[4xGirl]

i have a Specialized Allez steel road bike

it came with a Shimano 2300 52/39 crankset. it has an 8spd drive-train with downtube shifters and a crap shimano rear derailleur. i want to replace the crankset because i run it 1 by 8 plus the shimano one looks like butt. the bike is all chromed out and the 2300 is a dull gray color.
since i run it with a single front ring i want to use something in between the 52 and 39. i found this (Sugino RD2 Single Speed Cranksets include a 48-tooth 3/32" aluminum chainring) and love the look/ size.

it runs a 3/32 chain so will work with my 8spd rear. what i can't figure out is if it fits my bb. the 2300 and Sugino RD2 both run on a tapered bb, the Sugino says it needs a JIS square. Is that what my current 2300 is on?
what i am wondering is do i need a new bb or can i just swap out the cranks?
my current bb is a 68mm x 113mm english thread..... you think it will except the new cranks?

thanks in advance for all help

 

[Bicyclist]

You should be able to simply swap out cranks, without changing the BB. The only reason you would have to change BB would be to dial in your chainline, as they come with different spindle lengths.

EDIT: Just looked it up, the 2300 is an Octalink splined design whereas the Sugino cranks are square taper - you will have to change out your BB and play around with different widths to get a proper chainline. However, I can't help but think that you might be better off just keeping your double, as the bike will be a lot more versatile. Plus, with a single ring, you will encounter chain drop a lot more frequently if you don't keep the front derailleur.

 

[4xGirl]

i thought it was octalink too because on some sites it says it is. however, i took a crank off and they are definitely square taper. i have a chain catcher and crossing guard on it now... so, i would be losing the crossing guard, would that cause chain drops?
i am worried about chainline however. thanks for the help

 

[Bicyclist]

You should be fine then just replacing the cranks. In terms of chainline, if they're both square taper, it shouldn't be significantly different. If it is you can play around with spindle length, but I would only do that if the new cranks sat way more outboard, or didn't clear the chainstays. In any case I doubt you'll encounter issues, especially since you have a chain catcher. Do you mean you have a cyclocross-style bash guard? That would probably make things a little more secure as well.

 

[4xGirl]

You should be fine then just replacing the cranks. In terms of chainline, if they're both square taper, it shouldn't be significantly different. If it is you can play around with spindle length, but I would only do that if the new cranks sat way more outboard, or didn't clear the chainstays. In any case I doubt you'll encounter issues, especially since you have a chain catcher. Do you mean you have a cyclocross-style bash guard? That would probably make things a little more secure as well.

yes-a cyclocross style bash guard...
this helps a lot. the cranks list for $120.00 but i can get them for $65 thus it is worth a try. if it does not work as well as the current set-up i can always go back and most likely get my money back on the single crankset.
thanks so much for the help.
the specialized is my commuter bike and i love it for that.
i ride my wilier when i don't have to leave it locked up outside..

i don't work on them myself much but have lately begun to do a little.... so, the advise has been helpful