Fizzaly

Are the bottom bracket cups threaded normally on both the drive side and non drive side, im having a hard time getting the drive side one out and i wanted to make sure it is indeed RH thread like the non drive side, before i go to far and just get it in there tighter.

dabac

The short answer is - NO. Here's a link I recommend:https://sheldonbrown.com/gloss_bo-z.html#bottom

Fizzaly

Yeah thats what i thought but the threads inside the bottom bracket are not continuos the middle section is not threaded so i image that they cut it from both sides and to me it would make sense to use the same tap on both sides

HillRider

That would make no difference. The same tap, if long enough, could have threaded the bottom bracket shell completely across from one side or it could have been started from each side and the threads would have been the same in either event. A right-hand thread tap will cut right-hand threads from either side.

Your bottom bracket is almost certainly "English" threaded so the drive side is Left-Hand threaded (remove the cup by turning it clockwise) and the non-drive side is conventionally right hand threaded. To do this two entirely different taps are used.

dabac

But do note that BB cups can be stuck beyond belief, quite a few people have resorted to clamping the BB cup in a vise, and then used the whole frame as leverage to twist it out.

corkscrew

+1

https://www.sheldonbrown.com/tooltips/bbcups.html - Take a note at Sheldon's Fixed Cup removal tool. It only costs a few $$'s in hardware @ Ace and is rather effective.

*waves from Boise*

surreal

Heck, yes. I used the sheldon hardware bb removal tool on a terribly stuck cup on my wife's fuji, which is as old as i am. worked beautifully.

-rob

Sixty Fiver

Your '87 Kuwahara has standard English bb threading... the drive side threads are reversed so you need to turn things clockwise to remove them and the ShelBroCo fixed cup remover works better than anything else I have ever used.

Many of those old Kuwaharas ran very wide spindles in a 68mm shell to allow for proper chain alignment and if you have a straight stay model these tend to be much better than the bent stay models, if you find some Kenji script ion the seat tube this indicates that it was one of their hand built frames.

Fizzaly

there is some sort of script on the seat tube, i did manage to get the damned cup out, in the long run i resorted to welding a nut to the cup and using an impact gun to get it out, the threads are very good shape im gonna clean em up before putting in a new BB though

Fizzaly

Wave right back fellow boisean