UKC

Hi there,

I have a fixed/single speed bike (pearson touche) which I commute around London on. I currently have a 18T freewheel cog. I am tired of the brompton lot passing me on the flats - should I go down to a 16T? Will that be two low for the slight hills?

C

In reply to cmb621:

What do you have on the front?

Rule #5. That is all.

(Sorry). More seriously, how are you now on the hills? If you've got something in reserve with your 18T then why not make it harder. It will focus your technique and core strength.

In reply to cmb621: Depends how strong you are, just try it. Had a look at the dropouts but can't make it out too well, are they horizontal dropouts? You might need to take a link out of the chain. When I rode one I went for faster gears one my leg strength improved a bit.

In reply to cmb621:

Stick with the 18T (I assume it's 48 on front ie 72").

16T (81") is a bit heavy for commuting and you'd spent too much time sub 90 rpm than is good for you.

Eventually you will pedal at 110rpm...

In reply to cmb621:

i guess your running it as a single rather than fixed (i had one of the original 2 touche frame sets and felt it was better as a fixed). if you do change i would go 17t rather than 16

In reply to cmb621: Cheers for the replies - I have horizontal dropouts and have a Chain Tensioner fitted - Will I need to take a link out of the chain still? I think I am just going for 17t - that is what I have on fixed. I only have it on fixed cause I can go faster, but always feel a bit envious when I am peddling like mad downhill, when I could have a little rest freewheeling it.

In reply to cmb621: If it's got a chain tensioner I'd expect it'll be fine. The ones I looked at didn't seem to but the pictures weren't great.

In reply to cmb621:

Surely you don't run the chain tensioner when you have it fixed?

You don't need it at all if you have horizontal dropouts.

In reply to DaveHK: I am lying its a track fork end... so yes I use a track chain tensioner on fixed... I know nothing about this stuff. The man in Evans cycles suggested them. The tensioner that is.

In reply to DaveHK:

I'd assume it's this type of thing we're talking about rather than the jockey wheel type thing...

http://www.wiggle.co.uk/dmr-chain-tugs-chain-tensioner/

In reply to cmb621:

Like JLS says it sounds like a chain tug rather than a tensioner.

Chain tensioners are used to take up the slack chain in a singlespeed system. They look a bit like a rear mech. They don't work well with fixed wheel.

If your hub is threaded on both sides you can play about with ratios without committing to one.

In reply to cmb621:

Track ends are the same thing as horizontal dropouts.

Welcome to the geeky world of fixed wheel riding

In reply to cmb621: just buy a 17 and 16 t and experiment, it is not like it is hard to change or really or expensive. Just do not push to big gears especially if it is for commuting as your knees are not warmed up. Ps I have never ridden a single/ fixed bike on the road. Only on the track.

In reply to DaveHK:

Not quite the same: track fork ends open to the rear, horizontal droputs open to the front.

In reply to cmb621:

if you set up your chain right you should be able have quite a flexible sprocket setup i can switch easily between a 15t an 18t (could probably fit at 14t without chain issues)

In reply to Fruitbat:

Good point.

In reply to cmb621:

I am on a single speed with 48 - 18 and live in Crystal Palace. i get up the hills but its sometimes not pretty especially if tired. Problem is i am a big guy (92kg) which does me no favours for climbing. I would say over 8% i start to get into real trouble.

I do however have a speed of about 30kph (at the cadence of 90) along the flat which means i can overtake 'most' commuters and at higher cadence i can keep up with most roady's. IE heading along brixton rd into town the only people who can beat me are the ones running the lights or pushing big gears on road bikes.

As others have mentioned, try a few different set ups, go down 1 tooth at a time and you get a better feel for how things change.

Good luck!