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Speedo Pickup - OK to mount 'after' diff?
cloudy - 27/6/08 at 06:20 PM

The only sensible mounting point for my magnets appears to be on the output flange one side of the diff (Chain driven) The intention is to drill 4 holes and epoxy the tiny neodynium magnets into the output flange. The CV boot stops me mounting them "in" the CV bolts... The other possibility is drilling holes in the heads of the bolts securing the sprocket to the diff - But might have trouble getting the sensor alongside (It doesn't like being much off 90degrees to the magnet)

Does anyone see any likely problems with having the sensor on the output of the diff? Speed errors during cornering? Or will it be so negligible that I won't notice...

If anyone has any better suggestions for location please shout!





[Edited on 27/6/08 by cloudy]


blakep82 - 27/6/08 at 06:28 PM

anywhere after the gearbox should be fine i'd think...


BenB - 27/6/08 at 06:38 PM

I've got my speedo trigger wheel attached under the lobro bolts of the driveshaft. No problems. I wouldn't worry about inaccuracies when going round corners- it'll only make a big difference when at speed and if you're taking sharp corners at speed you'll be done for dangerous driving not speeding


blakep82 - 27/6/08 at 06:42 PM

just a thought (you've probably sorted this already) how will you keep oil in the diff?


Dave Ashurst - 27/6/08 at 07:32 PM

quote:
Originally posted by blakep82
just a thought (you've probably sorted this already) how will you keep oil in the diff?


...and grit out?

Looks great though.

rgds
D


richardh - 27/6/08 at 07:34 PM

if thats a KOSO pickup then stop right there..............................

KOSO n1 or whatever minimum radius read in circumference is 300mm (some are 500mm)
You wont get a good reading otherwise. and will fail sva

best to put it on the front wheel to get best reading - drill into one of the upright bolts and epoxy magnet in place...
weld or bolt pickup close.

if it must be towards rear then not sure where you'll mount it.

hope this helps


cloudy - 27/6/08 at 07:49 PM

Richard, I've tested with a magnet on the outside of a drill chuck up to well over 100mph with a stable reading. I think any issues you've had are caused by something else...

The manual even suggests using the sprocket bolt holes!

James

PS. the diff will have a cover made for it...


richardh - 27/6/08 at 08:00 PM

yeah true
i put mine on the end of prop and it didnt read true due to circumference of the prop being only 210mm.

its not the stability its the accuracy.
you only get a 10% over-read allowance.

if where you are going to mount it is larger then no probs

just wanted to save you a days worth of grief.

ps, what engine are you using? my r1 says it has 4 cylinders and 4 pistons (98 carb) and the rev counter i programmed this in and it ran out of revs before maxed out.

still awaiting instructions from koso europe to sort out
(others using this have had same problem in earlier threads on this site)
currently i set it to 4 pot 8piston and it revs same sounds as the bike. rode my mates round here to check

if none of above applies then fab. just wanted to spare u potential grief


cloudy - 27/6/08 at 08:03 PM

It depends on your bike, some will output 2 pulses per revolution...

The accuracy is purely dictated by how well you set up your wheel circumference. As long as the sensor is picking up the magnet every time it passes the speedo reading will be dead on...


richardh - 27/6/08 at 08:07 PM

provided the circumference setting on koso is correct and the number of magnets is right then you are totally correct.
that looks like a really cool vehicle y the way


cloudy - 27/6/08 at 08:11 PM

Another confusing point is the koso expects a pulse every 720 degrees when you set it to 4 stroke. If you connect it to the coil then as most bikes are wasted spark, it will spark every 360 degrees. If you connect directly to tacho output it will be the same - 1 or 2 pulses per 360 degrees. You will have to play with the settings to "fool" it into being right.


richardh - 27/6/08 at 08:18 PM

cheers, haynes manual didnt say that

that looks superb.......... proper "builder" not just "assemblers" like the rest of us


02GF74 - 30/6/08 at 10:20 AM

quote:
Originally posted by richardh

best to put it on the front wheel to get best reading - drill into one of the upright bolts and epoxy magnet in place...
weld or bolt pickup close.




that is not testable at SVA since they have one set of rollers.

I used bike speedo, magnet mounted in one of the two holes in rear drive flange (english axle) core plug style and have speedo take off gearbox too. I haven't noticed any difference in speeds when cornering, mainly becaause I haven;t been looking plus there is some lee way in reading the speeo anyway,