Question:
- What can I expect when I buy a /2 BMW? What do things like top end rebuilds cost?
Answer:
You can expect a lot of trouble, unless you buy a fully restored bike with bills, a journal and detailed photo's of the restauration. These bikes were very cheap in the seventies. A lot of people used them intensily, without too much maintanance. The bikes were transformed to dirtbikes and choppers. And they who didn't use the hacksaw to improve their BMW, usually tried to cut the running costs, by installing parts from later models, which fit in a lot of cases. Aftermarket silencers, tail and front lamps, seats etc. are also common. Really cared for bikes, which you can run as "authentic and original" are rare. And it is difficult to find the right looking second hand parts to restore a hacksawed bike to this type of used but nice finish.
It is not so difficult to restore to a glossy, as new, type of bike. Just expensive. Virtually all parts are still available or being remanufactured. At the veteran scene in Europe, the /2 is a very common sight. So there is a large industry around them. But be aware, not all remanufactured parts are of the same quality as the originals, and quite a few parts are manufactured in batches. When you miss the batch, you must wait until the next one starts. At the moment (10-'94) wheelrims are unobtainable, because Akront in Spain had fire damage that summer. This is just an example, but characteristic for the situation. Nonetheless, the parts supply is very healthy.
A lot of people are afraid for the mechanical state of their purchase. But the costs to repair the mechanical damage are usually less than the visual aspects. New or good second hand fenders, lamps and tanks are very costly. Paint spraying is expensive, just as all those little bits and pieces, like rubbers, emblems, nuts and bolts, etc. Here are some areas to watch out for:
- Get a workshop manual. Clymer has one for the /2's. The original BMW workshop manual is not very "userfriendly", but invaluable for all the data. A good German book is: "1000 tricks fuer schnelle BMW's" by H.J. Mai. ISBN: 3-613-01117-4 Also very usefull is a parts list. It contains exploded diagrams of all the parts of your bike. Very usefull for reassembly-time. Another nice book is: "How to restore your BMW motorcycle twins, 1950-1969" from Roland Slabon. It is about how your bike 'should' look like, what is original, what are period accesoires etc. Recomended.
- All the bearings in the cycle department. Especially headstock bearings are mostly scrap. You can update to tappered bearings. My bike also had very bad swingarm and wheel bearings.
- Watch out for signs of accidents in the past. Also common in the past was to remove the saddle mounting bracket, when another saddle was installed. The bracket should have two groups of 6 holes, and the saddle uses the 6 rear holes.
- Check the wheel alignment. Easily checked with a length of wire running along the wheels, that should touch the two tires in four places. Possible errors: Different width tires. Bent frame (common). Bent front fork with swing arm (common). Bent rear swingarm (not common). Rear swing arm not in the middle of the frame. Front swingarm shims not in the right position. The wheels are not running round. The rims are not spoked correctly relative to the hub.
- Shockabsorbers from Boge aren't the most reliable items. You can swap them for Koni dampers.
- The aluminium wheel rims are mostly heavily scratched and pitted.Polishing them is a horrible task. New rims are available.
- Other aluminium items, like the rear swingarm nut and the suspension parts, can be polished. Restoring to the 'right' original dull finish is more difficult.
- There is not so much chrome, so the chrome bill will be reasonable. New items are available, but usually not of the highest quality.
- Check the fenders for corossion damage. Especially the rear one is prone to rust. There is a wiring loom tunnel in there, which acts as a most perfect moisture trap. Watch out for bogged repairs with polyester. New fenders are horribly expensive.
- The headlamp shell is mostly rather dented and not round anymore. It needs a good craftsman to recreate the right shape.
- Tank can be rusty inside, when stored empty. Special sealing kits are available.
- The petrol tap will be leaking. Unless there is a later type fitted. The original tap has a cork lining which isn't for sale, and is difficult to make on your own. When you keep the tap always wet with petrol, it is possible to keep it reliable.
- Lots of bikes miss the original dim and horn switches. They are being re- made, but idotely expensive. The correct type has a sliding dimmer switch instead of a toggling switch.
- The battery tray will be affected by rust, but it is made from thick steel. More serious is it when acid has attacked the lower frame cross tube. There could be an extra "unoriginal" hole.
- All rubbers probably will be perished, but are readily available.
- Saddle's are being remade. Also parts are available. But it is very difficult to exchange the rubber saddle top whitout machinery. Maybe it is wiser to order a complete upperpart.
- Dual seats, covers and the miscelaneous parts are also still available, and are available on fleamarkets, as most people nowadays prefere a saddle.
- I hope your speedometer is still functioning. They can be repaired in a VDO workshop. When you shop around on the fleamarket for a replacement, you must look for a speedo that fits the cardan ratio.
- The engine is a reliable unit. But you will need an overhaul sometime:
- New valves and valve guides. The 8mm valves of the R69 and R69S are very strong, but I would advise you to exchange the 7mm valves always.
- Cylinderheads can crack. When looking for a second hand cylinderhead, look for cracks between the sparkplug hole and the valve seats. If it is a head with a steel bush for the sparkplug, look if it is pushed outwards a little bit. That is a sure sign for an advanced state of a cracked head. You can ride a long time with a crack, but someday you will loose compression. Some heads show the dents inside from a broken valve. If it's not too bad, you can reuse it. Also have a look at the exhaust threads, they are damaged in a lot of cases.
- Pistons in all sizes are readily available. Only the R69 and the R50S are a problem. Uli's advertises with German made pistons for all the types up to 3rd or 4th oversize. Watch out for the Italian repro's. They are too heavy and need to be installed with a lot of play, which causes piston slap.
- Small end bushes are not too strong. Big end roller bearings are strong, but they depend on clean oil. That can be a problem, because the thrower plates on the crankshaft, that clean the oil by centrifugal force, are full with sludge after +/- 50km. To clean them, you have to dissasemble the whole engine, so it is likeley to be neglected in the past. If you buy a bike with unknown history, then CLEAN THE OIL SLINGERS ASAP.
- I haven't dismantled a gearbox yet, but it is a relaible unit. Even when maltreated it can stand up for a long time. When you have to adjust the gear selection mechanism, you must bend the forks until correct. This is an akward business. The wear items in the gearbox are the shifting forks, the locking plates and the dogs on the gearwheels. Jumps out of third or fourth gear when riding hard. In later years BMW decreased the axial play of the three transmission shafts to 0.1 mm.
- The clutch is prone to the normal tear and wear. When you exchange the clutchplates, check the height of the diafragma spring. Look also at the splines in the cluth plate and on the gearbox input shaft. They need their spline lubrication job now and then, but are not nearly so critical as the later BMW's in this respect.
- The electrical department is not very complex. You need a new wiring loom when the wires are brittle. Not too expensive.
- Check the dynamo stator. Its rings should be clean and sparkling. When not you can turn them down, and cut back the isolation.
- Check if the magneto has a healthy spark. If not, maybe the rotating magnet isn't positioned correctly. Look it up in the workshop manual how it should be done and set it very precisely. When this doesn't help most probably the windings are shunting. The magneto has a hard life in a hot environment, and the old shellack insulation can be weakened after such a long time. When the bike has problems with restarting when hot, it could be a bad capacitor, but more probably it is such a bad magneto winding.