i built up the other and the chain dropped off in the 36t at the back. Changed it to a 113mm bb and it works fine now. Although I did fit a narrow/wide chainring at the same time.

Ring is actually on middle ring position.

Just ordered a 5mm shorter axle bb from crc….it’s a 70 x 113 there currently and shortest axle is 70 x 107. Italian thread obviously….

Un55 bb’s are great value!

SJS do them
http://www.sjscycles.co.uk/alloy-chainring-spacers-for-middle-outer-ring-pack-of-5-prod33189/

Ordered some from sjs….hopefully shorter axle bb plus some playing with spacers should have things aligned a bit better.

Thanks all.