749 Gearing And Fuel Range.

Hi I would be surprised if the gearing made that much difference to the mpg? But on the tank range I fill mine up bolt upright takes a little bit of balance in the petrol station but I think because the tank is flat topped I can get a lot more fuel in it, I use to get 80 to the tank I have had 120 to the light now ( that was a easy ride mind) so worth trying that

 

on reserve - 3 litres if thats when the light comes on, you should be good for 30 mls just taking it handy no problem. So id say if not ragging it 150mls should achievable (?)

 

The answer to your question is yes, your fuel consumption will increase. You will be using higher revs for the same speed regardless of gear. From my experience inadvertently using a 50 profile tyre instead of a 55 profile tyre which increased the revs by about 200/250rpm at 30mph, between 5 and 10 miles per 21 litre tank on a 1200 Multistrada. Andy

 

On my 999 going to 15-38 from standard (15-36) the mpg dropped from around 95 from full to the light to 90, with that ratio you can use the power without worrying too much about the front end lifting, anything over +3 on the rear and it would lift too easily. Not sure how the 749 would be affected but the recommended sprocket changes from the Shazaam tech library info is 14-43 (it will need a 98 link chain). I don't think it will wheelie with that as it is only two up from std. Have you tried an ecu remap which can be done to improve mpg as well as running or for out and out power. Its the best running improvement you can make to the bike and if it is running noisier pipes is pretty much a given otherwise consumption and power delivery will be compromised.

 

Is your mate in this video?

 

Up 4 on the rear. No wonder it wants to wheelie and fuel is impacted. Means higher in revs, so 70 is probably like 85-90 so will burn more

 

Surely it's all down to maths ..... in particular , percentages or ratios ( same thing really )

Any change in final drive gearing ratio is going to have effects on top speed , acceleration and fuel consumption ( at any given speed ) .

A made-up example :-

Changing from 43 tooth rear , to 44 tooth is about a 2.3 % increase in the number of teeth

So expect an increase in acceleration of 2.3 % , a decrease in top speed by the same amount , and 2.3 % more fuel used , at a constant 70 mph

Changing the front sprocket by one tooth will have a more dramatic effect
( because it's a bigger percentage change )
eg. 14 tooth to 15 tooth would be a 6.7 % increase

So we should see 6.7 % more top speed , 6.7 % less acceleration
and 6.7% better gas mileage at a constant 70 mph

I know that several other factors may be at work , but I find this useful as a rough guide

Just my two chetrum worth ....