GXP BSA BB

[PJO]

Item: Need a GXP bottom bracket for 68/73 BSA threaded shell
Location: Hobart or post
Price range/Willing to Pay: Cheaper than new
Extra Info: Turns out I don't have a spare as I thought I did and have just bought some cranks for one of my young fellas' bike.

 

[moorey]

I think I still have an off brand one that converts between 24mm and GXP. It was blue, if that matters…if I can find it.

 

[PJO]

I think I still have an off brand one that converts between 24mm and GXP. It was blue, if that matters…if I can find it.

How easy is it to convert between standard 24mm hollowtech and GXP? I'm more likely to have an old hollowtech BB. It looks like a spacer on the NDS between the 24mm bearing and 22mm crank would solve it. Anyone done that? I've seen them for sale on ebay but haven't jumped...

 

[moorey]

I

How easy is it to convert between standard 24mm hollowtech and GXP? I'm more likely to have an old hollowtech BB. It looks like a spacer on the NDS between the 24mm bearing and 22mm crank would solve it. Anyone done that? I've seen them for sale on ebay but haven't jumped...

Just a shim that slips in and out of NDS bearing.

 

[moorey]

DS bearing rough…probably why I removed it. I’d say you’re welcome to it, but from memory, it cost about the same new as post to you would be.

 

[PJO]

DS bearing rough…probably why I removed it. I’d say you’re welcome to it, but from memory, it cost about the same new as post to you would be.
View attachment 378198

And the little spacer worked fine to make it work with a GXP?
What are the dimensions (other than OD 24mm and ID 22mm)? How thick and what diameter is the lip, I might just get the old man to machine one for me.
EDIT: Also does the spacer go in from the outside or the inside. Looks to me like the NDS bearing for GXP should run against the step down in the crank axle, that would imply the spacer goes in from the inside?

 

[moorey]

Goes in from the inside…I’m pretty sure. I removed it to run shimano for a while.
I don’t have verniers, sorry. It’s the width of bearing so it sits flush from outside.
I can post you that part in an envelope for nix if you want to have a gander.

 

[moorey]

 

[PJO]

Thanks, reckon I can work it out from there, width of the bearing and looks to be about a 1mm thick lip.

 

[PJO]

...also what kind of person doesn't have vernier calipers??

 

[Tubbsy]

...also what kind of person doesn't have vernier calipers??

Curse of the trouserless

 

[moorey]

Thanks, reckon I can work it out from there, width of the bearing and looks to be about a 1mm thick lip.

Lip thickness if largely irrelevant. Good luck with it. Here if you need it.

 

[safreek]

And the little spacer worked fine to make it work with a GXP?
What are the dimensions (other than OD 24mm and ID 22mm)? How thick and what diameter is the lip, I might just get the old man to machine one for me.
EDIT: Also does the spacer go in from the outside or the inside. Looks to me like the NDS bearing for GXP should run against the step down in the crank axle, that would imply the spacer goes in from the inside?

Hey man, just did the spacer thing instead of getting the gxp bb.
Myself and a bike shop tried every way with the spacer, putting the spacer inside seemed right by the way it nestled in but when putting the cranks back on they would not go on properly.
Only way it worked properly was to push the spacer into the outside of the bb, now works perfectly. Hope that is helpful @PJO

 

[moorey]

Hey man, just did the spacer thing instead of getting the gxp bb.
Myself and a bike shop tried every way with the spacer, putting the spacer inside seemed right by the way it nestled in but when putting the cranks back on they would not go on properly.
Only way it worked properly was to push the spacer into the outside of the bb, now works perfectly. Hope that is helpful @PJO

That may have been 100%. It’s been ages since I fitted it. Running inside looks neater, and just checked, fits the crank fine, but can’t be sure. Maybe there’s different ones.

 

[safreek]

That may have been 100%. It’s been ages since I fitted it. Running inside looks neater, and just checked, fits the crank fine, but can’t be sure. Maybe there’s different ones.

Yeah, it was odd, both myself and lbs tried inside, it just looked right but didn't work. Tried it on 2 sets of cranks and same problem.
Maybe I should just buy the correct bbs

 

[moorey]

Maybe I should just buy the correct bbs

That’s not how you roll.

 

[safreek]

That’s not how you roll.

Most of the time my bikes don't either

 

[moorey]

Most of the time my bikes don't either

I see what you did there. I think I saw ZTTO GXP’s on Aliexpress cheap. They have to be as durable as SRAM ones.

 

[PJO]

Thanks guys, I'm still yet to look properly in the bike shed. Brief look the other night turned up a dead and dissected shim BB but I'm sure I had a spare. Will look again on the weekend before deciding what to do next. Pretty close to having all the parts together to start building the next bike for son 2.