Homemade single speed chain tensioner

[Matno]

This is the coolest idea I've seen yet. I'm going to make one. My brother in law had most of the parts I need and they're in the mail on their way here. My LBS was kind enough to give me an old rear derailleur for the bolt, pulley, etc. to complete the build. I will be an official single speeder by next week!

http://forums13.consumerreview.com/crforum?14@224.9Bi5akCt42E.4@.efc5391/0

[Old Proflexer]

i like it -

not sure what i'd do with it but i like it -

is that a spring tension unit with the main body of the brake arm?


not a single speeder  -  OP

[Matno]

Yup, the brake arm has a spring built in. You just drill a little hole in your dropout to anchor the spring (just like the little hole next to your V-brake studs). Easy install and looks like a fairly simple setup. We'll soon find out how much I like single speeding. I tried a few "test runs" with my 5000 (just left it in one gear the whole time and locked out the rear shock), but it didn't do justice to single speeding since it weighs about 6 pounds more than my new rig... It was still fun though. Amazing how much thinking goes on when you're constantly shifting gears.

[Old Proflexer]

i'd never thought about that -

guess i was busy thinking about a lot of other things

OP

[Carbon_Angus]

that looks really   and i think it would be okay if the SS was a hardtail or a FS that didn't have any "chain-growth".

otherwise it's gonna bust after a while (IMO), but it looks  
and is an interesting application.

i woulda put a singulator in your stocking if you had asked......~Santa

[zulu]

  Cool idea. I am in the process of making a low budget SS this is a way to go.

[rapiddescent]

I ride a singlespeed Razorback RS - I use the surly singulator - a fantastic product that has enough give to work with the suspension in 32x16.  The beauty of the singulator is that you can make it work under or over the chain - i.e. pulling the chain up or back.  

There is something slightly perverted about having a singlespeed razorback and lightweight disk brakes in singlespeed mode.  I like it.

callum
rdi

[debaucherous]

Forgive my ignorance, but why can't the chain be shortenerd to accomodate a single speed?  Why does there even have to be a tensioner?

[Carbon_Angus]

Forgive my ignorance, but why can't the chain be shortenerd to accomodate a single speed?  Why does there even have to be a tensioner?

you can't get it (chain) tight (taught) enough

the dropouts on a frame made for deraillers are vertical. singlespeed frames, BMX type bikes or other bikes with no der. have horizontal drops so you can pull the wheel and get your chain tension that way or some other fancy way..but the dropouts is your answer why.

FS bikes, especially, need something to accomdate the chain as it "grows" when the suspension is activated.

the singulator works well, so does a just a derailler pulley, or a whole old beat up derailler with the set screws keeping the chain in line works for those really lazy the sing.

and like callum said the sing works with spring tension both ways ( you need to take the spring out and reverse it)so you can run the chian over or under the wheel. FS is usually run over and hardtails under because of the chain growth thingy with FS bikes

[rapiddescent]

yeah, as angus says really.  the Razorback RS is the full suspension bike, the Razorback (no RS!!!) was a hardtail - although I'd still run a chain tensioner due to lack of horizontal dropouts.

Most full suspension bikes have slightly active setups that the suspension can be felt through the chain.  the most famous of these was Bob Girvins 'dig-in' effect that would effectively 'lock' the suspension when you were in granny ring to stop pedal-bob.  funny how Bob invented a no-bob suspension system!!!

Anyway, the result is that you need a tensioner.  You should all try singlespeed sometime on your third bike!  

callum
rdi