Final Drive Transplant _ Kudos 2 Chop!

[MAXIMAN]

Originally posted by pggg
I'd be careful with that backlash thing, if you guys know how to dial in those bevel gears in perfectly, even with the same shims as previous, BMW's strip their pinion gears, worn at the bottom of the pinion teeth - usually caused by owners stripping the driveshaft the wrong way.

If the pinion assembly were re-inserted XSactly the way it was removed...same shims...same torque...then how would the gear lash get out of tolerance?

I don't understand the statement "stripping the driveshaft the wrong way." Explain please.

[GNEPIG]

Someone was talking about putting a 16 inch special wheel on a standard and this might not work as the right swing arm on a standard is different (narrower) than a special as I have discovered while figuring out a way to put the standard wheel on the special.

.. my Ugly black bike is a Standard, it's been too many beers ago so i dont remember the specifics, but i put the Special rear wheel on it. had to mess with right side spacers.

.. good find Chops and nice presentation Maximan. one day when i fix me up a highway cruiser this will be a must have.

[MAXIMAN]

WOO FRICKIN HOO #2

Last night I rode 114 miles at 80 mph and got 36.7 mpg.

This morning I tested it at 70 mph. Went 121.3 miles on 3.02 gallons for a whopping 40.1 mpg. That's whopping for this full dressed behemoth. Normally I would have gotten 34 or 35 mpg tops at that speed.

Also I will report the drive housing is much cooler. Before I did this mod I rode the bike for a 100 miles highway...stopped and felt the drive housing. At that time it was uncomfortably warm to hold my bare hand on the unit for more than about 30 seconds.

After the mod it is simply warm. I can hold my hand o the drive body indefinitely and it doesn't burn.

I know this isn't scientific but it was done on similarly warm days at same speed and distance. Obviously the fact that the ring gear is spinning at 88% of what it was before must make a difference.

[xschop]

sweet

Why pay the Arabs any extra? Have you floored it in 4th gear yet on a hiway passing an 18 wheeler? The Blue Streak loves the power in this range.....

[MAXIMAN]

Re: sweet

Originally posted by xschop
Have you floored it in 4th gear yet ?

Nooop...mine doesn't have a floorboard...

[John]

And now for an even taller gear ratio

Try using the 18 inch wheel from the 750 Special. That on top of the 750 final drive would probably lower the RPM's even more. I know they aren't the same style as the XJ, but they'd look right at home on an XS.

[xschop]

xs750 rim

I have one that I kept to use as a vise for breaking the coupler nut on the final drive. That thing looked to funny on the Blue Streak. Whoever wants it can pay shipping and it's theirs....chop

[Dan Hodges]

Tall Wheels & Tall Tires

Originally posted by MAXIMAN
Gary

All things being equal a 17 inch 130/90 is always taller than a 130-/90 16.

I have never seen any thing wider than a 140 on an Eleven because generally it won't clear the shaft housing. If you know of some tire that is XSeptionally wide that will fit please inform. It would be interesting to know.

A 130-90 x 17 Bridgestone S-11 measures 26.4 inches in diameter and the 130-90x16 measures 25.4. A Dunlop Elite II or Elite III is 25.7 for the 16 and 26.18 for the 17.I bought a Bridgestone S-11 140-90x16 which measures 25.91 inches in diameter and it has just barely enough room for a piece of typing paper between the shaft housing and the tire on my special.This is not enough clearence as the tire gets very hot during the summer at sustained high speed.I have checked every 16 inch and 17 inch bias ply tire listed on the web and the 17 inch combination is at least 1/2 taller than a 16. Metzler has a 140-90 x16 that is 26.18 inches tall,almost as tall as the 130-90 x 17 but it will not fit unless you grind the shaft housing.There are several 17 inch tires made in the 80,70 and 60 series but the side wall is shorter and the diameter is less and the standard's 17 inch wheel is too narrow to accomodate any of them anyway.I have always ran Dunlop qualifiers and the 130-90x16 rear is only 25.3 inches tall,so the 26.4 inch 17 will be a noticeable improvement on the Interstate. At WOT the 17 is worth 6 mph versus the 16 if you have the horsepower to pull it.

[pggg]

Originally posted by MAXIMAN


If the pinion assembly were re-inserted XSactly the way it was removed...same shims...same torque...then how would the gear lash get out of tolerance?

I don't understand the statement "stripping the driveshaft the wrong way." Explain please.

Maybe not a big deal, but the ring and pinion are 'set' to extremely precise tolerances, I'd be nervous of simply re-bolting the bevel and ring back together without doing the backlash adjustment thing... My riding buddy wore out the ring on his old BMW, I saw the teeth when stripped, they were 'riding' off centre and worn down on the lower edges, he claims he re-assembled the old dunger 'by the book' too.. maybe I'm making too big a deal of it, but check out 'adjusting backlash' on the web - it's way over my head...

Also an 18 inch wheel is the last thing you need with that 3250@ 60mph ratio, any taller is just too much, a 16 inch wheel would be far better suited to that 750 ratio, trust me (asking a lot, I know) - 1st gear will end up intolerably tall for any sort of street riding, and the bike will become a PITA around town. Max, in 6 months time you guys will be agreeing with me

[MAXIMAN]

Originally posted by pggg


Also an 18 inch wheel is the last thing you need with that 3250@ 60mph ratio, any taller is just too much, a 16 inch wheel would be far better suited to that 750 ratio, trust me (asking a lot, I know) - 1st gear will end up intolerably tall for any sort of street riding, and the bike will become a PITA around town. Max, in 6 months time you guys will be agreeing with me

Where in the name of heaven did you get the idea I wanted to add an 18 inch wheel to this mix? Heck I wouldn't even add a 17" wheel. The bike is geared perfectly for what I want wiht a 16 inch wheel.

Are you actually reading these threads?

[pggg]

OK, I'll stop being a wet blanket now, glad you guys are pleased with the results.... for now...

[MAXIMAN]

Hehehehehe

You'll be making the conversion within a year...hehehehe.

But seriously... Like I said before this is not a mod for people that want a "holeshot" bike.

However I don't think it's geared too high. My ZRX1200 is revving 3400 at 60
3800 at 70
4400 at 80
5000 at 90 almost identical to the way the Eleven is geared after the transplant.

Granted the ZRX is making 112 hp and 80 ft-lbs right out of the crate. But it also turns a mid 10 quarter right out of the crate.

Lets just wait and see. In 6 months I'll have 10,000 to 15,000 miles on it. I'll report back to this thread next spring. If this mod sucks at that time I'll be the first to admit it...I'll be the first to "call off the dogs".

[50gary]

To figure any tire diameter and circumference:
EX: 140/80/17" 140 x .8 =112 x 2 =224/25.4 = 8.82 +17" =25.82 That's the diameter. Then, 25.82 x 3.2427 = 81.12" that's the circumference.
EX2: 130/90/16" 130 x 90 = 117 x 2 = 234/25.4 = 9.21 +16" = 25.21" That's the diameter. 25.21" x 3.1417 = 79.21" That's the circumference.
17" with 80 series tire =25.82" diameter
16" with 90 series tire =25.21" diameter

Dan, my 1978E standard has quite a bit of room on the right side of the tire to swingarm clearance about 1.5". This is with a stock wheel and a 5.10" x 17" tire. Right side as sitting on the bike.
Cheers, 50gary

[MAXIMAN]

Originally posted by 50gary
17" with 80 series tire =25.82" diameter
16" with 90 series tire =25.21" diameter

Dan, my 1978E standard has quite a bit of room on the right side of the tire to swingarm clearance about 1.5". This is with a stock wheel and a 5.10" x 17" tire. Right side as sitting on the bike.
Cheers, 50gary

And that's my point. the 17" tire (like the wheel) is generally taller. and a 17" 90 series would be even taller again.

I don't think Dan was talking about right side clearance. The problem occurs on the left side between the tire and shaft housing. The widest tire you can mount up on a Special is about 5.4 or 5.5 inches. Anything wider than that tread will rub once the tire heats up.

For instance Bridgestone makes one (140/80-17) in a V rated BT45...but it's 5.6 inches wide. It won't clear the shaft housing. Oh it might clear when you install it. But after you ride a while it will start rubbing. I know this from experience.

Another aspect to consider is rim width. The XS11 standard was deployed from the factory with a 2.5 x 17 rim. The afore mentioned tire only approved for 2.75 to 3.5 inch rims. And though you could physically fit the tire to the rim you wouldn't gain anything because the tire crown would be exagerated. You might even risk tire failure though not likely.

[pggg]

Guarantee Gar50 could slap together a good one, that R1 front end is gotta be a looker, XS850 eh, maybe a different ratio again? I'm joking Max, the XS is so torquey at all revs, you can ride the damn thing in 3rd all the time and go from 20mp thru to 110 mph with no gear changes. No sweat