money vs horsepower/CHAINDRIVE

[TopCatGr58]

Stupid question,

I know the OEM middle drive has 90wt for the drive shaft gears, but without them, looks like all that's needed is the main shaft bearings which I assume are self lubricated/sealed. But does the bearings on the engine side provide as a SEAL as well, to keep the regular engine oil from escaping out where the middle drive housing attaches to the engine, and the shaft stabs into the drive gear!?
T.C.

[pggg]

Thanks for that great info TC, coz as far as ratios, revs, and speed formulas go, my maths aren't up to scratch at the moment. I was guessing at around a 35-40T rear on a 17" or even an 18" rim. But that was only a blind guess. (very unproffesional I know) Taller gearing is VERY tempting as my hotted 1196 has mucho grunto. Chain is 120 links (192cm - 6ft 3") with a C clip. Adding or dropping links is no problemo.

[pggg]

Missed that last question. yeah, the OEM drive unit bearings are oil-fed, I replaced them with sealed bearings $20 each (NSK6006vvc3e & 6305vvc3). The drive unit's riddled with various oil holes and passages for the seperate gear oil. Engine oil is sealed at the engine side shaft hole.

[TopCatGr58]

Hey PGGG,

Thanks, and for the bearing info as well!! Those speeds are of course estimates, but I think fairly close. The 16" wheel was with a Dunlop EliteII at total diameter of 25.73", the Dunlop Sport tire I found sized at 200/50/17" was only 25.00", so it has a lower profile and smaller total diameter even though it's a larger rimmed tire! To fit that wide a tire you'll need a wider rim than the XS11s 3.50", like 6.00"!

The nice thing with chain drive is that you can customize the performance with a variety of rear sprockets!

With a 13T front, 35T rear, 4K rpm = ~73mph, taller than stock
with 40T, is around 64mph, close to stock.

Not sure how hard it is to find lesser teethed rear sprockets, around the 30 count, which would help make the total ratio taller while still using the 12T front for room clearance!
12T at 4K with 30T rear =~78mph, putting it over 150mph for top end! With the gained 20hp thru running Chain vs. shaft, it might be able to push it that fast?
T.C.

[pggg]

Much appreciated - I'll write down those figures as a guide. From measurements, the rear end can handle up to a 160 width tyre before sidewall/chain clearances get too close. The l/h koni shock may need teaking out a few mils for a good chain clearance also. Am now on the scavange for a suitable back rim. Am determined not to let many moths escape from the wallet!

[pggg]

Been tied up with that hassle called work so haven't mucked round on this chain system for a couple weeks. Did say a 160 was largest to fit - upon revision - make that 190 heh-heh. Don't want that big though, too impracticle. Currently have feelers out for a 4.5" rim to run a 160/70/17. It seems to be a common sized tyre. 5 mm smaller in diameter than a 130/90. Inside rear sprocket to rim centre needs to be around 110mm - 120mm. Would most probably need to tweak the sprocket in or out for perfect alignment. 118mm is bang on. The guys on an FJ site were swapping to 170 & 180 wheels/tyres easy enough with a bit of grinding and tweaking here and there. Am waiting on an Email from a wreckers up north. Slackers are slow in replying. Am itching to slap on a wheel and give this thing a performance test.

[Lord Grizzlon]

congratz on the xcellent work!! just curious, but can we use a fj middle drive to do the chain conversion also?

[TopCatGr58]

Hey PGGG,

If the tire you're looking at is 5mm narrower than the 130/90, then why bother with the slightly wider rim? Is the lower profile tire that much better for handling than the OEM style!? I know with cars, the smaller sidewall helps with tighter handling due to greatly reduced sidewall roll, but with our bikes, the tire is ROUND! Does the lower profile put a larger footprint contact patch on the ground? Is the curvature not as tight with the lower profile tire?

I'm asking all this cause I'm wondering about getting a 650 special rear wheel, which will have the proper chain sprocket bolt holes, and is the same style as the OEM XS11. It's also the same sized rim, so it would fit a 140/90/16 no problem, but I'm already running that now. Haven't checked to see if there's a wider profile than that, that will fit that RIM, but I don't think so?!

I wonder if you could unbolt the Drive shaft spline section from the rim, and mount a sprocket on the OEM rim!?
T.C.

[pggg]

Grizz, I'm pretty sure most of the FJ stuff is non-compatible with an XS motor so there'd be big dramas involved most likely. Yeah TC, am still open to all options, there's not much wrong with a 130. Going to a 160 is probably more "macho" than anything. Ahh - it'd look good! No problems with excess middle tyre wear with a 140 on the XS11 rim? I heard an XS650 has a smaller number of teeth on the sprocket than most, so that'd be another advantage in it's favour as well. No sweat to get taller gearing on the 11 with one. Is the 140/90/16 smaller or larger in diameter than the 130/90/17? Here's a pic of the problem facing the XS11 wheel. The sprocket has to be 100mm out from the bolt holes. At least the holes have rubber cushes. mmmm... any ideas anyone?

[superdave]

100mm sprocket issue

I was on vacation, Now getting back up to speed on your progress. why 100mm or 10cm ? is it way out there! trying to line up with the front sprocket ? correct ? Shimm whole rim to the left? or go with the 190 tire/rim ? will that help take up or allign sprockets? I like the 190 size tire thing but thats just the testosterone talking! hang in there. ps. saw a guy did his own gear exchange/ off set on a custum 650 twin. He set a 1" shaft with 2 pillow blocks (w) 2 sprockets/ all mounted to frame just behind tranny in front of swing arm pivot axes. Just line up the sprockets on the shaft with sprockets for the bike... Dont forget your key ways.. set screws... You could play with ratios or keep it 1 to 1. Time to play ! Geter Done !!!!!!!

[pggg]

Yeah Dave it looks way out there because an XS11 wheel is skinny on the left side. 11 - 12cm from wheel centre to align with front sprocket. No leeway to move the front sprocket. Actually, forget the XS11 wheel anyway, too much modification and hassle. Those rubber cushes are just floating in there with nothing to stop them pulling out - as the original rear pinion was locked by the axle nut. You'd need to machine a bloody great slab of alloy to set a sprocket then put in large thick uneven shaped steel washers then... blah! An XS650 wheel or some other sprocketed wheel would be way easier to rig up.

[pggg]

Just an update. After weeks of inaction, I got my A into G and scrounged a ZXR400 wheel with disc, cushdrive, axle, and a 38T sprocket. (Standard ZXR400 sprocket is 45T) Disc fits the wheel but is actually off a GPX750. Wheel takes a 160/70 17" tyre. Is a good looker. Sprocket needs tweaking out 11mm for a perfect chain alignment. Now need a 11mm thick alloy ring machined to place beneath the sprocket. Am in the process of welding on 2 axle slider plates to the swingarm rear.

Will also need to weld a kink to the L/h swingarm to get proper clearance from the rear sprocket. (Was hoping it might just scrape in, but no such luck) As for the caliper setup, can't be bothered shagging round with an XS caliper as the disc is a modern 230mm (XS disc is 300) Will simply use a ZXR caliper. $60 from a wrecker. Wheel, cush, axle, and disc cost $250. A brand new tyre will be another $200. (pre-loved are $80, but will go with new) Moths are now escaping from the wallet. Am just about there now though.

[pggg]

Chaindrive report.

The swingarm snapped, the rear wheel chewed it's bearings and seized, the sprockets stripped their teeth, the drive unit disintegrated, the gearbox vibrated to a halt, the chain snapped and demolished the crankcase and the whole machine is now written off. Anyone got a spare bike for sale?

[pggg]

Heh Heh - just jivin'

Here's a couple more pics of the final result of this chain thing. I know most people will be sick and tired of hearing about it by now, but anyways. One pic shows the brake setup. The caliper is twin opposed pistons (ZXR750) the connected pistons don't float sideways, so don't have the sliding bushes like the XS calipers. The bracket I used originally was a cut-down XS11 bracket, and it worked fine, but I found a stock ZXR bracket so swapped that on. They swing back/forward on a bearing as the torsion bar connects to the frame on those models. Allows for swingarm movement.

I rigged a CB350 torsion bar to lock to the original XS swingarm point. A drilled hole and splitpin does the trick, so the swinging bearing isn't actually neccassary anyway. The bar still pivots on the caliper for chain adjustment. Master cylinder is XS11 as is the hose - it's the longer front brake hose. The brake is an improvement on the XS brake for 'feel' as I find the large XS disc sometimes locks up too easily on sudden braking. Not an issue though.

The plastic chainguard is off a VTR250, and fitted well with some alterations. All these various parts are scavanged from bike-wreckers. List includes GPX600, GPX750, ZX6R, CR400(chain adjusters) CB350, ZXR750, VTR250, XS11oo, all rigged together with various hand modified bushes, spacers etc... This whole job cost around $600 - $700 including a new 160/60/17 Michelin macadam tyre. It's also quite possible to do it cheaper if you get lucky by finding bargain priced parts. I already had heaps of spare XS11 parts, so that made it cheaper for me.

Not having any fancy machinary, the main tools were hacksaw, drill, grindstone, sandpaper and file. Also about an hour of welding. Front sprockets and add-on axle sliders were precision machined by a local engineer. I've been riding this thing for quite a few weeks now, and it's all solid, strong and running smooth and trouble free. One of the Aussie guys, Glenno, is thinking of doing a spoked wheel version. I reckon that would look great on an old XS. Would be interesting to see.

[xs650mike]

Too bad!

Lookin' good pggg! Really looks businesslike. I like the dinoraptor claws comin' through the tank too.

Most people? What people? What brain-dead morons could get sick and tired of hearing about this project? Now we need a full report about what it's like to ride.