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[rcompton]

Originally Posted by Dustdevill

....and all the others....

Beautiful.

[StephenB]

'S time to present the Frankenbike I have just finished, after 2.5yrs and one season:
(click on pictures to enlarge)

---

Featuring

• 1990 BMW New Zealand R80GS Frame, legally registered in Ontario, Canada
• 985cc rebuilt engine with '77 R100S pistons+barrels (A-bore), 1980 R100CS big valve dual-plugged heads, 1983 R80RT bottom end (approx CR 9.7 and 70hp)
• Overhauled 40mm Bings, SLS system removed, jetted with 155 main jets, 2.66 needle jets (new needles) and 45 idle, 4th notch
• Low mileage stainless steel R100R exhaust system, "de-chromed" and weight relieved, seems to work very well with the rest of the engine
• OMEGA Electronic Ignition with two dual tower Dynatek 2.2Ohm (grey) ignition coils (backup: points-in-beancan ignition to go with the gray Dynatek dualcoil)
• remanufactured 280W altermator stator and new rotor (Rick Jones) (backup: known good spares)
• 1982 G/S gearbox, completely rebuilt and modified with a complete set of late design 17.5 Helical gears, mod'ed with a long 5th (HPN)
• 1987 R100RT monolever 32/10 4-lug final drive
• Monolever swingarm with 1 1/4 in extension, new U-joint on driveshaft
• front EXCEL tube-type rim 21x1.85, super-laced to a refurbished, low mileage 1993 GS front hub with extrastrong stainless steel spokes/nipples (Woody's Wheelworks)
• rear BMW tubeless rim 18in (X-lace stock R100R front), super-laced to a refurished, low mileage 1993 GS rear hub with extrastrong stainless steel spokes/nipples (Woody's Wheelworks)
• Stock 1989 GS Marcocchi 40mm forks with RaceTech Gold Valve
• CC Products fork brace from SJBMW
• New Ohlins Rear Shock, 95kg/mm spring set up for 220lbs and 1 1/4 in swingarm extension
• Brake modification to a 4-piston Brembo caliper (1999 BMW K1200S) with 13mm m/c and SS brakeline
• Large single beam 8" clearplastic Chrome Headlight with Xenon HID conversion (triples light output)
• Trailtech Vapor Motorcycle computer with digital voltmeter
• BMW Speedster windscreen
• Hyperlite Flashing Brake Light
• original GS Krauser luggage racks for equal size bags
• Corbin Gunfighter with beadrider

Currently setup for gravel with a 21" Pirelli Scorpion upfront and a Kenda 270 (4.50x18) (50/50) on the rear.

[richarddacat]

KEWL

Looks great, nice work

[advNZer?]

Not a very good pic of my PD.Its had a hard life but seems pretty sound .Loving it so far.A shot from a Tag O rama game

[dougs650]

very nice.
In that color scheme, they just look fast.

[Stagehand]

"they look like a piece of light ordinance"

as a promo I once read put it.

[Lornce]

Things started out well enough...

[Pezz_gs]

I was playing around with MSpaint and like this colour setup for the old GS PD



Like it with the black wheels
Please note: This is just a mock up.

[Stagehand]

Damn you're good with MS paint. That program is a mockery of a sham. I like the black and red a lot, but it needs just a touch of white somewhere.

[Scott Davis]

Scott from NC

1992 R100GS

[caponerd]

[Lornce]

Originally Posted by StephenB

[*]1987 R100RT monolever 32/10 4-lug final drive

You sure about that, Stephen?
Every 1000cc mono-boxer, RT or RS I've seen had a 33/11 or 3.00:1 final drive. 32/10 or 3.20:1 sounds more like an R80 piece.

Originally Posted by StephenB

[*]rear BMW tubeless rim 18in (X-lace stock R100R front), super-laced to a refurished, low mileage 1993 GS rear hub with extrastrong stainless steel spokes/nipples (Woody's Wheelworks)

Interesting mod. Have you compared the circumference of the 18" tire with the 17"? ie: Does this afford any appreciably taller gearing?

We're having a Tech Day on June 6th in Ancaster. Come on out if you're able. Check the Canada RF for details.

[StephenB]

Originally Posted by Lornce

You sure about that, Stephen?
Every 1000cc mono-boxer, RT or RS I've seen had a 33/11 or 3.00:1 final drive. 32/10 or 3.20:1 sounds more like an R80 piece.

You might be right, it could have been originally from a nekkid R80 Monolever, the R80RT had a 37/11. I didn't keep the transaction details from my original buy in Europe, dang. I was offered a 32:10 from a US breaker yard, supposedly from a Monolever R100RT.

Originally Posted by Lornce

Interesting mod. Have you compared the circumference of the 18" tire with the 17"? ie: Does this afford any appreciably taller gearing?

The 18" has the greater circumference. A lot greater since I had to cut off one inch of the undertranny canister. Whether that "affords" taller gearing I don't know. I choose to experiment with taller gearings for another reason: having a 1000cc engine in there and expecting a lot more long distance street riding in the next 2-3yrs I aimed at getting rpm down and mileage up for 70-80mph cruising speeds using the HPN long 5th + taller gearing. I have all three final drives (37/11, 32/10 and 33/11) and will do one season each to figure out what fits best. The 33/11 on my UK spedc'ed R100T was a very good setup so I think I'll end up with that eventually.

[Lornce]

Originally Posted by StephenB

The 18" has the greater circumference. A lot greater since I had to cut off one inch of the undertranny canister. Whether that "affords" taller gearing I don't know. I choose to experiment with taller gearings for another reason: having a 1000cc engine in there and expecting a lot more long distance street riding in the next 2-3yrs I aimed at getting rpm down and mileage up for 70-80mph cruising speeds using the HPN long 5th + taller gearing. I have all three final drives (37/11, 32/10 and 33/11) and will do one season each to figure out what fits best. The 33/11 on my UK spedc'ed R100T was a very good setup so I think I'll end up with that eventually.

You're doing some interesting work here, Stephen. And, imho, addressing some of the GS's major weaknesses.

1. The Para-Lever rear suspension works okay when carving up paved twisties, but it's terrible over corduroy road surfaces. Same thing on the Oilhead para-levers. The old twin shock boxers work far better in those situations. I expect the mono-lever boxers work better there, too.

2. A healthy 1000cc motor can easily pull more than the stock 34/11 3.09:1 gears with the stock 17" rear wheel.

If you don't mind, a couple of quick questions:
1. Rear rim width and tire size?
2. Inflated OD of the rear wheel/tire combo?

Thanks.

[StephenB]

The rim is a stock BMW (front R100R) 2.50 x 18 rim:





Tire is a Kenda 270 sized 4.50-18, the inflated OD of rim/tyre combo with 32PSI is approx. 680mm (26.8")