Hi, does anyone know what would be a suitable replacement BB for a 1991 Kona Cinder Cone? It's still running the original Suntour LTD with greasealer, but at almost 20 years old I feel it's probably going to need replacing before too long. I've kept it well greased and it seems OK at the moment, but be good to know what will fit (shimano octalink?) when the inevitable happens...
I want to keep the current Suntour XC LTD crank and Suntour Powerings if possible, mainly for cost reasons, though if you can't get BB's to fit Suntour anymore, then I may have to go Shimano for BB & crank :(
Info I'd like is what size i.e. 68/70/73???, 113/118/121 etc??? Looked at a shimano BB on CRC and the description was somewhat confusing:
• V2 MTB compatible
• E-type no
• Chain Line 47.5 & 50mm
• Spindle 22.2 chrome-moly steel/hollow type adapter aluminium
What the hell does that lot mean????
Starting with the last part, most of those details refer to aspects of Shimano's Octalink spline interface. The axle is 22.2mm in diameter, steel, hollow, and uses the V2 spline pattern - the second variant of Octalink. ''E type" refers to a specific type of front derailleur that attaches to a mounting plate clamped by the fixed flange of the drive-side bottom bracket cup (and "no" means that this unit isn't designed with that attachment in mind). "Chain Line" refers to the distance between the central plane of the bike frame, and the plane of the middle chainring - i.e. a measure of how far the drive train sits from the centre of the bike.
The late, great Sheldon Brown has better, fuller explanations of most of those terms:
When your Suntour bottom bracket gives up the ghost, you should be able to replace it with a similar sqare taper unit from another manufacturer - a Shimano UN72 for example. You may even find a New-old-stock (NOS - i.e. old but unused) Suntour model on eBay or via the classified section here.
The shell width of your frame should be 68mm (you can measure this easily with a ruler) and the spindle length will probably be around 122mm. To be certain, you need to take the cranks off and measure the spindle with a caliper - but perhaps somebody else knows for sure. I don't.
Calmes dans le demi-jour
Que les branches hautes font,
Pénétrons bien notre amour
De ce silence profond.