Acceleration on fixed wheel

lost_in_thought

So, hello there folk!

Firstly, I got taken out the other day on High Street Kensington by the unruly scootering child of a woman who had obviouusly not bothered with the green cross code, if the very kind cyclist who helped me to the pavement and called the ambulance is reading, thank-you!

Anyway, not back on the bike just yet due to rather a lot of cracks in the old ribcage, but wandering idly through the forum and thought I'd ask you all a question:

How do you accelerate quickly on your fixed wheel bikes? I love mine, great for fitness etc. and pretty much unhurt in the collision mentioned above, but it sure takes me a while to get going. I puch like blazes, but do wonder if I'm doing something wrong?

Any tips?

andyp

What gear are you running?

I ride a 48x18 gear, giving about 70 inches on a 700x25c tyre, around London and have no trouble accelerating on that.

ride_whenever

How stiff is your front end? Because I find (albeit on my SS, can't afford a fixie yet as well) that with a longer stem and weight off the saddle i can pin it pretty fast. Do you have drops or bullhorns? Maybe a bit of extra length so you can bring more upper body into play might help.

NorwegianBlue

Everybody is different, but...

When I first started riding single speed mountain bikes (which was long before I began to ride fixed) I started with a 38/16 gear. Yes I had to walk some gradients, but mostly I found the gear great for bowling along at speed. On a 62" gear and relatively chunky tyres (1.75" XC race tyres) acceleration isn't great, and added to the hill climbing problems I decided to try a lower gear.

People told me that single speeding was becoming an underground cult and almost everybody was running 32/16. 62" to 52" sounded like big jump, but I bolted in a 32T middle ring (single speed stuff wasn't yet widely available) and gave it a try. Acceleration and hill climbing improved markedly and better yet the morning after didn't come with aching legs. I was worried, however, that my top speed would suffer, but after a few short weeks I found I was having no trouble spinning faster to achieve similar speeds. To be perfectly honest I think my top speed was probably a little lower, but time made up on acceleration and managing to ride sections I had previously walked meant average speeds were, if anything, slightly higher.

My conversion back to road riding came with an US import Langster. I found the standard 48/16 (about 79" on 700x23c) eye popping on hills and acceleration in traffic frightenigly slow, so I converted to an 18T sprocket on the rear (giving about 70"). Having moved into the hills I find fixed a bit of a chore on downhills and have converted to a freewheel, and run about a 65" gear. I probably spin faster than is efficient on the flat, but there is precious little level road in the south pennines, and you get used to it after a while.

The moral of that long waffle is: If you want better acceleration lower your gear. You will, over time, compensate for any loss of cruising speed with a faster cadence.

As a side benefit you will feel fresher after a ride if there is much climbing to do. Consider the parallel of weight training; Lift the heaviest weight you can, you can probably do it only once and it hurts. Reduce the weight so you're still working hard, but you can manage twenty or so reps, slowly and you're exhausted at the end. This is like climbing in the highest gear you can manage. Now halve the weight. You may well find you can do forty reps in the same time as you did twenty before. This means you've done the same work, in the same time, so you have achieved the same power output, but you could carry on at the same rate for some time. So if you lower your gear and increase your cadence (within reason) and you'll feel fresher after a climb. And your speed up the hill may even be faster.

Some single speed/fixed riders brag about the big gear they turn. Others like to brag about the ridiculous cadence they can achieve on their low gear. I'm always more impressed by the latter group, mainly because I suspect they could get further up Knowle Lane then the former group, who would probably not make it round the first bend.

If you don't know Knowle Lane in Meltham Mills think yourself very lucky indeed.

Cheers,

GJ

rustychisel

seems to sum up my thinking... course, it's all in the torque of the legs. If you haven't got it you can't power off the line.

meagain

I find acceleration (well, more a slight increase in speed with my ability) quicker on fixed, even on a slight uphill as long as I'm moving just a little, I find. But these days I'm on only 60" else I can't get up the hill home (whichever direction I come from!).

I think that there must also be an age/inch direct relationship. When I was 50 I could get home on a 70. Now +10 on the former seems to demand -10 on the latter! 70/50, 80/40....90.....no, NO!

So, 30 y.o.s should be pushing out a 90".....

NorwegianBlue

If there's one thing that riding fixed, and to a lesser extent ss, conditions your legs to, it's spinning high cadences. In mountain biking circles it is assumed that single speed riders will have legs like the Pontypool front row (well like one of them;six legs would be silly) but most of the SS riders I've known have had skinny legs. I reckon it's caused spinning like a Hotpoint on the flat.

So I think as a result fixed and SS riders get less power in their legs over time and so tend to use a lower and lower gear as they get older. However they don't lose overall speed because they can spin faster.

Of course I don't have any statistics to back this up, but it sounds pretty convincing doesn't it? So that's my excuse for running 65" and I'm sticking to it

GJ

meagain

"most of the SS riders I've known have had skinny legs. I reckon it's caused spinning like a Hotpoint on the flat. "

At last! An excuse!!

BUICK

Just a thought but maybe it's down to having a heavy bike? You could spend on some light wheels maybe? I don't know what your fixed bike is - mine is just tipping 8kg and running 69". When I'm setting off from a standing start I start by standing but get up to speed in no time. If I was setting off seated I guess it would feel slower and harder to get up to battle velocity!

meagain

Heavy does not of course help - but then neither does age and 50 years of smoking!

Ste_S

lost_in_thought wrote:

So, hello there folk!

Firstly, I got taken out the other day on High Street Kensington by the unruly scootering child of a woman who had obviouusly not bothered with the green cross code, if the very kind cyclist who helped me to the pavement and called the ambulance is reading, thank-you!

Anyway, not back on the bike just yet due to rather a lot of cracks in the old ribcage, but wandering idly through the forum and thought I'd ask you all a question:

How do you accelerate quickly on your fixed wheel bikes? I love mine, great for fitness etc. and pretty much unhurt in the collision mentioned above, but it sure takes me a while to get going. I puch like blazes, but do wonder if I'm doing something wrong?

Any tips?

Here's Mr. Hoy's answer :-

lost_in_thought

Thanks all!

Well, I think the first step might be to find out what gear I am riding... and see if a lower one helps! I don't have trouble climbing hills really, but I only have a few small ones to deal with.

thanks again!