XS750 to XS896 big bore

Nanno
You are correct that the difference between the XS11 and the XS750/850 is the final drive.
From the Haynes workshop manual it details a few changes within the transmission to adjust overall drive ratios on the Yamaha triples. The 750 always had a 4.00 X 19 rear tire. The overall ratio was lowered on the XS750E to improve the acceleration and accomodate the increase to the redline from 7,500 to 9K. The 850 changed the rear tire to 4.5 X 17 and the special had a 130 X 16 rear.
The details from Haynes are:
XS750-2D
Overall ratios
1st = 13.285:1
2nd = 8.638:1
3rd = 7.069:1
4th = 5.955:1
5th = 5.201:1
Secondary spur = 1.063:1 (34/32T)
Middle gear = 1.056 (19/18T)

XS750E
Overall ratos
1st = 14.697:1 (32/13)
2nd = 9.483:1 (27/17)
3rd = 7.762:1 (26/20)
4th = 6.539:1 (23/21)
5th = 5.711:1 (22/23)

XS850
1st = 2.285:1 (32/14)
2nd = 1.588:1 (27/17)
3rd = 1.300:1 (26/20)
4th = 1.095:1 (23/21)
5th = 0.956:1 (22/23)

Secondary Spur Gear
XS850G (UK) 1.062:1 (34/32)
XS850G & H (US) 1.129:1 (35/31)
XS850SG, SH & LH 1.093:1 (35/32)

Middle Gear bevel ratio
1.055:1 (19/18)

Final Gear bevel ratio
2.909:1 (32/11)

So the best option to get longer legs on my XS750SE base gearbox appears to be to get a set of 34/32 secondary spur gears from a XS750-2D or XS850G (UK) model.
The middle gears appear to remain constant at 19/18 and the final drives are also constant at 32/11.
If anyone has any more information to help understand the gearing options I would be very happy to hear from you.
Cheers
Tim
 
The spur gears are kinda hard to get to, but i think i have one pair in the crates that my bike came in. I chose a later type with the twin locating grooves in the outer bearing race as they fit in the case. Might be why it has a lower gearing. Not doing anything about that!
 
Just two addendums:
1) 750ies ran a 4.00x18 in the back (I suppose this was a typo)
2) and I have never heard (or seen) an 850 with a 4.50x17 on the back (only the 1100s had these), AFAIK the 850 models came with the same 4.00x18 in the back. (At least that's what the papers on mine said overhere (Austria), but I think this will apply universally.)

That being said, if you space out the rear wheel of an XS1100, you may be able to squeeze in a 140/80-17, which should be a tad bigger than a 4.00x18.
 
750ies ran a 4.00x18 in

Yes my mistake.
Attached is the scan of the page out of the manual. On the triples site there are a few posts about swaping the 850 swing arm into the 750 to be able to use a wider rear tire!
 

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  • XS850 Wheels.jpg
    XS850 Wheels.jpg
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There is a guy in my town that has several XS750 and 850's to keep his daily driver going...and he had done exactly this... Always uses the 850 swingers for the winder tires.

Psy

Sent from my LG-H873 using Tapatalk
 
Interesting... I had definitely had a 4.00x18 on my XS850 hack with the Velorex sidecar. Shame about the swingarm, if I had know that, I would have swapped it out, so I have more room for snow-chains in Winter.
 
The left hand caliper has developed a slow leak between the seal and the caliper groove. When I rebuilt it, I did notice that there was some pitting in the grove where the seal sits. :mad:
Any tips as to how to fix?
I was thinking of trying either locktite or silastic gasket into the groove before resetting the seal, any thoughts???
 
XS750AU said:
The left hand caliper has developed a slow leak between the seal and the caliper groove. When I rebuilt it, I did notice that there was some pitting in the grove where the seal sits. :mad:
Any tips as to how to fix?
I was thinking of trying either locktite or silastic gasket into the groove before resetting the seal, any thoughts???
You need new pistons, yambits.co.uk have new ones
 
XS750AU said:
Pistons look perfect - not a single mark on them.
I read the whole thing wrong, sorry. I would try repairing the pitting with zinc soldering and finishing it on the lathe. Then buy new calipers after failing miserably
 
Fixed the leaking caliper on the weekend, by cleaning up the seal groove with 400 grit wet&dry. Then I put a little bit of black silicon where there was some pitting in the groove. Now no leaks. ;D
Took it out and got the "Road Worthy" certificate today. Then straight to the club scrutineer for the club inspection - almost there. Now I have to send the paperwork off to the club secretary to get the final signature before I can finally get the "Club Permit".
In Australia if you have a vehicle that is 25 years or older you can get "Club Permit" which allows you to ride 45 days per year. The cost for the permit is much lower than full registration. Club permit costs $76 where as full registration is more like $800. Also it make vehicle insurance much cheaper. Full comprehensive insurance for agreed replacement value is only costing me $116. All up a club permit is about 1/10th the cost of full registration, that is why any bikes over 25 years have significantly increased in value over the last 10yrs the "club permit" system has been available.
Happy days.
 
I'm in QLD, I'm curious about the club permit for my 71 CB450. How do they police the 45 days? and are there restrictions on which days those can be, ie do I have to be riding to a club meet or can it be just any old day? Being able to ride my bike once every week or two and have full comprehensive insurance on it for about a quarter of the cost of standard rego sounds great!
 
XS750AU said:
Fixed the leaking caliper on the weekend, by cleaning up the seal groove with 400 grit wet&dry. Then I put a little bit of black silicon where there was some pitting in the groove. Now no leaks. ;D
Took it out and got the "Road Worthy" certificate today. Then straight to the club scrutineer for the club inspection - almost there. Now I have to send the paperwork off to the club secretary to get the final signature before I can finally get the "Club Permit".
In Australia if you have a vehicle that is 25 years or older you can get "Club Permit" which allows you to ride 45 days per year. The cost for the permit is much lower than full registration. Club permit costs $76 where as full registration is more like $800. Also it make vehicle insurance much cheaper. Full comprehensive insurance for agreed replacement value is only costing me $116. All up a club permit is about 1/10th the cost of full registration, that is why any bikes over 25 years have significantly increased in value over the last 10yrs the "club permit" system has been available.
Happy days.


Those rules are nuts.
 
How do they police the 45 days? and are there restrictions on which days those can be, ie do I have to be riding to a club meet or can it be just any old day?

The only way it is policed, is if you are pulled up you must have entered the ride for that day in your log book!
You can ride on any day for any purpose, but only 45 days - or 90 days if you pay 2X the fee. I have never used 45 days, and now I have 2 bikes on club permits there is even less chance!

Those rules are nuts.

They work well for us. But there are some people starting to abuse the system which could spoil it for those who follow the rules. Always got to be some dick head who wants to abuse a good system.
 
XS750AU said:
The only way it is policed, is if you are pulled up you must have entered the ride for that day in your log book!
You can ride on any day for any purpose, but only 45 days - or 90 days if you pay 2X the fee. I have never used 45 days, and now I have 2 bikes on club permits there is even less chance!

They work well for us. But there are some people starting to abuse the system which could spoil it for those who follow the rules. Always got to be some dick head who wants to abuse a good system.

Fair enough. I guess I don't understand the point of limiting the number of days.
 
canyoncarver said:
Fair enough. I guess I don't understand the point of limiting the number of days.

If they have a similar system to Quebec then the registration fee has an insurance premium in it so if you ride a lot less you have less risk of accident that’s if you only ride 45 out of 365 days that’s about 1/8 which would be about 100 bucks versus the 800 it costs them currently for a full year.
Wish we had that in Quebec
 
My 1979 Chevy C10 is on a limited mileage plan. Similar deal, but based on mileage instead of days.
 
I don’t know how it works there
But in quebec they are one and the same.
Every registered vehicle has an insurance premium in the annual fee
It covers extra medical costs in the event of an accident, lost wages, and up to 1k$ of riding gear.
 
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