SS gearing

fenboy369

Hey all! I am about to sort out my old Dew Deluxe into a single speeder for commuting. Fed up with gears on it, never take it out of the big ring on the front and normally only use one or two on the back. So Single Speed it is.
Now, its a 48T on the front so will an 18 or 16 sproket on the back be best?
My trip is either 22 miles each way, (was doing that in about 1h10min average) or about 5 miles each way if I have to use the train. Ely to Cambridge so its fairly flat____________________________________________________ with only one little 'hill'.

lost_in_thought

TBH, sprockets aren't pricey, so I'd start with the 18t and go to the 16t if you find the 18 too spinny.

Saying that, 48/16 is perfectly acceptable in flat ol' London.

cjcp

If it's flat, and you're always in the big ring, I'd opt for a 50t. Alternatively, why not just use one sprocket on your existing bike?

ince

I just finished my ss with a 46t front 16t back and I have found onthe few trips I have done that this is fine on the flat. I'm even thinking of going to a 15t if I start finding it alittle to easy going.

Which gears do you use on the back? Just get what you find you use the most.

Kieran_Burns

i was thinking about this the other day and realised that for all the gears I have , I only use 3 (mainly). These are 50 21/18/16 with majority in the middle gear. It is good to have the option for others though.

vorsprung

Cambridge way is really flat
Where I live isn't
When I first got on single speed I initially had an 86" gear (42 x 13 on 28mm tyre on 700C)
This was fine except on the steeper hills
I hate to get off and walk so I geared way down to 66"
I did briefly try 73" but although the hills were still possible they were a bit taxing for a relaxing commute to work so I switched back. I used 66" for about a year.
I have recently switched to 70" and this doesn't seem any different on the hills to 66" but is pleasantly quicker on shallow slopes

For your 48 tooth chain ring on a 26" wheel, sheldon brown gear calc ( see http://www.sheldonbrown.com/gears/ ) gives the following teeth on cog vs gear inches

14 89.1
15 83.2
16 78.0
17 73.4
18 69.3

So based on my experience, if I was you ( which I'm not ) I'd use a 15 or even 14 tooth cog

fenboy369

Cheers guys and gals. I'll give it a go with an 18 and 16 kit for the rear.
The main reason is for fittness/lard removal and also the fact that I want something simple to plug into work on. I sometimes use the train, and it gets battered on there, so the simpler the better. My rear mech is just about knackered and the chain is proper stretched. Brakes are toasted and need new pads on the front (rear wont work due to new rear wheel not having 6 bolt option, only Centre Lock).
The cheapest option is SS, I'll only need a new front brake then, due to having intergrated shifters/brake levers.
I only have to brake twice on the way to work and have got used to only using the front anyway.
So I'll try 48:18/16 and get a new (smaller) sproket when my legs double in size