On my old Klein hardtail I had Middleburn XC Duo crankset, 8 speed cassette and matching chain. It worked perfectly for years.

Transfered the same compoments to my Cove Handjob and got terrible chain suck. I confirmed the BB length with Middleburn, 68/113, Sq Taper.

When I checked, the rivets on the inside of the outer chainring seemed to catch on the chain when it was on the inner ring. So I demmelled them flat! Chain suck all reduced, but when the chain is on the small sprocket at ther back, the outside of the chain rubs horrendously on the inside of the larger front chainring.

So I bought a longer BB, 118. Made little/no difference. I tried moving the whole crankset by hand out along the taper to find out how long the BB axle would need to be – too far to be realistic. I dont think the front mech (XT) would be able to reach that far.

Am I missing something, where am I going wrong? Any ideas welcome.
If its something simple you can call me a div, bring it on…

Don't use that gear. Seriously.

Or space out big chainring.

Thanks.

I did wonder if the chainrings were too close together.
And it did occurr to me to live with it.

Would bug me though, I'd like it perfect.

Space the rings with what, just washers etc?

I ran a handjob with an 8 spd/duo/113 for a couple of years. I suspect there's something wrong with your ring set up. can you do a picture?

I second "don't use it".

Even on road double applications it isn't adviseable to use little/little or big/big. Too drastic a cross and not good for the chain.

to the 'dont use it' people

the inner ring is just a few teeth smaller than a middle ring. think of the set up as just missing the granny, therefore you can get in all the ratios without straining the chain when in the psuedo-middle (obviously you cant go big/big)

I've been running mine since 2000 (blimey!)

Thanks guys.

I'll see if I can get some pics sorted, take a look.
Never done pics, yet.