Thinking of one tooth less...

[dickturpin]

Can the clever people on here describe the pro's and cons of putting one tooth less on the front sprocket?

[ChristoT]

Can the clever people on here describe the pro's and cons of putting one tooth less on the front sprocket?

1 more tooth front gives you better top end, but worse acceleration.

1 less tooth front is the opposite - better acceleration, but worse top end speed.

Many people add a tooth front, and drop a tooth at the rea simultaneously - means the bike goes even faster than just changing the front sprocket - but again, acceleration will suffer somewhat. 

[dickturpin]

I realise it may be difficult to put into words but how much difference will it make? will that naughty front wheel pop up more?

[ChristoT]

I realise it may be difficult to put into words but how much difference will it make? will that naughty front wheel pop up more?

If you drop a tooth, yes (stunt bikers do this to their bikes), if you go up a tooth, then no. Doing this makes the engine do fewer turns to do 1 full turn of the back wheel. Means that at top rpms, the rear wheel is turning faster (ergo, you go faster). However, the torque and power struggle more - so the bike will accelerate slower, and the front wheel should pop up less.

That being said, I haven't donw this mod on a Fazer. The only way to find out - TRIAL AND ERROR!!!  :woot mokin

[mickvp]

without going too much into detail:

the standard final drive ratio for the fazer is 3.200 (15 teeth at front, 48 in rear). changing up a tooth at the front will give you a final drive of 3.000, and changing down to 14 teeth on front will give you a final drive of 3.429.

if these numbers dont mean anything to you, all they mean that is that (in the case of a standard setup) for every 3.2 times the front sprocket rotates, the rear wheel will spin once. the smaller this number, the less turns it takes to rotate the rear wheel once. this means for any given RPM of the engine, the rear wheel will be going round faster, and so the top speed will increase (but the acceleration will decrease by the same top speed gain).

the same can be said about going the other way, it will take more turns to rotate the back wheel and so the top speed will come down, but torque and acceleration will increase a given amount. you can work this out in the % difference between the gear ratios for a rough guide (real world changes will vary slightly from the theory in my experience, but its a good starting point).

so if you go down a tooth from 15 to 14, you will lose 6.68% of your top speed, but gain the same in acceleration/torque.

If you go from 15 to 16 teeth, you will lose 6.25% of your acceleration/torque, but gain the same in top speed.

As I say, take some of these with a pinch of salt, because increased wind resistance etc will affect top speed as well, so this is by no means exact...




















...I think :rollin

[mickvp]

jst found this site, they have a live calculator with the FZS data on the list. should explain it a bit better than my mindless ramblings :lol :

http://www.gearingcommander.com//

[Punkstig]

Swap the rear sprocket for +2 teeth, similar to dropping a tooth on the front, if for some reason you don't like the changes its easier to swap the rear sprocket than the front (if you don't have impact drivers etc to hand for the front sprocket nut that is, plus for me with the fzs model front sprocket nut issues I'd rather leave it well alone as much as possible!)

[Ian-man]

I dropped one tooth on the front and increased one tooth on the back. It has increased acceleration but the engine needs about 500 extra rpm at 70mph so at. A given speed it is more buzzy and the miles per gallon has suffered for the same reason.
If you like lots of twisty frenetic short blasts then the extra acceleration is a hoot. If you do lots of motorway or high mileage then you need to take this into account. I get about 170 miles to a tank on this setup with mixed riding so I am thinking of going back to 15 on the front and leaving the 1 extra on the back.

[ghostbiker]

2 up on rear peps up the bike without making impossible to control or keep down.
Did it on mine and like it a lot.
But remember it will throw the speedo out. I used a speedo healer but that ain't a cheap mod.

[ChristoT]

2 up on rear peps up the bike without making impossible to control or keep down.
Did it on mine and like it a lot.
But remember it will throw the speedo out. I used a speedo healer but that ain't a cheap mod.

Er - really?

That may be true for bikes where the speed sensor is mounted to the front sprocket / driveshaft, but on the FZS600 at least, the speedo is driven from the front wheel, nothing to do with the sprockets! Isn't the Thou like this too?

EDIT: I now see the Thou's speedo sensor is off the driveshaft. I withdraw (as the bishop said to the actress).

[slimwilly]

It is a good mod to do,1 down on the front,,as for less top end , well how often are you near the limit, 1 tooth down is a bout 5% i have read, so not a lot of difference.
It makes A road riding a pleasure , on overtaking cars just twist and go.
I never altered my speedo as 5% is easy to see on the speedo,use a sat nav to check the correct speed and cross check your speedo.


I have the standard back on at the mo because i cant find my 16 toother,i went back to it for the euro trip but will go to 16 tooth if i find the fucker,,moving house and you loose all.


A lot of fuss about nothing , do it and enjoy.

[bigbluebear]

I have dropped a tooth on the front and the difference in acceleration is very noticeable especially if you are invanised too. It does drop the top end down a bit, but how often are you flat out in sixth...a few seconds at most before you run out of road, unless you risk doing it on the motorway

Check out the links from Pats Motorcycle Page on the pro's and con's below and the performance comparison table

http://www.cartestsoftware.com/fz1/15too...ation.html

http://www.cartestsoftware.com/fz1/image...ntable.gif

[Tmation]

IIRC the gen 1 has 16 front 44 rear. Going down to 15 front can also lead to faster chain wear due to small front, thats why lots of people add extra to the rear. Conversely front sprockets are cheap and rears  more expensive, if you only doo 3 - 4K a year go with the smaller front.


Oh and get a genuine new tab washer, only a few quid on ebay

[locksmith]

Thinking of one tooth less...

Walk into any pub, go up to the biggest bloke in the bar and call him a w*nker.