Bicycle speedometer

[FastDoc]

The speedometer on The Dirt Rat 2 does not work. The cable was broken but before ordering a new one I tried the old 'cable in the electric drill' trick. The odometer portion works but win't reset. The speedometer does not work at all. So I'm gonna scrap it.

A Trail Tech looks appealing but it's more than I need and I'd rather not spend the money on it, although it is a good deal.

All I need is a speedo and odometer.

Have any of you guys installed a bicycle speedmeter on a dirt bike? Any recomendations? Wired or wireless? Any concerns for interference from the spark plug?

TIA gentlemen!

[Weldangrind]

CDI interference is exactly why I'd stay away from wireless. I installed a wired bicycle speedo on my ATV, but I blew it; I should have bought one with a backlight.

You might need to chop and extend the cable, but you're handy with a soldering iron. The magnet attachment to the spokes will be cake, because that's what they're designed for. In my case, I had to drill and tap a hole in the rear sprocket.

Expect to pay around $25 for a decent unit with a back light.

[FastDoc]

Interesting you went with the rear sprocket. The only other bike I've seen with a rear wheel speedo drive is my BSA, or any BritBike for that matter.

Considering how much thicker The Dirt Rat's spokes are than a bicycle's, will the magnet mount OK?

I'm considering somehow mounting the sensor to the front brake caliper. Epoxy?

I don't think I need backlit, Dirtbikes and dark don't mix well. :wink:

[Weldangrind]

This one is worth trying for $11.00, including shipping: New multifunction Digital LCD Bicycle Bike Computer Odometer Speedometer (http://www.ebay.ca/itm/New-multifunction-Digital-LCD-Bicycle-Bike-Computer-Odometer-Speedometer-ZXCb-/150681165683?pt=LH_DefaultDomain_0&hash=item23154c1f73)

[Weldangrind]

Trust me (although I'm not a Doctor), you need a back light. If you ride through some trees or the sun is bright, you can't see the LCD screen.

I'd try the spoke first, because you won't have to contend with suspension travel. To mount the magnet on the rotor means enough length alongside the shock.

[FastDoc]

That looks like a great deal, but it's in Hong Kong...

[Weldangrind]

I buy junk from Hong Kong all the time. I just bought a new iPhone cover for Son of Weldangrind, and I think it was $2.50, including shipping. All done by Paypal.

[SpudRider]

As usual, I agree with Weld on all points. ;) Definitely get a wired bicycle unit with a backlight. :) Also, don't hesitate to buy eBay items from Hong Kong; I do it all the time. ;)

Spud :)

[cheesy]

I know this may sound a bit spendy, Doc, but as the sole rider of 14(I think) bicycles (with all different wheel sizes, I might add) I opted for a single Garmin hand held GPS and a bunch o' handlebar mounts. No fiddling around with mounting magnets or receivers and NO calculating wheel diameters.

Biggest drawback I've had is that my unit is an early Legend and it has a somewhat unhealthy appetite for AA batteries. Been using it since 05.

[FastDoc]

You know, not such a bad idea. I seriously need an off-road GPS and have been contemplating one for a long time...

[FastDoc]

I installed a $9 Wal Mart bicycle speedometer made by Bell tonight. :D

It took about an hour. It's VERY lightweight with a very light duty wire, we'll have to see how well it hold up but it seems to work spinning the wheel in the garage. I didn't ride the bike it's too late and too dark. I assume the spark/CDI won't interfere with a wired unit...

It has a bit of a lag response but it should be accurate, I measured and inputted the wheel circumference at 2083mm.

[Weldangrind]

Does it have a light?

[FastDoc]

No but since the bike doesn't have a light I figure I'm good to go. Won't be riding after dark.

[cheesy]

Nine bucks 8O.

Guess it has been a long time since I bought one. :D

[SpudRider]

I installed a $9 Wal Mart bicycle speedometer made by Bell tonight. :D

It took about an hour. It's VERY lightweight with a very light duty wire, we'll have to see how well it hold up but it seems to work spinning the wheel in the garage. I didn't ride the bike it's too late and too dark. I assume the spark/CDI won't interfere with a wired unit...

It has a bit of a lag response but it should be accurate, I measured and inputted the wheel circumference at 2083mm.
That's a nice score on the Bell speedometer, Doc! Is it this one?

http://www.acehardwareoutlet.com/productdetails.aspx?sku=8305245

Spud :)

[FastDoc]

That's it!

I rode the bike yesterday and it works very well. It's basic but all I wanted was a speedometer/odometer/trip meter and that's what I got.

I'll post some pics of the installation when I get a chance. Only time will tell how well it holds up under the harsh use I will be subjecting it to.

[Weldangrind]

Was it easy to mount the magnet on the spoke?

[FastDoc]

I JB welded a magnet to the brake rotor hub area. I did not use (lost :? ) the little magnet that came with the unit. I used a VERY strong puck shaped magnet that was on a cheap universal (dogbone type) wrench I had laying around from the parts store. It was designed to stick to the side of a toolbox. It's about 50 times stronger than the one I was supposed to use.

[Weldangrind]

I thought about using a rare Earth magnet with my speedo on the Beast, but the stocker worked beautifully. The benefit was that the magnet had a threaded stud that made mounting easy. I simply drilled and tapped a hole in the sprocket and secured the magnet with a little Loctite.