Building a 7/11 hybrid motor. Worth it?

[Oilschooled]

Hi All

Currently have a 750L in the beginning stages of full bike rebuild. Am also in possession of an 1127 lump. Was just wondering if building a hybrid motor from the two was actually worth the hassle or not? Obvs gaining the 6th gear is a primary bonus but am I missing any other benefits? 
The 750 block is scabby as hell & been poorly stored so in order for a decent renovation, would need to be removed & cleaned up anyway, so would like to explore all options now. Cheers 

[Captain Chaos]

Welcome on OSS. Post some pics of your 750L. Or better start a build thread.

If the 1100 engine is in good condition, just use it as it is. A 6th gear will not make much difference on a streetbike.

[Swiss Toni]

Welcome. Pictures, or it didn’t happen!

[wraith]

Welcome to OSS,

 

Unless you like building engine's for the fun of it, not that much gane to be had.

[fab]

12 hours ago, Oilschooled said:

Hi All

Currently have a 750L in the beginning stages of full bike rebuild. Am also in possession of an 1127 lump. Was just wondering if building a hybrid motor from the two was actually worth the hassle or not? Obvs gaining the 6th gear is a primary bonus but am I missing any other benefits? 
The 750 block is scabby as hell & been poorly stored so in order for a decent renovation, would need to be removed & cleaned up anyway, so would like to explore all options now. Cheers 

750L is a six speed

[Oilschooled]

1 hour ago, fab said:

750L is a six speed

Yea……..? I said that. What’s your point? 

Edited October 16, 2021 by Oilschooled

[dupersunc]

You fit the  750 gearbox into the 1127 cases, then do a mix and match clutch. No need to use the 750 cases. 

6speed conversion is worth while on a race bike, not sure it's worth it on a street bike.  They're supposedly a bit fragile with 1127 torque going through them.

[jonny1bump]

The point of the 1100 is it torque monster the 750 is rev monster, hence huge difference in red line, hence gearbox has been built to suit. I've seen so many broken 11 gearboxes and snapped dogs off gears myself which was scary so really can't understand why u put weaker gearbox in 11, but peeps do use them on track I personally wouldn't but I understand that can restrict you on certain tracks, depends if racing seriously or just playing too.

Decide where you want your power, choose ya engine and tune and cam to suit.

[dupersunc]

1 hour ago, jonny1bump said:

The point of the 1100 is it torque monster the 750 is rev monster, hence huge difference in red line, hence gearbox has been built to suit. I've seen so many broken 11 gearboxes and snapped dogs off gears myself which was scary so really can't understand why u put weaker gearbox in 11, but peeps do use them on track I personally wouldn't but I understand that can restrict you on certain tracks, depends if racing seriously or just playing too.

Decide where you want your power, choose ya engine and tune and cam to suit.

The correct answer as you know is to tune the knackers off a 1100 motor. The ratios are shit for track work, even for a stock motor, they are proper touring ratios.

The real answer is a 6speed Nova gearbox, but they are a tad spendy.  For a mild motor I firmly believe a 750 6spd is worth while, as long as you are prepared for the extra maintenance.

Edited October 17, 2021 by dupersunc

[Captain Chaos]

1 hour ago, dupersunc said:

The correct answer as you know is to install a turbo.

Fixed

[Captain Chaos]

Still waiting for pics of the 750L by the way.

[Joseph]

I daily a fully rebuilt 1216 with cams, head job, RS carbs etc etc and 6 speed box. Done 4500 km so far and not all that conservatively.

The gearing of the six speed is super cool compared to the 5 speed. The way it goes through the gear range is good

I would say it's worth it, and a street bike doesn't get thrashed like a track bike, so the lifespan of the box shouldn't be too much of a concern.

 

[TonyGee]

im always hunting for the 6th gear on 1100's/1200's  

[manden]

On 10/17/2021 at 4:50 PM, Joseph said:

I daily a fully rebuilt 1216 with cams, head job, RS carbs etc etc and 6 speed box. Done 4500 km so far and not all that conservatively.

The gearing of the six speed is super cool compared to the 5 speed. The way it goes through the gear range is good

I would say it's worth it, and a street bike doesn't get thrashed like a track bike, so the lifespan of the box shouldn't be too much of a concern.

 

Do you have any vid through the gears?

[Joseph]

I don't.

Wouldn't know where to start to do one either

I don't track the bike either so getting it healthily through the gear range would require reaching speeds not well looked at by the plod ? 

It would be subject to each and everyones interpretation anyway