View Full Version : Fixie conversion - big or small chainring?


crumjack
06-20-2006, 09:57 AM
My wife bought me a Nishiki 10 speed for fathers day that will become a fixie. The chainrings look ok but I'll have my LBS check them out. The crank is a 52/40. Is it better to use the 52 with a larger rear cog or go with the 40 up front? Or is this one of those things that doesn't matter?

roadfix
06-20-2006, 10:05 AM
Chances are, you'll be running a chainring on the inside of the crank spider to achieve a good chain line. The 40 should be fine. Trying to mount the 52 ring in place of the 40 might be a problem depending on how much frame clearance you have between the 52 ring the chainstay. If I were you, I'd stick with the 40 and just get rid of the 52.

eddie m
06-20-2006, 10:22 AM
Like roadfix said, clearance issues usually determine what you end up using, but there are some other cosiderations. A bigger chainring is a little more efficient, but more importantly a bigger ring puts less tension on the chain, and is therefor a little less likely to move the rear wheel out of place under hard pedaling. That's an important thing, especially if you are using a quick release wheel. I also like to use an inner ring on an outside position, or an outer ring on an inside position (which often doesn't work because of clearance issues), because when you reverse the rings, the chain is working on surfaces that do not have much wear. But the truth is all my fixed bikes have been built from parts from the bottom of my toolbox, and it doesn't matter too much as long as you get a good chainline and the right ratio.

Kram
06-20-2006, 04:17 PM
Another reason to stay with the 40; better availability of rear cogs (more variety). It's easier to find 15-18 t cogs than it is to find, say, 20+t. What model/year of Nishiki? I had one I just sold on e-bay this year. Sweet riding frame. (Tange 2 cro-mo.)

crumjack
06-20-2006, 07:19 PM
Looks like the 52 would have some issues clearing the chainstay and Kram's pont about cog availability makes sense. I know Nashbar has some larger cogs but I'm going to stick with my LBS for those.

What model/year of Nishiki?

The model is a Nishiki International. Its blue with gold lettering, fake silver at the end of the fork, 27 inch wheels. I'm guessing its an 80 or 81. The Dia-Compe brake levers are stamped 0980. The previous owner was sticker happy. I'm removing the added stickers but think I'll leave the two little Campy stickers that are on both sides of the fork. I find them amusing since its clear the only countries this bike has seen are the US and Japan. For five bucks, its an amazing bike.

I'm sure I'll have other questions along the way, both mechanical and cosmetic, so thanks in advance for your help. If someone wants to PM me how to post pics, I'll post them

jciv03
06-21-2006, 10:32 PM
Looks like the 52 would have some issues clearing the chainstay and Kram's pont about cog availability makes sense. I know Nashbar has some larger cogs but I'm going to stick with my LBS for those.



The model is a Nishiki International. Its blue with gold lettering, fake silver at the end of the fork, 27 inch wheels. I'm guessing its an 80 or 81. The Dia-Compe brake levers are stamped 0980. The previous owner was sticker happy. I'm removing the added stickers but think I'll leave the two little Campy stickers that are on both sides of the fork. I find them amusing since its clear the only countries this bike has seen are the US and Japan. For five bucks, its an amazing bike.

I'm sure I'll have other questions along the way, both mechanical and cosmetic, so thanks in advance for your help. If someone wants to PM me how to post pics, I'll post them

I have a vintage nishiki that I'm currently building up. It also came w/ a 52/40 sugino crank, so I'm assuming it's the same set up as yours. The problem with mine is that the 52 ring is attached to the crank arm, so it is not an option to take it off. The only removeable ring is the 40t ring. Is this the same issue as yours?

crumjack
06-22-2006, 06:28 AM
I have a vintage nishiki that I'm currently building up. It also came w/ a 52/40 sugino crank, so I'm assuming it's the same set up as yours. The problem with mine is that the 52 ring is attached to the crank arm, so it is not an option to take it off. The only removeable ring is the 40t ring. Is this the same issue as yours?

I haven't attempted to remove the chainrings yet but it looks like the bolts go thru both rings. The crank is a Sugino Super Maxy with blue accents painted onto the crankarms.

eddie m
06-22-2006, 06:58 AM
I have a vintage nishiki that I'm currently building up. It also came w/ a 52/40 sugino crank, so I'm assuming it's the same set up as yours. The problem with mine is that the 52 ring is attached to the crank arm, so it is not an option to take it off. The only removeable ring is the 40t ring. Is this the same issue as yours?
I've had a couple of those Sugino cranks over the years. They were used on a lot of less expensive bikes. The big ring is pressed over a flange on the arm, and the flange is peened over to hold the ring. I would watch to be sure that the ring didn't work loose on the arm if I used it for a fixed gear. If it's steel, you could braze the ring to the arm. If it's alloy, it's at least 30 years old and overdue for replacement, especially if you are going to use it on a fixed gear.

em