New Redline Cranks

[curtispro]

Now I know that this is not the done thing on these old school restoration projects, but I am looking to install a set of "New School" Redling Flight Cranks to my first build, its a long way from complete (I have not sent the fram off yet for a re-chrome) but I got the sealed bottom bracket kit yesterday and offered it up to my BB, the question is do I have to trim the blue tube that goes between the bearing cups ? as its seems to long for my BB, maybe i am being a bit stupid but only ever worked on one piece cranks before.

Thanks in advance

Jon

[moley]

To gauge the size of the spacer just......

Stick the spacer tube between the bearings/cups (use your spindle to make things easier) and hold it against your bottom bracket.  How much space is there left over?

Cranks dont work well when the bearings are pressed against the spacer and crushed (when the spacer+Bearings+cups is less the the width of the bottom bracket).  At the minimum the spacer+bearings+cups should be the same width as the bottom bracket.

Profile cranks like the spacer+bearing+cups to be a couple of mm bigger than the width of the bottom bracket with the drive side cup firmly pressed against the Bottom bracket and the non drive side to be a couple of mm slack against the bottom bracket.  This is because the crank arms are tightened against the bearings and spacers and it avoids crushing because they are tightened aginst each other.

Redline cranks (I think) dont need any slack in the setup.   They have crank spindle bolts and two side bolts so that the cranks can't loosen.   

My cranks came with 2 spacers (or maybe I nicked one from another crankset).  I think the blue one is for a different size bottom bracket.   Maybe you need the spacer from other one (Mid,US, Euro, Spanish)

How much slack have you got? 

[curtispro]

Cranks and spindle not arrived yet, just trying to get my head around things, maybe when i get the other parts things will be clear, I will have to get the calipers out and measure the BB, looks to me that there is about 2-3 mm too long by offering it up. So what you are saying is that the crank arms tighten up the bearings ??

[moley]

No!!

The cranks tighten up on the sealed Bearing casing and the spacer.   If the spacer is too short then the bearing casing is shifted and skews the bearings in the sealed casing and will cause them to bind (or at least not work their best) and also will crush them against  the cups. 

Wait until you have all of your gear then see what you need.  There are plenty of 19mm spacers available for other cranks so if you need to buy a new spacer then it would be better than filing down your spacer or maybe someone here has a spare one.

If the setup is slighter bigger than you bottom bracket then its ideal.   But 3mm or larger I'm not sure about.