Going Single Speed Quick

[mattyboi]

hey

i saw a artical a while ago in a magazine where he had taken or the gearing wire wire and changer of the bar but used the derailleur as a chain tensioner

could anyone tell me how to do it

thnaks

matt

[Mikee]

there is a spring on the top bit of the derailleur that lets it move sideways to change the gear. if you take this spring out you should be able to use the bottom half which has the rollers and a chaintensioner. sorry for the rubbish description! i have never done it myself but i have seen it been done loads of times before so it should work.

hope i have helped

[Skoze]

I used to just use the derailleur, adjust it to give a good chain line then cable tie the main body to the chainstay.

Worked a treat

[eskimo]

That makes hardly any sense. But i think i deciphered it

So you want to use your derailleur as a tensioner?

Remove the gripshift or whatever shifter you have from your bar. Plus remove the main cable.

Your want to cut the cable you removed to about 2"s long lets say. From the beginning (the lever end) (with the noble bit)

I'm hoping the chain is in the correct gear you want to use. Best of done that first.

Fit the 2" of cable to where it was previously removed from on the derailleur. But backwards! The nobble bit will stop the cable pulling through.

The derailleur needs to be held into place while you tighten the other end of the cable down.

The derailleur should sit fairly straight in the gear you wanted.

Now you can fine tune the gear. See pic.

You can also remove a few links of the chain and zip tie the derailleur to the frame to avoid it moving too. Then the only bit that tensions the chain in the lower arm which is still spring operated.

This applies to certain derailleurs only. Some fancy ones may not work like this, but this is how i've pretty much done it every time. Sometimes i removed one of the rollers/ cogs.

Someone else may be able to help to. Or explain it a hell allot better!

In the picture, the red is the cable.

[mattyboi]

cheers i not going to play tonght though because we got a ride in grvaesend tomorrrow and personaly dont want to ruin my bike ha

and just another thanks for the explanation

anyone got any pics of people that have done it for real

thanks matt

[r2wtrials]

i used to use just a rear mech as a tensioner.... some years ago. I used the cheap shimano short cage mech and just adjusted the screws on the back of it to keep it in one position then shorted the chain so the mech was almost at full stretch. I used a neoprene frame protector and let the mech rest up against it. was spot on until i landed on it one day and broke the mech hanger tab off!!!

[Jarl]

The two screws you can see just above where the cable enters the rear mech are the limit screws. The standard ones normally aren't long enough to successfully limit the rear mech travel, but any longer replacement screws will work- I'm fairly sure they're M3 thread, though they might be M4 (I don't have any callipers with me to check- left them at home!). Ebay is probably a good bet as a source. You can get away with 1 screw, but two is better. The single screw above the 2 limit screws (just next to where the rear mech bolts onto the frame/mech hanger) should be done up as tight as possible for maximum tension when using the rear mech as a tensioning device.

This picture is a pretty rubbish depiction of how the limit screws work. The red things are the limit screws, and the black thing is part of the rear mech. As you change gear, the black thing moves from left to right. The further in the limit screws, the less the rear mech can move. What you're aiming to do to use the rear mech as a tensioner is to get both the screws touching the black bit so the rear mech can't move. The stock screws aren't long enough to do this- they'll still leave a little bit of play even when fully in. Longer screws will go in further and push against the black bit to stop it moving. You can just use 1 (longer) screw- the lower limit (L screw) (or the upper limit (H screw) if you have a RR rear mech- if you do, you'll know what that means, if you don't know what that means then ignore everything in these brackets), and rely on spring tension to keep the black bit of the rear mech wedged up against the lower limit screw. However, this isn't as solid as using two screws.

To set up the two limit screws to run the mech as a tensioning device, do up the L screw until the rear mech is where you want it, then add half a turn. Now do up the H screw as hard as you can, and add a bit more tension to the L screw (if possible). This should have aligned the rear mech exactly where you want it. If it hasn't, then make a note of which direction it needs to go, slacken off the H screw and adjust the L screw as necessary (clockwise turn of the L screw moves the mech away from the frame/wheel), then torque up the H screw again.

Edited October 4, 2008 by Jarl

[mattyboi]

thaanks for all of the help guy il keep it in mind not to confident about doing that yet il just keep thr gay gears for now

and today riding was ruined by the truthfull british weather ha

Matt

Edited October 5, 2008 by mattyboi

[eskimo]

The two screws you can see just above where the cable enters the rear mech are the limit screws. The standard ones normally aren't long enough to successfully limit the rear mech travel, but any longer replacement screws will work

That's a great way of doing it. Just means trying to find the right bolts.

[Gogz-]

yo Matt . you can bring it in to my work and i can help you sort it out if you like .

I have done it for my bikes a few times . Its not v hard to do but its not easy at the same time

[mattyboi]

yo Matt . you can bring it in to my work and i can help you sort it out if you like .

I have done it for my bikes a few times . Its not v hard to do but its not easy at the same time

O lol how much do ou reckon it will be like cost, today a bit of a bummer wasnt it gogz69

Matt