[Ozzer]

What type of DH/FR cranks can I fit on a frame with an 83mm bb shell width and a rear spacing of 150mm in the back? What is the chainline (I know it's not the typical 50-51mm like on most XC frames)?

I'm trying to see what cranks I can get that would fit and have a good chainline. I know Saints is one of the obvious choice, model 805-1 (or something), but I'd like to go a bit lighter with maybe an XT w/outboard -but just not sure if the Integrated BB on the XT would fit the 83mm (and chainline)?

For those with Intense M3s with a rear 150mm spacing would know this fo sho!

 

[Wumpus]

From Sheldon Brown:

To measure rear chainline, the easiest way is to measure the distance from the inside of the rear fork end (or the outside of the axle locknut) to the middle of the sprocket. Double this, subtract it from the over-lock-nut dimension of the hub (or the frame spacing , which should be the same), then divide the result in half, and you have the rear chainline.

The rear chainline should equal the front -- I think.

 

[Ozzer]

That gave me a headache.
I'll just stick with the right size Saint crankset.. tnx!

 

[loco-gringo]

The Truvativ Howitzer BB with Holzfellers will work. I built a Haro X7 with those and a 150mm rear end yesterday.

I don't know about the chainline, but this had a double on it and it worked fine. It was an 83mm shell.

 

[Ozzer]

John, will an outboard XT type crankset work? I like for the weight factor.

 

[davep]

A 150 rear (symetrical) requires a 56 mm chainline. This can be had many ways. Saint 805s or diabolus for 83mm bb or an isis in 128 mm. There is also a howitzer set up for this chainline but I do not know the #s. The current XT crank are ONLY for a 68/73mm bb and give a 47.5 - 50 mm chainline. There have been a few roumers of an 83mm bb XT version for 07', but there has been NO official mention of it...

 

[loco-gringo]

John, will an outboard XT type crankset work? I like for the weight factor.

If you were to find the right spacer for the BB cups, the spindle would be too short.

With an 83mm shell, you are going to be stuck with heavier DH stuff.

I would be looking for ISIS stuff and planning to run Turbines or something.

I have some 5 bolt compacts I would swap if you wanted to run a DH ISIS BB and those arms. I am not running them on anything, but would want to keep a back up set of cranks.

If you want to try that route, let me know.

 

[loco-gringo]

Here is the lightest Howitzer BB, but it appears to be back ordered, most likely through QBP.

http://www.universalcycles.com/shopping/product_details.php?id=9461&category=5

 

[loco-gringo]

Here's the tech sheet for the Truvativ cranks. The BB claims to be 365 grams on Universal's site.

http://www.sram.com/_media/pdf/en/truvativ/specs/cranksets.pdf

 

[loco-gringo]

These are about 1150 - 1200 grams for the cranks, and likely includes the BB cups.

http://www.raceface.com/components/cranks/diabolus-crank.htm

 

[Ozzer]

Thanks.
I think I'm going the ISIS 83mm BB route and use my existing ISIS crnakset. XT was just cool with the finish and all..