Sprocket Size vs MPG - Help!

[boz469]

Gday,
first post here... We have just scored an AT (2000 RD07) after some time of debating whether to get one... It's a low mileage (15k) example with a few cosmetic issues due to prolonged storage, however very happy with the donation indeed...
It is being rebuilt to be used for a partially-handicapped rider, one of our lads who got hurt in Afghanistan... The AT will be made into a part-time trike, by being fitted with hydraulic 'training' wheels which deploy at speeds of under 5mph (safety feature to allow normal cornering).
We're also working on a BMW R1200C (which will be a ride-into trike), but that's a different story... The aim is to use these for a charity fundraiser (H4H) and by the new owners of the bikes themselves...

Now then, not having a detailed clue about these prior to taking up the project, I spent the entire time on the first ride looking for a non-existent 6th gear. It seems a complete oversight by Honda for not designing it with a 6th gear, but that's way above my pay bracket to be concerned about...

What I'm trying to achieve is purchase some off-the-shelf sprocket kits which will reduce the rpm and improve MPG, ie smaller front/larger rear or combination of both.

Is there a supplier which does this? If so, is there a variety of sizes and how much are the kits?

Thanks for your assistance in advance!

Kind Regards
Boz

[brko]

Hi
I normally use M&P/Busters for sprockets.
By the way you need larger front, smaller rear to reduce rpm's.
I went as low as 40t on the rear, some went further by adding 1t bigger front sprocket. Lifting needle with small washers helps improve bottom end.
Cheers

[boz469]

brko,
many thanks for the heads-up, didn't even realise what I'd written...
Would these be available off-the-shelf then? And how much did they set you back?
Cheers
Boz

[foz1969]

hi, welcome & good work, not that I've heard any dangerous reports, ( more "not as good as" or "wore-out much quicker than etc" ) but there seems to be a common thread to do with using original honda front sprocket ( with rubber cushion ) and original front brake discs. I normally run a 43 tooth ( orig-45 ) rear sprocket, not for Mpg, but to keep the revs/noise down slightly on the motorways. Much less (my opinion) than a 43 tooth rear sprocket would make travel around town very jerky- & could lead to damaging the front sprocket drive- which is the fear of fears for all AT riders. only my pennys worth. Anyway... good-luck with the project, any questions or probs & I'm sure that some of the AT Pro's will try and remedy them, starting with the easiest & simplest solutions.

[brko]

hi
check it out
www.m&p.co.uk
cheers

[underbeing]

I just replaced my rd03 chain and sprokets for the first time. I was suprised to find that the standard was 16/49. I'd been running 16/39. I thought that was how it was meant to be and I liked it. But now its like a new bike, i can overtake where ever i like! The dual carriageway speed seems far too revvy, but i don't really mind.

[Thunder]

I just replaced my rd03 chain and sprokets for the first time. I was suprised to find that the standard was 16/49. I'd been running 16/39. I thought that was how it was meant to be and I liked it. But now its like a new bike, i can overtake where ever i like! The dual carriageway speed seems far too revvy, but i don't really mind.

Standards 16/45 surely?

[underbeing]

definitely 16/49
thats what WEM sent as standard
I was about to sell my bike but now it feels like a different bike so i'll keep it for a while at least.

[Whealie]

I have a 17 front and 43 rear on mine, hardly used, and am going to be fitting standard RD04 when I finish the rebuild so yours for the taking if you'd like them.

It does make cruising at lower revs so cuts consumption on a long trip but about time has little effect on overall fuel consumption because you are simply in a lower gear to keep the revs up when in town.

What I did enjoy was leaving the lights and changing about twice to the four gear changes other bikes had to make. Feels just as as powerful but with fewer gear changes.

To ride at 30mph speed limit requires third gear though otherwise you get the judders.

Not sure if it is possible to undo the chain rather than just cut it off, but you'd be welcome to that too. Or just get yourself a new chain.

[myfirstxrv]

I'm in the 17/43 club.
Much better on a run and cruises at motorway speed much better.
Well worth the tradeoff for being a bit slower off the mark.
MPG not much changed (think this is due to going faster...)