Nearly pooh'd ...
 

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[Closed] Nearly pooh'd my Castelli's; speed wobble on road bike - how to prevent...?!

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(That's preventing the speed wobble, not the mess in my Castelli shorts.)

Hit 60km on a downhill into St. Andrews a few hours ago and suddenly got vibration and then speed wobble; only time I'd felt anything like it was when I had my first (and only so far...) puncture on the road bike earlier in the year. Slowed very gradually before pulling over and was surprised to find I didn't actually have a puncture.

I wasn't fully down in the drops so is having too little weight on the front or too light a grip on the bars a possible cause..?

Thanks for any advice; this really knocked my confidence!


 
Posted : 21/07/2015 7:18 pm
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Squeeze knees against top tube can help stop wobble. Might want to also check position


 
Posted : 21/07/2015 7:23 pm
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Go faster.
weight the front.

Don't panic, or move weight back or grab the brakes.


 
Posted : 21/07/2015 7:37 pm
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Dunno but what hill? I can't think of any steep and long enough for that. Strathkinnes?


 
Posted : 21/07/2015 7:41 pm
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Check your headset.


 
Posted : 21/07/2015 7:46 pm
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Thanks, all. I think that more weight over front needed!

Dunno but what hill? I can't think of any steep and long enough for that. Strathkinnes?

B9131 from Prior Muir down into St. A's. Plenty of hills in Fife, even this end - that was the second time the Garmin got up to 60km/h today.


 
Posted : 21/07/2015 7:50 pm
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Can happen if you're tensed up too much?


 
Posted : 21/07/2015 7:51 pm
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B9131 from Prior Muir down into St. A's. Plenty of hills in Fife, even this end

I know I grew up on Lucklawhill 🙂


 
Posted : 21/07/2015 7:58 pm
 mboy
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Get in the drops!

Relax your grip.

Get some more weight over the front axle.

What bike incidentally? Had a major speed wobble at 45mph on my old Merida, my new KTM was rock steady at over 50mph coming down the same hill in the same conditions...


 
Posted : 21/07/2015 8:01 pm
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I know I grew up on Lucklawhill 🙂

You managed to escape then!

I've only been in Fife for 2.5yrs or so and took to road biking since moving; the roads out our way are pretty (in my limited roadie opinion) pretty good for it. The cyclocross bike pretty much covers anything off-road this way.


 
Posted : 21/07/2015 8:06 pm
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I rode the Etape du Dales this year and it was frightening watching some people descending and the lack of control they had, the common denominator seemed to be a small saddle to stem drop, as above, more weight on the front, or if you have check your headset, as above too....


 
Posted : 21/07/2015 8:11 pm
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What bike incidentally?

Scott CR1, mboy. I do tend to ride rather upright so maybe need to get used to riding with more weight over the front.

As scott_mcavennie2 suggested I probably started to tense as soon as it started and the issue was then exacerbated.

...the common denominator seemed to be a small saddle to stem drop

Yeah, I think I can see this now - especially in my case. Headset all good.


 
Posted : 21/07/2015 8:11 pm
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Relax more..


 
Posted : 21/07/2015 8:18 pm
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common denominator seemed to be a small saddle to stem drop

Common denominator to those fairly new to road riding too 😉


 
Posted : 21/07/2015 8:22 pm
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It can happen on anything in the right conditions but human nature tends to make it worse as you correct, over-correct, over-over correct etc. Aviators call it PIO - Pilot Induced Oscillation.

Relaxing and trying NOT to correct it often helps. Motorcyclists will usually advise that you grip the tank with your knees/thighs. Sometimes, all that's necessary is to change the aerodynamics sufficiently (e.g. hang off the back or sit up).


 
Posted : 21/07/2015 8:23 pm
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Ride a mountain bike. Problem solved


 
Posted : 21/07/2015 8:27 pm
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I had it once on a banned strava segment....but corrected it very quickly .....I was too loose on the handlebars

Get down on the drops , head down,legs in ...and hold on for dear life...lol


 
Posted : 21/07/2015 9:09 pm
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I think it does help if you relax.
I've been told the grip the top tube with your knees story before, but I've no idea if it works.

But my conclusion is that some bikes have a tendency to do it, and some don't. That may involve bike and rider combinations being responsible, whereas other riders on the same bike will be ok. I've had two bikes in the past ten years that did it to me, while I've owned and ridden loads of others that have given me no worries whatsoever.

One of the offenders was a road bike and it dented my confidence so much it was spoiling my enjoyment of all bikes, so I sold it. The other was a CX bike made up as a hybrid. I bought a 2nd hand cheap carbon alternative frame, swapped all the parts over and rode all the same descents without a hint of a problem. Lakeland Passes that were a nightmare became a joy to descend again.

No idea why.

If you continue to get a problem...SELL the thing and get something else. Or do a frame swap like me.

Don't let it rule you.


 
Posted : 21/07/2015 9:14 pm
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[quote=gofasterstripes]Check your headset.

...and your wheel bearings.


 
Posted : 21/07/2015 9:20 pm
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As others have said, relax and it goes away.


 
Posted : 21/07/2015 9:22 pm
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Get on the drops and weight the front, hold the top-tube with your knees and no 'deathgrip' on the bars - you need to stay loose on the bike like you would offroad.


 
Posted : 22/07/2015 8:44 am
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I am terrified just thinking about doing 60kmph downhill on the hoods (?)

I had a CR1 until last year (those SL frames that were going cheap a couple of years ago), never experienced anything like that myself.


 
Posted : 22/07/2015 9:00 am
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I had a road bike that wobbled when no hands around 20mph - it was a lightweight skinny steel frame though.

I would check everything is tight and free from cracks though (the increased flex from a nearly full circumference crack could easily cause this), that the tyres are fully inflated and as said make sure you relax and grip the frame with your legs a little to stop this happening (in my case I just had to avoid riding no hands around 20mph).


 
Posted : 22/07/2015 9:11 am

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