Originally Posted by NoiZboy
Looks like a great offer, but what are the differences between the options listed for the R1150GS? Is the external reservoir only a matter of convenience, or does it offer additional capabilities/features? Sorry if I'm asking a dumb noob question, and thanks for the remarkable opportunity!
For the R1150GS there is One front shock and 4 rear shocks available
The front is a simple design Emulsion Type shock.
Emulsion type shocks are used for a lot of front BMW's and many HD rears.
They work very well for good ride quality when the amount of stroke is long such as on BMW fronts. They are the least expensive shock, as the use the least number of parts.
Rears Ohlins Offers these four shock:
The BM542 is the most expensive, it has adjustable Rebound Adjustable Compression, and a Hydraulic spring preload adjuster.
This shock is also special in that it has what Ohlins calls a Progressive Damping.
It uses 2 pistons, one like all the other 46 series Ohlins and the second additional damping need the end of the stroke. This is the best shock for any off road use.
This was first used by Ohlins in 2005/2006, I found it funny another brand is touting it as something new or unusal.
The BM940 is the standard road shock, not really made for off road use. It has the same Hydraulic spring preload adjuster but only Rebound adjustable.
The BM942 is the same as the BM940 but it is shorter to lower the back of the bike.
The BM045 is also the same as the BM940 but it does not have the Hydraulic Spring preload adjuster.
The rear shocks are one of three designs. Piggyback reservoir, Monotube with a remote reservoir, Monotube, or TTX.
Ohlins does not make a TTX for this bike, so for now I will skip that. Just let me say the TTX is the best of the bunch and the newest design as well.
The BM542 is a Monotube with a remote reservoir, The advantage is a little more oil, and easier to service (cheaper to service as well) than a Monotube.
The BM940, BM942, and BM045, are all Monotube shocks.
I prefer the Piggyback or remote reservoir.
All of these shocks are high pressure Nitrogen.
This is another one of the advantages of a TTX , it runs 1/3 to 1/2 the pressures of this design shock.