scale

I picked up a frameset and its rough but salvageable. Ill probably throw a modern wheelset under it and ride it around in the spring. I am wondering what length of bottom bracket was used in these. I want to look for a sealed unit but want to make sure i get something close to what was in there to begin with. Chances are i will use it as a single speed at this point or at least to start. IF it fits properly then ill probably update it to geared.

Anyone know the proper bb length i should be hunting for?

abshipp 

I've used a symmetric 116mm bottom bracket in mine running a 52/39 170mm crankset with no clearance issues. I have been thinking about going to 113mm since I've got a compact crank on there now and I'd like the chainline moved in a bit. I can't remember what it came with stock, though.

Your frame came from the factory spaced at 120mm I believe, so a modern wheelset will require cold setting. No worries, I did it to mine

scale

Thanks. i assumed the rear stays were bent in on one side when i saw that it was only 120mm. I will respace it to 130. I have already started the process. Thanks for the heads up and the spindle lengths.

dedhed

Spindle length is determined by the model of crankset used, and what it requires, not the bike model or frameset

reconnaissance

Part of the equation is the crankset you plan to use. I thought I might have the original one from my super le tour but it’s not in the box of take-off parts.

scale

Yeah...good point. I guess i should figure out what im using for a crankset first.


Thanks!

Phil_gretz

What is your overall budget for the project, and how much are you willing to spend on the crankset? Do you have a color scheme thought out? I ask, because you can pick-up "new, take-off" FSA Gossamer cranksets with external bearings pretty cheaply right now. They're black, though. No need to go with a square taper older crankset with cartridge bearing. You won't save any money, unless it's already in your parts bin.

If you're using a "modern" wheelset and respacing the rear dropouts, be very careful to measure for symmetry as you go. BE VERY CAREFUL. Then make certain that your dropouts are re-aligned to be parallel to the center plane of the frameset. Again, measure and re-measure until you're convinced. Pay close attention to the rear brake bridge as it meets the seat stays for signs of fatigue or cracking, especially with that frame. Go slow. Be careful.

scale

I have a few square taper cranksets laying around..just no bb or spindle.

I think i have a FSA crankset as well...just no external bb that i can recall. I should be able to source either at the local coop cheap enough.

leftthread

I was checking this recently on a '76 that I have. I'm overhauling another, see the thread on "what color would you paint a bike?"

The OEM crank, a Japan-made "Le Tour," had a 124.5mm spindle.
Of the two spindles I have, one was labelled "3S" and the other"3SA."
Spindle is 35-52-37.

Rear dropouts are wider for me; getting 125 on one of the frames.

A starting point. The crank you end using may well require a different length spindle to get the best chainline.

leftthread

I spent this morning hiking on a local wooded cross country course and county park. In an odd bit of synchronicity, when I got back to the parking lot, the vehicle parked next to mine had a burgundy red SLT 12.2 on it.