Bicycle Mechanics - 6 to 1 speed question

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA

View Full Version : 6 to 1 speed question

cradduck
06-26-07, 08:54 PM
A friend is looking at setting up a single speed on the cheap.

I took the six speed cassette of the wheel and it looks like it has a freehub design but one I haven't seen before. The largest three sprockets slide on to a larger diameter portion of th freehub and the next smaller two slide onto a smaller diameter portion of the freehub. The smallest (13t) then threads on to fix everything in place. Is is possible to convert this to a single speed and acheive a straight chainline?

Sheldon Brown
06-26-07, 09:29 PM
A friend is looking at setting up a single speed on the cheap.

I took the six speed cassette of the wheel and it looks like it has a freehub design but one I haven't seen before. The largest three sprockets slide on to a larger diameter portion of th freehub and the next smaller two slide onto a smaller diameter portion of the freehub. The smallest (13t) then threads on to fix everything in place. Is is possible to convert this to a single speed and acheive a straight chainline?
That's not a cassette, not a Freehub. It's an old style thread-on freewheel. You can unscrew the whole freewheel (with a special tool) and replace it with a single-speed freewheel or fixed gear sprocket. You will need to re-arrange spacers to correct the chainline, then re-dish the wheel to bring it back to the center of the frame.

See: http://sheldonbrown.com/freewheels

and: http://sheldonbrown.com/fixed-conversions

and: http://sheldonbrown.com/singlespeed

Sheldon "It's Doable" Brown
Daijoubu
06-26-07, 10:46 PM
or fixed gear sprocket.
Isn't that called a suicide hub then? :)

I've done what Sheldon said, took me about 3 hours

cradduck
06-27-07, 01:11 AM
Is the special tool for removing the freewheel something most bike shops would have?
Daijoubu
06-27-07, 05:51 AM
yes of course
Sheldon Brown
06-27-07, 09:18 AM
Isn't that called a suicide hub then? :)

I've done what Sheldon said, took me about 3 hours
Yes, but that's a stupid designation.

It's just as safe as a freewheel, as long as you have two brakes.

Sheldon "Misnomer" Brown
eddy m
06-27-07, 09:35 AM
It's only a "suicide hub" if you use it as a fixed gear. There's no issue at all if you use it with a single cog freewheel. As Sheldon said, there's really no problem using that kind of hub if you use brakes, and you need brakes no matter what kind of hub you use. It ironic thing is that it's mostly the guys who don't use brakes object to "suicide hubs."

em
Zouf
06-27-07, 10:36 AM
A friend is looking at setting up a single speed on the cheap.

I took the six speed cassette of the wheel and it looks like it has a freehub design but one I haven't seen before. The largest three sprockets slide on to a larger diameter portion of th freehub and the next smaller two slide onto a smaller diameter portion of the freehub. The smallest (13t) then threads on to fix everything in place. Is is possible to convert this to a single speed and acheive a straight chainline?
It's a freewheel. You can replace it by a single-speed freewheel, or modify it. Sometimes the middle gears are threaded on rather than slipped on, so you can pile up spacers to get the right chainline, and thread the cog you want in place.