Push

I have a 1990 Cannondale SM series frame that I want to build back into a ridable bike and have a question about BB/crankset compatibility.

1.) How do I know what will fit as far as BB's go?

2.) Can I use a Hollowtech BB/crankset in an older frame like this? (I am thinking about a Shimano LX FC-M582 Crankset if possible)

if not then what BB/crankset would work? the Cannondale Catalog says that what is in there now is a "Japanese sealed mechanism, bolt axle"

here is an image of the frame if that helps.

Bill Kapaun

You DON'T have a "sealed" mechanism!
It's just the old cup style, most likely a 68MM BB shell width.

IF you are getting a new crank, use the BB they recommend, assuming you have 135MM dropout spacing.
IF you have 126MM, it'll have to be about 4.5MM shorter.

Push

who is they? Cannondale? I want to upgrade the frame/bike a bit and would like to use that Shimano crankset if possible, the description says that it will work on a 68mm shell is there any reason that it wouldn't work? as long as the shell is in fact 68? I have that crankset/bb on another one of my bikes and I like it.

I am unsure of the spacing out back but I believe that in my researching the frame I read somewhere that it was 130mm? would that make sense?

SER71

What you should do first is remove the old crankset and bottom bracket and measure the bottom bracket shell diameter and length.

Bill Kapaun

"They" are whoever manufactures the crank.

Older MB's tended to be 126MM
Current MB's are 135MM
There are some sizes between those 2 during the "transition" to wider spacing.

Road bikes are typically 130MM.

I have no idea what a Cannondale "SM series" is.

What I was trying to get across is-
IF it's an older MB, you need to measure the drop out spacing.
New cranks assume you have 135MM spacing.
IF yours is less, you have to make allowances for the proper length BB. (basically, 1/2 the difference between the spacings)

IF it's a road bike, They assume 130MM spacing.

That;s ASSUMING you use a "road crank" for a road bike or a "mountain crank" for a MB.

Remove the rear wheel and measure inside to inside between the drop outs.
126MM is just a hair (1mm) under 5.0". (4-31/32" rounded off)
135MM is 5-5/16".
1MM = .03937"

Push

The serial number says 130mm spacing (I did not measure it myself I am going off what the serial number says) , its a 1990 SM400, and is a 22 inch frame which was confirmed through an email from Cannondale, I did ask about the bb/crank but no reply yet.

does the 130mm spacing mean that the crankset that I asked about won't work?