ok, can someone tell me about a descently priced bycycle speedo that can be mounted on the superhawk, and how to do it? can you use the bike as a powersource? I'd like one with an odometer.

 

I've seen several of the Sigma Speedometers on eBay and also on the Aerostitch website. The BC1200 is the one I plan on purchasing for my SHawk project.

 

Mine was found in a bicycle store.
I'm using the sigma BC800. Ok to use on one bike.
BC1200 have "2 setups" allowing to use on 2 different bikes.

BC800 works until 300 km/h ...

 

The only issue with these is the sensor wire, depending on applicaton location, can sometimes be too short. So, some folks try to use the newer "wireless" models. Don't. They aren't designed to be around electronics and won't work with the interference.

My only "gripe" with these units is the lack of a night light. I once found a different brand (pano-ram) sold at walmart for about $20 that came with a push button light which stayed on for about 5 secs. I left it on the VFR when I sold it and then found out that wallyworld no longer sells them (grrrr). Off road companies sell this identical plastic unit with a metal guard for $80!! hmmm, coinky-dink?

Now that I've committed to memory the actual speeds the VTR speedo corresponds to, I don't really need to see it at night anymore.

 

With stock speedo, speed is taken at the gearbox output. It counts the number of turns assuming sprockets are 16x41.
Since you have modify rear sprocket, the speed is now in error.
for you error is (43/16) / (41/16) = 1.0488 => 4.88%

 

stock speedo has an error about 5% stock sprockets .... Trip is more accurate.

So you've got a real speedo error about 10% ..... :wink:

 

Is the change in sproket typically the only thing that throws the speedometer off?

I haven't checked to determine if the used SH I bought has different size sprockets other than stock but it sure seems that it is ready 85 or 90 when it is really 75 to 80 mph. Any one else have the same problem?

 

yep. its a universal problem. the percentage of error is 10-11% so if it says you're doing 90, you're actually doing about 81. there is a fixit plugin at this site: http://www.blackrobotics.com/order.htm
but its kinda pricy.

 

Mine reads 10mph high @ 70 (true 70 reads 80)
That's with 16/43
(Stock is 16/41)
Checked against a calibrated Sigma.

~Jeffers

 

that gives 8.7 or about 10% high for a stock bike, and says yours reas 14% off.

Errors would seem to be linear - but someone suggested all of them are correct at one speed. If that speed is not 0 mph, then a box like the one linked to couldn't fix it unless it's a lot more complicated than they let on. So what's the story?
________
Ct50 Motra

 

I think the story is, the best solution is, a Sigma 1200 bike computer from REI's website for about $30

~Jeffers

 

Here's the link,

http://makeashorterlink.com/?L28851FAB

good price on a Sigma 1200

Nice large nombers in the display.

~Jeffers

 

Shoot, I forgot to mention I had a analog speedo (2000 Super Hawk) I guess the linked item wouldn't work for me anyways? oh well, I got the sigma, i guess I had better put it on before I get a ticket for going to slow!!!