Lowering Revs with sprockets

[ElkWorks]

Did a test run last night to an area im thinking of moving to, on the fazer as the drzs petrol tank isn't big enough 

the run is approx. 70-80mph stuff for around 40 miles, in which the revs are like 7k, has anyone used different teeth sprockets on the back to get the revs lower? and if so, how have you found it?

I couldn't sell the bike, so im gonna run it into the ground instead...

[Dead Eye]

Might be worth changing the front sprocket instead - a 1 tooth change on the front is equal to 3 teeth on the rear. It is also easier to access and change, plus you can check to see if you have the uprated 12mm sprocket nut ^^

You can mess around with the gearing here; http://gearingcommander.com

80 MPH in 6th is approximately 6400 RPM, by going up one tooth on the front, this drops to 6000 RPM

[johna6968]

+1 for larger front sprocket if economy is the goal..

[Paul]

I put a different rear sprocket on mine for a while, it's about 8 years ago, and I think it was off the YZF 750.


It did the job you're on about. 

[elbrownos]

80 MPH in 6th is approximately 6400 RPM, by going up one tooth on the front, this drops to 6000 RPM

That doesn't sound right, I've got standard gearing and 80 mph in 6th is nearly 7k rpm as ElkWorks says.

[Dead Eye]

I'm just going by what is shown on gearing commander - I don't remember what the speeds were on my 600. I think I remember 5900 RPM in 6th being 70mph though and gearing commander says 5600 so its possible someone has made a mistake with it

The 1000 gearing is correct though :|

Can any one confirm the correct sprocket ratio just to make sure? It's showing stock as 15F 48R

[darrsi]

I'm just going by what is shown on gearing commander - I don't remember what the speeds were on my 600. I think I remember 5900 RPM in 6th being 70mph though and gearing commander says 5600 so its possible someone has made a mistake with it

The 1000 gearing is correct though :|

Can any one confirm the correct sprocket ratio just to make sure? It's showing stock as 15F 48R

Yeah, that's correct.

[ElkWorks]

Cheers guys

I'll try +1 on the front then, and get a new chain and stock rear whilst im at it!

[Flak]

Cheers guys

I'll try +1 on the front then, and get a new chain and stock rear whilst im at it!

That's exactly what I did. Doesn't make much difference on the TLGP and a slight but noticeable drop in revs in top.

[Lumpy]

I went 4 down on the rear first time but 1 up on the front the last 3 changes, much better, 60mpg commuting and 250 miles out of a tank. One, and the only issue, was a new tyre is VERY close to the hugger at the front as the wheel is further forward, this was negated, in the main, by moving the hugger forward too. Much better than a standard set up.

[taurus66]

I changed my sprockets front up two teeth and two down on the rear and now at 70 my rpm is just between 4500 and 4750.. Have only rode it once so no absolutely sure. Will ride again today and take a better note.
But did make a massive difference, I wanted lower rpm for long distance, not so much for economy or top end.  Plus I have fitted krauser k2 panniers. So should make for a nice mid size tourer.

[Millietant]

After reading lots of recent posts on here in various threads, about gearing, I'm going with 2 teeth more on the front and 2 teeth less on the rear.


I've mentioned this is another post, but every bike I've owned, except for my Aprilia RSV, has felt very under-geared, especially my old KH 250. So, on every one of these bikes I've ended up going with 1 tooth more on the front and 2 teeth less on the back.


This has meant that I've never had to move move the wheel forward, or use a longer chain and in every case it's resulted in a much better cruising "feeling" and better economy. Riders for a long time have wanted instant acceleration at the touch of the throttle from a cruising speed in top gear, so manufacturers have geared the bikes as standard to cater for this as much as possible/practical - everything's a compromise.


Anyway, sprockets are cheap, so give it a try - just remember, old/stretched chain and new sprockets don't go well together (neither does a new chain on old worn sprockets).

[Lumpy]

Hmm, 2 up un front and 2 down on rear may give issues on steep climbs or heavily loaded to keep the torque up but try it and see, thats the way.

[clayt74]

With standard sprockets I get 60mph @5k
70mph @ 5.9k
80 mph @ 6.7k
Didn't try higher speeds.... Honest gov!

[ElkWorks]

I still haven't done this, but need to order new chain and sprockets anyway soon.

Tempted to go two up on the front now, and maybe one down on the rear.

I'll then use my drz4 sm for honing around on!

[Lumpy]

I still haven't done this, but need to order new chain and sprockets anyway soon.

Tempted to go two up on the front now, and maybe one down on the rear.

I'll then use my drz4 sm for honing around on!

2 up on the front and a standard length chain will cause the tyre to drag on the hugger if you have one fitted, I know this :-)


1 up on the front is the equivalent of 3 down on the back, 2 on the front the equvalent of 6 on the rear, it is quite drastic but would be interesting to know. I have tried 4 down on the back, and now run standard rear and one up on the front with standard length chain. Trouble is, 7k is about 100ish and the flat spot causes slow accelration when in top, easier to drop a gear to 110 and then hook top again. Depends how you ride but you con't want the torque of the engine to struggle in the higher gears on hills, 2 up on the front should be just about okay but will play havoc in certain situations. Standard gearing is far too buzzy for me, feels like a gear missing

[Paul]

I put a 45 tooth rear sprocket on mine, made a measurable difference.


Still got the sprocket, it's done about 9000 miles and is in good condition.


If anyone wants it, it's free to a good home, but you'll have to collect it.


I live in Bolton (North Manchester).

[Biker_Bob]

I went +1 on the front.
It takes less than a 1/4 hour (assuming you've got an air impact wrench) and has knocked about 7-800 RPM off in top gear.
I haven't noticed any difference in acceleration, bloody fast is bloody fast if you ask me.
It's a lot more relaxed now and 7K RPM cruising at 90(ish) is fine for the big miles.
IIRC it's doing about 4.5K RPM at 60MPH, it still picks up from there but a change down to 5th is needed for a quick squirt round the cars.
One thing though, it struggles to rev out in top, it gets to about 125 and runs out of puff so for top speed runs it's a case of 5th and scream it.

***All speed tests were done on private roads****

[Lumpy]

I went +1 on the front.
It takes less than a 1/4 hour (assuming you've got an air impact wrench) and has knocked about 7-800 RPM off in top gear.
I haven't noticed any difference in acceleration, bloody fast is bloody fast if you ask me.
It's a lot more relaxed now and 7K RPM cruising at 90(ish) is fine for the big miles.
IIRC it's doing about 4.5K RPM at 60MPH, it still picks up from there but a change down to 5th is needed for a quick squirt round the cars.
One thing though, it struggles to rev out in top, it gets to about 125 and runs out of puff so for top speed runs it's a case of 5th and scream it.

***All speed tests were done on private roads****

mine doesn't quite rev out but I am a heavy fooker, but shows 140 plus on the speedo with +1 on the front. My speed testing is done on public roads :-)

[taurus66]

Other than pulling off, I don't think there will be much hassle. I will soon have the bike fully kitted out with krauser k2 panniers and top box. Total storage of just over 100 litres. Should itseem lazy on steep inclines I could always drop a gear.

[taurus66]

Mind you, took the bike out this evening.. At 40 mph 2500rpm, 70mph 4750rpm,

[Lumpy]

Mind you, took the bike out this evening.. At 40 mph 2500rpm, 70mph 4750rpm,

far better than standard gearing, 120 tyre is far better too

[midden]

80 MPH in 6th is approximately 6400 RPM, by going up one tooth on the front, this drops to 6000 RPM

That doesn't sound right, I've got standard gearing and 80 mph in 6th is nearly 7k rpm as ElkWorks says.

I was going to say nearer 6k for me, so I'll have to go out for a spin later to double check....

[Mick-H]

Might have a try of this +1 tooth on the 1000.

[ElkWorks]

So, I finally got round to doing this over the weekend, hurried up by the fact my front sprocket started cracking and falling to pieces! 

+2F, -1R and new chain.

30mph - 2.1k(ish)
40mph - 3k
60mph - 4.5k
70mph-  5k

so theres approx. 1500-2000rpm drop in the revs at identical speeds to standard setup, and in all honesty it hasn't lost as much acceleration as I feared.

next test in two days is fuel consumption, on stock its averaging just over 60mpg.

I kind of wish id done this for donington now as I was so far up the rev range constantly to get the speed I needed, and the bike averaged 25mpg....



only in novice as my first track day in years, but did a 2.04 and beat a load of dedicated track bikes, including an R1 which I decided to gun for on the last session. he wasn't expecting me to come past on the brakes  (I say brakes, but due to my rear brake being seized, I was only using the front!  )