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Singlespeed & Fixed Gear - SS Crank Conversion Help

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cs1

01-15-11, 03:14 AM

I'm planning on doing a SS conversion this winter. The bike is a 1986 Specialized Rockhopper. It has 126mm rear spacing. I have the stock wheelset but haven't picked out a crank. Anyone have an idea on what crank/BB would work? Originally they came with a Specialized/Sugino triple with a 122mm BB. The stock crank is long gone.

This is going to be a budget build so try to be reasonable in your crank/BB choices.

Steev

01-15-11, 05:22 AM

Go get a similar bike for $20 off craigslist as a donor.

cs1

01-15-11, 12:23 PM

Go get a similar bike for $20 off craigslist as a donor.

I've been looking. Early Rockhoppers actually came equipped with Deore XT Deerhead groups. The last couple on ebay have gone for several hundred. My local, Cleveland OH, CL has really inflated prices.

I was more interested in what size BB I would need to get a decent chainline. Stock they used a 122mm. I know as a SS it wouldn't need anything that big.

Danzaxbonanza

01-15-11, 01:08 PM

Go to a co-op and see what kinds of cranks they have there. They might even have BB parts for you to get a good chainline.

Steev

01-15-11, 02:50 PM

I've been looking. Early Rockhoppers actually came equipped with Deore XT Deerhead groups. The last couple on ebay have gone for several hundred. My local, Cleveland OH, CL has really inflated prices.

I was more interested in what size BB I would need to get a decent chainline. Stock they used a 122mm. I know as a SS it wouldn't need anything that big.

A Rockhopper will have a 68mm English threaded BB shell. As for spindle length, that depends on the crankset you get. You usually get a crankset and buy a BB to match. With a donor bike, you could use the BB and spindle and have it correct. The donor doesn't have to be another Rockhopper.

relyt

01-15-11, 03:19 PM

Any crank will work as long as you buy the right size BB for it.

If you know what kind of Sugino crank was originally on the bike, you could probably find one on eBay or something.

cs1

01-15-11, 04:06 PM

The factory crank was what the vintage guys called a Specialized Flag crank. They were made by Sugino.
This isn't mine but that's what the stock crank looks like.

http://i553.photobucket.com/albums/jj396/cs1sales/FlagCrank.jpg