Hi,

I tried building my new frame up as a single-speed at the weekend, using an old tensioner from the DMR kit, but I couldn't get it to fit. The new frame is steel and the mech-hanger is part of the frame. The tensioner fits to the QR and to the mech-hanger but the shape of the frame/mech-hanger doesn't allow for the QR mount to fit in place.

I've noticed that there is another type of tensioner, the On-One Doofer for example, that only appears to mount on the mech-hanger.

Is this type the answer to my problems or does it have its own problems?

Cheers,

Ian

The Superstar on I used at first had a QR bolt with it, shaped to fit through the tensioner to a normal length QR.
Trouble was, the tensioner was at the limit of it's adjustment when positioned correctly. One slip of the wheel and it bent the QR.
So I bought an On-One job for £8 and have fitted, but not tried yet.

Guess that doesn't really answer your question! But at £8 the On-One is worth a try.

I've tried a fair few tensioners over the years, and IMO, the single jockey wheel ones (especially the unsprung) aren't up to the job.

The best tensioner I've found has been the Rolhoff DH tensioner, and a knackered old XT mech, yanked right forwards till the arm is pointed forwards.

I've just purchased a Surly Singulator, seems pretty good so far. It's sprung and has a jockey wheel with a cage.
Only bummer is you need an 18mm cone spanner to adjust spring tension on fitting

I bought a DMR tension seeker II which was £38 and it didn't impress me:

+ it fits on the mech hanger
+ it's a jockey with a cage, not a pulley
+ the jockey can be aligned and then fixed in place

– the spring kept bending
– the fastener that holds the spring is soft alloy and gets chewed up easily
– it whirrs quite a bit

Am managing without a tensioner at the moment.

Hmm, I think I may just change my plan and single-speed the old frame (which I know works with the DMR tensioner) and have the new one geared instead.

Thanks for the comments/experience.

Just get one of these and do away with those crappy bolt-on tensioners.

My on-one doofer seems to do exactly what it's supposed to

I got a Fireye job that looks the same as an on-one doofer. It works fine. No complaints at all.

$150 is quite a lot to spend for the EBB, but yes it looks neat.

Ok, using the "It's only £8" logic, I've ordered a doofer. If it's naff I'll switch SS/geared duties from one frame to the other 🙂

clubber – Member
My on-one doofer seems to do exactly what it's supposed to

That's what I like to hear. 🙂 Seemed fine on my test ride round the road anyway.

IME jockey wheel type tensioners work a lot better than rubber roller type tensioners – They give better chainline (rollers seem to create/allow side to side movement of chain) and jockeys also run smoother and quieter

Obviously neither are as good/tyrouble-free as a SS setup without any tensioner