Light bulbs 6 Volt & 12 Volt
List of 6 Volt and 12 Volt light bulbs for the R24 – R27, R51/2 – R68 and R50 – R69S models
Capacitor testing
The correct functioning of a capacitor can be measured with (for example) a FLUKE multimeter. The value specified by the manufacturer is 0.22 μF (microfarad). Over time, a capacitor’s performance can be expected to decline. The left photo shows a broken capacitor: the measured value is 0.131 nF (nanofarad) = 0.000131 μF The right photo shows a properly functioning capacitor: the measured value is 0.249 μF. This is 13% higher than the specified value, but this does not affect proper operation. The value specified by the manufacturer is a chosen ideal value for the expected average engine rpm. This value is therefore
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Bearing radial play specifications
The table below shows the radial clearance specifications for all bearings used on the R24 – R69S models
Tools for disassembling & rebuilding R51/3 – R68 and R50 – R69S engines
A comprehensive list of special and generic tools
Pistons aren’t round
It’s a wide spread misconception that pistons must be round / cylindrical. The opposite is true, This is a new Kolbenschmidt R27 piston 68.50 mm: From the Internet: Profile: If you roll a piston across a flat surface, you’ll notice it doesn’t roll in a straight line. This characteristic is called profile. Aluminum conducts heat significantly, so pistons are designed with a taper. The top of the piston (near the crown) has a smaller diameter than the bottom (near the skirt). The skirt itself is shaped like a barrel. This taper allows the
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Denfeld vs Pagusa saddle
The only difference between the Denfeld en Pagusa saddle is the saddle deck. There are small differences between the saddle deck frames: the shape of the frame and the front threaded bolt. The Pagusa saddle bolt it is a bit longer and has a spacer so that the front of the saddle deck sits +- 1.5 cm higher compared to the Denfeld saddle deck. The grain texture of the Denfeld rubber saddle deck surface is finer than the Pagusa grain texture. There is no quality difference All other parts are the same: subframe, Z-bracket, rubber spring, spring stop piece, mounting
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R51/3 – R69S engine gear set dimensions
Based on a sample of 74 gear sets, this graph shows the frequency of the different gear sets and the spread around the target dimension of +0.
List of bearings in the 1 & 2 cylinder engine, gearbox and final drive
Click thumbnail to open the list. R24 – R27 R51/3 – R68 R50 – R69S
Gearbox cam plate comparison
Comparison of the different gearbox cam plates used in the R24 – R27 and R50 – R69S models. For more information about the R50 – R69S shifting system, click following links: Smooth shifting R50 – R69S R50 – R69S Old and New style shifter mechanism
Gearbox problems: shafts do not turn smoothly after assembly.
This is specifically aimed at 1 cylinder and /2 gearboxes. If you’ve tried everything and you can’t figure why the gearbox shafts do not turn freely, you can use following very time consuming method 🙂 to determine the cause: Instead of putting all 3 shafts in at the same time, put in 1 shaft at the time. Remove the input shaft seal from the gearbox: the seal makes it harder to rotate the input shaft, making it difficult to assess whether the shaft is running freely. Remove the idler gear and kickstarter gear segment. Whenever you install (and remove) one
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Cleaning of rubber parts
Some rubber parts are still provided with a (wax) layer when shipped: a mold release agent. A cleaning solution with hot dish soap and water is enough to remove this layer. Use rubbing alcohol for stubborn stickiness. Although alcohol is an effective cleaner for most kinds of stickiness, you should only use this cleaning agent on rubber occasionally. Dampen a clean rag with alcohol and wipe at sticky areas until they are removed. Rinse the rubber with water afterwards. Exposing rubber too often or too long to alcohol may cause it to break down more quickly than normal.
BMW motorcycle wheel bearings, 1956 through 1969 by Duane Ausherman
Very informative and comprehensive treatise on the tapered wheel bearings. Click on the photo to go to the relevant webpage: