Hi,

I need help determining the width of my bottom bracket? I assume the diameter is 68mm. I tried popping the crank off with a pickle/tuning fork, like "thebikedude" demonstrates on youtube, but quickly realized it was a bad idea.

Its a 1986ish Schwinn Sprint. "Custom" crank and 10 speed "Suntour Hero" deraillers. Its near impossible to get a measurement as things are now. I'm hoping somebody has worked on this model or something similar and can help me out?

I'm going to get a crank puller online, but I'd like to order everything at once BB, crankpuller, BB wrench, tires, ect.
Will this puller work for my bike?
https://www.niagaracycle.com/categori...-arm-extractor

Here is a couple BB's I'm considering, will they work? Any recomendations?

https://www.niagaracycle.com/categori...ket-113mm-68mm
https://www.niagaracycle.com/categori...for-bracket-fd

Any other suggestions for bike specific tools I will need for this would be great, I think I need a BB wrench, but not sure which? I have $6k+ of automotive tools, but nothing bike specific.

Thanks for the help, this was my first road bike(trashday find) and really deserving of a restoration. It served me well for over a year as a daily commuter, before getting shelved for repair awhile back.

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Hopefully you have a set of vernier calipers in there, you can use that to measure the BB shell, invest in a BB puller like a Park CCP-22 https://www.parktool.com/product/cran...-cranks-ccp-22 once you have pulled the crank, you can measure the spindle length (it's more user friendly than the Niagara one you linked to, any good LBS should stock Park Tools)

Check out the Park Tools site for repair help,

For BB's https://www.parktool.com/blog/repair-...racket-service

For Cranks https://www.parktool.com/blog/repair-...e-spindle-type

Crank pullers are fairly universal, although there are exceptions (mainly some older french and italian stuff) but you should be OK with the one you linked to. As for the BB, the diameter isn't 68mm, because 68mm is about two and three-quarter inches, which is considerably bigger than that shell. The shell is probably 68mm wide. The crank appears to be a square taper crank.

The second BB you linked to is a) for a 73mm wide mountain bike BB shell and b) appears to be some sort of Octalink one, not a square taper, so it won't work, but the first one might. There are two main things to get right with square taper BB spindles, though: the length and the taper. Shimano use the Japanese Industrial Standard taper, and the other one is the ISO taper, I don't know what your crank is designed for. The two are fairly compatible with cranks designed for the other standard provided you correct for the fact that the effective spindle length is different, but it's generally a better idea to get stuff which matches.

What's wrong with the original bottom bracket? If it's wobbling, it can be adjusted, as it appears to be a cup-and-cone unit rather than a cartridge one like you're looking at replacing it with. You might want to clean it out and regrease it, though.

As a final point, the method you've seen for removing cranks is generally only used when the threads for the crank puller have stripped, but I've heard of it working reasonably well.

Thanks for replies. I linked to the 73mm by accident, corrected now. And I'll certainly check out the parktools site.
Also, I also should have said "I have access to $6k+". Bike is at my brothers with his tools, I'll ask about the vernier calipers, good suggestion.

The crank is wobbling horribly, I'm assuming it needs new bearings at the least. I started researching youtube videos and everyone recomended upgrading. This bike was a daily commuter for over a year, rain, wind and snow. An occasional shot of WD40(prob not the best thing) is all it got, so its got to be a mess in there.

The local bike shop wants $20 for a crank puller, so I'm trying to hold off until I can buy everything at once online. I was just hoping there was standard size BB/spindle taper that schwinn used, but I guess not.

I've been told by others that this is a japanese manufactured schwinn, so that would lead me to believe it uses the japanese industrial standard taper... but I don't really know, so I guess it's time to start pounding on it with the pickle fork again

"....so I guess it's time to start pounding on it with the pickle fork again"

Pounding on a bike is rarely the best approach. I'd suggest that you buy/borrow the correct tool for the job lest you damage your cranks/bottom bracket/frame. If you are unable to resist picking up a hammer, try to get some #6 (I think) Jacobs chuck wedges and use them to wedge off the cranks.

You did remove the bolts/nuts from the BB spindle before pounding away, right?

Unless you are going to replace both the crank and the bottom bracket, get the proper crank arm puller and avoid the pickle fork. Note you will also have to remove the nuts or bolts holding the crank arms in place (usually a 14 mm socket is needed) before the arms can be pulled. And yes, your crank has a JIS taper.

It's helpful to know where you are located when you are looking for assistance, but I see from another post you are in St. Louis. Why don't you just check out https://www.bworks.org/. Go there and either have them pop off your cranks (any shop or a friend with a puller could do the same) or rent some stand time at $5/hr. Once the cranks are off the lockring is easily removed with a hammer and screwdriver or large slip-joint pliers and a rag if you don't have a hook spanner. Your adjustable cup just needs a large adjustable wrench.

Once the BB bearing is disassembled you can inspect to see if it needs replacement and also measure the spindle (it's the spindle you are measuring, not the BB). Note that if you replace the BB you will also need to remove the fixed cup. DO NOT buy a fixed cup tool. Either fashion one (Google Sheldon fixed cup) or borrow one at bikeworks. Parktool.com/blog and sheldonbrown.com will tell you all you need to know about replacement compatibility and overhaul procedures, but the co-op would be best, as qualified in-person help trumps everything else.

Thanks all for the assistance!

dsbrantjr- yes, I did remove nuts from the spindle. And yes you are right, I probably shouldn't be pounding on it.

HillRider- I appreciate the confirmation on the JIS taper, thats a big help

cny-bikeman- Good suggestion on bikeworks, I didn't realize it was a co-op type operation that would allow you to wrench on bikes. I know a couple girls that volunteer with there child outreach program and I actually attended a party/benefit there a few months back. Guessing you must have ties to StL?

One word of caution - - - its kind of easy to find out you cross-threaded the fine threads in the cranks, too late.
Please dont ask how I know

If thats a loose ball BB, the puller is something you will use with some regularity.

The WD40 probably just dissolved what was left of the grease in there, and if you've got a lot of miles on it, the BB spindle will probably be pitted, even if the bearing cups are intact. I'd say fitting a cartridge BB is a repair, not an upgrade, at this point.

No, never been to Missouri, and I did not catch the hometown in your username. I found you were from St. Louis by looking at other posts. As for Bikeworks all I did was Google St. Louis bike co-op.

One trick I've used for a very long time is to turn a threaded part in the reverse direction until it drops into the lead-in for the thread. I've found that goes a long way toward preventing cross-threading.

That is a standard English thread road BB 1.37 X 24tpi, 68mm shell width. Standard crank tool will remove it. low end but servicable crank. You could also just replace the bearings and regrease the existing BB. I could probably dig around in the basement and find the spindle and measure the spindle length.

I bought a $40 barely used Raleigh at a yard sale and upgraded everything on my daughters.