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Old 02-20-05, 04:54 AM   #1
franktompson
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Handlebar stem for better stability; short or long?

I've recently become the proud owner of a Thorn Raven Sport Tour. Overall, great bike.

However, initially the steering was really wobbly. I thought it was just me, but eventually discovered the wrong forks had been fitted. Instead of a 47mm rake, a 42mm rake fork had been fitted. It was replaced immediately.

With the 47mm rake fork it is more stable (phew!) by a factor of, say, 50%. (I understand that this goes against conventional logic which I can't explain!) However, how do I get to what I regard as real stability like my current Trek 7500FX. Ravens are supposed to 'run on rails'.

The Raven comes with a number of height sizes, each of which includes a 'long' and a 'short' version. I opted for a short version because I like a fairly upright ride, but now wonder if I would be better off with a long version, and with a shorter handlebar stem. So the question is, would a shorter stem (with a longer frame) provide more stability? Grateful for any thoughts.

Also, I'm not entirely convinced by the Raven's 26" wheels. Any opinions?

Best regards to all,

Frank Tompson, Bath
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Old 02-20-05, 06:26 AM   #2
MichaelW
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Short TT/Long stem usually has a damping effect on steering input compared to long TT/short stem, so can reduce one of the causes of instability, but this is independant of the fork rake.
There is no instability problem with 26" wheels, these are well proven on touring bikes.

Every bike has a different feel and some are more responsive than others.You get used to a new steering setup.

Tony Oliver in his book Touring Bikes has a discussion of steering, esp how headtube angle interacts with fork trail.
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Old 02-20-05, 08:36 AM   #3
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are you riding loaded or empty? Given the nature of thorn's bike i wouldnt be suprised if they worked out the geometry based on a full loaded touring weight.. Slap some front panniers on it and see how the steering works...
Normally when you put a few pounds on the front wheel, steering is MUCH slower, so maybe they made it twichier to compensate?
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Old 02-20-05, 08:39 AM   #4
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One quick thing to check is your headset adjustment. If your fork doesn't flop over when you lean your bike from side to side, your headset is too tight. If that's the case, you'll get funny handling and have difficulty riding in a straight line.
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Old 02-26-05, 03:25 AM   #5
franktompson
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Thanks for the replies guys. Just in brief, the bike is not designed for front panniers, and the head set is fine. Many thanks for the suggestions anyway.

Best regards,
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