sigma bike computer

beckster · Post by **beckster** » Fri Dec 15, 2006 3:32 pm

Hi all,i would like to know from any of you that have fitted the sigma bike computer what your solution was to fitting a magnet to the brake disc and also what type of magnet you used,also what was you setting for your wheel size.

Max · Post by **Max** » Fri Dec 15, 2006 3:39 pm

I've got one fitted, I just used the plastic ties to hold the magnet to the brake disk. its a bit tight to the fork leg but works well. to work out the diameter of the wheel I put some paint on the tread and pushed the bike forward in a straightish line and measured the distance between the blobs.

beckster · Post by **beckster** » Fri Dec 15, 2006 3:42 pm

cheers,i'll have a poke at it tomorrow.

Max · Post by **Max** » Fri Dec 15, 2006 3:56 pm

Its been on there for a couple of years now and hasnt fallen off (yet)

Squiffythewombat · Post by **Squiffythewombat** » Fri Dec 15, 2006 4:21 pm

silly question i know:

Why fit one? is this just incase you dont have clock or something or is it more accurate?

Max · Post by **Max** » Fri Dec 15, 2006 4:27 pm

Squiffythewombat wrote:silly question i know:

Why fit one? is this just incase you dont have clock or something or is it more accurate?

No clock started it, then changing the gearing to 15/44 it was nice to know what speed you were actually doing (its about 20% different with the built in inaccuracy as well). It converts to kmh easily as well which is handy.

Post by **sirch345** » Fri Dec 15, 2006 7:14 pm

If you've not already seen this, Al put this up:-

http://www.vtr1000.org/faq_bikecomp.htm

Kitch · Post by **Kitch** » Fri Dec 15, 2006 7:43 pm

I mounted my magnet in the round holes between the rotor and carrier on the disc.

Worked fine, but even supposedly waterproof ones die under the British weather, even when mounted right up under the screen.

Squiffythewombat · Post by **Squiffythewombat** » Sat Dec 16, 2006 12:02 pm

Max wrote:
Squiffythewombat wrote:silly question i know:

Why fit one? is this just incase you dont have clock or something or is it more accurate?
No clock started it, then changing the gearing to 15/44 it was nice to know what speed you were actually doing (its about 20% different with the built in inaccuracy as well). It converts to kmh easily as well which is handy.

OOO im on 15/45 so im guessing my speedo reads some nice random speeds for me!

LotusSevenMan · Post by **LotusSevenMan** » Sat Dec 23, 2006 10:06 am

Oooh, thanks for the BC800 link Sirch.
I wondered how close to actual the speedo read with that front sprocket change etc.

I am now doubting that indicated 175mph flat out laying down over the tank............................................. in third!!!!

LotusSevenMan · Post by **LotusSevenMan** » Sat Dec 23, 2006 1:36 pm

These computer have now been supeceeded by the Sigma 1600.

Post by **sirch345** » Sat Dec 23, 2006 3:14 pm

LotusSevenMan wrote:Oooh, thanks for the BC800 link Sirch.
I wondered how close to actual the speedo read with that front sprocket change etc.

I am now doubting that indicated 175mph flat out laying down over the tank............................................. in third!!!!

LOL That's what happens when you lower the gearing, at that indicated speed I'm still in 2nd gear (standard gearing is marvelous)

LotusSevenMan · Post by **LotusSevenMan** » Sun Dec 24, 2006 11:50 am

Well I can hopefully rectify that problem with the newer Sigma model I won here!
11.98 ukp delivered seems OK to me (though not yet got it yet obviously as auction only just finished).
I have friends with Caterham Sevens and they use this one too as that car suffers from changes in wheels sizes and other variables (23,14,15 or 16", five or six speed gearbox, 3.92 or 3.72 differential gearing etc etc).
Strangely enough with me changing from 15 to 13" wheels, a six speed in place of the five and changing the diff from 3.92 to a 3.72 and then trying the speedo against sat nav it is the most accurate speedo I have ever known. Now only .4 mph overeading at 100mph (on a track of course) and pretty much exact all the rest of the scale above and below!!!

See:-
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... &rd=1&rd=1

Post by **sirch345** » Sun Dec 24, 2006 3:21 pm

LSM looks like you bagged yourself a bargin