F/R sprocket change on the 650

[Daimo]

Looking to movehouse, and travel will go up to over 1600 miles per month on the commute, most of which is on a long empty motorway.  Current gearing (standard) is really short, and using the gearing calculator, putting a 16 tooth on the front should give me about another 5mph at the same revs I generally sit at.  Its also roughly the same if you put a 2 teeth down on the rear

Has anyone done either of the above.

I've just found that the difference between what speeds I'm doing, and increasing engine revs in top by 500rpm, gives me a 9mpg difference in economy (with a tailwind I may add) which can be the difference between a 2 or 3 day fillup for me.

Thing is, its not exactly got much grunt in top gear, and whilst that doesn't bother me in the slightest for what I use it for, I'm wondering if the gearing change has that much difference on power usability.

Also hoping it'll help with the slower speed filtering, having to knock between 2nd and 3rd is annoying, where as a longer gearing means 2nd should be sufficient.

So, anyone changed their gearing on the the diddy 650, how's it ride?

[joethebike]

I've gone the full monty on my K5 650 with a 16T countershaft and a 45T rear sprocket and find it a perfect compromise for my style of riding. If you want a blast through the mountains the lower gears are there to use and for motorway use the motor feels much more relaxed at the lower revs.
Top gear is happy at engine speeds 4000 and above with a true 100kph at about 4500.
On 80 kph roads I generally use 5th gear at just below 4000rpm to sit on the speed limit.
However, don't expect much improvement in fuel consumption as my experience shows less than 1mpg.

[Hondaman]

There is another current post with answers to your questions.
1600 miles/month. Blimey!!!

[Willie Fawcett]

I have a 16 t sprocket spare , I live at GU7 2NF , only done under 50 miles on it , yours for £5 collected .  07724339898 .

[Willie Fawcett]

Sorry, sprocket not available as can not find it 

[Sam]

I fitted a 16 tooth front sprocket to my Wee when I had it. It made for a less buzzy & more relaxed ride at motorway speeds. But I noticed no difference in the mpg so I wouldn't recommend it if you want to improve fuel consumption!

[greywolf]

Sprocket changes do not affect mpg. The lower rpm and lower torque bhp at said lower rpm, requiring a slightly higher throttle opening, offset each other.

[Daimo]

I've gone the full monty on my K5 650 with a 16T countershaft and a 45T rear sprocket and find it a perfect compromise for my style of riding. If you want a blast through the mountains the lower gears are there to use and for motorway use the motor feels much more relaxed at the lower revs.
Top gear is happy at engine speeds 4000 and above with a true 100kph at about 4500.
On 80 kph roads I generally use 5th gear at just below 4000rpm to sit on the speed limit.
However, don't expect much improvement in fuel consumption as my experience shows less than 1mpg.

This is actually was I thinking of doing too.

As for fuel consumption, that sucks.  Its such a large difference between 6k and 6500k that I thought that bringing the revs down would help, especially over a 20+ mile motorway distance (rest is in the city).

For the sake of a £20 front sprocket, might try it anyway.

1600 odd miles yup, doing 1100, only got it brand new at the end of August last eyar and already got 8200 on it.  Get 4 days at the moment from a tank, and despite everyone saying the fuel counters out, mine seems to be right, even under-estimating sometimes.  I use the fuelly app and add it each time I fillup.  Even sitting at 6000rpm odd and town riding, still getting an average of 59-60mpg.

[greywolf]

It's speed that kills fuel economy much more than rpm. Bikes are aerodynamically very dirty. Go a little faster and use a lot more energy.

[obalanga]

it may be a pain but filling the tank fully means that on day one you are carrying about 10 kilos extra than you need. Keeping to 55-60mph ( I know, it's like asking a wolf to shepherd sheep) and carrying just what fuel you need will go further in saving you fuel. I had a 50 mile daily commute and worked out a tenner was 2 days of travel. Never failed me once.