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Proposed changes to WHPVA rules

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TheoS View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote TheoS Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2017 at 7:39am
Thanks, Dave, very good info!

It's astonishing how well these frail fairings protect their riders at incredible speeds. But I guess it's essential to check the suitability of any speed course with regard to hard obstacles alongside, as you have done. Round circuits won't have a problem as they generally have either an extra inside lane or at least space.

I am just reviewing an article on bicycle shimmy, the almost uncontrollable wobble which can develop at the front wheel at some speed, if the structure is insufficiently stiff and/or underdamped. (My Peter Ross sociable trike "Gem" absolutely needs a hydraulic steering damper.) Do you know if most of these crashes are do to this?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Woolly Hat Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2017 at 9:10am
It's an interesting question regarding the potential rule change and the problem of finding suitable venues for record attempts. 

Whether the rules are changed or not, i would have thought the best way forward (and paralleling other forms) is to have the record as an average of 2 runs in opposite directions within a certain time frame. 1 hour may be optimistic for a rider to recover but then that just makes the record more meaningful, even if it lowers the big number. 4 hours may be more realistic.
Certainly the 2 runs must be same day in order to minimise the effects of weather changes.

This method would compensate for both track and weather and eliminate the huge expense in creating a custom built facility.

Maybe there should be more emphasis brought to the 700m record again as suggested so that there can be a "realistic" record and an "unlimited" one? And at 700m there's probably a whole lot more venues that could be used to encourage more regular attempts at beating it? Would this record be able to be accommodated at the World Champs each year where more could be involved?
Ross Low Racer 77 - beware of unexpected changes of direction
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Post Options Post Options   Thanks (0) Thanks(0)   Quote legs_larry Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2017 at 12:00pm
Originally posted by TheoS TheoS wrote:

Thanks, Dave, very good info! It's astonishing how well these frail fairings protect their riders at incredible speeds. But I guess it's essential to check the suitability of any speed course with regard to hard obstacles alongside, as you have done. Round circuits won't have a problem as they generally have either an extra inside lane or at least space.
Most of the machines these days are a far cry from the "stick some fibre-glass around a separate bike", though, and even the ones that are in theory usable without all the bodywork in place will most likely have multiple layers of fancy composites, built-in roll structures and racing-car-style seat belts. You have to try really hard to write one off, as the University of Toronto team found out last month.
Originally posted by TheoS TheoS wrote:

I am just reviewing an article on bicycle shimmy, the almost uncontrollable wobble which can develop at the front wheel at some speed, if the structure is insufficiently stiff and/or underdamped. (My Peter Ross sociable trike "Gem" absolutely needs a hydraulic steering damper.) Do you know if most of these crashes are do to this?
I can only recall a couple of crashes attributed to steering wobbliness; Rob English's in the Kingcycle Mango in 2002 was caught on video. That machine had very little trail and a very short wheelbase. The Schroeder team had a problem with steering shimmy at a certain speed on a trike about five years ago; rider James Schroeder tried to power through it, whereupon both his video systems went out simultaneously. A trip into the scenery followed. But I'd reckon most crashes are down to unexpected gusts of wind, tyre issues or "dunno, I just lost it". Jonathan may be able to elaborate if he's reading.
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a bit ov a lyv wyr by slof standirds
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Neil F View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Neil F Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2017 at 1:57pm
I thought about this too but that doesn't get around the problem. Consider the timing strip in the middle of a U shaped valley. Running either way across the timing strip does not eliminate the height issue. If timings at the ends then just invert and you can see the problem.
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