Say I've got an old French road bike that I want to convert to a singlespeed (or, more probably, a three-speed). It has a double chainring with cottered cranks.
Ideal chainline is probably on the inner chainring. Conceivably, I could just leave the outer chainring on there...but if I decided to remove it, I'd have to remove the crankarm and use stack bolts to space everything out correctly--right?
Anyway, my question is: is it worth doing this? It's French cottered crank--so my odds of finding a new cotter pin are about nil, I'm guessing.
Say I've got an old French road bike that I want to convert to a singlespeed (or, more probably, a three-speed). It has a double chainring with cottered cranks.
Ideal chainline is probably on the inner chainring. Conceivably, I could just leave the outer chainring on there...but if I decided to remove it, I'd have to remove the crankarm and use stack bolts to space everything out correctly--right?
Shorter chainring bolts or spaces would do the trick, yes.
Quoted message said:
Anyway, my question is: is it worth doing this? It's French cottered crank--so my odds of finding a new cotter pin are about nil, I'm guessing.
Cotter pins aren't that hard to find. The bigger LBS's around Atlanta have them. What I'd look into is buying a new spindle for your cup.cone bottome bracket so you can have a new standard square taper cranks. That maybe be a bit out of budget. In that case, just leave the outer ring or get some spacers. hope this helps/hope I'm not wrong/an idiot. \\paul
-- Paul M. Hobson Georgia Institute of Technology ..:change the f to ph to reply:.
Cotter pins aren't that hard to find. The bigger LBS's around Atlanta have them. What I'd look into is buying a new spindle for your cup.cone bottome bracket so you can have a new standard square taper cranks. That maybe be a bit out of budget. In that case, just leave the outer ring or get some spacers. hope this helps/hope I'm not wrong/an idiot. \\paul
So, wait, sorry if I'm being thick here--
But is there any way of getting the chainring off without having to remove the crank-arm?
But is there any way of getting the chainring off without having to remove the crank-arm?
I guess that depends on the crank design, but most indeed do come off without having to remove the crank arm. A picture (pointer to, not posted here) would help.
--
David L. Johnson
__o | A mathematician is a machine for turning coffee into theorems. _`\(,_ | -- Paul Erdos (_)/ (_) |
Say I've got an old French road bike that I want to convert to a singlespeed (or, more probably, a three-speed). It has a double chainring with cottered cranks.
Ideal chainline is probably on the inner chainring. Conceivably, I could just leave the outer chainring on there...but if I decided to remove it, I'd have to remove the crankarm and use stack bolts to space everything out correctly--right?
Anyway, my question is: is it worth doing this? It's French cottered crank--so my odds of finding a new cotter pin are about nil, I'm guessing.
-Luigi
IIRC, it's theoretically possible to remove the chainrings on old French cottered steel cranks. As I recall, though, they were usually bolted down so tightly that you would round off the bolts before you got them off. At least that was the case with the Motobecane 10 speed I had in high school. -- mark
"Luigi de Guzman" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I'm delurking to post this.
Say I've got an old French road bike that I want to convert to a singlespeed (or, more probably, a three-speed). It has a double chainring with cottered cranks.
Ideal chainline is probably on the inner chainring. Conceivably, I could just leave the outer chainring on there...but if I decided to remove it, I'd have to remove the crankarm and use stack bolts to space everything out correctly--right?
Anyway, my question is: is it worth doing this? It's French cottered crank--so my odds of finding a new cotter pin are about nil, I'm guessing.
-Luigi
It should not be a big issue to get the cottered crank off so you can mess with the chainrings. http://www.sheldonbrown.com/cotters.html goes into how to remove one for maintenance. You really probably need to regrease the bottom bracket bearings anyway.
it bears mentioning that you are using a french bike ....the french do everything backwards and in their own sizes...their bottom brackets and such are unique, and what is now standard won't work, you may wish to leave the outerchainring alone....you could file off the teeth and use it as a chainguard however, and remove the front derailluer
Say I've got an old French road bike that I want to convert to a singlespeed (or, more probably, a three-speed). It has a double chainring with cottered cranks.
Ideal chainline is probably on the inner chainring. Conceivably, I could just leave the outer chainring on there...but if I decided to remove it, I'd have to remove the crankarm and use stack bolts to space everything out correctly--right?
Well, the alternative I suggest is to grind off the teeth from the outer chainring. The outer ring would then act as a bashguard and help keep grease marks off your pants/leg. Then you wouldn't have to worry about fiddling with spacers or getting new chainring bolts.
-- Dane Buson - [email hidden] "Benson, you are so free of the ravages of intelligence" -- Time Bandits
It should not be a big issue to get the cottered crank off so you can mess with the chainrings. http://www.sheldonbrown.com/cotters.html goes into how to remove one for maintenance.
The first trick, though, is to have a replacement cotter pin handy in case the original's threaded end becomes gibbled during removal, which has been known to occur despite the utmost care being taken. Having such a replacement is dependent on finding a LBS that has a selection of cotter pins /including/ ones having the exact dimensions needed. So the second trick is to have a sample to compare with or measure at the bike shop. But if you remove a cotter pin, you run the risk of wrecking it and then not being able to get a replacement.
Quoted message said:
You really probably need to regrease the bottom bracket bearings anyway.
This might be one case where installing an oil cap (a la Raleigh 3-speed) would be expedient.
cheers, Tom
-- -- Nothing is safe from me. Above address is just a spam midden. I'm really at: tkeats [curlicue] vcn [point] bc [point] ca
Having such a replacement is dependent on finding a LBS that has a selection of cotter pins /including/ ones having the exact dimensions needed.
If you're lucky enough to find a bike shop that has cotter pins, chances are they'll have an array of 'em in every size & taper except the one you need.
cheers, Tom
-- -- Nothing is safe from me. Above address is just a spam midden. I'm really at: tkeats [curlicue] vcn [point] bc [point] ca
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Quoted message said:
it bears mentioning that you are using a french bike ....the french do everything backwards and in their own sizes...their bottom brackets and such are unique, and what is now standard won't work, you may wish to leave the outerchainring alone....you could file off the teeth and use it as a chainguard however, and remove the front derailluer
What are you talking about? It's the rest of the world that's backwards.
pardon!!! I rode motobecanes for many years and loved the bikes, and it was only after I went to a different brand I found everyone else shifted the opposite direction, which caused a lot of missed gears for a while as I adapted to "the rest of the world" My use of the word "backwards" was perhaps not as appropriate as say "quirky"or "in reverse" hope no offense was taken, I forgot for a moment how far these notes travel....inna
Yes, keeping the outer ring on as a guard is a good alternative, and solves a bunch of issues. I did this for my hybrid bike, though I just crudely sawed off the outer ring's teeth instead of grinding:
In my experience almost all new cotter pins have to be slightly (sometimes heavily) shaped to fit. But since they're of a fairly soft alloy one can easily do this with a file.
Yes, keeping the outer ring on as a guard is a good alternative, and solves a bunch of issues. I did this for my hybrid bike, though I just crudely sawed off the outer ring's teeth instead of grinding:
