RG150 speedo's

**Meekey_Mouse** · 22nd September 2006, 11:16

Hey all... I've been told that there is some problem with the RG150's speedos, that they usually don't give you the correct speed. How many of you out there have this problem and is there some way you can fix it or is it just a matter of learning how much it is out and remembering that as you ride?

Thanks

Jaz

**Wasp** · 22nd September 2006, 11:20

My bandits speedo isnt 100% accurate, my old bike's (VTZ) speedo was horribly out by 10km/h at 50km/h and exponentially increasing (faster i went the more it slipped) - the speed warning light comes on when the speedo shows 95 km/h - only ever got there a few times.

point being, all speedos arn't exactly accurate because of things like tyre sizes and pressures along with other things too.

also FYI for a speedo to pass a warrent it only needs to work not be accurate.

**MSTRS:Me** · 22nd September 2006, 11:20

I believe that all speedos are made to read faster than vehicle is actually travelling. Motorcycles seem to be worse that cages for this.

**MSTRS:Me** · 22nd September 2006, 11:22

Originally Posted by Wasp

... the speed warning light comes on when the speedo shows 95 km/h - only ever got there a few times.
...

So your's reads slow???

**kiwifruit** · 22nd September 2006, 11:22

Yep, all speedos read high, esp bikes as MSTRS says.
The smaller bikes are even worse, but i think its a good thing personally.
My mates rg150 was doing 88 on my speedo (gsxr1000) at a claimed 100 on the rg speedo.
Better that way then the other!

**Wasp** · 22nd September 2006, 11:29

yes mine read slow, insanity_rules has it now.

I beleive it was the nylon threads or something behind the actually needle itself that slips by a certain amount, it was worn (damaged?) so it slipped more than it was supposed to. the way it worked was basically two plates that slipped past each other - the faster you go the more it pulls on the needles plate causing it to be kept at a higher elevation. kinda like slipping your clutch all the time i guess.

as for my current bike (gsf250) it reads 5km/h over for every 50km/h (so it shows 50 im doing 45) havnt tested this vs gps or anything though.

**Jeaves** · 22nd September 2006, 11:34

115km/h on my RG's speedo is 100km/h

8500-9000rpm in top gear should be about 100k for ya (RG150)

**MSTRS:Me** · 22nd September 2006, 11:34

Originally Posted by Wasp

yes mine read slow, insanity_rules has it now.

I beleive it was the nylon threads or something behind the actually needle itself that slips by a certain amount, it was worn (damaged?) so it slipped more than it was supposed to. the way it worked was basically two plates that slipped past each other - the faster you go the more it pulls on the needles plate causing it to be kept at a higher elevation. kinda like slipping your clutch all the time i guess.

as for my current bike (gsf250) it reads 5km/h over for every 50km/h (so it shows 50 im doing 45) havnt tested this vs gps or anything though.

Speedos work by having an electrical field generated by moving. This causes the needle to move. The faster you go, the greater the 'field', and the further the needle moves. Your GSF sounds about right although 'most' seem to be around 5/100

**JeremyW** · 22nd September 2006, 11:43

Originally Posted by MSTRS

Speedos work by having an electrical field generated by moving. This causes the needle to move. The faster you go, the greater the 'field', and the further the needle moves. Your GSF sounds about right although 'most' seem to be around 5/100

My TR110 speedo just had a worm gear. It was almost perfect at 50km/h when I tested it against a GPS and out by 5km/h at 100.

**McJim** · 22nd September 2006, 11:49

I find it's best not to look at the instruments - the road is much more interesting and you can tell when you're going too fast - it's when your bowels starts to clench with fear!

**MSTRS:Me** · 22nd September 2006, 11:50

Originally Posted by JeremyW

My TR110 speedo just had a worm gear. It was almost perfect at 50km/h when I tested it against a GPS and out by 5km/h at 100.

Yep that'd be right. The worm gear is turned by the cable, which is turned by a similar worm gear at the hub. At the speedo end, the worm gear turns a unit that generates electricity (resistance) that causes the needle to move. In the case of a gearbox-driven speedo, the field is created at that end and is supplied to the speedo unit by wiring.

**MSTRS:Me** · 22nd September 2006, 11:50

Originally Posted by McJim

I find it's best not to look at the instruments - the road is much more interesting and you can tell when you're going too fast - it's when your bowels starts to clench with fear!

....or the red'n'blues are a dead giveaway!!!

**JeremyW** · 22nd September 2006, 12:18

Originally Posted by MSTRS

Yep that'd be right. The worm gear is turned by the cable, which is turned by a similar worm gear at the hub. At the speedo end, the worm gear turns a unit that generates electricity (resistance) that causes the needle to move. In the case of a gearbox-driven speedo, the field is created at that end and is supplied to the speedo unit by wiring.

Well you learn something everyday

**Magua** · 22nd September 2006, 12:46

Zorst and I take 8,000rpm to mean 100kph on our rgs. I followed a friend before I sat my restricted and 30kph was an indicated 38, 50kph was an indicated 61.

You get used to it after a while.