Noob Error.

[Guest]

Basically, I got a new chain & rear sprocket. Didn't realise the previous owner had fiddled with the gearing and now my gearing isn't how I want it to be. It's kinda back to standard now and feels horrible. Rather than buying a new sprocket and going to the effort of taking the wheel off, I was thinking I could easily and cheaply put a 14t on the front to put it back to where it was. Would this, for any reason be a bad idea? It's a CBR600 1999, it gets thrashed a bit (if that makes a difference). Thanks

[uk190]

google gearing calculators. it will tell you what sprcket combinations work.

tbh, if you changed the chain and rear sprocket you should have changed the front. that way you will garantee that the pitch matches etc.

[Tango]

Welcome to the Forum mate.......pop over to the Newbies section and introduce yourself when you can.....

So what is the standard size front sprocket for that bike?......reducing the front sprocket by 1 tooth will increase the acceleration....but the tradeoff is higher revs when cruising and obviously less MPG when cruising at a set speed compared to the standard sprocket.....

Reducing the front sprocket by 1 tooth has a bigger effect than changing the rear sprocket by 1 tooth.....so it really depends what you are after.....

Changing the sprocket sizes is common practice....and doesn't normally present any problems.....

[Tango]

BTW....deleted the duplicate posts.....

[Guest]

Riding my bike is one thing but I literally have no idea what I'm doing in regards to fixing bikes, gearing, anything. Before, I could sail up to 140 and creep to 160 but now, in the time I would've been at 140, I'll be doing 110. Now it would take me so long to get to 140, it would be dangerous. The acceleration is poor now, it doesn't pull me through the gears. I want it back the way it wad really. It was a lot quicker. You reckon I should just buy a whole new c&s kit?

[uk190]

Riding my bike is one thing but I literally have no idea what I'm doing in regards to fixing bikes, gearing, anything. Before, I could sail up to 140 and creep to 160 but now, in the time I would've been at 140, I'll be doing 110. Now it would take me so long to get to 140, it would be dangerous. The acceleration is poor now, it doesn't pull me through the gears. I want it back the way it wad really. It was a lot quicker. You reckon I should just buy a whole new c&s kit?

 

not if, as stated in your first post, youve already just bought one. just buy a smaller front sprocket.

for future reference, the amount of teeth is stamped onto each sprocket.

check this out http://www.sprocketcalculator.com/

[Guest]

Ok, so had a bit of a fiddle. My gearing is 16 on the front and 44 on the back... Would replacing the 16 with a 14 be a bad idea?? Would I get my snappy acceleration back?

[uk190]

what did the calc say?

and yes, a smaller front sprocket increases acceleration, just like it does on a push bike.

[Guest]

It says: 14T 44T (ratio)3.14 (torque)+12.5% (speed)-12.5

Surely that suggests I'd lose speed?

[Stu]

try this one http://www.gearingcommander.com/

[Tango]

It's a trade off mate......smaller front sprocket = faster acceleration/lower top speed....and vice versa.... All of this is to a point obviously......you can't put a huge front sprocket on and expect to hit 200mph.....

Don't forget that if your speedo is driven off the gearbox or the ECU then any changes to the gearing by changing sprockets away from standard will introduce errors in your speedo reading.....

[uk190]

It says: 14T 44T (ratio)3.14 (torque)+12.5% (speed)-12.5

Surely that suggests I'd lose speed?

 

acceleration increased = top speed reduced.

you asked for increased acceleration, not an increase in top speed. yhou cant have both without increase engine power..

[buggerit]

Im in the same place at the minute. My cb has a top speed of 121 if I drop a front sprocket by 1 I get a lot more acceleration I checked on gearing comander.com but a top speed of 113. Or I can drop both by 1 get better acceleration and a top speed of 116. For me I dont use top speed too much im more after acceleration. Im guessing it will only throw the speedo out slightly like this.

[Guest]

I know that but before I thought it was a nice combination of acceleration and top end. I thought most 600's top end was about 160 anyway, so I was suprised to find out that before it was geared for acceleration. However, hitting 140 would take a hell of a lot of road at the moment. Either way, I just want to know if it would be a bad idea to leave the rear on there (44t) and whack a 14t on the front (from 16).

Another thing, even after all of this, my fuel consumption actually has got worse. Any ideas what that could be? Seems counter-intuitive.

[Tango]

As I said...be carefull that your speedo is reading correctly.....and this will also affect the odometer......could be that previously your speedo was reading 160....but you were in fact doing 140......check using a Satnav....

2 teeth down on the front sprocket is a big change mate.......unless you are really looking for drag-strip starts all the time I'd be inclined to take it down just 1 tooth and see how that goes.....

[uk190]

have u still got the old sprocket tht you removed?

if so look to see what size it is and calculate what size front sprocket would give the same final drive.

failing that, buy new sprockets and experiment on the track to see which ones suit your expectations the best.

[Guest]

Tango- It has a speedohealer on it to compensate for gearing. I'm guessing that switched it to a more accurate reading...I hope.

[Guest]

Cheers Uk90.. I think I'm just gonna put a 14T on the front and see how it goes. Worst case scenario, I take it off and put old one back on. Only £25.

[uk190]

Tango- It has a speedohealer on it to compensate for gearing. I'm guessing that switched it to a more accurate reading...I hope.

 

i dont think speedo healers are automatic. fairly sure the one on my gsxr5750 had to bee adjusted manuallly in increments. ie 3% plus etc.

[Stu]

the healtech speedohealer v4 is not automatic and has to be programmed but can be done in increments of 0.1%

not sure on earlier models though!

[Mr Fro]

Maybe bear in mind the chain length, I have a few sprockets kicking about and match them up so I can vary my final drive whilst using the same chain.

[Guest]

Can I not just move the wheel back?

[Mr Fro]

Of course, but there are limits. You still need to be able to adjust the chain to set the correct slack. Plus I'm lazy and don't want a fortune in random chains kicking about in the garage.