What’s the correct way of adjusting chain length if you have say 17, 18 & 20t cogs. Would you set it with the 17t cog first?

Erm, thats not singlespeed, that’s three speed surely?

If you change gears for riding in different places / conditions then you may as well have a geared bike.

Anyway, chain will need to be long enough to work with the 20 so I guess set it so wheel is as far forward as possible in the dropouts with the 20 and hope the dropouts are long enough when you run a 17?

Are you expecting to shift between them, manually or otherwise? You using a tensioner or a single speed frame?

Sorry it’s a case of first time ss on the 29er so not sure what ratio I am going to run 😀 I ran 32:17 on my 26 so it’s for trial and error.

I’m sure there’s some sort of gear inch calculator that will work it out for you. Have a look on sheldonbrowns site.

I know about all the gear inch stuff. I go for ow it feels rather than faffing with maths.

32:19 would be as close to identical as you can get

Try 32:18 first – I used to run 32:17 on my 26, but tried 32:18 when I changed to 29 (with rigid front) and have not wanted a lower gear yet…