I've had an Orange Evo 02 mountain bike for about three years now. The bike itself is at least six years old though. I used to take the bike to my local bikeshop for servicing and repairs when I was at university but now that I am working I decided to buy some tools and start servicing the bike myself with the hope of learling enough to eventually build my own bike. Anyways, I have stripped the bike down and taken everything off except the headset and handlebars. The bottom bracket doesn't rotate particularly freely and is quite coroded on the outside. Part of the threads on the frame where the bottom bracket goes in are also coroded, but its only the last three threads and I don't think the bottom bracket even catches these threads. So I want to replace the bottom bracket. The old one is a square tapered type. Make: Shimano Model: BB-UN40 Other numbers on the unit: 68 , BC 1.37 x 24
I would like to replace it with an Octalink bottom bracket but I think they are of larger diameter and won't fit into my frame. I have looked on the internet and a replacement for the old one only costs £12. I would like something a bit better than that. I will be upgrading to an XT drivetrain soon so an XT bottom bracket would be nice. What are my options here? If you've read this far, thanks for your patience.
So I want to replace the bottom bracket. The old one is a square tapered type. Make: Shimano Model: BB-UN40 Other numbers on the unit: 68 , BC 1.37 x 24
I would like to replace it with an Octalink bottom bracket but I think they are of larger diameter and won't fit into my frame. I have looked on the internet and a replacement for the old one only costs £12. I would like something a bit better than that. I will be upgrading to an XT drivetrain soon so an XT bottom bracket would be nice. What are my options here? If you've read this far, thanks for your patience.
Stop smoking carpet. Your BB is english thread with a 68 mm shell width.An octalink BB works perfectly in it,but has to be matched to an octalink crank.Be advised that there are 2 octalink splines patterns and they are not compatible.
Man, It's completely ridiculous how manufacturers are going to the complete merger of cranksets and bottom brackets - I want some choice in terms of the grade and composition of my set-up. Might as well just buy an Ashtabula one-piece crank. 😉
insertnamehere said:
I've had an Orange Evo 02 mountain bike for about three years now. The bike itself is at least six years old though. I used to take the bike to my local bikeshop for servicing and repairs when I was at university but now that I am working I decided to buy some tools and start servicing the bike myself with the hope of learling enough to eventually build my own bike. Anyways, I have stripped the bike down and taken everything off except the headset and handlebars. The bottom bracket doesn't rotate particularly freely and is quite coroded on the outside. Part of the threads on the frame where the bottom bracket goes in are also coroded, but its only the last three threads and I don't think the bottom bracket even catches these threads. So I want to replace the bottom bracket. The old one is a square tapered type. Make: Shimano Model: BB-UN40 Other numbers on the unit: 68 , BC 1.37 x 24
I would like to replace it with an Octalink bottom bracket but I think they are of larger diameter and won't fit into my frame. I have looked on the internet and a replacement for the old one only costs £12. I would like something a bit better than that. I will be upgrading to an XT drivetrain soon so an XT bottom bracket would be nice. What are my options here? If you've read this far, thanks for your patience.
Well, I've changed my mind and decided to buy new chainrings instead of a new chainset so I just need a direct replacement for my old bottom bracket. As I said before, I want one of slightly better quality. Something in the £20-£40 price range would be ideal. I know nothing about bottom bracket sizing and so I am asking you all for help. Any suggestions? I seem to have run into a minor problem with replacement chainrings as well. I measured my old chainrings and found them to be 104mm and 64mm BCD. After scouring the net for parts once again I found that the outer chainrings seem to come in two different types. Here are the two chainrings: TA 104 4-arm outer 18mm 42 44 46 50 TA 104 4-arm outer 23mm 42 44 46 50 I know that TA is the manufacturer and the last 4 numbers are the number of teeth on the ring, but what is the difference between the 18mm and 23mm versions? The middle and inner chainrings don't seem to have any simalar sizing scheme. Thanx for the help guys.
Why not just keep it simple, buy a Shimano Deore Crankset and matching Octalink BB? They are quite cheap and 9 speed too. 😎 Mr B has already spoken, its English thread and 68mm, that's it. Any LBS can supply those.
Why not just keep it simple, buy a Shimano Deore Crankset and matching Octalink BB? They are quite cheap and 9 speed too. 😎 Mr B has already spoken, its English thread and 68mm, that's it. Any LBS can supply those.
It's OK. I've got the bottom bracket sorted, but I still fon't know what the difference is between an 18mm and a 23mm outer chainring.
18, 23mm, I just put a ruler over a few cranksets, 2 MTB ones have a rise of 18mm from the middle chainring to the outer, and the road crankset has 23mm rise from the middle to the outer... all triples..
18, 23mm, I just put a ruler over a few cranksets, 2 MTB ones have a rise of 18mm from the middle chainring to the outer, and the road crankset has 23mm rise from the middle to the outer... all triples..
That's not how it's done.The difference is BCD,tooth count and bolt hole pattern.
