WGB 

Bike frame has a 68mm BB shell. It was just powdercoated and BB has been chased and faced. Zero issues with that service.

I traded for a triple crank and it came with a used but seemingly good sealed BB. I have no experience with sealed BB's.

I inserted the BB and then threaded in the non-drive side cup with no issues. The drive side cup screws in halfway and stopped. It simple will not thread further. I sought help from two mechanics. Neither of them could get it in further. "Old school" cups have no issue threading which suggested to me that it was a defective drive side cup. I would rather give up on the BB and buy a new sealed one and install that or simply return to the old school fixed cup with greased bearings system. the mechanic thought it might be a 121 or 122mm size but I can't see ordering based on guessing.

My issue is "If I return to the old school fixed cup with greased bearings system, what size (length) axle would I need?"

And, how do I order? There seems to be a bewildering amount of choices.


The crankset is an SR Apex set with 170mm cranks. I have not yet reinstalled the crank wheels as I am in process of polishing them and the cranks.

AnkleWork

I give up.

bikemig 

I actually have one of these and found a webpage with the info on the BB length. Even more amazingly I had the right length spindle for that crank in my parts box and the right cups.

The info you need is here, https://www.bikeforums.net/classic-v...ld-thread.html

Post 6 has the technical info you are looking for.

That is an 86 bcd crank (a stronglight 99 crank). Chainrings are available from some UK vendors (I think spa cycles has them).

WGB 

I give up.

Sorry if I didn't make sense. I'll try again.

I have a bike with a 68mm bottom bracket. I wanted to install a triple crank. Triple is an SR Apex. The Apex crankset came with a used sealed BB. Unfortunately the drive side cup that came with the sealed BB shown in photos will not thread into the shell. Threads of shell have been chased and other, older style fixed cups thread in. I cannot simply use an older fixed cup with a sealed BB.

I want to get a new BB set, either a sealed unit or return to the loose bearing system I am familiar with.

Unfortunately I am unsure what size BB cartridge to order or alternatively, what size axle to use. Just asking if anyone knows what would fit.

WGB 

@bikemig - Thanks! Looking at your post now.

tomtomtom123

According to his post, the left is 32mm and right is 37.5mm, with a total spindle length of 121.5mm.

Shimano UN55 is the standard BSA JIS square tapered BB, for $12. Do you know if your cranks are JIS square tapered?

The actual lengths of UN55 are different from what they're labeled. Some are also not symmetric. Usually the left side is a little longer than the right side. But there is one or two models that were symmetric. I had measured a few a long time ago when I was replacing the BB on my old bike, but I don't have the measurements anymore.

There is this forum post where a person measured them. But it will vary depending on who is measuring and how they did it. I remember getting different measurements from what that person wrote.
https://forum.cyclinguk.org/viewtopic.php?t=105385

Since the left side is a little longer than the right side, and the old BB specs showing the right side originally longer, you might need to add 2 to 3mm of spacers under the right side BB cup.

As for why the replacement BB didn't thread all the way in, if you had already cleaned up the threads in the BB shell by running the correct die cutter through it, then either the threads are not deep enough, or the threads on the "used" BB are damaged.

WGB 

I checked Spa Cycles. No listing for any axles that are that part number or size.

May have to try the WTB thread.

WGB 

The threads on the "used" BB are damaged

That is my belief as well. I just had the frame powder coated and don't want to force the cup in. I thought that the Suntour cranks were different than all other Japanese tapers

"The taper was smaller than on most other BB axles. Other cranks would bottom out at the inside of the taper; SunTour and Campagnolo cranks would not engage fully with axles of other brands. -- John Allen"

Bill Kapaun

Looking at bikmig's thread-
Left offset =32mm
Right offset = 37.5mm

An "old school" spindle is a 3S.
Symmetrical equivalent cartridge = 127mm.

Sheldon has a chart.
Scroll down about 3 "clicks"
https://www.sheldonbrown.com/bbsize.html

bikemig 

No the axles are not available there (try eBay?); 86 bcd chainrings are available.

WGB 

@bikemig - The actual chainwheels are in great shape, just took them off to polish them.



Not sure anyone makes Suntour compatible cartridge or axles. There was a used cartridge which I think was a duplicate of the one I have for $45 on eBay but with no cups!

EDIT: it does have cups but it was $49.99 and not paying that for a used cartridge.


I'll try a WTB ad or trade and maybe get a hit. If not may have to seek a new triple.

rccardr 

I've used that SR Apex crank on multiple bikes, both as a double (with granny hardware removed) and as a triple. As a double, 116 usually works. As a triple, 122 usually works. Standard Shimano cartridge style BB in English threading will do the job just fine. They are available on eBay and Amazon for cheap.

WGB 

@rccardr - Sorry if the answer should be obvious but would this work?

https://www.ebay.com/itm/Shimano-Bot...IAAOSwvjtcljU2

or with 122 were you referring to a steel axle like these?

https://www.ebay.com/itm/Bicycle-Cot...HS_SvTkwKtq97w

WGB 

OOPS!! Just realized I was searching for SUNTOUR axle and not SR!
@tomtomtom123 - Assuming then that SR takes JIS square tapers?

JohnDThompson 

Since a standard cup threads in fine, that makes a good case for the threads on the mounting rings being the problem.

FWIW, I've found that Phil BB cartridge mounting rings fit on those SunTour cartridges.

tomtomtom123

I don't know what the standard is on the SR cranks. You could search the internet to find out, but when I looked on Google, I got people saying it was both either JIS or ISO, but it's impossible to be both at the same time.

ThermionicScott 

Just for clarity, you've tried threading in the DS cup without the NDS cup and cartridge installed? Usually the process with cartridge BBs is to install the cartridge unit and DS cup first and torque it down before even putting on the NDS cup and torquing that down. The NDS cup threads in far enough to mate with the cartridge unit and stops wherever it stops in order to hold its end in place. Thus, if you try installing the NDS side first and just keep going with it, there is the chance that it will block the DS cup from threading in all the way. Especially since your bottom bracket is designed to work with BB shells up to 70mm! (There are some cheap Shimano units that install in the opposite order, but let's ignore them for now...)

In general, I've found that aluminum cups for cartridge bottom brackets fit much tighter than old-school steel cups, so one might think it's stopping when it just needs a bit more torque. I don't think this is the root of your issue since the shop rats have also had trouble, but it's something to keep in mind.

WGB 

Thank you all!

Yes, did check google but again, not definite answer on tapers. We did try to thread in just the D side cup but never went in. I may try to torque the drive side cup , theory being that a thin aluminum cup won't damage steel threads. Local Co-op doesn't have the specific tool for these cups so might call up a local bike shop and ask how much to tighten just the cup into the frame.

I will probably have to try the advice of rccardr and buy a Shimano UN cartridge BB in 122mm and see if that works as I suspect the cup is finished

Wesley