Elizabeth Gardiner

I think it all evens out at 88mph.

On Mon, Jun 16, 2014 at 12:32 PM, Bill Nye wrote:

> While you are technically correct, that is only part of the story.
>
> The relativity of time is actually going to slow down the OBRA clock in
> relation to the head unit and cause the scorers to measure a faster time
> than the Powertap. Unfortunately, Mary's Peak is a hill climb so you have
> to consider the effects of gravitational time dilation. Gravitational
> fields are weaker at the top, where the finish clock is based. Because of
> this the finish clock moves faster than our riders clock!
>
> If you ride at just the right speed so that these effects balance each
> other out you won't have this problem anymore.
>
> Hope that helps.
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Bill Nye

While you are technically correct, that is only part of the story.

The relativity of time is actually going to slow down the OBRA clock in relation to the head unit and cause the scorers to measure a faster time than the Powertap. Unfortunately, Mary's Peak is a hill climb so you have to consider the effects of gravitational time dilation. Gravitational fields are weaker at the top, where the finish clock is based. Because of this the finish clock moves faster than our riders clock!

If you ride at just the right speed so that these effects balance each other out you won't have this problem anymore.

Hope that helps.

Mike Wise

Time is relative and it slows down as you go faster. If you traveled to Pluto and back next weekend, we'd all be dead when you got home. So maybe that solves your mystery?

Joe Tysoe

I've had an "issue" with my LYC head at TT events and "official race
timing" on a few occasions.

On a number of occasions I've seen a delta of about 30 seconds between my
LYC (& Strava measuring the same time as the LYC) and OBRA race timing.
Other times the numbers are pretty well aligned.

Not sure why this is happening and it's obviously a little frustrating to
think I'm racing to do XX:YY time and then get another number (about 30s
slower)- for example, yesterday I was sure I was going inside under an hour
at MP TT only to see I was shy of that.

Is there something I'm missing in getting the LYC set up or ready before
starting a TT?

There isn't much to the LYC- they just need be switched on and they time as
soon as the bike rolls. Perhaps I'm missing something?