Measurement Accuracy

[BTBR]

Before I start spouting of at my dealer for selling me a bike that has a speedo that is on the plus side in measuring the miles, just how true is the are they on the SPIII or any other GPS for that matter?

I rode to work to day using the SPIII to measure the distance, the GPS said it was 31 miles while the OE speedo said it was 33 miles

Times that by twelve months at 12,000 miles p/a works out to...errr.....arrr....hmmm....... a lot of extra miles, therefore more servicing costs?

Any thoughts?

BTBR

 

[(RIP) sherpa]

speedo

Welcome to the world of BMW BTBR
This is a well known fault of the GS range - the drive is 10% out and needs replacing with the one from an 1150 R - some dealers are doing this under warranty but if you have to buy one its about £30 and takes 15 minutes to fit - I've done it and its cured it to within about 1mph against the SPC III

If you have a bike with 20,000 miles on then its only done 18,000 miles - gets quite expensive with regard to service intervals!

Sherps

 

[BBB61]

I've done the mod too, and it brings the speedo and odometer accuracy down from 10 to 2%. I had a speedo reading of 118mph against a GPS reading of 115.

I was working out the speedo accuracy on my new Triumph the other day. The speedo was well out, in the region of 12-15% overread, but the odometer reading was only 1% out. Bizarre!!

Bob

 

[BTBR]

Re: speedo

Welcome to the world of BMW BTBR
This is a well known fault of the GS range - the drive is 10% out and needs replacing with the one from an 1150 R - some dealers are doing this under warranty but if you have to buy one its about £30 and takes 15 minutes to fit - I've done it and its cured it to within about 1mph against the SPC III

If you have a bike with 20,000 miles on then its only done 18,000 miles - gets quite expensive with regard to service intervals!

Sherps

Cheers Sherps, most interesting. Looks like its a phone call to the dealer tomorrow morning then.

Plus the Volvo dealer as well coz the car is worst than the bike!!



BTBR

 

[K2R]

I believe I used one from the RT and its quite close. The number was 62122306532. You might want to check with others to be sure. I paid $50USD a year ago. And, my odo matches the GPS just about exactly.

 

[BTBR]

Before I contacted the dealer I carried out a couple of more tests this morning.

The speedo (according to the SPIII) is 9.2% over, across a number of varing speeds ranging from 40 to 80mph.

So armed with this factual evidence I contacted the dealer this morning who in turn has contacted BMW Tech Support.

The end result being that BMW DO NOT accept that there is a problem and therefore will not replace it under warranty. They "claim" that by using the speedo drive from the 1150R would make it worse coz the wheels are 2" smaller in diameter.
Dont know coz I have no knowledge of the 1150R.

But I am now going to contact BMW Tech support and try from another angle.

In the meantime can anyone give me the name of a dealer that has replaced one under warranty please.

Cheers

BTBR

 

[K2R]

More Speedo Info

 

[BTBR]

Thanks for the link, interesting even if it was a while ago, however the dealer will still not budge and will not replace it under warranty....

So I have now spoken direct to BMW Customer Service who suggested that I take it back to the delear so that they can check it. So I rang the dealer again and explained wot BMW had said "But what are WE going to measure it against ?" was the reply?

But they did make rather a sweeping statement, and I quote " a GPS is not accurate as is does not measure around corners, therefore it cannot be used as a true measuring device"

Prehaps someone with more knowledge about GPS would like to comment about this please?

BTBR

 

[Deleted Member MM]

Thanks for the link, interesting even if it was a while ago, however the dealer will still not budge and will not replace it under warranty....

So I have now spoken direct to BMW Customer Service who suggested that I take it back to the delear so that they can check it. So I rang the dealer again and explained wot BMW had said "But what are WE going to measure it against ?" was the reply?

But they did make rather a sweeping statement, and I quote " a GPS is not accurate as is does not measure around corners, therefore it cannot be used as a true measuring device"

My Dealer got exactly the same response from BMW UK. The GS uses a 3.0:1 ratio. The R1100R & R1150R use 2.6:1 ratio for the 17" wheel, drives are different the R1150R does not fit GS wheel. I believe the drive you need is 2.875:1 as fitted to 18" R spoked wheels but please check with the likes of Motorworks first.

I'm running alloys on my GSA with 2.6:1 drive and speedo over reads as it did with original wheels. A deliberate ploy by the manufacturer then