One more question on the 750 mod

[jurgenkoppen]

Is there a particular year for the 750 hub I should search for.
As well , I have my eye on a '78 750 18"rim to further improve the ratio.
Or is that going to backfire on me somehow?
Thanks Jürgen

[TomB]

Hi Jurgen

I looked into the 18inch rim idea and bought the wheel and final drive, sorry don't know what year it is, the problem with the rim I have is its narrower than the XS11 rim.

I'm not sure if all the XS750 rims are the same width.

Try checking HERE

[xschop]

over the top

the xs750 rim is much narrower (is that a word?) and the farthest I would push it (gearing wise) would be to install the 750 FD with the 17" xs11 rim. your take off will be really sluggish if you put on the 18" if you are doing stop and go traffic....IMHO don't do it

[TomB]

Narrower is an English word, I should know.

Even you lads over the pond use it occasionally Click

The XS750 rim I have is 18 x 2.15

My Standard rim is 17 x 2.50

My Special rim is 16 x 3.00

I've just been out in my garage to check

[jurgenkoppen]

OK, I keep my rim

Thank you all for checking and measuring.
So now I just will hunt down the XS 850 FD and be on my merry way into modification land. If I get a 5mpg improvement just by changing the FD, I'll be content with that . (for now at least, until my new Metzelers 880s are worn out)
Can't wait to get at least a slightly better mileage on my bike then my daughter is getting in her VW Golf....

[AlanB]

Hi Guys,

Surely if the 750 can pull the higher ratio AND the taller wheel, the 1100 should manage it?

AlanB

[TopCatGr58]

Hey ALan,

A member a while back inquired about whether the tranny gears were the same as the 1100, and I looked at the fiche, and they were NOT the same. I am thinking that the 750 possibly had lower ratio gears in the tranny, so the engine is possibly turning a little faster, it does redline a bit higher than the 1100??
T.C.

[xschop]

750 gears

T.C.'s right. the 750 had higher ratio gears, but the real trivia question to know is the middle drive from a 750e is even lower and could be slapped on the 1100 for drag racing...

[xschop]

here

bottom left page, just find one and bolt it on for the sleeper xs11....http://www.biker.net/roadtest/xs750e/xs750e%20test.htm

[AlanB]

Hi Guys,

There MAY be two different ratios for the middle drive, but there are a couple of major flaws in that article; Firstly, you do NOT need to split the cases to change the middle box, and second, the middle ratio is a mile away from 3.5:1......... it is pretty close to 1:1...........

In other words, the two gears in the middle box are nearly the same size. One of the gears in the REAR bevel is three and a bit times the size of the other, but in the middle box they are almost the same.

I will guess that what this article is actually trying to say, is that the last of the 750s used the 1100 rear bevel.

About 10 years ago, I blew the middle box on my SG to bits; gear teeth and bits of casing all over the road! I replaced it with one from a 750 (one bolt at the bottom instead of two) The ratios were identical.

Quite happy to be proved wrong; just voicing an opinion (from a long way off!)

AlanB

[pggg]

Come on all you 750 mod folk, confide with me now, you've ridden your 'New Improved' XS11's for a while now, are not some of you starting to wistfully think back to when you had good ole original XS11 stomp and performance? Remember back when you had INSTANT power to the pavement, anywhere, any time? Just maaaaybeee thinkin' your elevens are now feelin' a bit - shall we say - bland?

[xschop]

diff

there is a difference (number of gear teeth in the middle drive). Some people get the OLD Tech Terms confused (me included) @ secondardy ratios etc. The trannys have a gear ratio after the main tranny and before the middle drives on these bikes....CMIIR,but I believe it is the ratio of the MIDDLE DRIVEN GEAR that some of the old tech articles talk about....AS FAR AS THE 750 FD MOD.... I STILL ACCELERATE AS FAST AS BEFORE, THE ENGINE DOESN'T WRAP OUT LIKE IT USED TO....AND A SIDE BENIFIT IS THE GEAR CHANGES ARE WAYYYYYY SMOOTHER NOW....STILL NOT GOING BACK....BUT THANKS FOR THE SUGGESTION PGGG

[TomB]

Can you lads give me a bit of clarification on this.

Is it the Specials with 16 inch rear wheels that you lads are doing the XS750 rear drive mod on.

I just wondered if the the smaller diameter wheel made them geared lower than the Standards with the 17 inch rear wheel.

If it is does the mod bring the Specials gearing in line with the Standards

[xschop]

lads

the 16in and 17in wheel will work. if the 17 has a higher profile tire, then you get even lower revs. I have the 16" special with normal profile and think it's the best gear ratio for 1st gear launching and 5th gear hiway cruising/ rev reduction....best of both worlds

[DiverRay]

Tom,
I have a standard, with the 17" rear rim. I'm happy with the ratios, and the pull is good going over the 1,800' hill every day. I now get a constant 42 MPG, and only have to down shift if I REALLY need a fast getaway.