Fuzzy's Fixed

[border-rider]

I think bounce comes from the body having to learn a new set of muscle memory.

Your upper body strength keeps you rooted in the saddle and lets you put the power down, it also lets you control your cadance.

Your legs need something to push against for power, you are also going to get backlash if you are trying to spin, if you haven't got it in the arms shoulders and chest you will bounce.

yes, that sounds very likely.

I can def. spin faster when I've got better upper body strength.  I like bullhorn bars cos I can brace myself against them well on descents.

[Zoidburg]

This is why Sir Chris has an upper body and thick neck like a judo medalist and not a cyclist.

[teethgrinder]

TG will just have to ride a bit more on fixed to attain your level of souplesse.

I'm pretty supple. I do use a pretty big gear which doesn't help souplesse, but when I went from an 83 to a 65 for a weekend to ride the Porkers 400 I clocked 207rpm on one descent. If I rode more on a low gear I could probably go faster.

[border-rider]

TG will just have to ride a bit more on fixed to attain your level of souplesse.

I'm pretty supple.

I thought you might be

[Ian H]

I think bounce comes from the body having to learn a new set of muscle memory.

Your upper body strength keeps you rooted in the saddle and lets you put the power down, it also lets you control your cadance.

Your legs need something to push against for power, you are also going to get backlash if you are trying to spin, if you haven't got it in the arms shoulders and chest you will bounce.

I find just teaching/reminding myself to pedal more smoothly is the biggest help to reducing bounce.

I can also still remember my first attempt at a fast unbraked descent on fixed (some 20 odd years ago). I was bouncing so much I got double-vision.

[Zoidburg]

Oh you can pedal smoothly alright but thats in your legs, you still have two big lumps of muscle and bone flying up and down and newtons law is going to try and push you skward.

Relaxed spinny legs, upper body holding all that down in place as it spins.

[Tewdric]

Oh you can pedal smoothly alright but thats in your legs, you still have two big lumps of muscle and bone flying up and down and newtons law is going to try and push you skward.

Relaxed spinny legs, upper body holding all that down in place as it spins.

I think that's my problem - I have large, heavy legs and I can't move them quickly enough to keep them spinning fast without a significant reaction from my upper body!

[MSeries]

My cadence down hill is increasing as I get more experienced and probably also helped by the gym work. Much improved core strength and upper body strength since my broken pelvis.

[teethgrinder]

[I think that's my problem - I have large, heavy legs and I can't move them quickly enough to keep them spinning fast without a significant reaction from my upper body!

Sir Hoy has pretty big legs and can spin fast.

It's core stability that stops your upper body doing the high speed funky chicken when you spin fast.

[Wendy]

I'm not sure it is that simple - why does the bounce only occur at a certain speed, and in a narrow range?

Above and below the bounce speed I feel very smooth, and the last few times I went to ~185rpm (38mph) that was the smoothest of all.  Like butter, I could look around and enjoy.  I realise quite a few people have gone much faster than this.

[Zoidburg]

Because it's outside the range of muscle memory, change your gearing or cadance and work on it.

Nothing mystical about it.

[Wendy]

It's a good theory, but it doesn't fit well under analysis.  Given my hilly commute, I'm going up and down the range of speeds, so spend at least some time at just about every rpm I normally use.  The bounce rpm is well inside that range, meaning that I cross the bounce range often, and sometimes spend fair amounts of time in it.  Secondly, if muscle memory were the issue, bounce might only occur outside the normal riding range, or at one particular speed that was almost never used.  Instead it's happening at commonly used cadences, where one would expect to have acquired plenty of muscle memory.

I suspect much the same goes for others too?

[Zoidburg]

And when the bounce happens do you try and stop it or just go through it to another cadance? I am guessing the second because it's outside your comfort zone, the body is made up of lots of different muscle groups with slow and fast twitch bundles which are going to be used more or less at certain times, there is going to be the odd overlap when your body is performing a certain action where it can't quite decide which muscle to use. This is why boxers vary their training, both speed and range of motion to make sure it all works with a certainty.

You are reading to much psuedo science into this.

[Wendy]

I've done both, sometimes hill/wind demands that I stay in the bouncy zone.  I'm quite happy to, it's not as though the bounce is violent, it's just not as smooth as I would like.  I've spent a fair amount of time trying to see what I can do to make the bounce worse, and what makes it better.  Better pedalling helps to a small degree, but only changing the cadence will make it go away completely.

p.s. you might like to read a little about muscle memory from someone who knows a lot more about it than either of us:
Muscle Memory and Skating by Erika Kennington

I was just humouring the theory earlier, it should be fairly obvious that it's not relevant to the bounce.

[Zoidburg]

And back on the ignore list you go.

Sigh.

 

[Tewdric]

[I think that's my problem - I have large, heavy legs and I can't move them quickly enough to keep them spinning fast without a significant reaction from my upper body!

Sir Hoy has pretty big legs and can spin fast.

It's core stability that stops your upper body doing the high speed funky chicken when you spin fast.

I should have very good core stability from playing regularly as a rugby forward and gym work.  I'm sure that fluid 30 mph+ technique will come with time but I've done several hundred miles on the langster now and my pub bike before that! 

I'm not that worried to be honest - it's a hoot and provides good entertainment to anyone around, and it is only on steepish downhills that I chicken out and brake.

[Ian H]

I find I bounce more when I first get back on fixed after time on gears. Which I think means my technique/style must change subtly according to which I'm riding.

[teethgrinder]

I should have very good core stability from playing regularly as a rugby forward and gym work.  I'm sure that fluid 30 mph+ technique will come with time but I've done several hundred miles on the langster now and my pub bike before that! 

I should have very strong legs because I cycle a lot and can comfortably ride an 83" fixed up a 1:10 hill. But if I run a mile or so my legs will hrta bit and they'll be stiff the next day. Maybe I have weak legs...

[MSeries]

I have strong legs because I lift weights like Chris Hoy does.

[Fixedwheelnut]

 When I first started on fixed I used to max out around 130rpm but with practise and help from my fixed riding club mates I soon gradually increased this.
 My morning commute [when I'm riding again] usually see's me around 160-180rpm down Gravel Hill on 67" gear.

 I find the bounce range starts around 145rpm to 160 rpm then smooths out until over 180 rpm when the back of the bike starts skipping around due to the centrifugal force of the weight of your legs.

 To help your self through the bouncy bits try and relax the hips not the legs and grip the bars firmly but not so tight the shoulders are rigid, this allows the flex to be absorbed by the body in a way, then try moving your feet out of the way of the rising pedal as that is the one that creates the bounce, the down stroke pedal more or less takes care of it's self.

 Putting the effort in to spin fast helps control bounce but does accelerate you down hill fast and when the muscles tire and go tight you need brakes to trim the speed.

[caveat] I am no expert if this advice fails you and you are thrown from a bucking bike at 180 rpm + it's not my fault  Good luck [caveat]

 My max is 205rpm 41mph on a 67.5" gear 23c tyres and that was not for long maxing out in the dip of a hill where you can slow down up the other side 

[teethgrinder]

  To help your self through the bouncy bits ...


 ...then try moving your feet out of the way of the rising pedal as that is the one that creates the bounce, the down stroke pedal more or less takes care of it's self.

That's good advice.
The downstroke engages your core muscles. So does the upstroke. The downstroke is very easy for both leg and core muscles whereas the upstroke is much more difficult for both legs and core. I would gues that doing one and not the other throws things off balance. I try to push and pull anyway or at least not rest my foot on the pedal on the upstroke.

If you don't do that yourself, have a go and see how little effort you need on the downstroke to do the same speed as you was before when you rested yourfot on the pedal on the upstroke. You might start to feel it in your stomach muscles.

[fuzzy]

Fakenger Fuzzy 

Oi! I know where you work.....

[fuzzy]

Welcome to the fixed fold, Fuzzy 

 

[fuzzy]

Having read through the replies in this thread and The Bounce thread, I'm starting to wonder what I have gotten myself into