# Rear wheel "bouncing"???



## bohanan22 (Oct 21, 2009)

Background: I am new to road biking (June 2009) and recently started racing.

I have recently started to notice that when I attack/chase an attack/sprint that sometimes my rear wheel will almost "bounce" around. It happens only when I am out of the saddle but regardless of whether or not I am on the hoods or in the drops.

I am sure it is technique or positioning, but I do not know what is causing it and how to correct it. It just seems like all the power I am putting out is not being transfered to the road and can not be very efficent.

Like I said, I "assume" technique or positioning is the culprit but you know what they say about assuming! Any help and/or clarifing questions are welcome. 

Brett


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## Ventruck (Mar 9, 2009)

Somtimes, there is that tendency to turn your "un-weighting" into "pulling" - too much pulling force -, which can lift and upset the rear end of the bike. Smooth out the stroke.

Aside from that, you are out of the saddle, and so there's the possibility you're too far forward.


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## spade2you (May 12, 2009)

Ventruck said:


> Aside from that, you are out of the saddle, and so there's the possibility you're too far forward.


That would be my first guess. I've heard the rule of thumb is that if your shoulders are in front of your hands, it takes too much weight off the back wheel. Shorter axles can make this more pronounced.


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## KMan (Feb 3, 2004)

*bouncing*

what the others have said.......you are leaning forward and pulling up on the pedals actually pulling the rear of the bike off the ground a fraction causing the rear wheel to loos traction. A second thing not mentioned is it could be the bikes geometry as well. 

I had a Feld bike several years ago (coming off a Cannondale) Never had this happen while riding the Cannondale, but with the Felt, I would have this exact same thing happen quite often. While hammining up short steep hills out of the saddle I was lifting the rear wheel off the road a bit. Ended up with an Orbea and the promlem 99.9% has dissapeared. Don't know if it was the geometry of the Felt or if I had the bike set up slightly different. Could try raising your bars a cm or 2 just to test if it makes a difference.

Michael


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## sdeeer (Aug 12, 2008)

another tip is to keep your butt a bit further back or use the next easier gear.


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## woodys737 (Dec 31, 2005)

Can you rule out tire pressure?


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## bohanan22 (Oct 21, 2009)

woodys737 said:


> Can you rule out tire pressure?


I believe I can...until Saturday I would have said no. I ususlly run a higher tire pressure (145 psi), but during Saturday's race it was raining so I ran 110 psi. I still had the above mentioned problems.

Brett


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## Undecided (Apr 2, 2007)

bohanan22 said:


> I believe I can...until Saturday I would have said no. I ususlly run a higher tire pressure (145 psi)


Just curious, but why so high?

Re your original question, do you know whether your cadence makes a difference? Does starting the all-out phase of your sprint at a relatively lower cadence make the problem more pronounced than starting at a higher cadence?


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## bohanan22 (Oct 21, 2009)

Undecided said:


> Just curious, but why so high?
> 
> Re your original question, do you know whether your cadence makes a difference? Does starting the all-out phase of your sprint at a relatively lower cadence make the problem more pronounced than starting at a higher cadence?


In regards to the tire pressure...110-115 sometimes feels like a marshmellow to me. 145 is harsh at times but solid!

As far a cadence goes, it is not an issue of too high of cadence and bouncing in the saddle. I looked back at a power file from a recent race and during the final sprint, where my tire was bouncing, my cadence was my usual 95-110.

Brett


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## Undecided (Apr 2, 2007)

bohanan22 said:


> In regards to the tire pressure...110-115 sometimes feels like a marshmellow to me. 145 is harsh at times but solid!
> 
> As far a cadence goes, it is not an issue of too high of cadence and bouncing in the saddle. I looked back at a power file from a recent race and during the final sprint, where my tire was bouncing, my cadence was my usual 95-110.
> 
> Brett


I was thinking too low a cadence, actually. If I'm caught sprinting in too big a gear, I have a tough time putting maximum torque out at the crank without pulling up, which is I think what causes the bouncing at the wheel.


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## cxwrench (Nov 9, 2004)

bohanan22 said:


> In regards to the tire pressure...110-115 sometimes feels like a marshmellow to me. 145 is harsh at times but solid!
> 
> As far a cadence goes, it is not an issue of too high of cadence and bouncing in the saddle. I looked back at a power file from a recent race and during the final sprint, where my tire was bouncing, my cadence was my usual 95-110.
> 
> Brett


push down and forward on the pedals when you're sprinting. concentrate on that, and pulling the rr tire off the road should stop.

145 is WAYYYYYY too much pressure. you're actually increasing rolling resistance and dramatically reducing traction. how much do you weigh? as an example, i'm 165 and i run 85psi rear/80 frt in my road tubeless, and 100/95 in my tubulars. on a concrete velodrome i run 130ish, at adt 170, but it's obviously perfectly smooth.


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## Kerry Irons (Feb 25, 2002)

*Rock hard tires*



bohanan22 said:


> In regards to the tire pressure...110-115 sometimes feels like a marshmellow to me. 145 is harsh at times but solid!


"Feels like" is not the same as "is." Unless you are quite heavy, 145 psi just means faster tire wear, poor traction, and discomfort. Also quite possibly higher rolling resistance if the pavement is rough because the extra-hard tire bounces backward when it hits the rough stuff instead of absorbing it. Rubber tires may feel like marshmallows compared to steel rims on the pavement, but you can appreciate that the tires are a better concept, right?


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## spade2you (May 12, 2009)

bohanan22 said:


> As far a cadence goes, it is not an issue of too high of cadence and bouncing in the saddle. I looked back at a power file from a recent race and during the final sprint, where my tire was bouncing, my cadence was my usual 95-110.


So, when you're at this high cadence it's the wheel bouncing and not you? I only ask because some riders will bounce a little when at a much higher than normal cadence.


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## dhfreak (Sep 12, 2009)

Too far forward, happens to everyone sometimes.

Mike


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## scarecrow (Oct 7, 2007)

I get the same thing and it is usually because I am to far forward on the bike while out of the saddle. I have noticed it during a race and on the next lap stayed back further when out of the saddle and that solved the problem.


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