Raleigh Gran Prix BB Question
10-20-09 | 07:40 PM
#1
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Raleigh Gran Prix BB Question
I am working on a Gran Prix from the early 70's for a friend. I would love to ditch the heavy, steel cottered crankset in favor of an alloy one (cotterless of course!). The bb shell is 70mm and I seem tpo remember that this denotes the proprietary Raleigh threading. Can anyone tell me what the easiest/least expensive path is to convert this crankset?
10-20-09 | 08:41 PM
#3
Super Course fan
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From: Lost on the windswept plains of the Great Black Swamp
a #5 spindle should get you there.
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10-21-09 | 12:01 AM
#4
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Are the threads Whitworth , at this age ? If so, I do not think that you can replace the bb cups with a Japanese set. Anyone know for sure, for my future reference ?
10-21-09 | 05:50 AM
#5
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10-21-09 | 06:07 AM
#6
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When you have the old crankset off and the new one not yet on, weigh them both. I'm curious exactly how much weight you'll save. When I compared the steel Williams crank on my Norman to a late 90's Shimano 105, I found the weight difference to be pretty negligible.
Replacing the cups is not an option; Raleigh used a proprietary 26 tpi thread while 24 tpi is standard. You can run a 24 tpi tap through there, but it will remove a lot more material than you want. Fortunately, as OFG said, there is no need to replace the cups.
Replacing the cups is not an option; Raleigh used a proprietary 26 tpi thread while 24 tpi is standard. You can run a 24 tpi tap through there, but it will remove a lot more material than you want. Fortunately, as OFG said, there is no need to replace the cups.
10-21-09 | 10:41 AM
#7
formerly turdsandwich
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From: Charlotte, NC
Bikes: 1993 Specialized Allez Pro, 1984 Trek 520, 198? Ross Mt St Helens, 1980 Raleigh Super Gran Prix, 197? Raleigh Gran Prix SS City Banger, 2012 Lynskey ProCross Disc
^Cup replacement is an option but you'd have to buy expensive Phil cups to replace them. I just put a 5 spindle in my GP and it's working well.
10-22-09 | 10:43 AM
#8
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From: Berwyn PA
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Thanks all for the info. Where can you get a #5 spindle? If ebay, is there a specific search you would use like #5 spindle (duh) or something else?
10-22-09 | 11:52 AM
#10
aka Tom Reingold
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From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
True that steel cranks themselves are not bad or excessively heavy, but the chainrings bend too easily and need truing. Also, the cotter pins are a *****. I remember Nervar made a steel cotterless crank. Nothing wrong with that.
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Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog
“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author
Please email me rather than PM'ing me. Thanks.
