Fitting/Fabricating a Scooter Rack.......

[BGD]

OK guys ‘n gals, some advice, wisdom and guidance needed, por favor:

 

We’ve got a Euramobil coachbuilt 4 berth overcab MH, on a 1992 Peugeot J5 chassiscab (think Talbot Express or Citroen C25, as they are exactly the same).

Because it's only the stubby 4 berth version, the rear overhang of the body behind the rear axle is relatively short, which should mean that carrying the scooter on a rear mounted rack should not hugely affect the front versus rear axleweight balance, particularly if the fabricated scooter rack holds the scooter as closely as possible to the rear wall of the MH.

 

I want to get a scooter rack fitted to the rear of the MH, which will take my existing Suzuki Bergman 150cc scooter. Total actual weight of scooter, inc fuel, top-box, etc is just under 150kgs.

 

Because the van had “saggy bottom” syndrome when we got it, I’ve already fitted Grayston heavy duty twin coil springs on top of each side of the rear axle to assist the tired old leaf springs, and they’ve been fantastic - we now have a very “pert-bottomed” MH.

 

There’s no towbar or towbar subframe fitted to the van, and I don’t need one – a permanently fixed-in-place scooter rack would be fine for us.

 

As we are in Spain, I think I’ll probably have to go a local fabricators to get one custom-made and welded up/fixed onto our MH.

 

But before I go ahead, is there any advice from those of you who’ve previously made-up/bought/fixed on similar scooter racks that I should be bearing in mind?

(Apart from the immediately obvious max vehicle weight and max axle weight issues)

 

Muchas gracias.

 

 

 

 

[Mel B]

Hi Brucie, nice to see ya, to see ya, nice!!!

 

Sorry ... couldn't resist!

 

Back to the plot ...

 

I designed a rack and we had it made by a local fabricator. Our old Elddis had a 'bump bar' at the rear mounted on 2 rails which attached to the chassis, the 2 rails were 1.5" square hollow tubing, we cut the ends off at the rear of the van and the fabricator made a rack with poles that slotted into these rails for about 12" lenght, a hole was then drilled in the rails, through near the end of the poles (about 10" point) under the van through which we could put either bolts or strong padlocks to lock the poles in place. This meant that we could put the rack on or off as required.

 

The rack itself was just simply 2 box sections of outer runners, about 5ft long, running parallel with about an 8" gap with cross runners at each end and then at about 18" in from each end, the bike wheels then dropped between these cross runners and were strapped in. We also had long pole welded vertically in a position the right position (it will depend on your bike where is best) so that the bike could be fastened to it to ensure it was secured to prevent back to front and/or side to side movement when in transit. It worked a treat, the rack itself (which we still have) only took a minute to put on and take off and the bike itself only about 2 minutes to lift on and strap down.

 

As your bike is a bit heavier you may need to add some sort of ramp to aid getting it up on the rack in the first place - perhaps some adapted small car ramps could do the trick and they are cheap as chips.

[Guest JudgeMental]

 

I would first visit a weighbridge and see what spare capacity you have to play with and take it from there.

 

Any weight placed behind the rear axle (because of the fulcrum effect) will add more weight to axle load then items actual weight, if you get my drift...

 

maybe someone knows how to work it out.

 

 

[livewire]

I am in the process of doing the same.

 

The calculation for effect on axle weights is:

 

F=existing Front axle load (before adding new rear load)

R=existing Rear axle load (before adding new rear load)

L = weight of new rear load

W=wheelbase

O=Overhang centre rear axle to centre of mass of new rear load

 

Add new rear load, and

 

NewF = F - L*O/W

NewR = R + (O+W)*L/W

 

As my van has a rear lounge and I do not carry pasengers which would normally sit at the very back, personally I'm happy to chance it without going to a weighbridge.

 

Also I have fitted air suspension that should allow me to finely adjust as is necessary.

 

Hope this helps.

[Bill Ord]

I very much doubt if you have enough payload. 150kg for the scooter; add 50kg for the rack and fittings and you can see where I'm coming from. Then consider the effect on rear axle and it looks doubtful. However this doesn't seem to put most users off and would only be a problem in case of an accident or the police stopping and weighing you. It would be interesting to have some figures after completion of the job as it is a FAQ.

 

Bill Ord

[BGD]

Thanks to all for cooments/advice.

 

I'm minded to go the Mel B type route: a couple of hefty box section bars running back from the rear main chassis crossmember, then with a simple aluminium "U" section long thin plate bolted across them for the scooter wheels to sit in, and some sort of extra "U" section piece to use as an on/off ramp. Also an extra vertical bar (or two) to strap the scooter to once it is in place on the runner.

 

I've just seen some incredibly sexy hydraulically operated racks - the Easylifter is one, but there are others - where you frop the ramp to ground level, run the scooter onto it, then just pump it up with the handle (seems to involve a bottle jack type arrangement to raise/lower the thing.

 

Look fantastic. Also Fantastically pricey.

 

Don't suppose anyone has one of those Easylifter racks knocking around in their garage that they want to donate to a poor wandering Minstrel in Spain as a Christmas prezzie????????????

 

:-D

 

 

[tonyishuk]

livewire - 2007-12-02 10:37 AM

 

I am in the process of doing the same.

 

The calculation for effect on axle weights is:

 

F=existing Front axle load (before adding new rear load)

R=existing Rear axle load (before adding new rear load)

L = weight of new rear load

W=wheelbase

O=Overhang centre rear axle to centre of mass of new rear load

 

Add new rear load, and

 

NewF = F - L*O/W

NewR = R + (O+W)*L/W

 

 

Hope this helps.

 

Many thanks,

 

I assume its all metres and kilograms, nothing fancy like newtons, foot lbs (shows my age !)

 

Rgds

[Mel B]

Brucie

 

You get quite a few advertised in the MMM mag on the cash mart pages and also in the ads at the back, but I don't think you want to pay those prices do you my sweet? ;-)

[peteS]

 

Don't suppose anyone has one of those Easylifter racks knocking around in their garage that they want to donate to a poor wandering Minstrel in Spain as a Christmas prezzie????????????

 

:-D

 

 

Not donate but I have one going for £200 inc lighting board and heavy duty towball.

 

Mine is set up for a mobility scooter but you could add a channel for a scooter easily.

 

Pete

 

[livewire]

tonyishuk - 2007-12-02 1:43 PM

 

livewire - 2007-12-02 10:37 AM

 

I am in the process of doing the same.

 

The calculation for effect on axle weights is:

 

F=existing Front axle load (before adding new rear load)

R=existing Rear axle load (before adding new rear load)

L = weight of new rear load

W=wheelbase

O=Overhang centre rear axle to centre of mass of new rear load

 

Add new rear load, and

 

NewF = F - L*O/W

NewR = R + (O+W)*L/W

 

 

Hope this helps.

 

Many thanks,

 

I assume its all metres and kilograms, nothing fancy like newtons, foot lbs (shows my age !)

 

Rgds

 

I'm ot a mathematician, but looking at the equation, I reckon it will work in metric or imperial.

[Clive]

I,ve just done the maths for a potential new motorhome based on the 5 tonne Merc chassis. I weighed all the stuff we carry or today put into a trailer and it already came to a quarter of a tonne over the max GVW without counting bedclothes, sauces and the like.

So Dig out those bathroom scales to weigh the bits that are not inside your motorhome when you take it to the weighbridge. Add in the water at 1Kg/litre, yourselves (notionally 150Kg for 2 people) and do the maths as described above not forgetting to allow for the overhang.

I hope it works out for you but I have my doubts. We are now looking a a 6 tone base vehicle to do what we require and stay legal!

C.

 

[Brian Kirby]

livewire - 2007-12-02 10:37 AM I am in the process of doing the same. The calculation for effect on axle weights is: F=existing Front axle load (before adding new rear load) R=existing Rear axle load (before adding new rear load) L = weight of new rear load W=wheelbase O=Overhang centre rear axle to centre of mass of new rear load Add new rear load, and NewF = F - L*O/W NewR = R + (O+W)*L/W As my van has a rear lounge and I do not carry pasengers which would normally sit at the very back, personally I'm happy to chance it without going to a weighbridge. Also I have fitted air suspension that should allow me to finely adjust as is necessary. Hope this helps.

There is a problem with the formula for New R.  Try this instead: New R = R+L+(F-New F).  Using Livewire's formula above, the sum of New F and New R is less than the raw added load, which it cannot be.  They must equal the added load.  What comes off the front is transferred to the rear, plus the added load itself.

I think if you do as suggested, and take the van to a weighbridge, you'll get quite a surprise when you add the relevant weights and measurements!

Since your van already has assisters at the rear my guess is it is already close to its permitted rear axle maximum.  Whether that would be close above, or close below, I couldn't possibly comment!  Taking an already "shot" rear suspension that is relying on crutches, and then asking it to carry an additional 200 or so Kg, seems liable to get you prosecuted by RSPCS (Royal Society for the Prevention of Cruelty to Suspensions).  Or even the fuzz!

Chance it without visiting the weighbridge?  Well, there's no point in doing the calculations (even the right ones!), then, is there?  Come on, are you a gambler or not!!?  :-)

[SID RAT]

I ran the formula using dummy numbers and it worked OK. I know this isn't the correct way to test a formula but maybe I went wrong somewhere.

 

Taking 1000kg as the original front axle load and 2000 for the rear, a new load of 100 kgs, a wheelbase of 5metres and an overhang of 1m you get

 

1000-100 x 1/5 = 1000 - 20 = 980

 

2000-6 x 100/5 = 2000 - 6x20 = 2120

 

Total is 3100 which should be right.

 

But then it might be one of those circumstances where one set of numbers just happen to work. Not empirical proof.

 

 

[Brian Kirby]

Sid

Where does the 6 come from, and since when was 2000 - 120 = 2120?

[BGD]

Pete S -

 

I've sent you a PM...........

 

 

 

[timofleeds]

Hi BGD, before you do anything, do you have your vehicle ITV done in Spain? If you do check with them if you are allowed to fabricate your own rack and fit it as I know you can not do this with a tow bar and any tow bar that is fitted has to have its own ITV and has to be added to the vehicle log book after being profesionally fitted and confirmed as being type approved for the EU. This may save you a lot of work and expense.

 

Regards Tim

[SID RAT]

Sorry there was a typo

 

That should be 2000 PLUS 6 x 100/5 as shown in the original formula.

 

The 6 is the sum of the overhang (1m) plus the wheelbase (5m), again from the original formula

 

2000 plus 6 x 20 = 2120

[Brian Kirby]

Thanks Sid

Sorry if my earlier post seemed a bit abrupt.  It was - I was rushing it! 

Both formulas yield the same result then, which is odd, because when I tried the "NewR" I couldn't get an answer that made sense.  Must have been me, but I still can't spot my error!  Apologies all round, and you now have two ways to calculate the rear axle load!

I'd still get the rear load checked, though, as it is safer to know what the starting point really is, than to make assumptions.

[SID RAT]

Hi Brian

 

No, you weren't abrupt at all. I was though. I knew I'd dropped off somewhere in that formula, but I must have read it several times and couldn't see it. I'm a bad tempered s.o.b. when I make silly mistakes, as my wife will trestify. Repeatedly. So, my apologies to you for snarling.

 

And, as you say, we now have two ways of calculating axle loads.

 

Regards

 

Patrick