Speed Wobble - Should I give up on this bike?

p.c.spencer
p.c.spencer Posts: 5
in Road general
Hello

Thanks in advance for any advice given. Last year I traded in my trusty Boardman pro carbon for a spanking new disc brake aero bike. It cost a lot of money and looks very pretty.

However, I’ve struggled to get comfortable on it in general - finding it twitchy. But more importantly on two occasions in the same conditions on the same patch of road I’ve experienced very scary high-speed wobble. This has occurred on the stock wheels and on some nice carbon ones.
I’ve never experienced this on any other bike and I’m now considering taking the hit and selling it.

I’ve heard that some fatter tyres at lower pressure might damp the effect or that it could even be a defect with the frame. I guess what I’m wondering is am I just going to be throwing good money after bad? What do you think?

Comments

  • sungod
    sungod Posts: 17,365
    wobble/shimmy is complex, if it's a frame from a reputable manufacturer i'd assume it's not inherently dodgy

    if you've encountered wobble before, you may be reacting and tensing up/trying to fight the bars, which can make things worse, human reaction time isn't fast enough

    try techniques to damp/stop the wobble, stay calm and...
    press one/both knees hard against the top tube
    unload weight from the saddle
    relax arms, don't tense up/fight the bars
    sloooooowly apply the rear brake

    my bike - faster than god's and twice as shiny
  • PMark
    PMark Posts: 160
    How is your headset? Does the handlebars feel loose at all if you try and move them side or side, or do you feel the handlebars stick at all when turning?

    I ask because I have seen people report issues with some frames that have full internal cable routing (cables go through the stem), where the headset has become loose.
  • MattFalle
    MattFalle Posts: 11,644
    initial comments as above plus reeeeeeeeeeelax - don't clamp up, shoulders relaxed, llike you're playing the piano.

    its a different geo from the B'man, so will feel different.

    no need fot fat tyres, lower pressures, all that jazz.

    does it only happen on this one patch of road?

    .
    The camera down the willy isn't anything like as bad as it sounds.
  • p.c.spencer
    p.c.spencer Posts: 5
    Thanks guys. It’s on a long straight decent that it’s happening. Around 40mph. It’s hard to steady because it’s a sloping top tube that you can’t get your legs around.

    When I’ve read up on this it seems the bike does have some suspect characteristics. Long seat post. Frame accused of poor lateral stiffness in one review. There seem to be a number of possible issues that are blamed for this though. I’ll deffo check the headset!

    It could well be that I’m getting a little nervous and introducing bad vibes to the frame! That being said I’ve matched those speeds on a steel frame without the same issues.

    I guess I should make a concerted effort to make friends with it in the first instance!
  • DeVlaeminck
    DeVlaeminck Posts: 9,104
    If there is no fault as such - like the headset - it's really a case of how confident you are that you can manage it.

    I wouldn't say don't sell it, the last thing you want at 40mph is to be worrying about speed wobble. At the same time there probably are things you can do to stop it happening and people have listed the usual suspects above.

    The only bike I owned it used to happen on was a flexy 24" 531c framed bike built with a short wheelbase as was the fashion for crit racing at the time - but I was also new to riding (as a sport) so there was probably rider error in there too - being too tense etc.

    [Castle Donington Ladies FC - going up in '22]
  • MattFalle
    MattFalle Posts: 11,644
    What bike is it dude?
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • p.c.spencer
    p.c.spencer Posts: 5
    3T Strada. I think I may have bought a Ferrari when what I need is a Volvo 😅
  • rwoofer
    rwoofer Posts: 222
    I had a BMC that had speed wobble. Changed absolutely everything on the bike, but couldn't get rid of it. Subsequently bought another 5 road bikes none of which showed any hint of speed wobble, so sold the BMC in the end.
  • MattFalle
    MattFalle Posts: 11,644
    p.c.spencer said:

    3T Strada. I think I may have bought a Ferrari when what I need is a Volvo 😅

    and all ok everywhere else?

    .
    The camera down the willy isn't anything like as bad as it sounds.
  • MattFalle
    MattFalle Posts: 11,644
    Friggin' cool bike by the way. any pics?
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • p.c.spencer
    p.c.spencer Posts: 5
    No pics I’m afraid. Maybe that’s the reason for the wobble. It’s pissed off that I’ve not paid it enough attention…
  • MattFalle
    MattFalle Posts: 11,644
    p.c.spencer said:

    No pics I’m afraid. Maybe that’s the reason for the wobble. It’s pissed off that I’ve not paid it enough attention…

    ah - i seecehere you comin' from.

    my s3 was the same - i just hadn't bonded with it so didn't care about it.

    went away on it a couple of weeks go, bonded, its now the bee's knees.
    .
    The camera down the willy isn't anything like as bad as it sounds.
  • trevor.hall12
    trevor.hall12 Posts: 487
    Finding it twitchy often comes from the stem length ,would it be possible to go longer up front .
    I had a derosa that was crazy to steer when I got it with an 80 mm stem ,lengthened it to 100 and it cured the problem .
    As said above it does seem like yiu are anticipating the bad part and possibly getting uptight on approach .
  • photonic69
    photonic69 Posts: 2,820
    Get a similar sized riding buddy to try it on the same stretch for you? Might eliminate or confirm rider induced problems?


    Sometimes. Maybe. Possibly.

  • p.c.spencer
    p.c.spencer Posts: 5
    edited July 2022
    trevor.hall12 said:

    Finding it twitchy often comes from the stem length ,would it be possible to go longer up front .
    I had a derosa that was crazy to steer when I got it with an 80 mm stem ,lengthened it to 100 and it cured the problem .

    This is an interesting point, it’s got a short wheelbase and I definitely don’t feel stretched out on it as it is at the moment. Will maybe try a cheap long stem and see how it effects the ride.


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