: Another tech question

[Randy Grein]

Kerry, are you saying that all GPS devices have the same high  
accuracy? It should be obvious that tire size (governed by all things  
you mentioned) has a direct effect on speedo reading, but we're  
talking about a 20% change in reading with no (as far as we know)  
changes in the front. Seems like there's more to the story, but  
nothing else comes to mind.

Randy Grein, WMRRA #41

On Oct 29, 2007, at 6:11 AM, Kerry Driskell wrote:

>   A GPS is the most accurate way to check your actual speed. I run  
> one most
> of the time,in place of the instruments. It will show a difference  
> of at
> least 8 mph,depending on the speed,tire brand,size and inflation  
> pressure.
> All car speed-o's are off also. My KTM is almost spot on.You can  
> also run a
> Sigma bicycle speedo ,once you calibrate it.It will be accurate.
>
> -----Original Message-----
> From: Margie [mailto:gcarper1 at charter.net]
> Sent: Sunday, October 28, 2007 5:30 PM
> To: Suzuki SV650 Mailing List
> Subject: Re: : Another tech question
>
>>>>> Margie wrote:
>>>>>> Changed the rear sprocket and now the speedo is 10mph too  
>>>>>> fast.  Is
>>>>>> there any way to adjust?
>>>>> zoran wrote:
>>>> sprocket size has nothing to do with speedo reading on sv.
>>>
>>> Zoran is, of course, correct. My streetbike's speedo error is due  
>>> to a
>>> change in the speedo-drive at the front wheel (long story), and  
>>> not due
>>> to sprocket changes.  I need more coffee before replying to  
>>> emails on
>>> weekends, obviously. Margie: how did you determine you were  
>>> showing 10mph
>
>>> too high? And this changed at the time you swapped sprockets? Did  
>>> you
>>> make any other changes at the same time?  -W
>>>
>
>
>
>
>> I checked it using a Garmin GPS  660
>