Will a Sunlite Threadless Bottom Bracket Work for a Raleigh Cotterless Conversion?
 

Among the (way too) many bike projects I have underway is a conversion of a Raleigh Grand Prix to pseudo-Clubman. I'm also changing a lot of the parts out for aluminium, including the entire drive train.

I said to myself "Self, get yourself a Velo Orange English threaded bottom bracket" and thought that would do the trick, but I spaced off the proprietary Raleigh threading. Oops! Back to the drawing board.

I know there are numerous ways to convert a Raleigh from cottered to cotterless and I'd gladly use one of those if I thought it would be a straightforward process. Unfortunately, the most commonly recommended ways of doing this don't seem like they'll work right now. An example of this is that Phil Wood is sold out of all of the "even close to the right length" spindles in their sealed bottom bracket. Velo Orange doesn't seem to sell their threadless bottom bracket anymore. I've pretty much hit dead ends in most of approaches I thought about trying.

In looking around for a solution to my problem, I came across the Sunlite Repair Threadless bottom bracket (https://www.modernbike.com/sunlite-t...tripped-frames) and this looks like it would work for what I have in mind. Has anyone used one of these to convert from a cottered to cotterless crank?

FYI, the drive train I'm planning is a Sturmey-Archer S-RF3 hub and a Handsome Cycles 42 tooth single-speed crankset. I'm also getting a Sturmey-Archer front hub and a buddy who owns a bike shop said he'd be happy to lace the hubs to some Sun M13-II rims that I have. I'm also planning on white fenders, a Brooks B17, using the stock Weinmann brakes with new levers and the original bars and stem. The last change I'm planning is an aluminium seat post.

I'm sincerely hoping that this is the worst of the parts-finding problems that I encounter with this project.

Here's my starting point:

https://cimg4.ibsrv.net/gimg/bikefor...7248b1e75a.jpg

What I did was get a set of aluminium Italian bb cups, turned the 36x1 off and cut 26tpi threads on them.

But you have to have a lathe (or a friend with a lathe).

How did you cut the threads? Did you have a suitable die, or was it done on the lathe? And were the cups solid aluminum, or did they have a steel race pressed into them?

Ohh, that would be such a pain to do on the lathe!! Difficult fixturing. And no second chance if you mess it up and cut too deep or the work shifts in the chuck!

I would rather save the time and buy Phil Wood rings. You don't want to spend the money on a whole Phil Wood cartridge, so you just get the rings and use a Shimano UN300. It will work. They are the same diameter.

I have used the Sunlite threadless (came with a frame with stripped threads). It kept loosening up on me. I eventually welded and retapped.

Other things you can do include using the existing cup and cone system but putting a square taper cup and cone spindle in. They normally work with the Raleigh cups. Sheldon Brown has a thing about this on his site.

I did this on a Raleigh Sports, worked out very well. Used the Raleigh cups, a 73mm Shimano JIS square-taper spindle, and 6mm grade 25 ball bearings. Went together perfectly, no fiddling involved.

Lathe, and they were aluminium cartridge-unit cups:

https://cimg5.ibsrv.net/gimg/bikefor...b7f6ea47e3.jpg

I've also had a Sunlite repair cartridge loosen up on me in a Raleigh bb shell. I drenched the threads in blue loctite and tightened it as hard as I could, and that seemed to fix the problem... haven't seen the bike in a few years though, can't guarantee it didn't loosen up again. Another unprofessional repair I've seen work on a Raleigh is to face the bottom bracket shell to 68mm and run a normal bb tap through it, then install a cartridge bottom bracket. It tightened up nicely with no sign of threads pulling out.

Thanks! I would be happy to use a Phil Wood bottom bracket, but they're sold out of all of the spindle lengths that are even close to the 118mm that I need for my crankset. The Phil cups and UN300s are both available, though, and I think I'll give it a shot with these.

I would love to try this approach, but I've had zero luck finding an appropriate spindle.

Depending on your setup, this one appears to be asymmetrical and reasonably close in overall length (122mm). It might work if (a) either side gives you an acceptable chainline, and (b) you could live with 4mm additional Q.

https://www.ebay.com/itm/325490268204

Photo of spindle alongside metric ruler is included in listing.

I did the same thing with an old UO8 Peu. It held for over a year then loosened when riding in +105°F Texas heat. At repair I cleaned it up, reinstalled with Loctite Blue and then drilled a small hole into the edge of the bottom bracket to run a small retaining screw in it. It has held for over 8 years now.

Sunlite Thread-less Bottom Bracket. Sorry no pics, its not in the stable right now.

My old 70's UO8 rescue was a real education for me. I have no problems considering the use of another Sunlite Thread-less bottom bracket again. Installing that little holding screw was not a problem. Now getting the old cups off? Well that's another knuckle busting story... Ha

Thanks very much! Well worth giving a try. Just ordered.

Thanks again!

You're welcome. Hope it works for you.