I have a spare cross frame and parts that I'm contemplating building up singlespeed. What are my options other than a tensioner.
TBH I'm thinking about cost, as it will only be used for winter 'rides' and I already have a crosser and winter road hack.

Samuri as you might see this what gear do you use for 700c off road?

Same as for MTB SS! If you have vertical dropours you'll need to find a magic gear or use a tensioner. Or get some work done on your frame (track ends).

I use 39:16 on 700c but I reckon I could go a bit bigger. Skinny tyres fly.

you could always go with an eccentric external BB or a eccentric hub.

i use 42:18 on my pompino – seems to be about right. I do have a 20T freewheel for a bigger day out (SDW trip) but it's never been used.

I'd recommend about 38:16. As above, skinny tyres and big wheels go quick. You can always go 14 or 18 on the back if you find it too easy/hard.

My current pompino is 44:16 which is ….challenging, offroad in the hills.

Just been pointed to an eccentric B/B for normal frames that takes HT11.

I use an On-One doofer on mine, never dropped a chain, the gearing is 34:16, it sometimes feels a bit low on the flat, but I ride some steep hills and also go out with the kids/pub so it works for me.

44:16 – blimey!!

About 60" gearing on skinny tyres feels as easy as about 45" on a fat 26" to me.

If you can't manage a magic ratio your options are:

Forward Components

Exentriker

ENO hub

These parts aren't cheap, but if you don't like them are very easily saleable. My preference is the Forward Components one (I have all 3)

The advantage of the Eccentric External BB is that your bike does not appear any different and you can whack a geared wheel in without removing the BB

The Forward Components eccentric BB solution looks really good if you don't mind spending that kind of cash. I would be happier spending less and using a tensioner.

i use 38/16 pretty decent all round. Samuri is it you with the white pomp with karate monkey forks. If so hows the ride and do you know the a to c of the old pomp forks. Thanks

I also use 42/18. Thats around the FoD as an xc bike. No moster hills here and short sharp mega steeps can be run faster than you mates will granny gear up them.
As above what frame? An old steel one with hrozontal dropouts can be run very cheaply with a a freewheel space to whatever you have dropout wise.

No it's a brand new alloy one sat doing nowt. TBH for the money those Eccentrics cost I might as well gear it up.
Trying not to spend on this, if I don't go the tensioner route I'll get some second hand Shimano bar end shifters and take it from there.

My Pomp's in the kitchen awaiting tonight's ride so I thought I'd measure that A-C dimension for Firestarter. It's 395mm.

thanks simon 😉

I raced most of the nw league cross season on 34/16…with mild success.

Yeah, the karate monkey forks are a bit long to be honest, it'll never be a nippy bike in the singletrack with those things on. Nice and relaxed though and with that gear and those forks, going down big hills is a relatively calm experience. If riding a rigid fixie down rocky trails can ever be considered calm.

i use a WI Eccentric Eric ENO hub – works a treat – 38 x 18 for local mud plugging

oldgit

I've got an old bolt up chain tensioner you can have it you want to give it a try

Let me know and I'll take it with me to Woburn on Sunday (be there about 10.30ish)