[luoma]

I tried a bicycle computer today. A cheap Schwinn from Wally World like a few others on this thread have mentioned. I measured the radius of a 26 in mountain bike wheel and it appeared to be the same as my 19 in front on the RE, so I calibrated it as such (please correct me if I'm wrong). I attached the magnet fairly close to the hub so that it would be as close to the ppick-up as possible, but obviously not close enough, because I get no reading. Any suggestions?

[1Blackwolf1]

  I have the same cheapo on my Whizzer copy.  It has to almost touch to pick-up the impulse.  Maybe on a motorcycle it could be glued/bonded to the rim so it is close enough.  Just went and did a rough measurement, looks to be about 1/16th of an inch space between the mag and readout unit.  Will.

[soulforge]

I'm also trying to install one too.
What I have found is that since it is for bicycle the usuall magnetic is very weak, thus requires the sensor to be as close as possible.
I am trying out some strong industrial magnetics instead of the original weak one.
Before installing, check if you get a reading and check the maximum distance between magnetic and sensor.
I am installing mine on the rear tire. The sensor is attached to the chain cover.
Still checking for the optimum radius though, because I was wondering whether different radius selection would differ the results,
Good luck. Bong

[1Blackwolf1]

  Yes it will I mis entered the value the first time and had to re-enter when I was getting somewhere around 50 mph on my Whizzer.  Re-entered the value and got 21 mph, more believable for a 2 1/2 hp engine.  Will.

[luoma]

I got a bike speedo to work. I had to use a stringer magney and hot glue it to the edge of the rim. That got it close enough. As it turns out, my speedo was a bit optimistic at lower speeds, then shows accurate at 50-55, then becomes pesimistic at higher speeds. Obviously a faulty magnetic pick-up inside the speedo. At an indicated 60-62 mph, I am actually going 68-70. No wonder my friend on his Kaw complains that I like to ride too fast.

[geoffbaker]

Congrats, that's the first speedo I've heard of that wasn't ridiculously optimistic through the whole range!

Mine was consistently about ten percent on the plus side. I always imagined the factory set it that way to keep the speeders happy

[luoma]

I wish mine was consistently optimistic geoff. At least I could compensate for that. Mine worked OK up to about 50-60, then went bananas. I think one of the intenal magnets came loose and slipped out of place.

[1Blackwolf1]

  I'd go get a Smiths replica but wonder if they are any closer to correct, (also like the backwards dial).   And with losing losing some illumination, don't want a double whammy, ..inaccurate and dim and night.  What more could you ask for? WIll.

[mbevo1]

Well...

I goofed around with the Sigma speedo I bought online - couldn't make it work.  Called the vendor and they agreed with my speculation that the sensor wasn't working.  Shipped it back and picked up a Schwinn model at Wally World. 

Used one of the Radio Shack rare earth magnets (3/16" but STRONG) and superglued it to the rim.  Glued the pickup to a small dowel to get the spacing right and zipped the pickup to a fender stay.  Measured a circumference of 1994 mm for the front wheel.

I LIKE IT !  Speed is within 1 mph of GPS and the trip odometer is nicer than my mileage posit note on the handelbar clamp. 

Turns out, my stock speedo indicates 5 mph high from 30-45 and about 7mph high up to 55.  Seldom go faster than that, so haven't checked.

Best $10 project I've had in a while...

Mike and Stumpy in Michigan