Bicycle Mechanics - Old bike BB/Crank questions

My mother (who knows a bit about wrenching--taught me to fix a flat way back when) is trying to fix my grandfather's (82 years old) old 3-speed, Phillips, vintage 1950s or 60s. He is very much attached to his current bike, doesn't want a new one, and would buy an x-mart bike if he had to buy a new one, which is something my mother and I are trying to avoid.

The crank is cottored, and either the crank or the bb spindle are worn, making the crank slip when pedaling on the downstroke. Where my mother lives, she has access to lots of old bike parts and tools from a local bike co-op. So, she was thinking of taking my father's old Phillip (which he doesn't ride since I built him a 70s roadbike converted to 3speed), removing the old crank, getting new cotter pins, and giving my grandfather's bike the new crank. Unfortunately, the bike is in florida, and I won't be going down there to take care of this myself.

Questions:

Can we rule out spindle failure? Is it definately the crank that is the problem?

Say we wanted to convert the crank to a cottored one. Are BB shell threadings the same on english three-speeds and 68mm bb newer bikes?

Do we need to worry about chainline? If we were to go with an old cottorless bb and old cottored crank (probably raided from a disassembled 10-speed), what chainline range would we need?

Could a modern cartrige BB work? I have a used one laying around, that I could pass on to her next time I visit.

If all else fails, can anyone recommend a good lbs for old bikes around Pompano Beach, Florida?

Can we rule out spindle failure? Is it definately the crank that is the problem?

it sounds like a misadjusted three-speed, loose cotter, or rare but possibly the chainring is starting to seperate from the crankarm. there's not enough description to determine which. if it's a loose cotter pin or failing crank, and she wants to overhaul/modify it, move on to the other questions.


Say we wanted to convert the crank to a cottored one. Are BB shell threadings the same on english three-speeds and 68mm bb newer bikes?

older philips nominally use the same threading as BSC, "newer" ones use whitworth which is 26 TPI vs 24 TPI.


Do we need to worry about chainline? If we were to go with an old cottorless bb and old cottored crank (probably raided from a disassembled 10-speed), what chainline range would we need?

Cotterless cups may not work, see above. better yet, see sheldon's article on Raleigh parts interchangeability.

About the same as any single speed, 40 to 42 mm. Sturmey-archer hubs allow for quite a bit of change in chainline, as there are usually two spacers and the cog is dished.


Could a modern cartrige BB work? I have a used one laying around, that I could pass on to her next time I visit.

I've forced them into bikes before, the diameter is the same and the threading is close, they don't fight to hard in. But not the best of plans, and then you've got to find a crank that'll give you a good chainline with your BB.

Thanks--its definately the crank or the spindle, you can wobble it back and forth while hoding the other crank when the bike is still. Shame that the BB threadings arent compatible.

What tools does one need to get a cottored BB out (AFTER the crank is off?) Just a wrench and a lockring tool?

Thanks--its definately the crank or the spindle, you can wobble it back and forth while hoding the other crank when the bike is still. Shame that the BB threadings arent compatible.

What tools does one need to get a cottored BB out (AFTER the crank is off?) Just a wrench and a lockring tool?

if you can hold one crankarm still and shake the other around, it's a bad cotter pin, not the BB. you'll be able to tell which, as you can see the crankarm rotating slightly around the spindle before resistance is met (most likely the left arm, just like on cotterless). you may need to shim the spindle if it's been ridden loose for a while. you'll need a 9.5 mm cotter. unless the BB is so bad it won't take a reasonable adjustment, i wouldn't even bother opening it up, just adjust it and shoot some oil through the oiler port, assuming there is one (or down the seat tube if you want to get real shade tree).

^^^You are both a gentleman and a scholar.

errah, i hope that's a good thing, i haven't associated with those terms in quite a whiles... good luck.

I've pulled cottered crank BB axles out (can't stand them!) and installed tapered square axles in their place. While I'm at it I clean/grease the bearings. This allows me to update an old frame to a newer, lighter crank that doesn't get loose or squeak, and is MUCH easier to remove when needed. I don't know about the threading differences, but I don't have to, because I use the same bearing cups.