Alright I know you all told me not to, but I’m glad I did it. I have a 1975 Raleigh Grand Prix in Carmine Red, and the crank is my favorite part of the bike (and I have 2 spares). The bottom bracket was original so I decided to see what my options for replacement are. There are no brand-new replacements that fit my needs – the Brampton cups and Phillips spindle are made for each other, and replacing either without the other results in a poor fit. New cups are thicker with slightly smaller races, and replacement spindles are a mess – whether it be the wrong length or the wrong distance between races.
Thus my quest was to make a spindle that met 3 requirements:
1 – fit my crank
2 – machined to fit modern cups
3 – was sized such that it would transfer to any standard 68mm shell
Now, I had some factors in my favor. My frame was manufactured in Worksop, England (serial number starting with a W) rather than Nottingham, and thus avoids the dreaded Raleigh 26-thread-per-inch frame problems.
Sutherland’s 6th edition was also instrumental in assisting me, as it answered several questions. It confirmed the left-center-right dimensions of the spindle (for me to accurately modify), it confirmed the races were designed for each other and could not be swapped individually (cups or spindle), and most importantly, it confirmed that old English bicycles such as this one often came with undersized 66-67mm bottom brackets (nominally 68). This is very important because test-fitting a standard square-taper spindle with a 52mm center dimension (from which the races were copied) resulted in the adjustable cup sticking out too far. I was confused because it was clear that the bb had never been re-faced. So I decided to go for 51mm and have the cup stick out just a tiny bit, but still fit in a standard frame.
The resulting spindle meets all these requirements – I can use any off-the-shelf standard cups during refurbishments (I chose Action/Yamamoto/Y.M.T. cups because they seemed the nicest), and I may someday transfer the crank to a coffee-brown Raleigh Super Course, International, or some other similar-era Raleigh frame if I decide to give this one a rest.
The pin depth is something you’ll probably critique, so I’ll discuss it briefly. The original setup required “raleigh-cut” pins from bikesmithdesign.com. My plan was to re-use these dimensions, but the machinist cut the landings a tiny tiny bit deeper, resulting in the pin going deeper. This is fine, however, because the nut still threads on fine when the pins are very strongly pressed in with a proper press. I have two options – I can either keep running the original-style pins and cut the threads back (so they protrude less on both sides, which would actually be nice) or I can instead switch to standard-cut pins, which would actually make the setup even more standard and future-proof.
I think this time I won’t answer questions about cost, because you all will decry it as a waste of money. And perhaps it is. But I wanted to share it, because I’m super excited to have the original crank back on, and I just completed a nice first-summer ride from Chicagoland to Ottawa and camped for 2 nights. It works very well and rides crazy smooth. :)