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FredRydr
07-31-2007, 01:42 PM
I was told years ago that an oilhead could not be towed using one of those front wheel holders that slip into a hitch. The reason given was that the lubrication system of the drivetrain would not function, destroying either the rear, the shaft or the gearbox (I forget which).

Does anyone have specific knowledge of the new design of the hexheads' drivetrain sufficient to say if this is still true?

Fred
'07 R


Photo: There are purpose-built units for towing a motorcycle with the front wheel off the ground, but this guy had more imagination.

PAGoldsby
07-31-2007, 01:53 PM
Those wacky Flemish ...

althotos
08-19-2008, 01:49 PM
Hi Fred.
Did you ever find out if you could tow your bike on it's rear wheel?

I would like to get a towing cradle for the hitch on my truck so that I can
take my bike in to the shop for servicing, but I also read that you can't tow
shaft bikes on their rear wheels.
Thanks.
----------------
aj,
hollywood,fl
2000 R1100RT, 59K miles

darrylri
08-19-2008, 02:50 PM
I was told, long ago, not to coast engine-off down long grades. This was in the era of airheads, before they were called that. The reason given (all safety concerns aside) was that, in the transmission, the input shaft's rotation provided for lubrication of the gears. I do not know if this applies to any of the other bikes BMW has built since then...

thtduck
08-19-2008, 03:04 PM
Probably shouldn't say anything because I'm guessing here. Bet transmission damage could occur because the bike is out of gear and therefore the all the workings are not turning that maybe required for bearing lubrication. When I drove tow truck many moons ago this was and is an issue w/ large trucks. That's why you see them remove the drive shaft before towing.

ANDYVH
08-22-2008, 03:16 PM
I would only do that temporarily, maybe just to get the bike to the dealer, within 25 miles tops. On bikes with shaft drive I don't think its a good idea. When you consider the angle of the bike in the towing position, the fluid in the final drive seeks level and may get close to the vent on the top of the drive hub (especially older designs). That could cause the fluid to "pump out" of the vent.

With the rear wheel on the ground/spinning, the driveshaft is spinning, which means some sections of the tranny internals are spinning also. Doesn't matter if the tranny is in neutral. Keep in mind, when the tranny is in neutral when the engine is running with the clutch out, the tranny input shaft is still spinning. But the gear "dogs" are not engaged to any gearsets, so no motion is transferred to the output shaft. But, if you spin the rear wheel, it does spin the parts on the tranny ouput side. With the tilt of the bike the tranny fluid may not sufficiently lube all the spinning parts. Maybe it does, maybe it doesn't, you wanna take that chance?

Even with the bike in neutral, there may be enough "hydraulic action" in the tranny, at least until it gets up to temperature and the oil thins out, that the tranny input shaft may spin. That means the clutch pack may also spin slightly, especially if your clutch hub splines are dry. That may cause some clutch wear.

For the very few times most any of us have to haul a bike to the dealer, rent a U-haul trailer, or a pickup truck. Certainly, never tow a drive-shaft equipped bike on the rear tire only as a regular practice, such as those out there with RVs.

JK
08-23-2008, 03:58 PM
I would only do that temporarily, maybe just to get the bike to the dealer, within 25 miles tops. On bikes with shaft drive I don't think its a good idea. When you consider the angle of the bike in the towing position, the fluid in the final drive seeks level and may get close to the vent on the top of the drive hub (especially older designs). That could cause the fluid to "pump out" of the vent.

With the rear wheel on the ground/spinning, the driveshaft is spinning, which means some sections of the tranny internals are spinning also. Doesn't matter if the tranny is in neutral. Keep in mind, when the tranny is in neutral when the engine is running with the clutch out, the tranny input shaft is still spinning. But the gear "dogs" are not engaged to any gearsets, so no motion is transferred to the output shaft. But, if you spin the rear wheel, it does spin the parts on the tranny ouput side. With the tilt of the bike the tranny fluid may not sufficiently lube all the spinning parts. Maybe it does, maybe it doesn't, you wanna take that chance?

Even with the bike in neutral, there may be enough "hydraulic action" in the tranny, at least until it gets up to temperature and the oil thins out, that the tranny input shaft may spin. That means the clutch pack may also spin slightly, especially if your clutch hub splines are dry. That may cause some clutch wear.

For the very few times most any of us have to haul a bike to the dealer, rent a U-haul trailer, or a pickup truck. Certainly, never tow a drive-shaft equipped bike on the rear tire only as a regular practice, such as those out there with RVs.

Concur.

Another consideration against long distant use of this towing practice are the side-loads to the front forks, shocks, seals, and stearing head, as they're forced to operate outside of their design parameters.

Likewise, the front tire rim, on which the bike is secured/anchored to the carrier, will experience similar undesireable static and dynamic side-loads.

FWIW

J.K. :wow

rocketman
08-23-2008, 04:30 PM
A guy I worked with years ago told me his attempt to tow his bike by tieing it by te handlebars with rope to the back of a car. Hmmmm guess how far he got when the rope became tought? Yup about 3 inches and down it went for another 10-15 feet being dragged on its side till he got his buddy's attention! Ha Ha!

I just shook my head in disbelief, and this guy was an engineer, granted an electrical engineer, but still......

RM