shapelike

This just occured to me: I've been searching around for the "perfect" ss crankset to use on my single speed cyclocross build, but I don' think anything out there will work properly.

The deal:
- IRO Rob Roy (I want to use it spaced at 130mm)
- Phil Wood low flange track hubs + bmx freewheel (single fixed)
- I want to go external bearings, hollow axle for the crankset

Anything out there that's a dedicated ss/fg crankset like this seems to be designed for either mountain use (50/52mm chainline) or has too large a bcd (I'll be running a chainring in the 30s for racing). It seems to me that I'll need to run a compact double (inner ring) if this is going to work. That doesn't bother me because hopefully even with a chain guard it'll still end up being lighter than the equivalent Raceface/Truvativ offering/etc.

... or am I high?

Seggybop

I'm going to get a Shimano Alfine crank for this purpose once I get some more $$.
shimano page
They aren't sold in America yet, so I'm having someone send me one from abroad.

shogun17

I'm using a truvativ Elita cycloscross crankset for my road fixie. Light enough, plenty stiff, looks pretty good.

fix

I don't know about the measurements, but the compact double with no FD is pretty standard for CX racers. You don't need a chain guard (if you mean bash guard), because the big ring does it for you. If you mean chain guard like the thing that keeps the chain on line hanging off the seat tube, then I don't know what to tell you.

shapelike

Ya, I mean chain guard like:
https://www.jensonusa.com/store/imgWr...ARM.jpg&type=3

Not like:
https://us.st11.yimg.com/us.st.yimg.c...ld_1934_112429

Aeroplane

I don't understand why your chainring is so small, can't you just put on a bigger freewheel to lower your gearing?

Unless it's a clearance thing. Then I'd say go with the compact double crankset.

shapelike

It's a clearance thing and to a lesser extent an "easy availability until I can get a cheap W.I. freewheel" thing.

dutret

If you don't have gears on the back you probably don't really need the chainguard to keep the chain on. If the bike is going to be a commuter too they are nice for keeping pants clean though.

Are you trying to do double chainguards? What frame can't fit a 39 on the inside of a normal double?

jfmckenna

I think you are high

You won't need a chainguard (like a typical single ring cross set up if that is what you are talking about) if you are able to get your chain tension right. You do have track ends or eno type hub right?

shapelike

Don't worry about the chainguard, it's essentially just to keep things looking clean. I'd love to be able to run the ring on the outside of the spider but I have a personal hatred for rings on the inside.

The bike's going to be used for everything from commuting to training to serving as a single speed class/pit bike for racing cx this fall.

jfmckenna

If the ring on the inside bothers you then you may be able to get a shorter BB spindle and mount it on the outside. It worked for me.

legalize_it

get a SS MTB hub, it will give you the chainline you want to use an ext BB crankset, and also give you wider spaced flanges thus a stronger rear wheel.

dutret

..

shapelike

jfmckenna, I'd like to do this w/out going square taper.

legalize_it, I'd like to go w/ the Phil track hubs because I can get them single fixed, unlike their mtb hubs. With an axle swap I can move this wheelset over to whatever silly fg bike I build up a year from now if I like.

Dutret, clearance as in going over things on xc trails, not chainstay.

Oh well, looks like I'm after a double.

Seggybop

shapelike, what's wrong with the alfine crank? it seems to meet all the requirements from your OP.

Aeroplane

130 BCD.