v-twin gearing for barbs

[Lucius]

Any hints on v-twin gearing at barbagallo? Was thinking to drop one tooth on front.

I use third alot and is more oftern than not, not revving enough. Only through turn 2to3 third gear gets revved out heaps which would mean if i dropped one front tooth i'd use fourth through 2&3.

[Nero Diablo]

On your four speed kicker soft tail or your SS100 Brough superior?

[Lucius]

On your four speed kicker soft tail or your SS100 Brough superior?

gunbus-1.jpg

[TurboR1]

What sort of V-Twin? Are you riding a VTR250 or Sitting on a 200BHP Desmosedici? Or something in between?

[Lucius]

what sort of v-twin? Are you riding a vtr250 or sitting on a 200bhp desmosedici? Or something in between?

rc8r

[ninjaa]

Mmmm the rc8 that was pitted towards the end, near one of the driveways, with your wife? Bloody nice, sorry i've got no input

[quattro750]

trick is to get to max hp down the hill just before braking and hopefully leave it in one gear for 2345. that way you can focus on riding the thing through the technical part of the track. prbly 1 tooth on front if not adding to rear

q

[Lucius]

Mmmm the rc8 that was pitted towards the end, near one of the driveways, with your wife? Bloody nice, sorry i've got no input

yeah.

Sounds right to me quattro, think ill start with -1 on front and play around with it from there.

[TurboR1]

Twins are a bit tricky in the way they put out their power and torque so much differently to inline 4's.

Most of the 1000cc 4's tend to go 1 tooth down on the front and 2 up on the rear, generally that gives you a 2nd to 5th gear range. You most likely won't have to go that extreme as you will have enough torque down low to pull out off corners and at the same time you won't run out of RPM down the long straight.

As a general rule of thumb, 1 tooth on the front is equal to 3 teeth on the back. Additionally you don't want to go more than 2 teeth down on the front (unlikely you ever would want to) as the radius of the sprocket starts to get quite small and it will put a lot of strain on the chain.

[Termi-nal]

I've got a Honda VTR1000 SP2, which by no means puts out the same amount of power as your RC8 R, and probably doesn't rev out as high either: 122hp and 10,500rpm respectively. But to give you an idea, from my point of view, I've gone -1 at the front (16 - 15) and +2 at the back (40 - 42). Now keeping in my mind I'm not a terribly fast rider (avg 68 sec laps around Barbs), I'm hitting the red line and starting to run out of steam down the hill towards turn 7. I am definitely leaning towards putting the 40 tooth rear sprocket back on.

On a side note, isn't the Desmosedici a V4?

[TurboR1]

On a side note, isn't the Desmosedici a V4?

I was wondering if anyone was going to pick up on that.

[Lucius]

Twins are a bit tricky in the way they put out their power and torque so much differently to inline 4's.

Most of the 1000cc 4's tend to go 1 tooth down on the front and 2 up on the rear, generally that gives you a 2nd to 5th gear range. You most likely won't have to go that extreme as you will have enough torque down low to pull out off corners and at the same time you won't run out of RPM down the long straight.

As a general rule of thumb, 1 tooth on the front is equal to 3 teeth on the back. Additionally you don't want to go more than 2 teeth down on the front (unlikely you ever would want to) as the radius of the sprocket starts to get quite small and it will put a lot of strain on the chain.

I think -1 on the front should suit it well. At the moment exiting T7 it doesn't have enough rev's in 3rd (relying on torque to pull me out) and I'm bearly getting into 6th down the back straight. Also going through T2&3 it rev's it's nut off giving me quite a back vibration in the handle bars. Was thinking gearing down would give me more rev's in T7, a more useful 6th and I'd just use 4th gear through T2,3&4

[Drasius]

You were stock before correct?

[Lucius]

yeah

[Slipin]

I'd be curious what the international rider used in

Kings 08 . He was running a rc8 . then and had 3 mechanics working on the bike . Depending on ktm having changed the internal gearing on ur current stee . Be a long shot . But maybe ask who ever donated the bike dealer wise if they remember the ext gearing .

In any case shouldn't be to hard to find a solution with all the talent on the forum !! Iv got an sv1000 and looking at doin a few track days . But she's a lil shy on hp comp to the rc8 . Still their are slot of guys runin twins up their . I run a 16/42 520 set up with a heap of pwr mods prob 118hp ATM but bikes basically for stunting . Monos and show boating

[robwas]

Lap times will have an impact on the gearing required.
As your lap times come down you will need to use higher gears or more revs so from what you have explained then the 1 down on the front or two up on the rear would be a good start.
When you get faster you may find that you want to go back to the original set up as you are coming off turn 7 with enough speed to use 3rd in the higher rev range and turns 2, 3 & 4 will be good in 4th.