Singlespeed & Fixed Gear - Little Question

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incanus
10-20-05, 10:55 AM
I'm planning to build a single speed bike out of a late 70's road frame. I was wandering if it will need a special hub or a regular road bike hub will do.
Thank you for answering!
Fantomas
10-20-05, 11:13 AM
well, technically there is a way to make the "regular" hub work however it's a bad idea in my opinion.
NYC Bikes makes a nice flip flop rear for about fifty bucks... Flip flop meaning you can run a fixed cog on one side and a single speed (free wheel) on the other side of the hub if you wish. This is what I would recomend. Or just buy the hub itself and have the wheel rebuilt.
Incanus, I'm by far not an expert here, but a search will find a plethora of info for your question. But from what I know, you can remove the cassette from your old hub and spin on a single speed gear with no lockring. To go fixed, you can make a suicide hub by spinning on a track cog and add a bottom bracket lock ring - along with a dose of loc-tite. Single speed will be safe as there is no back pressure when slowing your cadence. True (and safe!) fixed gear demands a fixed gear hub - two separate threads, the lockring thread reversed so nothing will loosen. You'll still want a good chain-line. Visit Sheldon Browns site for more good info...
isotopesope
10-20-05, 11:29 AM
if you use an old road wheel, you'll also have to redish the rim to be centered between the axle's locknuts to get a proper chainline. please please please make this a single speed and not a bumbike fixie.
Fantomas
10-20-05, 11:51 AM
please please please make this a single speed and not a bumbike fixie.
ditto
queerpunk
10-20-05, 12:14 PM
It's likely that what you'll need to do is remove the cluster of gears from the rear wheel (you'll need a couple of special tools to do this, or you can have a bike shop do it), and screw on a single speed freewheel. You're going to want a straight chainline, and you want the rim centered, and those take some finagling--check out www.sheldonbrown.com for lots and lots of singlespeed and fixed gear information.
when they say "bumbike," they mean a style of turning an ordinary threaded hub into a fixed gear by screwing a track cog on, followed by a bottom bracket lockring, and usint Loctite or JBWeld to hold it all together. This differs from a track hub, because a track hub has a smaller set of threads that are reverse-threaded (lefty righty). You screw on a track cog, and then on the reverse threads, screw on a lockring snug against the track cog. That way, backpressure on the pedals doesn't unscrew the track cog--it tries, but that pressure only tightens the lockring. get it?
Anyway, to answer your initial question, you can make do with the old rear wheel.
Of course, the quickest and dirtiest way to make a single speed is to figure out what gear you like, take off all the derailleurs and remove the exess chain.
eddiebrannan
10-20-05, 12:44 PM
nah it's much easier than these guys are making out. you don't need to redish or anything.
to make a quick and easy ss out of a road bike you remove the cogs from the cassette. you keep the cog you want and use either cassette spacers (from lbs) of cut down vinyl drainpipe to place that cog at the correct point along the cassette spindle to achieve correct chainline (straight line, viewed from above/behind) between cog and chainring.
change the chain to a bmx one, as road chains are designed to flex along their length to facilitate shifting. you don't want that.
throw out your derailleur and shifters and you're done. have fun
MAD Rider
10-20-05, 01:05 PM
nah it's much easier than these guys are making out. you don't need to redish or anything.
to make a quick and easy ss out of a road bike you remove the cogs from the cassette. you keep the cog you want and use either cassette spacers (from lbs) of cut down vinyl drainpipe to place that cog at the correct point along the cassette spindle to achieve correct chainline (straight line, viewed from above/behind) between cog and chainring.
change the chain to a bmx one, as road chains are designed to flex along their length to facilitate shifting. you don't want that.
throw out your derailleur and shifters and you're done. have fun
Only problem with your thought is if the bike is from the 70's it probably has the cogs attached thecassette so they may not come off. On my bike that was the case.
I'm guilty of having a bumbike, sorry for those who don't approve. I've spent a total of $25 for it and it works for me. I did it that way because I didn't want to spend a lot of money on something I wasn't sure I was going to like. Also the frame is a little too big for me, to the tune of 6 cm, I am in the process of buying parts to build a nicer fixed and that one will not be a bumbike. IMO if you want to build a bumbike, go for it, if you end up liking the feel, save up for some new rims/hubs with sealed bearings they tend to have a much smother ride.
Sheldon Brown
10-20-05, 01:27 PM
please please please make this a single speed and not a bumbike fixie.
Why? Fixed is more fun! it's perfectly safe as long as he or she leaves the brakes in place.
Sheldon "http://sheldonbrown.com/fixed" Brown
+-----------------------------------------+
| There is a remedy for everything; |
| it is called death. |
| --Portuguese Proverb |
+-----------------------------------------+
jfmckenna
10-20-05, 02:30 PM
Yea whats wrong with a bum bike fixie I think they have a lot of class. And I vote for trying to remove cassette cogs too. I've done this about 5 times before. It can be a real PIA but you can hook a chain up just right to use it in the frame as a tool to back pedal the cogs right off of the free wheel. I don't know about 70's freewheals but its worked for me on an old 80's Puegot. Some have special tools required for sure and I doubt your LBS will even want to touch it. If you do use the chain and frame method you may want to put the wheel in an old frame as it takes so much pressure sometimes you can bend the stays.
MAD Rider
10-20-05, 02:38 PM
My lbs had the right tool, it was like $6 park too so a decent tool, only bad thing is I doubt I will ever use it again ...
Cynikal
10-20-05, 02:41 PM
I have to agree with Sheldon here. The "bumbike" is fine if you use a brake but I don't think this is the orig poster's question.
There are two types of rear hubs. A freewheel hub and a freehub. A freewheel hub uses a thread on type of cassette. This cassette is all one piece and cannot be taken apart (for these purposes.) With this hub all you need is to remove the cassette and thread on a new BMX freewheel. You should also need to respace the hub to correct your chain line and then recenter the rim.
With a freehub the freewheel is built into the hub and the cassette can be taken apart. You can use a series of spacers and use one of the cogs (or a BMX cog which works better- no ramping.)
humancongereel
10-20-05, 03:21 PM
Why? Fixed is more fun! it's perfectly safe as long as he or she leaves the brakes in place.
Sheldon "http://sheldonbrown.com/fixed" Brown
+-----------------------------------------+
| There is a remedy for everything; |
| it is called death. |
| --Portuguese Proverb |
+-----------------------------------------+
both brakes, or just the front?
Sheldon Brown
10-20-05, 08:03 PM
both brakes, or just the front?
If you don't have a proper track hub with a left-threaded lockring, my advice is to keep both brakes on.
With a proper track hub, I don't see the need for a rear brake.
Sheldon "It Depends" Brown
+--------------------------------------------------+
| Take sides! Always take sides! |
| You will sometimes be wrong--but the man who |
| refuses to take sides must _always_ be wrong. |
| Heaven save us from poltroons who fear |
| to make a choice. --Robert A. Heinlein |
+--------------------------------------------------+
Sheldon Brown
10-20-05, 08:14 PM
I have to agree with Sheldon here. The "bumbike" is fine if you use a brake but I don't think this is the orig poster's question.
There are two types of rear hubs. A freewheel hub and a freehub. A freewheel hub uses a thread on type of cassette.
You create confusion by calling a freewheel a "cassette." It's a freewheel.
See: http://sheldonbrown.com/free-k7
This cassette [freewheel] is all one piece and cannot be taken apart (for these purposes.) With this hub all you need is to remove the cassette and thread on a new BMX freewheel. You should also need to respace the hub to correct your chain line and then recenter the rim.
With a freehub the freewheel is built into the hub and the cassette can be taken apart. You can use a series of spacers and use one of the cogs (or a BMX cog which works better- no ramping.)
Or, if you're handy, you can "fix" a cassette body. I did this for my Bianchi B.a.S.S singlespeed MTB (http://sheldonbrown.org/bass) . I wanted an on-road and off-road gear, but unfortunately this frame has old-fashioned rear-opening fork ends, which make it very awkward to use a flip flop hub.
I got an old Shimano MTB cassette Freehub, removed the body and ran a bead of braze around the back end of the Freehub body, immobilizing it. When I bolted the body back onto the hub, it was fixed-gear cassette hub.
I put on a 14 and an 18 tooth BMX sprocket with a buncha spacers. It's got a double chainwheel setup, with a 42 and a 38 tooth ring. Since there's a 4 tooth difference at each end, I've got two gears with the same chain length and approximately the same axle position in the dropout. The 42/14 is an excellent street gear, and the 38/18 works well off road, though I must admit that I hardly ever take it off road.
Sheldon "Try This At Your Own Risk" Brown
+-------------------------------------------------------------+
| The reasonable man adapts himself to the world; the |
| unreasonable one persists in trying to adapt the world |
| to himself. Therefore all progress depends on the |
| unreasonable man. -- George Bernard Shaw |
+-------------------------------------------------------------+
incanus
10-21-05, 04:37 PM
Thanks for all the info.
So basically i can use a regular road hub and take all the chainrings i don't wanna use?
Thanks!
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