Dangerous steering - headset or something else?

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JackPozzi
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Joined: Sun Jan 21, 2007 13:53 pm

Dangerous steering - headset or something else?

Postby JackPozzi » Sat Feb 02, 2013 14:09 pm

Just been out for a test run on my latest tt bike that has been built up over the winter and waiting for a semi-dry day to give it a spin.

Results aren't good, the steering is imposible control, especially at speed.

Difficult to describe the problem, but it seems that all the little slight adjusments that you subconsciously make to stay in a straight line when compensating for the wind or uneven road surfaces are massively amplified so they become full on turns and I suddenly find myself riding a couple of feet away from the line I was previously on, trying to adjust back the other way and having the same problem. It happens at all speeds but obviously the effects get worse as I go faster. It's doing it when I'm riding on the TT extensions on on the base bar as well.

I've had a couple of TT bikes before this one so I know they don't handle as well as a normal bike but this is way off the scale from where it should be.

I'm guessing it's most likely a problem with the headset, even though that and the frame are brand new and I had that fitted by a very good bike mechanic. I'll be taking it in to the LBS next week for him to have a look at to see if he can figure it out but in the meantime has anyone got any other suggestions for what might be causing it please?

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nicklouse
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Re: Dangerous steering - headset or something else?

Postby nicklouse » Sat Feb 02, 2013 14:39 pm

any play in the headset? if no then it will not be the headset.

what frame and fork?
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giropaul
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Joined: Mon May 26, 2008 12:47 pm

Re: Dangerous steering - headset or something else?

Postby giropaul » Sat Feb 02, 2013 14:41 pm

Cables too tight?

JackPozzi
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Joined: Sun Jan 21, 2007 13:53 pm

Re: Dangerous steering - headset or something else?

Postby JackPozzi » Sat Feb 02, 2013 14:51 pm

No play, and everything feels nice and smooth when turning the bars on a workstand.

Pinarello FT1 frameset - thinking about it the mechanic didn't fit the headset as it was already in place, but he did check it was all there and fitted correctly before I took the frame away.

Cables are long enought to allow full range of movement.

giropaul
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Joined: Mon May 26, 2008 12:47 pm

Re: Dangerous steering - headset or something else?

Postby giropaul » Sat Feb 02, 2013 15:18 pm

I'm assuming original forks to match frame?

JackPozzi
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Re: Dangerous steering - headset or something else?

Postby JackPozzi » Sat Feb 02, 2013 15:21 pm

Sorry, yes, FP8 forks as per orginal spec

giropaul
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Re: Dangerous steering - headset or something else?

Postby giropaul » Sat Feb 02, 2013 15:22 pm

I see that the FT1 is an "exclusively triathlon" frame - maybe they just assume that the rider won't be going in a straight line. :twisted:

JackPozzi
Posts: 1112
Joined: Sun Jan 21, 2007 13:53 pm

Re: Dangerous steering - headset or something else?

Postby JackPozzi » Sat Feb 02, 2013 15:26 pm

giropaul wrote:I see that the FT1 is an "exclusively triathlon" frame - maybe they just assume that the rider won't be going in a straight line. :twisted:


:) Good point, hadn't thought of that, I'll try riding wobbly, perhaps it's designed to counteract the natural insticts of a trianderthal...

JackPozzi
Posts: 1112
Joined: Sun Jan 21, 2007 13:53 pm

Re: Dangerous steering - headset or something else?

Postby JackPozzi » Tue Feb 05, 2013 17:01 pm

Turned out the shoulder in the head tube that the lower headset bearing sits on was a fraction too deep, so although everything seemed fine when the bike was in a workstand, with the weight of a rider on it the headtube was bottoming out on the forks causing them to bind slightly. My frame now weighs slightly less and has a tiny bit less frontal area, and most importantly, is actually rideable :)


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