Singlespeed gearing - help!

Berniethebike · Post by **Berniethebike** » 30 Jun 2007, 7:13pm

Hi all,
I'm going to change my 90s Giant Peloton to a single speed - not sure why - I just want to try it! I know this is entirely personal but I want to get some idea before I change it and get it wrong!!
I live in South Lakes/Kendal area so it's pretty hilly and wanted to get an idea of the number of inches people would recommend?
I'm thinking of somewhere in the mid 60s to early 70s interms of inches......any thoughts?

Cheers

Bernie

gaz · Post by **gaz** » 30 Jun 2007, 8:08pm

Berniethebike · Post by **Berniethebike** » 30 Jun 2007, 9:02pm

Freewheel definately.

meic · Post by **meic** » 30 Jun 2007, 9:50pm

How about trying one of your favourite rides and seeing which is the highest of your present gears that you can get around your ride on. If there is an exceptional steep bit that you would walk up instead then do so and dont count that stretch.
I personally couldnt ride with more than 30-40 inch in my area! However I appreciate part of the point of the exercise is to stretch such abilities.

DaveP · Post by **DaveP** » 1 Jul 2007, 3:41pm

Hmmm. I thought the idea of using single speed was to choose a gear low enough to spin in :lol:

Use your exisiting gears to home in on a ratio that you can get around in without straining. Your knees will thank you!

Post by Si » 1 Jul 2007, 3:53pm

It's a difficult one to advise on as the ideal gearing will vary depending upon different rider's power outputs and fitness.

I've got my road going SS set up with 63inch gear. My choice is based upon being an, at best, average climber who lives in a moderatly flat to rolling area. If it were fixed I'd probably have it a little higher so that I didn't spin out on down hills, but with the SS I can coast down so can have a slightly lower gear to get me up the hills. I reckon that I can probably stagger up the odd bit of 1 in 7 with this but wouldn't want to be on a long ride with loads of steep stuff.

My MTB SS is around 55inch - this is OK for short bits of road work as long as I don't want to get anywhere fast but would do my head in on a ride of any length.

twicewithchips · Post by **twicewithchips** » 1 Jul 2007, 4:49pm

Although the real answer seems to be 'it depends', my 2p says that mid 60s to low 70s is about right. Some of this depends on the fixed/free decision - you don't have to keep up with the freewheel going down the other side, so can get away with a lower gear. I commute on fixed 48 x 19 which seems to suit, and got to it pretty much by trial and error (South Yorkshire and the Peak Disitrict). Go for the biggest gear you can push up the steepest hill round about and that'll probably be a good start, but expect to want a bigger gear after a while.

For a free I'd go for lower than that, but suspect it would probably depend on what was in the shed at the time. If you are converting a casette hub, a Surly singulator (or equivalent) will let you run just one cog on the middle of the casette. The advantage of course being that you can work through the whole casette to find the best cog to use.

Berniethebike · Post by **Berniethebike** » 2 Jul 2007, 11:11am

Well thanks guys - this is all great stuff.
Never heard of a Surly Singulator before - sounds like a bad-tempered teenager to me!
I'll research!
Cheers
Bernie

Post by Si » 2 Jul 2007, 12:12pm

Unless they've redesigned it, I'd avoid a singulator as the spring is prone to failure. I used a Tension Seeker and found it much better.

Also, I'd be wary of trying to make up for crap chain line with a tensioner at the rear unless you fit a mech or retainer to the front too!

loiner · Post by **loiner** » 2 Jul 2007, 7:59pm

anything above 70 would be too big for me in your neck of the woods

twicewithchips · Post by **twicewithchips** » 2 Jul 2007, 8:17pm

Sorry, didn't mean a singulator at all, riding with a freewheel has addled my brains.

I thought I was talking about one of these:
One One Singlespeed Converter Kit

http://www.on-one.co.uk/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=74&MMN_position=80:80

dunno if there's a shimano 7 or campag version available elsewhere though.

Looks to me like you'll get 2mm each way to play with your chainline if you need it. If you've got vertical dropouts you might want a tensioner of some sort (note Si's comments), or a lot of luck with a magic gear (Sheldon being your man there I suspect). All kinda depends on the parts available, but human ingenuity never ceases to amaze me.

piedwagtail91 · Post by **piedwagtail91** » 2 Jul 2007, 8:42pm

i came down the lakes and though kendal on our club 200 in 24 at the weekend. i was on fixed of 47 x 20 or 63.5 and found it just about right for dunmail and the climb out of keswick on the A591,we follwed the A591 to kendal through burnside and the gear seemed just about right on the climbs. i had been using 48 x 20 which although not a lot different on paper made hills a tiny bit easier.
i think anything around this would be a good starting point.

glueman · Post by **glueman** » 3 Jul 2007, 8:52am

About 62" for a freewheel, 67" on fixed. You can gear lower with the freewheel because you won't be spinning out downhill.

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Singlespeed gearing - help!

Singlespeed gearing - help!

Single speed gearing.