Well the sows ear project is progressing very slowly and i am now at the point where i am looking to fit sprockets. Got a 12 tooth crankshaft sprocket fitted so what is the best combination gearbox and rear sprocket that people have found 

12x64

My Drayton is 12 60

Any more offers ? 

both my draytons are 12 55 rear, i guess your type of sections and riding style matter i  use second quite a bit so not to high,

13/  56/58

Hmm confusing. I ride mostly rocks and have a low second gear option fitted. Decisions decisions 

Just a question. My feeble memory seems to recollect that there used to be perceived wisdom that one sprocket should be an odd number to even out wear on the sprockets. Do people not bother with this any more or is my brain cell having a wobbly ?

My bike is fitted with Rickman hubs and I am sure they go up in jumps of 2, so if you need an even number front sprocket to get the right option changing the rear by one tooth is not an option.

Changing the front by 1 to get your odd/even affect would then be too much of a jump, so rideability has to take preference over perceived chain wear.

Mine  is 13/58 and has low 2nd gear

What chain size does everyone use ?

Good question . I was thinking 428 but some local riders use 420 .

I always try to run the smallest sprockets possible anyway. I was just wondering what was the most common used combination to use as a starting point. I tend to prefer a slightly higher ratio and to use the clutch occasionally as i find this effectively gives me a "longer" gear and reduces the need to change gear in a section. Thanks for the responses everybody