Single speed - talk to me

[composite]

So I have got fed up of the 2 sprockets on the cassette that I was "managing". Yesterday I snapped a chain on the way to work and today on the way home the rear mech spring went. I have been running this drive train into the ground for ages now so it doesn't owe me anything but I have decided to go single speed.

My P7 has sliding drop outs so I can go for proper single speed and not need a tensioner. I'm going to go with the superstar sprocket and spacers as per Stu's suggestion as it's cheap and I'm sure will do the job nicely.

So question about ratios. I'm going to be using this mostly as my commuter but still want the off road option.

I happen to have a new 36 tooth chain ring laying around and thought that maybe a 16 tooth rear might be about right? Then I could get a 32 chain ring and 20 rear to slap on if I know I want to go off road. Alternatively I could go dingle speed with these same ratios as chain length should be right. Added bonus of not needing new chain ring bolts either.

Roughly what sort of sprocket size difference in chain length does a sliding drop out cater for? So if for instance I wanted to swap from a 20 to 18 will I get away with not having to shorten the chain, just moving the drop out?

Hmm just thought, I have never moved the drop outs in 3.5 years of having the frame. I wonder if the bolts are going to move?

[Bearbonesnorm]

Roughly what sort of sprocket size difference in chain length does a sliding drop out cater for? So if for instance I wanted to swap from a 20 to 18 will I get away with not having to shorten the chain, just moving the drop out?

Dropout adjustment should deal with that fine.

I used to run my SS crosser 39:18 and it was okay on the road but possibly a touch spinny ... required good legs off road

[voodoo_simon]

Is it 26inch wheel? If so, my commute bike has a 44x18 on it and for mountain biking, it used to have a 32x16 and then changed to 32x18 for bike-packing.

29er currently has 32x16 but this is way too big and is getting changed to 32x20 this week

[jamiep]

Suggest the £15 SSC spacer/sprocket kit rather than the £10 one because the former has the wider sprocket.....and comes in bling colours.

On my 26" commuter I run 16X40, which gets me around Edinburgh's city centre hills fine on the road. Spinny on any downhill but that is the trade-off for getting up the hills. I would want 36T up front if I was to go on anything but easy off road.

I suggest whacking on your 36T and getting a 16T sprocket with the kit from SSC as well as a 18T from them too (again, their wide version) - is it cheaper/easier to tinker with sprockets than rings. What gears are on your bikes currently - try a ratio you think you might like and work out what that would be on your geared bike and then just go for a test run within moving your thumbs. You thumbs do remain twitchy for a good few weeks but it passes. ;-)

If tinkering further, work out ratios so you don't go smaller than 16T sprocket because 14T or less may not give enough chain wrap.

3/32 KMC chain with 5-8 speed split link. If you need a half link to get tension (you shouldn't with your dropouts) they are £1.50 from winstanley's bmx.

I'm not a beardy hippy but I love riding SS now. So long as you accept that you aren't getting anywhere fast, it is a fun way to ride - kinda like a fixie uphill because you want to maintain speed and so plan ahead, and swooping around like on a cruiser when downhill because if you pedal you'd just spin.

[Charliecres]

I run 44/16 on a 26in commute bike. It's fine apart from really steep hills where it's a bit of a grunt. Off-road I use 32/16 for 26in and 32/18 for 29in. Your numbers sound a bit spinny to me but may be OK if you're going up and down steepish hills most of the time.

[FLV]

Chain length can be found out pretty easily.

http://www.rbracing-rsr.com/chainlength.html

Given that it is possible to end up with a half link, or a wheel stuck at the max adjustment I found a brief bit of research went a long way...

What I did is find out my chainstay length, minimum and maximum 430mm-447mm for me, I then added 2mm to the min and took away from the max to allow for tolerances. (you'll have to convert to inches for the above link) This gives you your adjustment range.

Enter 0.5" for chain pitch for a bike
Enter your chosen Front
Enter your chosen Rear#1
Tickle the chain stay length figure until you get an even and round number to the 1SF in the number of links (avoids a half link)

Now substitute the sprocket for you preferred #2.
Now Tickle the chainstay length to return the chain links to the previous figure until you either pass your max or min adjustment
Do Not forget about chain stretch (so dont be too close to max adjustment on the chain stay)



If I wanted to do this on an elmariachi,
I could use a 32/19 off road (17.095" Chainstay L)
The smallest I could change my rear to with is 16 (17.455" Chainstay L)
*Theoretically a 15 would work but its too close to max for me to allow for chain stretch*
*Also theoretically, I cant use a 20 as the chainstay will be too short, in reality once the chain has stretched I probably could*




For info, I ride 32/19 in the peak.

[composite]

So I rode in this morning on my 29er in 32/14. It was spinny for most of it and out the saddle for other bits.

I guess 36/16 on my 26er is going to be very slightly less spinny, but still spinny.

I suppose the big ring on the current set up is possibly serviceable. Maybe I should try 44/20 to start. Maybe I set the bike up with 44/36 on the front and a 20 on the back and run 2 chains depending on if commuting or off roading.

This chain alright yeah?
http://www.charliethebikemonger.com/kmc ... 2-41-p.asp

[Cheeky Monkey]

Ah, the simplicity of singlespeed

[FLV]

This chain alright yeah?
http://www.charliethebikemonger.com/kmc ... 2-41-p.asp

Yup. Thats the one I use. No issues to speak of.

[composite]

If I wasn't still wanting it for off road I think it would be simple but more importantly cheap to run.

Maybe I should just go full commuter 44/20, put the skinny tyres on and have done with it.

[FLV]

Ah, the simplicity of singlespeed

You should see how complicated I can make a geared bike....

[composite]

I put the skinny tyres on and with 44/20 is was a bit spinny. Anything over 14mph was road runner legs. Just about to order a 16 or 17.

[composite]

So I have been riding it now for a few weeks and I'm digging the single speed. I have ended up running 44/17. Here's a few pics. :)

[ianfitz]

Ah, the simplicity of singlespeed

You should see how complicated I can make a geared bike....

Not a joke ;-)

[Zippy]

Ah, the simplicity of singlespeed

You should see how complicated I can make a geared bike....

Not a joke ;-)

Pah, complicated stuff is just lots of simple stuff put together.

[Ian]

Wheels look a bit small

[Ben98]

I like the dropouts, they seem like a very good way of having a bike that can easily run ss or gears?

[Teetosugars]

32:16 for me around the flat plains of Cheshire...
Just rekindled my love for the Singlespeed, as I've been riding my 97 & Fargo over the winter..

[composite]

Wheels look a bit small

Don't help that it's a 29er fork! Some serious mud clearance now though.

I like the dropouts, they seem like a very good way of having a bike that can easily run ss or gears?

It is exactly that Ben and now I can say it works very well for both.

The models previous to this one (it's a 2010) only used 2 bolts and a lot of people found problems with slippage. They eventually made a new replacement drop out that used the rack mount hole as a third bolt.