X9 Owners & Riders Club

The X Files ~ The Piaggio X Series => X7 & X8 Specific Stuff => Topic started by: sixpenny on October 06, 2015, 14:41:38



Title: Towing with rear wheel on road
Post by: sixpenny on October 06, 2015, 14:41:38
Hi Guys
Thinking of towing scooter behind campervan with front wheel hitched up on tow bar. Would this do any harm to CVT?
Thanks
George


Title: Re: Towing with rear wheel on road
Post by: The Bern on October 06, 2015, 14:51:49
I wouldn't have though it would be a good thing to do, when the axle spins fast enough to make the clutch solid it will try to keep the engine spinning, similar in principal to why you shouldn't tow an automatic car.
Is it easy to remove the belt on your machine ? if so then that would be the best option


Title: Re: Towing with rear wheel on road
Post by: Mike H on October 06, 2015, 17:50:29
Yes won't work, clutch will be engaged at > walking pace or whatever it is and be turning the engine.


Title: Re: Towing with rear wheel on road
Post by: Dave Milnes on October 07, 2015, 07:21:58
Are you sure? The shaft connected to the wheel is the bit doing the free wheeling which has the clutch drum not the centrifugal shoes attached. The belt, rear pulley and the clutch hub are what needs to be spinning to throw out the clutch shoes and these are what are connected to the motor. They will be stationary unless the engine is running.
The only real danger is if you have a weak or broken clutch spring that may flap and make contact with the drum, but it wouldn't have the force to really grab and turn it.

The MOT brake rolling road doesn't engage the clutch. If it did you could push and bump start a scooter.

Automatic cars are different as the wheels are directly connected to the output gears of the transmission and are designed to run under hydraulic control from pressure created by the engine driving the torque converter.


Title: Re: Towing with rear wheel on road
Post by: roadster on October 07, 2015, 07:32:21
I reckon Dave is right about that and you can easily check it by trying to freewheel down a steep hill with the engine off. Even so I would be a bit worried about going a long way at speed just because it puts continuous reverse load on the gearbox and may overheat the oil with unknown consequences. If you are prepared to bumble along at 40 to 50 mph its probably OK and you could always check after 10 miles or so to see that the gearbox casing is not abnormally hot.


Title: Re: Towing with rear wheel on road
Post by: bingboy on October 07, 2015, 07:49:14
I would go on Daves conclusions as I was writing similar myself at the time of his answer, and I would say the that it would be impossible for gear oil to overheat because of the mechanical involvement within the gearbox drive.
 ( My conclusions) :I could not see why you cannot tow as you have explained sixpenny! As the engine has to actuate the vario and clutches with centrifugal thrust and nothing would be engaged!! Thus the only resistance would be in your rear Reduction Unit of which is filled with oil for lubrication.


Title: Re: Towing with rear wheel on road
Post by: Dave Milnes on October 07, 2015, 09:58:55
As long as you don't exceed the speeds and distances that the bike is designed to work when under it's own power it should be OK. You will produce wear on the hub gearbox and you will wear the opposite sides of the gear teeth but it will add up to only the same wear total as if you had ridden the bike under it's own power for the same distance. Shouldn't be a problem as the gearboxes are not a weak point in any way.

The only other wear that will take place abnormally is the inner needle rollers that the rear pulley runs on which will equate to the same as leaving the engine running all the time you are towing... so potentially several hours per day.
When the bike is being ridden, this only happens at idle, as when the clutch bites the shaft from the clutch drum and the clutch/pulley assy all spin at the same speed. To alleviate this I'd simply re-grease these rollers at regular intervals with a good gob of quality grease and keep my eye on them. I doubt a problem would be caused by the odd days towing a couple of days a year but probably best to avoid prolonged high speed towing.


Title: Re: Towing with rear wheel on road
Post by: The Bern on October 07, 2015, 10:24:46
Are you sure? The shaft connected to the wheel is the bit doing the free wheeling which has the clutch drum not the centrifugal shoes attached.

I'm a plank  :blush:

:redface: That's TWICE this year  :redface:


Title: Re: Towing with rear wheel on road
Post by: Mr.Chips on October 07, 2015, 11:23:16
Possibly, but if you hadn't said what you said it might not have prompted such detailed explanations which have given me, at least, an insight into the whole business.  :thumbup:

 :ph34r:


Title: Re: Towing with rear wheel on road
Post by: Mike H on October 07, 2015, 17:35:51
OK Dave's probably right but I still wouldn't fancy it.



Title: Re: Towing with rear wheel on road
Post by: Dave Milnes on October 07, 2015, 19:14:00
It's quite a regular thing for scooters like the Atlantic (same motor) to be towed behind RV's in the states and they seem to get away with it.  :whistle:

If I were Bern though I'd use my two planks and make a ramp and put it inside my camper van. Safer. :)


Title: Re: Towing with rear wheel on road
Post by: The Bern on October 07, 2015, 22:38:53
 ::lol:: Good 'un Dave  :thumbup:


Title: Re: Towing with rear wheel on road
Post by: roadster on October 08, 2015, 08:55:01
... similar in principal to why you shouldn't tow an automatic car.

The exact reason manufacturers don't allow cars to be towed  with driven wheels on the ground varies according to the design but one good reason is if the towed automatic car is accidentally dropped into park at speed. Here is one I repaired earlier:-
(http://www.x9gallery.co.uk/home/albums/userpics/10056/normal_IMG_2043.JPG)

This is a ZF output shaft, from memory I don't think a Borg Warner would allow that to happen.


Title: Re: Towing with rear wheel on road
Post by: Mike H on October 08, 2015, 10:11:06
Do you get engine braking with these shoe and drum type clutches? Have never experienced one.


Title: Re: Towing with rear wheel on road
Post by: Dave Milnes on October 08, 2015, 10:33:52
The X-series doesn't do engine braking like a Tmax or Burgman though you get it from higher speeds but as you drop to sub 20 mph there can be a sudden loss of connection.
Going down steep hills slowly can need lots of brake application although if you lift the revs slightly the clutch will re-engage and you can get back some engine braking.

(Edited Roasters BBCode to reveal the pic)


Title: Re: Towing with rear wheel on road
Post by: Mike H on October 08, 2015, 14:38:35
Ah right OK, very interesting, I asked 'cause I get LOTS of engine braking with the X10 as it has the multi-plate wet clutch, soon as it's over walking pace it's engaged, and has to be below to come off; it's done by centrifugal rollers and dish plate very like the variator at the front. Very little braking is needed down hills.

Because of this clutch design I can't seeing it being towed, the oil drag could cause the driving side to also be spun up and then it will become engaged.


Title: Re: Towing with rear wheel on road
Post by: Dave Milnes on October 08, 2015, 15:34:19
Quite likely if any sort of fluid is present, they don't like being reverse driven.


Title: Re: Towing with rear wheel on road
Post by: sixpenny on October 11, 2015, 14:03:35
Thanks for all your info guys. On balance I think I will try a tow of say 10 miles & check things out
George


Title: Re: Towing with rear wheel on road
Post by: Mike H on October 11, 2015, 17:43:21
Can you do that and also listen for any unusual noises?  :o



Title: Re: Towing with rear wheel on road
Post by: Olympus on October 25, 2015, 15:45:41
Find a hill somewhere or decent slope at the top kill the engine and let is coast down gathering speed ....you will easily detect if there is engagement or indeed drag...
I used to drag my 250SL behind our motorhome without any issues at all


Title: Re: Towing with rear wheel on road
Post by: sixpenny on October 26, 2015, 08:34:25
Great idea...thanks. I'll try that
George