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This thread has given me an appreciation for the cranks on my Pug.
The bottom bracket is a little sloppy (bearings?) so i was going to replace everything. I think I'll try to repair what i have and keep the cottered cranks. http://bikeforums.net/attachment.php...hmentid=281425 |
Ode to the cotter pin, shear pin and woodruff key!
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Originally Posted by Captain Blight
(Post 14901122)
I wonder if solid CF would be stiff enough to get a crankarm that slender.
I'm sure carbon fibers will want to buckle when in compression though they are phenomenal in tension. Problem is how can a slender one be designed to stay together under those loads? Makes me wonder why a carbon fiber can't be made with a, let's say, 15 mm diameter? |
Originally Posted by 3alarmer
(Post 14899855)
No, the spindles are not all the same. There are charts in Sutherland's4th and 5th editions
that list this information in a handy format, which i cannot find to cut and paste right now. ISO, French, Italian are all nominally 16mm in diameter, 15.9mm actual English is smaller.....5/8 " diameter, 15.8mm actual Sometimes you might be able to get away with a swap like this if you use the correct crank to go with the same spindle. By far the most vexing thing in swapping these is the various incompatibilities between cups and spindles, and the different (and seemingly endless) positioning of the cone shoulders and the flats, as well as the lengths and offsets. If you can find a copy of Sutherland's to look at (4th, 5th editions) online or at a bike shop, it explains a lot of this very nicely. Or you can just measure and experiment. It's unlikely the swap you have in mind will work, though anything is possible. You'd have to use your Raleigh cups if they are Raleigh threaded, and the chances of the French spindle and crank to fit it going in there properly are pretty slender. |
Originally Posted by jrecoi
(Post 14902237)
Actually, this works, since I want to put in a French crank, with the slightly larger spindle hole onto an English spindle.
But it ought to work for a little while, and if it makes you happy, feel free. |
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Actually, I think you misunderstand the force dynamics that occur at the spindle/crank interface. |
Even more generally, the tolerances between spindles and BB's and cotterpins are fussy even when they're from the same country. Try to use an Bayliss axle in Raleigh cups?
Some enterprising shop rats mechanics do surprise, crossing odd standards with filed and forced cottered shears capped with queer continental cups and it works. Too rarely. |
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When I tried to install a Stronglight cottered crank on my Legnano Gran Premio I, the Legnano spindle was just a tad too big. Though it took a while, I managed to clean it up enough to get it to work and work it does. This is how I got that old crank to fit and work like a charm on the Legnano. When I got a second Legnano GP frame, one that actually fits me, I moved the crank over and it is still working perfectly...
http://www.mytenspeeds.com/My_TenSpe..._Measure_2.jpg Here is the Legnano as it is today. I decided to not paint and just ride the bicycle. I love it! http://bikeforums.net/attachment.php...hmentid=281626 http://bikeforums.net/attachment.php...hmentid=281627 http://bikeforums.net/attachment.php...hmentid=281628 http://bikeforums.net/attachment.php...hmentid=281629 |
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Posted these cottered crank pics before but what the heck, 5-pin Magistroni "Senior"
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What's the weight penalty for a steel cottered crank vs. alloy? For example, if I went to the trouble and expense of replacing the cottered crank on a 70"s U0-8 with an 80's alloy Sugino crankset, how much weight would I save?
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Originally Posted by jrecoi
(Post 14899165)
How much clearance does the chainring give you compared to the original Raleigh cranks? I want to do something similar with my Raleigh Sports, in order to have replaceable chainrings but keep the cottered crank clearances that thus far have worked well with the chaincase.
BTW, French Durax arms were bored to fit the Raleigh spindle and 9.5 cotters. |
nothing cottered in my collection right now...which sorta makes me sad...
cottered cranks are the coolest |
I struggled mightily trying to keep cottered cranks on my bikes tight on their spindles when I was a kid....After all the smashed, mushroomed and stripped and stuck cotters I went through (yes, I was just a kid that had only hammers, flat bladed screwdrivers and a big adjustable wrenches available for tools after all....:rolleyes:), I never want to ever deal with them again since I discovered non-cottered cranks in college....
Chombi |
Contrary to popular opinion, cottered cranks are beautiful, easy to work on, and almost indestructable!
http://i254.photobucket.com/albums/h...inprocess2.jpg http://i254.photobucket.com/albums/h...Record016a.jpg http://i254.photobucket.com/albums/h...ow-1938012.jpg http://i254.photobucket.com/albums/h...M/DSCF9371.jpg |
Originally Posted by bikamper
(Post 14907782)
I'm not sure I really understand the question but I'll give it a shot. Clearances are good for the set up I have. This is a 48T TA ring and I have about a pinky amount of space between the chain ring and the chain stay. As for a chain case, dunno. This frame has a boss for one but it's never had one on my watch.
BTW, French Durax arms were bored to fit the Raleigh spindle and 9.5 cotters. |
Originally Posted by jrecoi
(Post 14909300)
I'm not sure what you mean, did the Durax arms came like that, or did you drill them out?
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This may be a dumb question, but from reading between the lines on this thread, it seems that cottered cranks were thinner because they were steel, not aluminum, is that right? Is it not possible to make elegant, slender steel cranks with a square taper/crank bolt interface to get the best of both worlds?
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Originally Posted by clubman
(Post 14898485)
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Originally Posted by RubeRad
(Post 14911364)
This may be a dumb question, but from reading between the lines on this thread, it seems that cottered cranks were thinner because they were steel, not aluminum, is that right? Is it not possible to make elegant, slender steel cranks with a square taper/crank bolt interface to get the best of both worlds?
Either way I think cottered cranks have there place. I definitely can not agree that they are the best looking but that is all personal opinion. -Aron |
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Double the vintage charm of cottered cranks! Our 1975-6 Raleigh Sprites in that beautiful metallic emerald green. M'Ladys bike still retains the "R" nut on the pin.
http://bikeforums.net/attachment.php...hmentid=281918http://bikeforums.net/attachment.php...hmentid=281919 http://bikeforums.net/attachment.php...hmentid=281920 |
Originally Posted by RubeRad
(Post 14911364)
Is it not possible to make elegant, slender steel cranks with a square taper/crank bolt interface to get the best of both worlds?
Originally Posted by Motopecane
(Post 14911426)
I have a set of square taper cranks that are solid steel but they are nothing ornamental. They just came off a lower end bike. So yes it would be possible but I don't think companies are in the market to manufacture steel square taper cranks that weight significantly more than alloy ones.
http://images.andale.com/f2/115/106/...l_crankset.jpg |
Beautiful photos.
Steel is real. |
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