I'm not sure about the accuracy of a radar gun, but the loop where a do a lot of my riding has two signs with radar that display speed that are usually accurate within a half mile per hour or so. Are you thinking of getting one?

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Mike Sparks


I have competed well, I have finished the race, I have kept the faith.

From experience, the radar gun is accurate to 1mph which is as accurate as the po-po need. Maybe there is a special version for baseball which displays more digits, couldn't speak to that version. As far as police radar, it'd pick up a cyclist but only if there wasn't a lot of traffic around and likely speed would have to be over 12-13mph for it to read. This doesn't sound like a problem for your son, but I'm not real clear on why you'd bother when you can measure speed directly on the bike?

Unbeleavably, Hot Wheels, makes a Radar gun for measuring the speed of slot cars, it's pretty accurate to 99mph in real speed and can be set for scale and cost $39.99 at Walmart. It's in the toy dept. where the model cars etc. are. I've used it to measure my R/C cars and slot cars at various tracks.

Why do you need it?

Sergio will not race triathlons (not competitively) in 2007. He finished 5th in a close sprint at this year's Road Nationals and wants to give it a shot next year but with his training focusing on cycling.

We spent this afternoon at a dragster track (nice place to practice sprinting, all for ourselves) trying to see what was his top speed using the very short rollout of 6.10 m required by the Mexican Cycling Federation for the 13-14 y/o AG. Using 21 mm tubulars Sergio is allowed to use a gear ratio no higher than 52x18 to road race. Triathlon rules allow for the 12-13 AG a higher rollout (he races triathlon on a 54x17).

Every single time I change the 52 chainring to a 54 and take away a cog from his cassette to set his bike to road race he gets upset and gives a long-winded speech (with all the bad words permitted included) about this "ridiculous" rule. He mentions that he is more at risk (and he might be right) hurting himself in a sprint with such a low rollout than with an unrestricted rollout.

The point is that those rules will not change and he has to do his best trying to get the highest speed possible on that 52x18 ratio. His wheels do some dancing at around 145 rpm. I can only imagine how is it going to be in the next months.

We tried using his Polar CS200CAD computer to measure top speed in those sprints but I had some erratic results. I am not sure how fast that computer is updating the speed but my impression is that a radar gun could make things easier for us. I told him to read his top speed after each sprint and I noticed that he had to punch several buttons to get there. I figured that a speed gun would let us concentrate on checking the most important matters.

Here we go again... and I thought that I was going to get a little rest (and at least a little surf fishing time for me) in 2008 ;)

Thanks for your comments,

Sergio

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Note: English is not my first language. Please read this translated post considering that.

John, can you please test this gun on a cycle when you have the time? I would have never imagined that such a "toy" radar gun existed.

Sergio

PD Can you please check your messages. Thanks beforehand.

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Note: English is not my first language. Please read this translated post considering that.

What a hoot. I'll check my local Walmart (Canada) & see if they have it.

I have a sponsored athlete that's also an OPP officer that brings out a laser to measure speed at the local TT. I'll have to ask him "Why not the radar?"

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Paul "Speedy" Gonsalves
http://www.rollingthundercanada.com
RollingThunderCanada

Canadian distributor for HED Cycling, Blue Competition, Akona Biospeed & Aerus Composites

$20.00 now.

http://www.walmart.com/...o?product_id=4661205

Sergio

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Note: English is not my first language. Please read this translated post considering that.

[reply]a laser to measure speed at the local TT. I'll have to ask him "Why not the radar?"[/reply]

because the laser is a lot more accurate? not to mention that you can 'aim it' very precisely at exactly the car/cyclist you are interested in?

Makes sense

Thx

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Paul "Speedy" Gonsalves
http://www.rollingthundercanada.com
RollingThunderCanada

Canadian distributor for HED Cycling, Blue Competition, Akona Biospeed & Aerus Composites

A couple of things. As far as gear restrictions, well, I think they're a good idea. Being able to produce a lot of power at a high cadence is always a beneficial skill, particularly if he ever decides to do any racing on the track.

As far as gear size, I wonder if you'd be better served by using a more efficient gear combo, such as a 38x14 (if that gear makes it on the rollout test with those tires).

Lastly, when your son starts complaining about gear size, let him read this article. This flying 200 meter time is fast by today's standards:http://www.cyclingnews.com/features/?id=2006/woodland_zimmerman

Here's the important part: "Just an ancient, a dinosaur good only for his age? Ponder this: on a bike weighing 12kg, on soft tyres 38mm across, without toe-straps and on a gear of 17 x 7, he rode the last 200m in 12 seconds. Many an amateur would be pleased with that today. And if that 17 x 7 gear sounds odd, it's because track riders used inch-pitch chains. In today's half-inch pitch, the gear would be 34 x 14. In other words, minute. The cycling mathematician, Dave Lefèvre, says that according to whether that was exactly 12 seconds or closer to 13, and depending on the precise size of the wheel (which could have been larger then than now), Zimmerman may have pedalled between about 170 and 185 revolutions a minute."

He is racing a Felt TK2 at the track (I hope Ger ard does not read this ;) ). That bike came originally with 48x14. He never rode with that gearing. Since new he has used a 46x16 to give him a rollout of 6.05 m. The original rollout of the TK2 was 7.21 m.

The velodrome is something else. The State coach wants him there but I just do not know if he really wants to go that way in the next years.

Interesting reading about Zimmerman. Thanks for the link.

Sergio

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Note: English is not my first language. Please read this translated post considering that.

Since you put a question mark after your comments, I'm assuming you don't know and are just guessing. As far as speed, the laser's I've seen only display 1mph and would not be any more accurate than a radar. Actually radar is easier to use because if the laser is shifting points of aim due to unsteady operator, it will show incorrect speeds. However, it would be easier to pick up an individual cyclist if you are using the laser properly. Also, the laser is "cooler" to use since lots of departments don't have them and they are usually only issued to traffic officers. If Sergio knows any cops, he'd be better served by borrowing the laser and operator but still, radar would work fine IMHO

What's the range on this? By that I mean how close do you have to be for it to work? The gun is powered by AAA batteries, so I can't see that it would be all that powerful, but it would be fun to try.

The range is only about 40 ft, ok for bikes and R/C cars, it's not good enough for bike pacs or swimming.

I think that radar gun can be of some use. At that prize there is little risk, particularly with an 11 year old kid in the house.

Everything looks good John.

Thanks again.

Sergio

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Note: English is not my first language. Please read this translated post considering that.

I'm surprised no one's talked about measuring their pet's speed. Maybe I'll finally be able to settle the debate as to who's cat is faster - mine or my sister's :P