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Spjallen 10-Aug-2012 13:41

Class A Gearing
 
Just playing with gearing for Donny GP. Lots of riders seem to think 15t front is the way a head and gear for speed, so 15 44/45?

Others seem to use a 15t with 48 rear and others 14 with 42! What's the best and why? Pieman don't answer, you just tell me less brake and more throttle and always use 14 46!!

:eek:

skidlids 10-Aug-2012 14:23

some of the differences are dependent on if its a 5-Speed or 6-Speed box.
And what works for one rider doesn't always work for another due to different styles and corner speed.
Case in point, Dallas tried running the same gearing at Cadwell as Andy C, but found it didn't work for him
Both have 6-speed engines which both had a rebuild pre season at Louigi Moto

I don't stand a snowballs chance in hell of using the same gearing as either of them as I carry nowhere near their corner speed.
So i'll probably start with 14/46 as usual

dunlop0_1 10-Aug-2012 15:10

Quote:

Originally Posted by Spjallen
Just playing with gearing for Donny GP. Lots of riders seem to think 15t front is the way a head and gear for speed, so 15 44/45?

Others seem to use a 15t with 48 rear and others 14 with 42! What's the best and why? Pieman don't answer, you just tell me less brake and more throttle and always use 14 46!!

:eek:



Yes you know I will tell you that. :frog:
and the two wannabe's :p (Andy and Dallas) couldn't get within 1 second of the Cadwell lap record.
Can't just remember who holds it but I bet he had 14/46 fitted. :lol:

Spjallen 17-Aug-2012 12:30

Okay I still don’t understand properly.

If I were to run a 15 / 48 that would be similar to a 14 / 45 on ratios. Apart from the riding styles and personnel preference argument, what is the actual benefit and why would you run one than the other?

I get the benefit of the smaller front sprocket should equal quicker acceleration, smaller rear sprocket for top speed argument, but why would you choose one of these gearings over the other??

banger san 17-Aug-2012 12:56

Quote:

Originally Posted by Spjallen
but why would you choose one of these gearings over the other??


Probably as simple as those were the sprockets that came with the bike

Cranker V2 17-Aug-2012 13:15

to ahcieve drive out of corners, reduce gearshifts between corner, het max revs at the end of the longest straight. These are a few of the parametets that people use to define what gearing to run. Add in rider weight (porky boy or skinny chick), wind strength, wind direction, YOUR corner exit speed, OYU coner entry speed, bhp, torque, style of riding. All these factors impact upon the ideal gearing............

dunlop0_1 17-Aug-2012 16:09

Quote:

Originally Posted by Spjallen
Okay I still don’t understand properly.

If I were to run a 15 / 48 that would be similar to a 14 / 45 on ratios. Apart from the riding styles and personnel preference argument, what is the actual benefit and why would you run one than the other?

I get the benefit of the smaller front sprocket should equal quicker acceleration, smaller rear sprocket for top speed argument, but why would you choose one of these gearings over the other??



Divide the big one by the little one so 48/14 = 3.428 which means (i think) the little one has to turn 3.428 times to make the big one turn once.

Thus setting a datum point for you to decide what gearing may suit your style/skill or haircut. :D

badgerpilot 17-Aug-2012 17:18

Run whatever feels good to you, if what you've got on suits you then stay with it, I've not changed since Brands last year. :eek:






We are talking about underpants aren't we? :D

Spjallen 17-Aug-2012 17:48

My haircut, or lack of it, is just fine thank you Pieman, it's my corner speed I need to sort out!!

bradders 17-Aug-2012 18:25

Its an art. I learned a great lesson at Doom lastyrar which has helped o end mbut alsomfind as I go thru a weekend (new bike) i need to go gradually smaller on the rear as my speed picks up and I start running out of revs on the fastest part.

bally71 24-Aug-2012 16:58

i've been on 14:42 ... is that geared a little low then? :lol:

Yogi 02-Dec-2012 20:23

Quote:

Originally Posted by Spjallen
Okay I still don’t understand properly.

If I were to run a 15 / 48 that would be similar to a 14 / 45 on ratios. Apart from the riding styles and personnel preference argument, what is the actual benefit and why would you run one than the other?

I get the benefit of the smaller front sprocket should equal quicker acceleration, smaller rear sprocket for top speed argument, but why would you choose one of these gearings over the other??


As you say this is the same ratio 3.2 and 3.21 respectively, so wouldn't make any difference to acceleration or top speed at rev limit, but with 15/48 you are running 4 teeth more than 14/45, so for the same length of chain the rear wheel will be 2 links closer to the swing arm pivot, (assuming there is enough adjustment) In theory, this shorter wheelbase will make the bike turn more quickly, but it will be less stable at high speed, and maybe lift the rear when hard on the brakes.

I have 14/46 at the moment, Roxy has 15/46 both with 5 speed box, the consensus seems to be not to mess with sprockets too much .

So what gearing do you all use and does anybody change gearing for different circuits, or is it not necessary ????

Spjallen 02-Dec-2012 22:23

I changed things a lot last year from circuit to circuit. To be honest I think you need to find a gearing you like and work from there. I know the pieman ran 14 46 all year when he won the championship.


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