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There's a straight, mostly level 400 meter stretch of road near my house that would be nice for a cal course. But I am not going to think about establishing one on this busy road which has no shoulders.

I am thinking about laying out a cal course on the adjacent sidewalk. This is a concrete sidewalk, consisting of 5' square sections. The seams are about 3/4" across and range from ~ 1/4 to 1/2 inch deep. I don't anticipate these seams potentially creating any potential inaccuracies.

Anyone see any problem with this?

Last edited by Race Resources LLC
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The road and the sidewalk are separated by grass. This is not a road I would prefer to ride a bike on at any time of day. It's narrow, unlit, and many motorists drive far above the posted speed limit here.

With my hybrid bike tires, I do not anticipate any distortion caused by the small sidewalk seams, but a venerable certifier I spoke to raised a question about this. I am not certain about comparing because of the aforementioned risk. 

Any other thoughts or suggestions - anyone? 

For sidewalks one does not required specific distances, use a seam (nails in concrete do not work) on the sidewalk, minimal distance 300.00m is all that is needed. End points can be easily found.

Recently been using dedicated bike lanes or pathways, chose a section with little traffic on it, thus very little interference. Street crossing can have you stop for a traffic light, minor inconvenience.

Parked vehicles like CarToGo have messed my up too many times.

We have several cal courses on sidewalks.  They are unlikely to have cars parked (legally or not) on them.  They are much safer in terms of traffic.  We mark the ends of the course by drilling (star drill & hammer) a 3/4-inch diameter, 1-inch deep hole and fill it with paint.  We carry a (hated plastic) drinking straw to blow the dust out of the hole.  We have also tried drilling a small pilot hole then pounding a PK nail into it.  This requires carrying a battery powered drill.  We abandoned this after the first use because we didn't want to add the complexity of remembering to bring a charged drill to each measurement likely to need a new cal course.

As for the joints in the sidewalk, we assume they cause no more inaccuracy than the cracks, potholes, storm drains and assorted bumps encountered in the road along the measured course.

Certainly one can drill into concrete but one does not always have the equipment with us, particularly when out of town. Sidewalks are not always a continuous 300m lenght, but more likely to be convenient.

I find dedicated bike paths are very useful, they tend to be convenient and quite readily available. Most are a section of the roadway separated with a curbing, best part free of vehicles. Cyclists are more accommodating when we stop at locations not expected.

The important aspect is having a access to 300m with interference from parked vehicles.

Ride safe.

Marcel LaMontagne

> On Feb 1, 2020, at 6:52 AM, Road Course Measurement Forums <> wrote:

Thanks for the good comments, gentlemen. I agree that the small cracks shouldn't pose a problem. We certainly encounter worse on many courses.

My plan is to compare rides on this new course with a previously established one within the same hour or so to see what differences there may be. I don't expect any significant difference.

Though your technique is to be commended, Guidos, I have had some success driving nails into concrete. I will look up the specs on what kind of nails I have used and report on how it goes when I certify the sidewalk course. I remember that the process requires slow, careful hammering. When done properly, the nail goes in without bending or shattering the concrete. 

Last edited by Race Resources LLC
daverogers posted:

Be aware that all concrete is not created equally.

I know, Dave. I bought a little "nail guide" with which to hold the nail vertical while I try to pound it in. If this doesn't work, I am hoping the little break in the concrete surface by the first nail will facilitate the hammering in of the second one. I purchased nails - expensive ones - which are designed specifically for going through concrete.

As soon as we get some clement weather here in Maryland, I'm going to give it a go. I'll report my results. Being able to calibrate near my house on a level, paved surface that is free of auto traffic and that is sparsely used is a convenience I have been seeking for a long time.

I bought a couple of masonry bits- one a little larger than the shaft of the MAG nails I was using, and one a little larger than the head- and, with a rechargeable drill, drilled a hole deep enough that the nail would drop into it and be flush.  I then put enough glue into the hole that it oozed out a bit when the nail was dropped into the hole.  It'd take some serious effort to dislodge such a nail.

Yes looking forward to that comparison, between smooth pavement and sidewalk with joints. Most of my comparisons using standard road bike tires have resulted in fewer counts on rougher surfaces. So I generally try to calibrate on smooth surfaces-- of course calibration on the "same" surface as the course is best. (Using quotes because it's tricky to assess surfaces.)

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