RPM/speed

[06STER]

I have just fitted a speedo healer to compensate for 18T front sprocket change (rear 42), done GPS compare and set % ,accordingly, now within .3kmh of gps. My concern now is that i feel that RPM is to hi for speed, checked on gearing commander it says approx 3700rpm/100kph mine reads approx 4100rpm
is this reading norm or do i need to look further.

[DaveM]

Hi 06STER

I am not trying to be a smart arse or anything, but why is this a concern?

It makes virtually zero difference to fuel consumption.

Just wondering that's all.

cheers
DaveM

[06STER]

more curious than anything why there seems to be a discrepancy with the gear/speed/rpm on the web sight, or is there a calculation to confirm all ok

[oldndumb]

Why are you opting to ignore the gearingcommander instructions?

All calculations are based on the specific gearing data of a bike either entered by you or loaded from the database.
All information provided is based on theoretical calculations in optimal conditions and therefore it will differ from reality. For instance all chain calculation are without taking into account the chain wear and current tension. Also all calculations depend on the M.P.RPM entered but there is no guarantee that your bike will actually reach M.P.RPM. This depends on the power your bike delivers and mainly the wind resistance.
So please use all results as guidelines rather then facts !

[Shovelstrokeed]

My calculations show 4100 RPM at roughly 100 KPH is about right for 18/42 gearing. What's the problem?

[06STER]

no problem curiosity at the difference and thought the expertise on this forum would give me good advice if there was an issue