Looking to save a few quid on a replacement bb for a 100mm shell. All of the 100mm shell external 24mm bb seem to be £40 upwards.
Deore bb can be had for £13 but the plastic spacer tube won't be long enough.
Do I need it? Does it space the bearings to prevent side loading when tightening the cranks, or is it just to prevent crud getting to the internal bearing seals?
I THINK it is crud prevention and I've certainly run without them before but I wouldn't want to guarantee it won't shorten the BBS life one way or another.
I've found the life span of external BBS so variable I wouldn't know whether it made much of difference anyway. Since have gone for many months, others a lot less.
Sometimes, I've taken a BB out and found that while the rest of the frame is dry, the tube has sealed some water in making sure the bearing is nice and damp.
I was in the same boat with the fatbike and just didn't bother about it. But I do generally fit them just because it still feels like the right thing.
I CADed one for a 100mm BB and got one 3D printed for £5.
I also 'think' the tube is for crud prevention only, but then i'm not sure what stops you cranking the crank bolt down and crushing/squeezing the bearings
Daffy, where did you get one printed for £5?
I had a similar concern with the fatbike, but then realised I've got an EBB in there, so no need!
Can't you just reuse the old one? (eg. I used a road bike BB cups and put the old tube that was the right size back in).
Just cut the tube in half and use a bit of plastic bottle rolled inside the two halves to extend it.
If you really want one, get 2 normal ones and cut them down then stick them back together, sorted. (I own a 3D printer, but if I felt like I needed a spacer in the BB, I wouldn't print it, I'd do this)
iMaterialise.
I too own a 3D printer and would go down the pop bottle route... If I was bothered.
Pop bottle suggestion received loud and clear 🙂
