swapping front wheels

[pggg]

O.K. here's a nightmare, swapping this XJ900 wheel to the XS11 front end. They're a bit different huh?

of course nothing ever runs smooth, I want to keep the XS axle(17mm diameter) XJ900 is 15mm, and of course the reguired bearing size 42 x 17 is a 'rare one' - just what you wanna hear, yeah right, but there's a 40 x 17, a 1mm thick strip of plastic will fix that, but of course the inner spacer tubes are different lengths so extra spacers needed, then of course this is all just piffle compared to the major disc/fork/caliper drama that's sure to follow...

[pggg]

[81xsproject]

is that going to get you a wider tire, or just a cooler rim?

[xschop]

xs wheel

hey pggg, I tought you were going to put the 18 inch rd400 wheel on. I have an 18" xs750 rear wheel that will fit on the front end with some new bearings... Would look really cool...BTW, the new FD from the xs750 pulls strong up-hill against the wind, 5th gear of course...

[pggg]

81, both! and half inch lower with 18 inch rim. Chop, the RD400 rims don't give that extra bit wider tyre, which I wanted to closer match the rear 160 radial, that XJ rim takes a fatter V rated 110 tyre, (probably will need to hang way off the bike to get round corners, cool ) also the 3 spoke wheel 'matches' my 3 spoke rear, about the XS750 rear, wouldn't it be lop-sided for the front? Speedo drive hassles too. Yeah the taller gearing is great for relaxed cruises, I get around an extra 2 kilometres per litre fuel economy, I used to get around 14 kilometres per litre(which is pretty good anyway) now I'm getting 16 kilometres per litre most tank fills, that's around 300 kilometres with still more to go as you can squeeze 24 litres into a standard tank!

[xschop]

gass sssippping

Yeah, I am still on my tank fill up from almost 2 weeks back and forth to the job site.... would have had to fill up alreadt with the old FD...And yes the xs750 would be a little lop sided but is a 2.5 width....

[pggg]

Getting this front wheel sorted,
A. XS11 bearing 47mm X 17mm.
B. XJ900 bearing 42 X 15. Means a 42 X 17 needed to fit the XS11 axle... but 42 X 17 is an expensive rare size
C. A common 40 X 17 bearing.
D. Metal bands snipped from 1mm tin plate - gives the perfect fit
E. XS11 spacer needs skimming down on a lathe to match the XJ900 oil seal.
F. XS11 inner spacer gets a washer to match the XJ900 spacer length.
Also here's some revealing figures - weight of XS11 rim/tyre/discs is 34.2 lbs.
Weight of XJ900 wider rim/tyre/discs is 28.7 lbs.
Weight of one XJ900 disc is 2 lbs 12 oz.
Weight of one XS11 disc is 6.5 lbs! Yep those XS discs are SOLID!

[50gary]

That's a weight svings of 5.3# hugeamount for a very large rotating mass. Plus it will quicken the XS steering because of the 1/2" lower wheel. 5.3# at 100 MPH is literally a ton of weight. This is called dynamic weight. Reduction of weight on the rim - one ounce of weight on the rim is equal to about 25# of weight at 100MPH. 85oz x 25# = 2125 but not all of the added weight is exactly on the rim. Therefore, rotating weight also has the effect on braking and turning.
Cheers, 50gary

[TopCatGr58]

Hey Gary and PGGG,

And easier way would be just to get the rotors from MikesXS.
3.6lbs vs. 6.2lbs : 2.6 lbs savings per rotor, 5.2 total! A little pricey, but you get new unwarped rotors as well, and no axle swap headaches!
T.C.

[xschop]

light rotors

Or you can put on some vfr800 rotors, mine are about done...will post here soon....super light

[pggg]

Gar, good one, so we can say there's a whole ton of weight being lost then. Without lying. T.C. - wonder why the mikesXS discs are so much lighter? Chop, 5-hole VFR800 discs on a 6-hole XS11 wheel - sounds tricky!!

[pggg]

If it's just for weight loss then there'd be heaps better wheels than a clunky old XJ900 wheel, the modern stuff is featherlite , seems to handle it, braking from 300kph and things, maybe a battleship sized XS makes more stress at less speed, who knows, XJ900 18 inch wheel is HEAVIER than an XS wheel, stockier and wider, with lighter axle and parts, I'm going with the heavy XS axle. The discs are the difference, the bearings, spacers, axles is the easy bit the XJ discs sit 15mm lower in the calipers, and angles and complicated sh**t starts happening like the discs losing about 8 - 10mm of swept area added to the lesser area as it's XJ 267mm & XS 297mm, at least it sits clear in the caliper(1.5mm closer to the edge) and so on and so on..

[50gary]

More weights etc, I took my standard 17" X2.50" rear (complete with rotor and tire) weighed it on the digital scale and wow, 45 freekin' pounds. Together with the weight of the standard front wheel assy. of 39.5 pounds that's a total of 84.5# of unsprung and rotating weight. Never forget that less rotating weight allows the brakes to work much better too.
Cheers, 50gary