Bouncing at high cadences

Bobbing in the saddle is nothing to do with "resonant frequencies" or frame materials.

It is because of your taut buttocks. You could bounce a penny off them puppies.

What frame are you using Dammit? It's a Fuji track, isn't it?

I get this bounce now that I've got the Charge but I'd put it down the the steel frame. Old bike didn't do it but it is 501, which is a bit stiffer I think and it's HEAVY. Like MTB heavy.

I guess if you hit the resonant frequency of anything then you will get a bounce effect (take the Tacoma Narrows bridge - that famous old B&W footage of the suspension bridge wobbling and ripping itself apart). But I thought an alu frame would be stiff enough to resist that.

Bounce and flex from the saddle rails? Mine is noticeably less bouncy since I changed the saddle from a Charge Spoon to a wide Specialized Alias.

lower your saddle

Yeah, if you look at the pros on the roller races. They can spin at over 200rpm and they keep their whole upper body completely still!

I'll drop the saddle before I leave tonight, see if I can hit 200 RPM down Kennington Road with no bounce.

Knock over a few pecan danishes too...

Once you go beyond 100rpm, slowly move to pushing and pulling on the horizontals rather than diagonals or verticals. Try it, it smooths out the pedal strokes.

100 RPM is 21.7 miles per hour, I'll give that a go also.

lower your saddle

OK, I have to adjust the saddle anyway today, so I'll drop the post a little as well while I'm there.

you should be able to drop your heel at the lowest point of the crank rev.

your knee should be slightly bent when your foot is horizontal and the crank is at it's lowest point and in line with the seat tube.

God forbid BMMF sees this and we have to start talking about ankling!

Is that an anagram?

I always set the saddle height so that my leg is at full extension/dead straight with my heel on the pedal- is this not the hard and fast rule that I had supposed it to be?

For 'normal' cadences probably yes, for high speed spinning and track riding go lower. Rollapaluza set the saddles up really really low.

I always set the saddle height so that my leg is at full extension/dead straight with my heel on the pedal- is this not the hard and fast rule that I had supposed it to be?

it's more of a very basic rule of thumb actually, because your shoe/pedal type and foot length make a difference.

also, track riders* tend to have a slightly lower saddle than mtb'ers and roadies, to facilitate smooth pedaling whilst seated at high cadences.

You shouldn't ever have a "locked" out leg, this causes your hips to be pulled into the pedal stroke and rock, which in turn upsets the balance of your core which contributes to the bouncing

*I include any fixed wheel rider for this example

Leg is never locked straight when clipped in/ball of foot over pedal axle, but I'll drop the saddle and see if that makes a difference.

According to the Rabbit calculator 200 RPM is 43.4 mph, so if I can hit that down Kennington Road I should be ready for Rollapalooza.

You do also have to concentrate on core stability, relaxed but solidly placed. imagine the gut area is made of stone, or lead and it is the centre of you and the bike as you pedal. upper body and arms should be relaxed but not floppy. It also helps if your bar height and reach is set up correctly to distribute your weight and balance optimally. This is why many novices find it easier to spin whilst sitting upright, as the weight is taken from the arms/shoulders and placed over the saddle, keeping the core stable, unfortunately this become counter productive once you get into higher cadences, varying between people but maybe around 190-200RPM. This isn't to say people can't still pedal smoothly at 200RPM whilst sitting right back, but these are all considerations.

http://www.londonfgss.com/thread8907.html

relax zee kneez

The Norf Downs :)

my max has been 199rpm once on Riverhill Sevenoaks and 198 several times Ide Hill and when on Audaxes elsewhere.

It has to be a combination of feeling loose and brave enough on the day a steep straight hill with a smooth road surface and preferably one that dips out and rises again :)

I must admit I shit myself once trying to get 200rpm on Ide Hill once, I knew 40mph on 68" should do it and was hanging on thighs burning when the back wheel skipped out at 38mph on a patch of gravel on the slight right hand bend halfway down, I locked up skidding the bike straight again but couldn't go from 0rpm back to 180+ instantly and got thrown up out of the saddle and locked it up again skidding the other way.

I looked like a rodeo rider on a Bucking Bronco until I got it back under control at about 25mph, all I kept thinking was I'm in lycra this is gonna fukin hurt.

My mate Mike behind me said "did you see the skidmarks back on the road" I said "there nothing to the ones in my shorts right now"

I usually get 160-170 down Gravel Hill on my commute to work I had 180rpm yesterday morning

That made me smile. know that feeling of trying to get back in tune with your bike oh to well!

You do also have to concentrate on core stability, relaxed but solidly placed. imagine the gut area is made of stone, or lead and it is the centre of you and the bike as you pedal. upper body and arms should be relaxed but not floppy. It also helps if your bar height and reach is set up correctly to distribute your weight and balance optimally.

i'd echo this. pulling your stomach muscles in and holding your core helps make you hips feel lighter, if you rotate your hands away from the center of your bike you shoulders will drop in. then concentrate on flattening your back/stomach. i imagine my body is two seperate parts. waist down and waist up. concentrating on your core (inside your abs) and keeping your upper body in a good shape so you don't have to grip like a pompey whore allows your legs to flow that little bit more freely.

That and practice - i still ride with one leg at a time to improve my pedal stroke on each leg. i find it helps making the stoke fluid

raising your saddle is more likely to sort this out: the bouncing is probably due to space between your arse and seat

How do you measure your rpm? Do you actually count it or have a speedo device thing? The bouncing happens to me a bit. I might try all the smooth circles stuff but up to now I've just been bracing my arse into my saddle - works ok, hard on my wrists and arms though :/

Cadence sensor measures rpm. Yoga or pilates will teach you fine control over core muscles. When spinning at over 30 mph on 48/19 I need to tighten up the pelvic muscles, referred to as bandas in yoga.

How do you measure your rpm? Do you actually count it or have a speedo device thing? The bouncing happens to me a bit. I might try all the smooth circles stuff but up to now I've just been bracing my arse into my saddle - works ok, hard on my wrists and arms though :/

Can do it with a cheap coomputer to measure your MPH, then check that against that rabbit gearing/cadence chart.

better to develop a fluid, relaxed pedal stroke than ride around gripping your bike like Hippy with a cherry ripe.