Transmission swap on a Monster? want to go from 5 to 6 speeds

[mangeldbug]

I'm slowly frankenbiking my Monster M750S.  I swapped in adjustable forks from an S2R1000, adjustable rear spring from an S4, a slipper clutch from a 696...and after doing a few long trips where I am searching for an extra gear (just got back from the Indianapolis MotoGP) my husband was wondering about swapping in a 6-speed tranny from maybe a 695 or 800 motor for my stock 5-speed.

Is this crazy?  Anyone know what 6-speed transmissions may pop into my 750 engine?  Thanks!  

Did a quick search of a few key words and came up with NO results.  If someone has actually done this please link me...

[stopintime]

My S2R 800 now has 750 cases/big bore cylinders ++ with my 800 six speed in it - no mechanical mods required.

Mind you, the gear drum and neutral light switches are not compatible (won't work) so I ended up with a constant neutral light (allows me to run it with the side stand down and to start it in gear with the clutch lever pulled, but that also means it can be started in gear (!) and that I have to search blindly for neutral)

I don't know if you get an extra gear with this mod. Maybe the ratios are different from first through fifth...

[DarkMonster620]

there's a OEM kit for this . . .just, can't find the book with the PN

[caperix]

I think the OEM kit was just the 6 speed out of a M400.  The latter 620's got the same transmission.  The 695 & 800 have different ratios but should also fit in the case.  You may run into the same issue as stopintime with the nuetal switch but any of those transmissions should fit the case.

[DarkMonster620]

I think the OEM kit was just the 6 speed out of a M400.  The latter 620's got the same transmission.  The 695 & 800 have different ratios but should also fit in the case.  You may run into the same issue as stopintime with the nuetal switch but any of those transmissions should fit the case.

No, I meant a 6 speed conversion for the 5 speed . . . gotta find book with PN . .

[Speeddog]

The OEM kit was the same parts as what's in the 620/695/800 6-speeds.

Not all 620's came with 6-speeds, darks came with 5-speeds.

Compared to what's in your 750, the 6-speed would feel very much the same in 1st-3rd, then a more normal jump to 4th (rather than the big jump), a 5th a bit more than halfway between the 4th-5th, and then a 6th a bit taller than the 5th.

Not a much bigger range overall, really just diced up smaller and better.

For the amount of aggro involved for what you'd get, I'd recommend swapping in an 800 instead.
More juice *and* the 6-speed.

[weemonster]

I always thought the casings were too narrow.

[Dirty Duc]

According to Brad Black's site:
"The 6 speed gearbox from the larger engines won't fit the small 2v engines, due to the shafts being slightly further apart.  The new 6 speed gearbox from the 800SS/M engines will fit, and is much the same as the 6 speed gearbox from the 400 engine I am told.  Ducati Performance is also offering this gearbox kit as a part for the small 2v engines. "

[brad black]

According to Brad Black's site:
"The 6 speed gearbox from the larger engines won't fit the small 2v engines, due to the shafts being slightly further apart.  The new 6 speed gearbox from the 800SS/M engines will fit, and is much the same as the 6 speed gearbox from the 400 engine I am told.  Ducati Performance is also offering this gearbox kit as a part for the small 2v engines. "

I was wrong.  the 400 box is totally different ratio wise.  it's a very wide ratio box.

dp kit was 96429098B.

all the 620 we got prior to 2005 were 5 speed.  I think the ones with two piston calipers were also 6 speeds, 2005 and 2006.  they do feel much sportier.  6 speed has a big gap 1 - 2, then they're fairly close above that.

I bought a 696 6 speed box to try to fit to my pre 98 bikes, will need a few mods of the cut off wheel kind.

for the money it will cost, i'd buy an 800 motor.  or buy a 900ssie motor and get serious.  or a 1000.  how about an 1100evo?

[mangeldbug]

Great feedback all, thanks.  Lots to consider and price out.  If I am going to be splitting cases (something we've done before, just never on a Ducati) my husband suggested waiting until internal bearings needed to be replaced or something.  Which wouldnt be for a while.  Or ever depending.  I have about 24k on the bike now.  

What I was really hoping to accomplish with this is not really an "extra gear" but better ratios with the 6 speed vs the 5.  I dont ever really need another gear unless Im blasting down the highway, and the only part of the gear box Im really not thrilled about is the big difference between 1st and 2nd.  Im winding it out and I feel like I have too much torque in 1st in really slow tight corners, but Im lugging in 2nd.  Seems the 6 speed wont really improve this.

It is a a kind of involved wrenching project.  ...maybe if I can find an 800 motor for a steal I can do that down the line.  My 696 slipper should also fit in there...or did the 800 Monster come with its own slipper?

[Dirty Duc]

800ie was the regular clutch, 800 S2R was APTC...

[stopintime]

....and I feel like I have too much torque in 1st in really slow tight corners, but Im lugging in 2nd.  Seems the 6 speed wont really improve this.

 ....My 696 slipper should also fit in there..

The 1 - 2 gap is my 6 speed experience too    It can be made somewhat less problematic by gearing it down with smaller front and/or larger rear sprockets, but that hurts at high speeds.

The 696 APTC will fit and it's without the 'dual-mass' drive and spring loaded driven (clutch basket) primary gears. Those are NOT well suited for hard use - broke two of them last year... YMMV

[brad black]

as a comparison, if you assume an equivalent first gear, 6th is like adding 2 teeth to the rear compared to 5th.  so almost like changing from a 14 tooth to 15 tooth front sprocket.  which is what I was sometimes doing depending on my mood on my 750.

the big block wide ratio box is much wider, whereas the big block close ratio 6 speed box has the same spread as your 5 speed.

on the tt-f1 forum there was a guy building an 800 race motor that they were putting a 5 speed in , as they say the 5 speed was worth 2 seconds a lap over the 6 speed due to less shifting.  6 speed feels better on a road bike ime.

that's why I say go big block, and get a real 6 speed.

[mangeldbug]

I had a 15 tooth front stock, so I dropped to a 14 tooth when I was commuting on the Duc all the time.  Now I have a dedicated commuter, and the Duc is for twisties and touring.  I think Im going to put the 15 tooth back on and see what that does for me right now.

Thanks again all, great info!