High Speed Wobble

Andyb10

This weekend was travelling down hill on my Argon 18 Platinum (Fulcrum 1) Wheels doing just over 40mph when serious handle bar shaking set (think tank slapper in motorbike terms), which left me unable to brake and totally out of control.
Eventually bike did slow down as I reached a flatter bit of road but it was my scariest moment ever on a bike (including being knocked off)

Not sure what caused this but there were quite strong winds on Sunday so could have been cross wind but never had this before.

Anyone else experienced this or might have any ides as to cause?

piedwagtail91

no idea as to the cause, i had it happen once on a very flexy bike. pressing both knees against the top tube usually stops it.

Chris James

It's called shimmy. No-one seems to know the cause. I had it on an old 531c frame, but only on 23mm tryes! Very scary.

Overgripping makes it worse, but when you have experienced it once it tends to make you overgrip!

Grasping the top tube between your knees, or even resting one knee aginst it, definitely helps. Also try to relax as best you can. Not easy though if the bike is actually shimmying.

Andyb10

Thanks, at least I know what to call it now and will give it try (if I can unclench everything!). Am going to my LBS tomorrow anyway as I think my wheels need servicing which may not have helped.

andyp

There has been threads on this before;

http://www.bikeradar.com/forums/viewtop ... t=12570145

heavymental

Google 'shimmy' and do a search on this forum as well. You'll find alot of possible solutions that you can bear in mind when riding at speed in future. Its very scary though. Dented my confidence for a long time when I had it on my last bike.

Andyb10

Thanks for the link - thinking about it I was pretty tense on the bike - must be the combination of my age and speed I was going!!