Raleigh Grand Prix Conversion Issues
Join Date: Sep 2008
I posted yesterday and got some helpful advice. I am trying to get some lower gearing on my 73' Grand Prix. Where I am at now, the three options, and these work in combination are:
1. If I can find one, keep the original bottom bracket but try and find a series 7 spindle that is supposed to fit a Raleigh bottom bracket and be long enough to mount a MTB 3 ring crankset. This is supposed to be the cheapest option as I can keep the cottered cranks and don't need a new bottom bracket. Anyone know where to find series 7 spindles? They seem to be rare.
2. Alternatively, supposedly I can get a Shimano UN72 bottom bracket cartridge, which according to Sheldon Brown's site, and when combined with Phil Wood rings, will work in a Raleigh T26 threaded bracket housing, which is a nonstandard type. Does anyone know if a UN72, which I found for cheap on eBay, with "italian threading" will make a difference? The Brown site is silent on the type of threading and just implies that the UN72 will fit the Raleigh/ The UN72 has a removeable mounting ring on the right side.
3. Whether I use option one or two above, apparently I can get some more gearing by putting a 6-7 speed freewheel (which is supposed to mount on a standard hub as I would like to use the original screw on hub which is in fine shape) and screwing it on to the hub I have. I have looked at a Shimano with "alpine gearing" that supposedly works with friction shifters. I understand I may have to add spacers to maintain the right chain line but that it should work with my existing skewers and, since the frame is steel, according the Sheldon Brown site, I should be able to stretch the rear stays enough by hand to take this larger hub/freewheel assembly or, if that doesn't work, spread the frame sufficiently by cold setting.
Any comments suggestions on the above, particularly how I might come by older spindles?