First ride on the tandem through proper mud today and the constant chain suck made it almost impossible.
It’s got 3×8 42-32-22 x 11-30 with Shimano Revoshift twist shifters and a Shimano Acera rear derailleur.
We’re only getting chain suck on the granny ring, no problem at all on the middle ring, which got me thinking about trying 2×8.

Putting the numbers in to http://sheldonbrown.com/gears/ it looks like with an 11-34 on the back, we would only effectively lose the bottom two gears. I reckon we could live with that.

Does that sound like a good solution, or should we be looking at a better quality granny ring, chain and rear derrailleur to cure the problem ?

Long term, I’m waiting for a cheap Rohloff hub to turn up on ebay, meanwhile £10 for a cassette is cheap enough and the derailleur is good for a 34t bottom gear and 43t total range.
(42-32)+(34-11)=33 Have I got that right ?

Morning bump as I didn’t get a reply last night.
Derailleurs are a bit of a novelty to me, I’m used to Rohloff or single speed.
I’ve heard of chain suck, but never experienced it before.
This site goes in to some detail and gives high pedalling loads as a contributing factor. That’s always going to be worse on a tandem, so should we just give up on the granny ring and go for 42-32 x 11-34 ?

I was always under the impression that chainsuck occurs due to worn teeth on the chainring not releasing the chain, is this not the case?

not always davesmate.

my on-ones chainsucking – it has a brand new chain , cassette , 22tooth ring and 34 tooth ring.

granny ring sucks awful.

Going 2×8 might fix the problem, but unless you’re able to change the chain line you might get problems with the middle ring wearing quickly due to the chain not running straight enough in lowest gear. Replacing the smallest chainring with something good quality and slightly larger (24 or even 26) may be a better idea. Tandems tend to punish equipment due to all the extra forces of carrying two people around and IMHO acera gearing is probably on the limit for off-road tandeming.

@trail rat – what’s causing that then?

I’ve gone through 3 granny rings in a little over 4 years. That may sound a lot but I figure granny is the one I grind away in the most and everytime I’ve had chainsuck that’s what the problem has been. Never had to change a middle or big ring.

We bought the tandem second hand with only about 20 miles on it and we’ve only been out three times on it so far, so the transmission is still like new.
Acera is the bottom of the range, so I did wonder if better quality components would help. Presumably the granny ring is stamped, so maybe a machined, bigger one would be better.
There was mention,on another thread, of bottom gear sprockets on the cassette folding in half with the power of two riders, which makes me a bit wary of upping from a 30 to a 34 anyway.

i dont know and thats half the battle.

first step will be to fit an XT ring -the one i fitted was a stamped deore one.