6 speed 1127 sprocket sizing

[Damienga15de]

Whats the recommended sprocket sizing for a 6 speed 1127, i currently run a 14/48 will this work, 

[Joseph]

16x43 i'm running on mine. That was sorted out via www.gearingcommander.com and their online configurator. It gives identical top speed result on a GSXR 1127 with GSXR 750 gear ratios

Edited July 26, 2022 by Joseph

[Gixer1460]

10 hours ago, Damienga15de said:

Whats the recommended sprocket sizing for a 6 speed 1127, i currently run a 14/48 will this work, 

That's pretty short gearing for an 1100 even with a 6 speed - I bet it's a lot of changes! The 14 front isn't good for the chain - 15 or 16 better and if you like the feel of current gearing then either a 51 or 54 respectively would match those fronts. IMO 15/45 is good all round ratio's

[Joseph]

On 7/27/2022 at 10:16 AM, Gixer1460 said:

That's pretty short gearing for an 1100 even with a 6 speed - I bet it's a lot of changes! The 14 front isn't good for the chain - 15 or 16 better and if you like the feel of current gearing then either a 51 or 54 respectively would match those fronts. IMO 15/45 is good all round ratio's

At 11000 rpm in top gear, 1127 with 750 6 speed gearing theoretically gives :

15x51 : 192 km/h

15x45 : 216 km/h

16x54 : 205 km/h

16x43 : 257 km/h

At 5000 rpm, stock 1127 stock sprockets 

15x48 : 259 km/h

Edited July 29, 2022 by Joseph

[Gixer1460]

Eh? How does 15/45 get 216kph and 15/48 get 259kph when the latter is lower geared than the former ?

15/45 is std for 1127 GSXR if memory serves me correctly, 15/48 would be Blandit stylee !

[Joseph]

5 minutes ago, Gixer1460 said:

Eh? How does 15/45 get 216kph and 15/48 get 259kph when the latter is lower geared than the former ?

With a different gearbox ? Not sure 

[Joseph]

15x45 stock bandit 12

15x48 stock GSXR 11

As per JT Sprockets 

[Gixer1460]

1 hour ago, Joseph said:

With a different gearbox ? Not sure 

Well, 750RR 6th gear = 1.2:1 whilst GSXR1100L 5th gear = 0.91 (I didn't realise GSXR11 was overdrive top gear!) The primary ratio's are likely different between 750 / 1100 but they never get quoted! Its interesting looking at the two gearsets ratio's, I can sort of see the appeal of the 750 ratio's but still feel they are wasted for a 1100

Comparison 750RR 1st 2.38, 2nd 1.88, 3rd 1.62, 4th 1.45, 5th 1.29 and 6th 1.20

Whilst           1100 L  1st 2.38, 2nd 1.63, 3rd 1.25, 4th 1.05, and 5th 0.91

[Joseph]

I didn't see@Damienga15demention using a 750 double R box ?

Info found for normal readily available 750R box is :

2.76, 2.06, 1.64, 1.4, 1.22, 1.09

(Same on all OC 750s and teapots)

Seems logical to need taller gearing for use in the 11 ?

Anyways, i actually do run a 1216 with 6 speed in real life.

I use it daily with 16x43 sprockets and gives ample and correct speed range without wheelying all the way up the gearbox like it would with the factory 15x48 setup. (Which could be cool, if you don't look at fuel prices these days )

Edited July 27, 2022 by Joseph

[Gixer1460]

I'm no 750 aficionado so a 6sp is a 6sp is a 6sp to me LOL! Hmmm - lower in 1st, lower in top! You could run the 5sp and only use 4 lowest gears for roughly same relative gearing ! 

[george 1100]

This is a great tool

https://www.blocklayer.com/rpm-gear.aspx

 

[Joseph]

6 hours ago, Gixer1460 said:

I'm no 750 aficionado so a 6sp is a 6sp is a 6sp to me LOL! Hmmm - lower in 1st, lower in top! You could run the 5sp and only use 4 lowest gears for roughly same relative gearing ! 

The initial question wasn't "is it good to use a 6 speed box in an 1127". 

And the first response gave the required info anyway

[dupersunc]

750 and 1100 primary gear ratios are very different.  This is a critical factor.  

I've got all the numbers worked out for mine some where, I'll dig them out.

[Joseph]

Primaries :

GSXR 750 : 1.74

GSXF 1100 : 1.523

GSXR 1127 : 1.56

Edited July 28, 2022 by Joseph

[Lachie04]

Just to throw span and two cents in 
the idea of a six speed box is to gaining closer ratios not overall speed
I would have calculated the gearing against max torque figure as that is where the most benefit is made IMO  (but then I may have had a beer or two)
otherwise you're just changing gear 10k sooner and more often just to get to a top speed 

Idea of close ratio box is to get better drive out of a greater variety of corners  

[Oilyspanner]

Have just done some calculator work, using Joseph's ratios and a tyre circumference of 79 inches.

16:43 final drive gives 1st gear 5.8 mph/1000 rev = 62.64 at 10,800 revs

6th gear  14.68 mph/1000 = 158.54 at 10,800.   The speedo would read more than this.

Std 1127r 5th gear is 16.15 mph/1000 revs by comparison. 

If you can fit a 17t front sprocket with a 43 rear = 6th 15.59 mph/1000 & 168 mph

1st = 6.15 mph/1000 & 66.51 at rev limiter

It's not worth doing the other ratios as they'll be closer than the std box anyway. 

Depends what you want  ? 

[Oilyspanner]

Forgot to add, definitely don't use 14/48 !!!!!

[george 1100]

1 hour ago, Oilyspanner said:

Have just done some calculator work, using Joseph's ratios and a tyre circumference of 79 inches.

16:43 final drive gives 1st gear 5.8 mph/1000 rev = 62.64 at 10,800 revs

6th gear  14.68 mph/1000 = 158.54 at 10,800.   The speedo would read more than this.

Std 1127r 5th gear is 16.15 mph/1000 revs by comparison. 

If you can fit a 17t front sprocket with a 43 rear = 6th 15.59 mph/1000 & 168 mph

1st = 6.15 mph/1000 & 66.51 at rev limiter

It's not worth doing the other ratios as they'll be closer than the std box anyway. 

Depends what you want  ? 

Did you calculate that with a 1.56 primary?

[george 1100]

On 7/27/2022 at 7:00 PM, Joseph said:

At 5000 rpm in top gear, 1127 with 750 6 speed gearing theoretically gives :

15x51 : 192 km/h

15x45 : 216 km/h

16x54 : 205 km/h

16x43 : 257 km/h

At 5000 rpm, stock 1127 stock sprockets 

15x48 : 259 km/h

5000rpm? 

[Joseph]

Nope that would be 11000, i wrote the lowest end of the graph i asked for on GC (5000-11000)

Edited July 29, 2022 by Joseph

[Oilyspanner]

Just got back from helping my elderly parents. I've just realised that the primary drive will be the same, not changed to 750r - this would make more sense .... 1.565:1  not 1.74:1

15:48 gives, 6th  148mph   1st 58mph at 10800 revs

But Joseph's  16 : 43 looks really good 

1st 6.44 mph/1000 revs  69.6mph

6th   16.31 mph/1000revs   176.24 mph at 10,800 revs 

 

[george 1100]

16:43 in mph and kph. The rpm's noted in the tachometer are the rpm drops per gear change. For example, redline in 1st, change to second, rpm drops to 8061, redline 2nd, change to 3rd, rpm drops to 8598 and so on

Edited July 29, 2022 by george 1100

[dupersunc]

8 hours ago, Oilyspanner said:

Just got back from helping my elderly parents. I've just realised that the primary drive will be the same, not changed to 750r - this would make more sense .... 1.565:1  not 1.74:1

15:48 gives, 6th  148mph   1st 58mph at 10800 revs

But Joseph's  16 : 43 looks really good 

1st 6.44 mph/1000 revs  69.6mph

6th   16.31 mph/1000revs   176.24 mph at 10,800 revs 

 

You'll do we to pull 176mph anywhere unless you have a very very healthy. motor.

Little point in gearing a oil boiler for much more than 155mph in my experience.

[Joseph]

Yeah it is the theory, it doesn't take in account wind resistance and all the real life factors when you're on the road.

That said the 16 43 i'm using is with my 1216/cams/head/RS full package so it has more than enough to pull the bike

[TonyGee]

I'll never get this thing about silly speeds and massive power on public roads with all the dickheads and old ladies in the way