2003 Alphard 2.4 Rear Axle Load Limit

[The Menace]

I'm thinking of adding a scooter towbar rack and a 110kg Honda scooter to the rear of the campervan and wanted to know if the rear axle can take the extra load, I've replaced the rear spare wheel with a donut LPG tank so that will have added some extra weight. Any thoughts/comments would be appreciated. Thanks, Nigel

[ThuMentaliss]

...and the tyre load is......

[The Menace]

Max. load is 825kg

[Jenny Smedley]

Thank you for that, I was wondering too. 

[pcous]

Hi Nigel,

The Japanese de-registration document for our Alphard Gen 1states unladen (kerb) weight 1870kg and gross weight 2255kg. So there's a difference of 385kg between unladen and laden weight for the base Alphard, but I haven’t found a breakdown in the figures for front and rear separately when laden.

Weight distribution unladen for the car is 1070kg front / 800kg rear, but ours was converted to a campervan on import and LPG shortly after, which affects the unladen weight distribution; the extra weight loading more onto the rear axle than the front. When we use the towbar for bikes, the weight distribution obviously shifts again, not only increasing rear axle load further, but also decreasing front axle load (because of the pivot effect of the weight on the bike rack, depending on its distance from the rear axle). So there are a few things to consider.

We decided the only effective way to understand the axle loads was to put the Alphard on a weighbridge. After messing about on a weighbridge several times, putting the whole vehicle on then the rear only (and subtracting the difference), we worked out the unladen and laden weights for each axle on our campervan. For yours, you’d then need to add the weight of bike rack and scooter, and assume both load onto the rear axle. If you want to, you can calculate the additional pivot effect on both axles. This might be worth considering, to ensure the front load doesn’t reduce too much and lighten the steering - see http://www.caravanguard.co.uk/news/how-to-calculate-your-motorhome’s-safe-weight-limits-4104/  I know some people have also considered fitting uprated rear coil springs to address the extra weight.

Our towbar has a nose weight limit of 75kg. This is obviously meant for caravan nose weights, but gives an indication of the weight the towbar will take with a bike rack attached. So you’d need to have a rack that could take 110kg for your scooter and a towbar capable of taking the weight of both scooter and bike rack, depending on how it’s fitted to the rear of the Alphard. Our towbar fitting was restricted because, like you, we’d used the spare wheel area for an LPG tank.

Once you know what load you have on the rear axle, you can then consider tyres and ratings. Divide the axle weight by 2 to get a load for each tyre....  As you know, tyres are weight (and speed) rated, so your tyre rating of 825kg would support an axle load of 1650kg max (although you wouldn’t want to be operating at or near the max rating). Also, bear in mind the overall gross vehicle weight (GVW) limit of 2255kg.