Tinman10

I managed to lock up the back wheel earlier in top gear (riding slow fortunately). When I stopped the chain tensioner was jammed in the cassette! I suspect it was because of folding or unfolding it earlier incorrectly. So I managed to fix it by breaking the chain and unscrewing it then putting it back on then joining the chain back up. I've set it so it's locked in position and above the chain in all gears. But it seems very high in 1st and 2nd gears; almost vertical. Should it be able to pivot ie not be tightly screwed up? Should it be almost vertical in lower gears? It's a Shimano 105 derailleur and Hyperglide cassette. It's bent in a curved shape now - all the ones I've seen in photos are completely straight. I'll try to attach a photo.




Steve

energyandair

The wire bail on my 24 speed (3x8) is locked into position and just clears the chain when the chain is on the smallest ring. It angles up at about 70 deg when its on the largest ring.

The range of positions will vary depending upon the gear cluster range and derailleur you have

jur

Sticking up high in low gear will be correct. Mine used to touch the tyre almost.

bhkyte

I didn't get off and remove long grass trapped in it recently and it jammed into the chain and locked the back wheel also. Went the other way from yours past the chain. Bit of a mess but sort of straightened out ok. Mine touches the big Apple tyres very slightly in highest gear. Personally I prefer mine locked in place so it does not drop whilst riding.
It was my own fault I bent mine for carry on with a field of grass hanging off my gear transmission!

timo888 

I would be grateful for some info on the type of chain tensioner shown in this video.

BruceMetras

BIRDY Chain Tensioner

timo888 

Also, if anyone can tell me the maker of this tensioner, I'd be grateful:

timo888 

Thank you, Bruce. Your reply arrived just as I had added a second style of tensioner to my query.

BruceMetras

Looks like the RIDEA chain HOOK for Birdy or something very similar.

timo888 

Thanks again for your help, Bruce.

timo888 

I don't really understand what the device shown in jur's picture from 2014 is supposed to do. When the rear wheel is folded under, does that device merely give the chain something to drape over? It's not meant to hold the chain taut, is it?

BruceMetras

Jur's pic shows a stock Birdy chain retaining guide...as the wheel folds under, the black part of the guide straddles the chain .. the length of the derailleur determines how much chain slack the guide can handle.. the idea is to keep the chain off of the ground (and on the chainring) when the wheel is folded under.. if you were to run a short cage derailleur and the stock guide, the chain would sit on the ground when the wheel is folded under and would be more prone to come off of the chainring when you go to unfold the rear wheel .. that is why you see long cage derailleurs on most Birdy models that use a stock chain guide ..