BB Lengths.

How do I work out what BB length I need?

The logical part of me says that I should do the following
Remove cranks,
Measure the length of current BB,
Work out the difference in chainline from my old Surly & EAI to the new Goldtec & EAI hub combination.
Order the appropriate BB.

Unfortunately the fool in me has ordered a different set of cranks (Sugino 75s) which run on an ISO taper. My old cranks were dura-ace and ran on JIS.

I've worked out the finer details.
1/8 EAI cog on Goldtec hub gives 46.23 chainline

I'm going to be ordering a Phil BB so it's adjustable to an extent but I'd still like to get the correct length if possible just so the cranks aren't offset.

Dog's tells me it should be a 111mm which would equate to a 110.5 "campagnolo" according to the Phil site.
Is he wrong? Am I just thinking too much? Should I sell my bike and buy a space hopper? Help!

I have only bought two cranks brand new (both road) but both of them came with documentation telling me that x length b.b gave me a y chainline so I just used that as my reference point (remembering that your b.b is symmetric so double the difference is needed if you get me). So try waiting and see if the cranks come with any documentation.

Alternatively Mr Brown says that an iso crank on a jis b.b will run 4.5 mm further out (from memory google jis / iso inter-changeability to check) so wait unlit your new cranks come put your iso cranks on your jis b.b measure the chainline and use the 4.5 mm and your current crank length to work out what you want.

That my only ideas.

P.S Buy a spacehopper too.

see the JIS royce ones at 107mm will work as well ;)

dogsballs see the JIS royce ones at 107mm will work as well ;)

I'm not buying your Royce BB. You'll have to hawk it to someone else :]

Object [quote]dogsballs see the JIS royce ones at 107mm will work as well ;)

I'm not buying your Royce BB. You'll have to hawk it to someone else :][/quote]sshh, it's titanium and has feelings.

You're talking the equivelent of promising my bike some expensive underwear purchased from Liberties then taking her to topshop's kiddy section!

you pedo

Shut up chris and get the ms. to buy my cranks

workin on it

Coolio.

i just clicked about the cranks ;)

emily, a 111mm is the best size for your hub/sprocket/crank combo.

Cheers Murtle.

your very welcome buddy