Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > Class A Gearing

[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??

[banger san]

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]

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]

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.

[badgerpilot]

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.






We are talking about underpants aren't we?

[Spjallen]

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

[bradders]

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]

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

[Yogi]

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]

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.