Towbar in a kit car.

Towbar in a kit car.

Author
Discussion

ColinM50

Original Poster:

2,630 posts

174 months

Friday 13th March 2015
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I'd like to fit a towbar on my Royale Sabre kit car to tow a heavy (1400Kg) twin wheel caravan. The car's got two hefty 3 inch square chassis rails running the full length of the car and a cross bar at the back where the bumper brackets then mount. I GUESS I could bolt some sort of bar to this cross rails and then a brace from the centre of the cross bar to another chassis member further back.

This all looks and sounds pretty good to me and I think it'd be structurally sound and fit for purpose, Anybody any ideas as to whether this would work?

I did train as an mechanical tech so have some mechanical knowledge but I'd really like a second opinion since I'd hate the 'van to fall off the back of the car. SWMBO would be most unimpressed.

Is there anyone I could get to "certify" this mod?

Here's a few pics showing the various bars. Pics were taken laying on the ground. The bar with the red lead paint is the cross member, you can see the bumper towards the top














big block

19 posts

161 months

Friday 13th March 2015
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Hi Colin having built a few kits over the years never a Royale Sabre tho, the best advice would be to contact the owners club or automotive creation limited who I believe now own the rights to Sabre, don't just assume as they are other factors that might land you in trouble if you fit a one and the chassis was not tested or designed for the stresses of towing,you would not be insured if an accident happened with a non conforming towbar. Better safe than sorry.

Fastpedeller

3,848 posts

145 months

Sunday 15th March 2015
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One thing that would worry me (aside from your concerns re strength of chassis/fittings) is the weight of the caravan compared with the towing vehicle - I'd not tow a 1400kg caravan with a 1000?kg vehicle - asking for trouble.

Steffan

10,362 posts

227 months

Sunday 15th March 2015
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Fastpedeller said:
One thing that would worry me (aside from your concerns re strength of chassis/fittings) is the weight of the caravan compared with the towing vehicle - I'd not tow a 1400kg caravan with a 1000?kg vehicle - asking for trouble.
Indeed.

I have been building and driving kit cars since 1963 and I am still building them. Should finish a couple more this year, God willing.

A tow bar could be fitted and I would expect most decent tow bar specialist to be able to devise a way of doing this on the Sabre. Nice kit car. Good looking and they drive well. I like the car. I think that is achievable.

However realistically the weight of the towed caravan would be way too much for safe towing I would have thought. Possibly dangerously so. I can well understand why you want to do this but I think it would be unwise. There are heavier kit cars about but I really think this is not likely to actually work safely.

I am sorry to say I cannot see an answer to this conundrum. Pity because I can well understand the interest. Caravanning in Drophhead cars is particularly fun IME.

cerberatony

417 posts

183 months

Sunday 15th March 2015
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Legally speaking I dont believe you can tow something heavier than the tow vehicle. As a rule of thumb max tow weight is max kerb weight of towing vehicle, Caravan clubs recommend 85% of kerb weight as a guide line.

ColinM50

Original Poster:

2,630 posts

174 months

Tuesday 17th March 2015
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@fastpedlar, Steffan and cerbertony. Yes, you're right the 'van is probably over the limit for the weight of the car, I'd not thought too much about that to be honest. Is it a legal limit or just recommendations? I've got many years experience of towing 'vans, boats and trailers and the "plan" is to just tow the van to shows, e.g. Stoneleigh and stay overnight rather than take two cars. I'm not planning on long distance trips, just gentle motorway driving, but of course if it works OK things could change.

My wife will only drive an auto so won't drive the Sabre and to be really helpful she refuses to even try driving my BMW 530 on it's own let alone with the 'van on the back, hence the idea of using the Sabre.

Short of getting a new wife, and I've had this one 40 years so she's almost fully trained, can't see too many ways round the problem.laugh

Going back to my original question, and this is aimed really at "experts" like Steffan or Stuart Mills, do you know anyone who could design a towbar mounting system or check over and sign off what I'm planning to do? I've asked Towsure and they're not interested, they say the time and cost involved wouldn't be economic. So if I just designed my own, where would that leave me legally in the event of an accident?read

Steffan

10,362 posts

227 months

Tuesday 17th March 2015
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ColinM50 said:
@fastpedlar, Steffan and cerbertony. Yes, you're right the 'van is probably over the limit for the weight of the car, I'd not thought too much about that to be honest. Is it a legal limit or just recommendations? I've got many years experience of towing 'vans, boats and trailers and the "plan" is to just tow the van to shows, e.g. Stoneleigh and stay overnight rather than take two cars. I'm not planning on long distance trips, just gentle motorway driving, but of course if it works OK things could change.

My wife will only drive an auto so won't drive the Sabre and to be really helpful she refuses to even try driving my BMW 530 on it's own let alone with the 'van on the back, hence the idea of using the Sabre.

Short of getting a new wife, and I've had this one 40 years so she's almost fully trained, can't see too many ways round the problem.laugh

Going back to my original question, and this is aimed really at "experts" like Steffan or Stuart Mills, do you know anyone who could design a towbar mounting system or check over and sign off what I'm planning to do? I've asked Towsure and they're not interested, they say the time and cost involved wouldn't be economic. So if I just designed my own, where would that leave me legally in the event of an accident?read
Stuart Mills is unquestionably and exepert on kit cars but I have merely built a fair few and I am still doing so in my 70th year.

Stuart Mills may well be able to give a definitive answer and I have ways found him both very approachable and very helpful. He may very well be abe to give you definitive advice. The towing regulations do include advice on the weights of the towed and towing vehicle I think. Modern cars all have towing limits identified by the manufacturers.

Your Royale comes from another era and without wishing to be unhelpful, I rather think thst this is not advisable personally. I have towed a fair bit over the years and spun a Range Rover whilst towing a TVR racer in very very heavy rain, long long ago. Started snaking and away the rig went nothing I could do. Miraculously no damage at all the rig just spun. It was night time and the road was totally deserted and we ended up facing the right way. Pure fluke! Taught me a real lesson because that rig was totally legal and had all the safety devices preventing snaking, assisted spring, upgraded shocks etc. and the RR was condierably heavier then the trailer and racer. As I discovered when they go, they go. I would be very cautious personally because of my experience long ago.

Lovely car and I wish you well enjoying it. Best of luck in your search.

Fastpedeller

3,848 posts

145 months

Tuesday 17th March 2015
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What's required for a kit car is one of these..... only 195kg and folds down to 1m high