Crank help!

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GUSMC

'Lil Knee Scuffer
Apr 29, 2020
23
Glasgow, Scotland
Hi folks, I recently purchased a 1951 CWC Western Flyer. I had noted a very old and unusual weld joining the right hand pedal to the crank but keen to give it a whirl I took it out for a spin. All went fine until the pedal fell off due to the weld failing. On inspection both the old pedal and the crank have completely stripped threads.
Apart from stripping and rebuiding my Schwinn, I have limited experience of Amercian-style one piece crank systems; so my question is: how universal are they?
Width of bottom bracket = 68mm
Length of crank (centre axle to centre pedal axle) = 7" / 180mm

Being in the UK Im happy to go with the easiest fix for this one and not so concerned with finding a period perfect replacement.
I guess my question is: are there any other measurements I should be looking out for?

Any help appreciated, cheers from Scotland!

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bloo

'Lil Knee Scuffer
Jul 31, 2020
14
50
Washington State
There are only 2 common kinds of those one piece cranks: 1) Schwinn and 2) everything else.

If you put a Schwinn crank in a non-Schwinn (or vice versa), you must change all the parts (cones, cups, bearings, hardware, etc.) but it does fit in the frame. The chainring fits either kind and the so do the pedals.
 

The Carolina Rambler

Finally riding a big boys bike
Nov 25, 2018
146
24
North Carolina
Have you considered taking the crank out of the bike, and perhaps going to a machine shop and having it rethreaded? I had a screw socket on a 1940s electric fan done like that once; it had stripped out. It might cost a bit though, just depends on the machine shop. That might be the easiest option, since it could be a little harder finding just the right crank, plus then, you can still say your bike has the original cranks, and not replacements. The downside is the cost; perhaps between $50 & $100 to have something like that done I would guess. It might also be worth checking an older radiator shop, as places like that may have many of the same capabilities as a machine shop, but a lower prices.
 
Last edited:

GUSMC

'Lil Knee Scuffer
Apr 29, 2020
23
Glasgow, Scotland
There are only 2 common kinds of those one piece cranks: 1) Schwinn and 2) everything else.

If you put a Schwinn crank in a non-Schwinn (or vice versa), you must change all the parts (cones, cups, bearings, hardware, etc.) but it does fit in the frame. The chainring fits either kind and the so do the pedals.
Ok great thanks - well that's good to know. Makes it a bit easier!
 

GUSMC

'Lil Knee Scuffer
Apr 29, 2020
23
Glasgow, Scotland
Have you considered taking the crank out of the bike, and perhaps going to a machine shop and having it rethreaded? I had a screw socket on a 1940s electric fan done like that once; it had stripped out. It might cost a bit though, just depends on the machine shop. That might be the easiest option, since it could be a little harder finding just the right crank, plus then, you can still say your bike has the original cranks, and not replacements. The downside is the cost; perhaps between $50 & $100 to have something like that done I would guess. It might also be worth checking an older radiator shop, as places like that may have many of the same capabilities as a machine shop, but a lower prices.
I have. I was even considering enlarging to a 9/16" thread and then could probably find easier replacement pedals in the UK (1/2" is not at all common here)
There is a decent engineering machine shop near me on the River Clyde that I have used on occasion. And because they're used to big jobs like making steel girders for bridges or building engines, they have never charged me but ask only for a donation into their charity box, so I might try 'em on Monday. Thanks
 

The Carolina Rambler

Finally riding a big boys bike
Nov 25, 2018
146
24
North Carolina
I have. I was even considering enlarging to a 9/16" thread and then could probably find easier replacement pedals in the UK (1/2" is not at all common here)
There is a decent engineering machine shop near me on the River Clyde that I have used on occasion. And because they're used to big jobs like making steel girders for bridges or building engines, they have never charged me but ask only for a donation into their charity box, so I might try 'em on Monday. Thanks
That sounds like a good idea. When I was a child, I had a small repair similar to this that I needed done by a machine shop once, and when I went there to see how much to have it done, the rate was very reasonable. All it cost me was 2 jars of preserves, and $5 in the collection at church!, I reckon because I was a kid.
 

AndyA

Finally riding a big boys bike
Nov 24, 2017
201
72
bergen county
GUSMC:
I don't know about Scotland, but in the USA one-piece (Ashtabula) cranks are readily available. To follow up on Mr. Bloo's comment, they all fit into threadless bottom brackets with a diameter of 51.3 mm (healthy 2").
Have fun!
1239733
 

GUSMC

'Lil Knee Scuffer
Apr 29, 2020
23
Glasgow, Scotland
GUSMC:
I don't know about Scotland, but in the USA one-piece (Ashtabula) cranks are readily available. To follow up on Mr. Bloo's comment, they all fit into threadless bottom brackets with a diameter of 51.3 mm (healthy 2").
Have fun!
1239733
Thanks for the pic and the info! In Scotland one-piece cranks are not really embedded in British bicycle history - with the effect that they are not readily available at all. (From about the age of 8 years old Ive been knocking worn out cotter pins into cranks with a hammer).I went to 5 bike shops yesterday and all told me that one-piece cranks are only found in children's bikes and very cheap adult bikes. Thanks for telling me their proper name. Now I can irritate my local bike shops even further by asking to see their range of Ashtabula cranks.
I'll find one on ebay!
 

AndyA

Finally riding a big boys bike
Nov 24, 2017
201
72
bergen county
GUSMC:
I like your style: irritation by vocabulary. The "very cheap adult bikes" angle might be worth pursuing. The cranks on cheap bikes (e.g. Huffy) usually have crummy chrome, but are serviceable. You may be able to find a used bike for parts (girls bikes are usually cheaper and in better condition).
 
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bloo

'Lil Knee Scuffer
Jul 31, 2020
14
50
Washington State
To clear up a little confusion (or maybe add to it) Ashtabula was a manufacturer, not a type of crank despite what wikipedia says. They were the best of the best and were mainly a supplier to Schwinn. They are basically unbreakable.

When I said there were 2 categories, Shcwinn and everyone else, I was referring to Chicago USA made Schwinns with (usually) Ashtabula-made cranks in them. I would suspect that newer Schwinns made by others after the factory closed would probably not have a proprietary Schwinn-threaded crank in them.

If you get a crank out of an old USA Schwinn it will be an unbreakable piece, but you will have to change your bearing set (all of it).

The trouble with the "everything else" category is that it might be every bit as good as USA Schwinn. Plenty of the stuff we see on this site is. Heck, even Ashtabula themselves made some cranks with the "everything else" threads on them during the early BMX era. On the other hand, you might wind up with something out of an 80s department store bike that is almost as soft as lead. It is so hard to tell from pictures exactly what you are getting.

Speaking of soft as lead, In about 81 I got an new trail cruiser made by one of those companies that makes department store bikes. The crank broke off at the pedal hole on the first day I had it. I put a real Ashtabula BMX crank and some Schwinn bearings in it and never looked back. I only bring this up because that pedal hole is a highly stressed area, and I don't think it would be a good idea to bore it out to 3/4".
 
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all riders

Look Ma, No Hands!
Jun 11, 2020
89
56
Austin, Tx
If you go the machine shop route, remember one pedal hole is left-hand threaded (the left side--non drive side). If they don't thread it that way, you'll be picking your pedal off the pavement every 3 minutes. I see now--the picture clearly shows it to be the drive -side--never mind
 
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