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1993 R100GS PD

1993 BMW R100GSPD Motorcycle Rebuild Project

Logbook of the rebuild from June 29, 2005 to August 6, 2006

June 29, 2005

Thanks to my Dad and his financial contribution, I was able to acquire a 1993 R100GS PD with a salvage title 200mls from home. The pictures in the auction were promising. The bike had run 13219mls, was salvaged 1995 (so as a two year old) and then stored for 10 yrs on a salvage yard under a canvas cover, with the cylinders filled with oil. From the pictures and as far as structural damage was concerned, I was prepared for a frame damaged beyond repair, damaged forks and some of the plastic broken. Here are some more pictures. The forks actually do not stick and lock pretty straight. Could I be that lucky? It will take a couple of weeks before I can start work, but I may have to check the forks beforehand.

July 2, 2005

Just could not leave my hands off it today, so I did some wrenching, removing and some examination:

The bike got a hit from about 45 into the right side. I crushed the crashbar into the right cylinder without leaving considerable damage there, not even the oilcooler is damaged, just some scratches. Here is the first list of examined parts and their condition:

Here are a few more pictures.

July 2, 2005

Another day of examination and from what I have seen so far, one thing is clear to me: the (really not beautiful) purple frame mounting bracket (aka 'roo bar) prevented major damage to the bike. The energy of the impact to the RH crashbar and RH side of the frame mounting bracket was absorbed by the bracket and the frame. Look at the two gussets: RH side is about straight, LH side is curled (click the picture for higher resolution).

The distortion of the frame bracket left the instrument panel severly damaged, but, LH and RH sidepanels are ok and so are the instruments, at least cosmetically. As far as I can see and feel, forks and handlebar are not damaged, the RH handguard is not even scratched, the mastercylinder is undamaged, so the impact must have been only on the lower part od the bike, maybe a stump of a tree, who knows. Bottom line: the energy was absorbed by Fairing bracjet, crashbar and frame to the effect, that these were the only parts damaged, plus the front engine cover, LH (!) mirror and instrument cluster panel.

Here is the list of parts I examined today:

Here are a few more pictures.

Over the past two days, I had a chance to think about my initial plans as well. I was planning to build the bike on monolever basis but this newly acquired GS sort of changed everything. I will now rebuild the bike as is with a new/used GS frame, ride it a season and go from there. The monolever G/S will be kept and continued on a sideline.

July 4, 2005

Another day of examination. Did do some work on the rear of the bike, removed subframe, luggage carrier, muffler and stuff:

July 6, 2005

Did not want to do any work today on this bike (need to work on my Dad's /5) but couldn't take my hands of it. Plan for today: get it running on both cylinders. First establish who is the culprit: right hand side! Spark? ok! Check gas in float bowl? Voila, clogged and all the rest of it. After 30 minutes soaking and some brass brush treatment, she is running (and smoking like hell). Mission accomplished.

Next change of fluids:

In order to get the new oil distributed, I jacked the bike up to have the rear wheel move freely. Started bike, 2nd gear ... I have a rattle can! The gearbox is gone (after 13k miles) the PO must have beat the hell out of this bike. Well, I guess I (or better Bruno at Bruno's Machine & Repair) will have to deal with it ... one day.
July 26, 2005

Removed the gearbox today to work on it and look what I have found:

July 30, 2005:

Parts I have acquired so far:

August 26, 2005:
I have worked the carbs and had them fully refurbished: completely disassembled, soaked in lacquer thinner, cleaned in an ultrasonic bath, all new o-rings and gaskets, diaphragm, float bowl valves and idle mixture screws. Bruno looked at my gearbox: the clipring was missing (and added), everything else was fine, no excessive wear. We found the area where the particles were coming from, normal wear and tear, says the expert. He undercut the 5th gear, couple of seals and the gearbox is as good as new. All other parts had meanwhile arrived as well and except for the frame they were all as expected.
December 1, 2005:
I had an issue with another set of GS fork legs that I bought as an replacement for the stock G/S forks. That however forced me to have a closer look at the forks and ... they weren't straight as I initially thought. One is 4mm out, the other one 7mm ... sigh. This is the bad one:

December 11, 2005:
I replaced both fork tubes with a set of vgc second hand ones and changed both forks seals (40x52x10). Richard @ The Motorcycle Machinist took excellent care of the bent ones. They are perfectly straight now with no obvious material weaknesses and will be used for the front end conversion of my '82 G/S which is not as front heavy as the PD with the 38l tank. These BMW progressive springs ("Sportfeder") will be used here on the PD:

December 12, 2005:
Forks are back together (second hand tubes and BMW "Sportfeder" progressive fork springs), the rims polished and the wheels equipped with new shiny Metzeler Enduro 3 which I bought on my last business trip in England.

December 29, 2005:
A lot of complaints have been raised on the reliability of the Valeo starter (D6RA 15), so I checked it on loose magnets or any other signs of wear. A pretty straight forward maintenance job if you just want to do that, plenty of times described, e.g. here at airheads.org. The brush holder can just be removed from the motor case, no hidden screws or rivets, just literally tear it off. Beware of the brush springs. If you let them snap when removing the brushes, they might damage part of the bakelite brush holder. This is how all the parts look like:

The magnets seemed to be solidly glued. As a preventive measure, I decided to fill the gaps between the magnets with epoxy so that, in case one gets loose, it is still in a compound with the other three magnets and won't disintegrate. Even if all magnets get loose, they stay connected in a ring, the epoxy fillings hopefully preventing rotation. Brushes are ok, so all is put back together.

February 11, 2006:
Had a quick look at the alternator, all measurements in spec, brushes are only a few mm worn, so in line with mileage of the bike.

April 23, 2006:
I removed the clutch today for inspection, derust and reassembly. As could be expected, the clutch shows no wear after 13000mls: no recesses in backing plate or pressure plate, the friction plate is with 5.95mm well within the limit, better call it not worn. Here the finished product (click on the picture to get more close-up in high resolution):

May 10, 2006:
The batteryholder came back from the paintshop. It got a black epoxy undercoat and a semi gloss black overcoat, nothing fancy.

May 26, 2006:
I acquired a frame (VIN #6417154) in Germany, manufactured 03/1990 as a R100GS PD, type approval granted on 10-April-1990, first registered 27-Feb-1991. My Dad helped shipping it, but overall, it took 4 months to get it here. The frame is in overall good condition for age, with the usual paint chips and scour marks. Some of the rear end has been touched up and do show some surface rust. Nothing that would irritate though. The frame is sound, all tabs work and some aluminum material helps with attaching the huge indicator relais which wasn't part of the pre-92 models.

The high resolution pictures of the new frame are here.

I also took care of the engine, cleaned it up using Simple Green and brass brushes, just to show what's underneath. It cleaned up very nicely:

June 17, 2006:
I was adjusting the rear U-joint tapered roller bearings of the final drive and after torqueing the left bolt to 105Nm and the right one to 20Nm (before backing of to 7-9Nm) , I felt the notches, really BAD notches, so both bearings will be replaced.

Upon checking both pin bolts, I figured the inner one needed replacement too, it is already slightly oval (approx 2-3 thou out of round) as you can tell from the picture below:

I assembled the front triple trees and took pictures of the races. After cleaning and polishing them over with red scotch brit, they appear to have no notches whatsoever, a clean surface with no wear marks at all. The bearings are alike, no pitting, no weather or corrsion marks:

June 2, 2006:
Assembly has started. From here on, I will fill up the space with pictures of the assembly at various stages:

It is done:

End of loogbook: I sold the bike after the resurrection.
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