Is this a good deal for the money?

Ah, i see.
But cogs are readily available up to 22t; both EAI and Surly cogs go up to 22t.
3:1 ratios are good gear wise, but will give you much fewer skid spots. But yeah, with a 41t chainring you've still got plenty of scope for running a spinny gear.

Oh 22t cool, and as you said 144bcd only go down to 42 tooth.

If I go for the stronglights, I'll just have to search around for a 42t chainring and something like 15 and 20 tooth cog. It's just all too much to figure out, I can't be fucked!!

Will your dropouts/track-ends and chain length accommodate such a change?

At worst I'll have to swap around the chain, which I shouldn't really do because of different amounts of wear on different chains and how they wear the cogs. I heard someone say that dropouts should be able to take something like a 3-4 tooth change in the cog. hopefully I didn't just make that up.

Ok, does anyone know any 144 bcd, (preferably) 170mm cranks, without a chainring for £50-70ish squids, similar quality to those stronglights mentioned above, by any chance. It seems the stronglights have been temporarily discontinued/out of stock according to hubjub, and ribble.

I can find 41 tooth 144 bcd chainrings for £20-25, so thats all good.

Thanks all for the help so far.

RPM, I have to use a 103mm sugino BB with my stronglights to get the 42mm line. so there.

that's because you're a freak of nature.

there's always the transmission database for as much drivetrain geekery as you can handle

you can use messengers with 107 BB if you move the chainring on the inside of the spider...

Ok, does anyone know any 144 bcd, (preferably) 170mm cranks, without a chainring for £50-70ish squids, similar quality to those stronglights mentioned above, by any chance. It seems the stronglights have been temporarily discontinued/out of stock according to hubjub, and ribble.
I can find 41 tooth 144 bcd chainrings for £20-25, so thats all good.
Thanks all for the help so far.

http://www.totalcycling.com/index.php/product/parts_accessories/cranksets_track/FC_MICHE_144.html ??

http://www.byercycles.co.uk/05R0908.html Zenith?