This is how I attached a wireless speedometer to the A-bike.
Nothing in this construction should leave a mark or make a hole in the bike. It can be completely removed.
Many pictures.
Parts needed:
A wireless speedometer- I use a $20 bell '15 function wireless'
Stainless steel hose clamps- the ones with the screw.
L frame is a "2 1/2 inch by 2 1/2 inch" zink plated corner brace.
Glue - I use a product called 'liquid nails' not as strong as epoxy, but repairable and cleanable.
Nylon pull ties- they come in packages of 100
This is where the wireless sensor will be when it is mounted.
Mounting the magnet on the wheel-
Open the stainless steel hose clamp, put it around the hub, and close it with the small screw of the magnet between it and the hub somewhere. The ones I used were to small, so I put two end to end.
Attaching the sensor to the L brace and that to the bike frame-
The 13 4 inch long cable ties; several are attached to each other to make longer loops, give some spring to
the frame. The 3 on the bike body above the splash guard are to keep the frame at the correct angle forward and back.
I have a large messy glob of white glue holding the magnet sensor to the metal frame, and a tie to the sensor in case the glue ever breaks.
The contraption has a pretty close tolerance, with the sensor being only 2 mm from the magnet, this is adjustable by the straps at the top end of the L frame.
Before I trimmed the tails: it is easier to see the placement.
None of the ties are closer than 4 mm from the tire, and that one is at the end of the L frame as a safety strap at the end of the sensor.
The wheel diameter is set in MM, and the instructions come with a 24 inch setting, use 1/4 of that.
The display mounted on the fold brace, at the point with the 'no foot' sticker.
The display is removable from the mount, which is just small enough to fit when the frame is fully closed.
It is on cable ties, and can move freely along the length of the pipe.
See it here with the bike completely closed, next to the frame lock hole.
Why is the display on the Fold brace and not on the handlebars where it should be?
Insufficient range.
The sensor on a full size bike would be less than 2 feet from the readout.
On this bike it is only sensitive enough to receive at just past the press lock springs.
It is still very readable, this model has fairly large numbers.
My Max speed recorded so far is 14.4 mph in the weeks of riding that I've done since attaching this.
This is my observation on my own biking speeds.
http://abikecentral.com/forum/viewtopic.php?t=271
