Singlespeed Build Question : chainrings..
 

I am planning to build up a single speed using an old steel frame. I plan to use the shimano Sante cranks (in sublime condition) but they come in 39t/53t combination. My cogset gives me a 16t and 18t cog (actually a freehub conversion kit). I'm thinking that 42t will be ok for this cog set.

Will i need 110mm or 130mm BCD chainrings? I am thinking 130mm at the moment.

Also if I want to only have one chainring on the crank, can I re-use the bolts that was used for double chainring configuration?


The reason for swapping is mainly because of the size (39 too small and 53 too large!) and that the ones on the Sante are actually BioPace chainrings which may not be suitable for singlespeed/fixie due to varying chain tension (I do not use a tensioner as the frame has horizontal campy dropouts).

Thanks.

Yuck, biopace....

Anyways, your answers are 130 and maybe. You can reuse the bolts if you also get chainring spacers to take up the space the missing ring leaves. Or you have to buy new shorter stack singlespeed bolts.

according to sheldon brown, biopace cranks are fine and dandy for SS AND fixed gear use. I have an old trek steel roadie with biopace which i love. i dont know what it is about that bike, but it seems that the combination of parts plus the frame itself was taylor made for me. i have ridden many bikes, but this one just clicks.

anyway, i would try and keep the biopace cranks, i like them.

Get the 42T and short stack chainring bolts. Sheldon used a Biopace ring on one of his fixed gear bikes but save it or sell it to somebody to offset the new ring.

If you have to run the chainring on the inside to get a good chainline, you can get one of the BBG bashguards. Relatively inexpensive, especially compared to the Salsa one, you can reuse the double chainring bolts and they come in different colors if you're into that.

Tried this and it wasn't to my liking. 42x16 wasn't enough top end as I ride almost 100% rural. For an urban, heavy traffic, filtering type ride though, it's probably perfect. So, I bought a 46t Rocket Ring...should've got a 48. :p They're made to accomodate 110 or 130mm bolt patterns. Went to a local hardware store and got 10 3/8" star washers for under a dollar. This was enough to take up the slack of the double chainring bolts. 2 on each unit. One needs to use some lubricant and channel locks to mount them on the chainring bolt sleeve, but they WILL fit I promise.

Like another poster said, mount your chainring on the inside of your crankset for a staighter chainline. Or one can order a Sugino 103mm bb from www.universalcycles.com for about 40.00. They've got one for 31.00 and one for 38.00. They only come in 68mm threading, though. They mount w/a Park BB-2 tool.

thanks for the help so far!

I'm thinking if I do not change the chainrings. Say retain the biopace 53t...

- can i use it with this Wippermann 1Z1 chain?
http://www.chainreactioncycles.com/M...?ModelID=11284

- will it also work with the Gusset 1-ER SS conversion kit (I am using an old freehub type wheel)
http://www.chainreactioncycles.com/M...?ModelID=17776

- should i remove the 39t and put the 53t in its place (closer to the crank) or just leave it as it is?

I'm not a quick rider on my roadie. Cadence ave between 90-100rpm achieving cruising speeds of about 30-35km/h which is ideal for me. The gusset comes with 2 cogs; 16t and 18t.......will using the 18t in conjunction with a 53t chainring be 'killing' myself? Its mostly flat roads out here (urban, sub-urban....there's no such thing as rural in Singapore!)

thanks!