How to Shorten Trailer?

[Neil R]

Hello all, I have a Ribcraft 5.45 on a Rapide trailer.

After about six years, I've finally decided to do something about the length of the trailer drawbar - to my mind the hitch assembly / front draw-bar sticks out about 30" more than it needs to. Plenty of folk have made a similar observation over the years. The overall length causes a fair degree of embarrasment when I try and park the trailer in our normal holiday parking space.

The factors I've considered are:

Possibility for car / trailer collision during very tight turning

That the tailgate can still be opened when hitched up

The probable need to move the axle to re-balance the hitch loads

The change in trailer handling - more sensitive in reverse?

Physical clash of any parts - e.g handbrake spring tube

Will need to shorten brake cable.

Will need to protect all cut surfaces. (Suggestions please!)

I can't see any show-stoppers from the above; this looks *almost* as simple as removing the two (12mm?) bolts which attach the whole Bradley coupling/hitch/brake assesmbly from the trailer's square section front tube, cutting off the aplicable length, and and re-mounting the unit further back.

Have I missed anything?

One area I know I'm going to have some hassle is re-locating or re-sourcing the small round steel tube which lives inside the square section tube where the front 12mm attachment bolt does it's thing. I assume this tube provides both crush resistance for the square tube and also extra 'load bearing' area for the attachment bolt. It looks like it could be a real pain to try and remove and re-use the old one - it goes right through (rather than sits snugly inside) the square tube, and was obviously then pressed / hammered /peened to keep the whole thing firmly in place. The fact that the rear holes (with no such crush-tube) have slightly 'ovalled' is telling me that this crush tube is pretty much essential, at least at the front location?

Any tips on how to attack this crush tube would be much welcomed - in particular does anyone know where I could obtain some very small quantities of what looks like 12mm / half inch internal dia steel tube - needs a reasonable wall thickness.

Any other hints and tips much appreciated. I have an engineering background but please assume DIY type tools and facilities only!

[Nos4r2]

You forgot 'car will probably get wet while launching'.

It'll be easier to reverse as it is.

You can protect cut surfaces with spray on zinc paint. It doesn't look as good as galvanizing but after a few coats it'll work as well.

[Neil R]

Thanks for the zinc input - will get myself some.

Yes the car in the water issue had occurred to me, but I can't actually remember the last time I didn't use either the mandatory tractor (Beadnell, hopefully re-opening soon) or a let-down rope.

[Poly]

Is the trailer too long or the boat just too far back on the trailer? Could you just move all the hardward forward - it sounds like more work - but if your trailer is like mine would involve no cutting/drilling etc just bolting and unbolting of clamps. If you have to move the axle you are already going to have to do this sort of stuff.

Just a suggestion (and if you decide it was a waste of time you can move it all back).

[Hugh Jardon]

to be honest my trailer is a bit long as well and when i picked up the trailer i was of the thinking that i should shorten it by 24-30 inchs

however

over time i have come to realise this is a huge bonus for me as it means the car is that much further away from the water

attached is a pic of it so you can see how this compares to yours

personally i feel it is a big benefit for me....and....i can upgrade to a 7 - 7.5m boat and keep the trailer

[jwalker]

Neil R, it sounds as though you pretty much have the measure of it. The anti-crush tubes are a good idea and you can make them by cutting a length of tube to the internal dimension of the drawbar tube and then tapping it into place down the inside of the drawbar. A couple of things work against you here. The new holes you have drilled will have burrs on the inside and if your tube is a slight interference fit, which is a good idea to prevent it moving out of place, then it will get caught on the burrs. Obviously you're going to have to get a file down the inside of the drawbar to remove the burrs. Also, the inside of the drawbar will have a seam, if it's on the bottom or top it will be in the way. Filing a V notch in the end of the anti-crush tube will avoid the seam and it is also helpful because it guides the anti-crush tube on its journey down the inside of the square tube. If the seam happens to be on the bottom of the tube, you may have difficulty drilling accurately from the top because the end of the drill will run and keep jumping the seam. If this is the case, mark carefully around the tube and drill from the underside.

Just painting the cut off ends will be fine, the galvanising will still work to protect the steel surprisingly well. I've used zinc loaded paint and I wouldn't use it again. It works by sacrificing itself so your painted ends will quickly deteriorate.

If you can't source suitable anti-crush tube, you could have a machine shop drill out a piece of ø20 bar. This has the advantage of making the tube thick walled to spread the load of the through bolts.

Good luck.

[alexm]

Originally Posted by Neil R

I can't see any show-stoppers from the above; this looks *almost* as simple as removing the two (12mm?) bolts which attach the whole Bradley coupling/hitch/brake assesmbly from the trailer's square section front tube, cutting off the aplicable length, and and re-mounting the unit further back.

Does your trailer allow you to loosen some U-bolts and slide the whole front bar backwards? If so I would have thought this would be easier than cutting the other end off?

[jyasaki]

Originally Posted by jwalker

Just painting the cut off ends will be fine, the galvanising will still work to protect the steel surprisingly well. I've used zinc loaded paint and I wouldn't use it again. It works by sacrificing itself so your painted ends will quickly deteriorate.

No offense intended here, Mr. Walker, but the hot dip galvanising on the tube does the same thing. Granted, it's thicker than the spray on stuff will be, and has a better molecular bond to the steel, but I would think that a few coats of the spray on stuff (cold galvanising) with a coat of something like epoxy paint over the top should hold up pretty well.

If you really want to protect the steel, there are a few paints out there that suck up and disperse moisture as they cure; supposedly they will stop any existing corrosion as well as prevent new corrosion from occuring. Pricey, though, and something of a pain to apply.

jky

[jwalker]

Originally Posted by jyasaki

No offense intended here, Mr. Walker, but the hot dip galvanising on the tube does the same thing. Granted, it's thicker than the spray on stuff will be, and has a better molecular bond to the steel, but I would think that a few coats of the spray on stuff (cold galvanising) with a coat of something like epoxy paint over the top should hold up pretty well.

Well, not quite. If the galvanising is complete, then there is no steel for it to sacrifice itself for. However, what I found with the galvanising paint was that the zinc quite quickly sacrificed itself and that left the paint part porous which held water and in itself was not a complete cover for the steel it was protecting. It took little time for it to deteriourate. As mentioned, I've drilled holes in galvanised steel and left them with no protection other than the galvanising around them and they seem fine. I've also got unprotected U bolts on my trailer and, although they do rust a bit they'll not a horrible mess. I once painted a galvanised trailer and that was a big mistake.

[codprawn]

Are you on about the zinc weld through primers etc than come in an aerosol? Because they are really crap.

Epoxy zinc or Epoxy aluminium is totally different stuff - really hard wearing and brilliant at stopping corrosion. I used it on an old trailer that had all the galv coming off - trailer still looks like new 5 years later out in all weathers and used on the beach!!!

[jwalker]

Originally Posted by codprawn

Are you on about the zinc weld through primers etc than come in an aerosol? Because they are really crap.

I'm referring to paint which is about 50% zinc. As jky said, it was labelled as cold galvanising on the tin. There is a big difference in levels of zinc corrosion in fresh water and salt water. Actually, I had a rethink about the zinc paint and it is more likely that it deteriorated quickly because of its reaction with the salt water rather than its sacrifice protecting the steel of the trailer.

[Mollers]

Originally Posted by Hugh Jardon

to be honest my trailer is a bit long as well and when i picked up the trailer i was of the thinking that i should shorten it by 24-30 inchs

however

over time i have come to realise this is a huge bonus for me as it means the car is that much further away from the water

attached is a pic of it so you can see how this compares to yours

personally i feel it is a big benefit for me....and....i can upgrade to a 7 - 7.5m boat and keep the trailer

Not easy to sell a 'trailer boat' without a trailer unless you adjust the price accordingly which defeats the object somewhat.

[Downhilldai]

But if his boat were to sink or get nicked from the harbour, he'd have a nice trailer, ready for the 7-7.5 m replacement .........unless, of course, someone nicked the trailer while the boat was sinking...........

[Mollers]

Originally Posted by Downhilldai

But if his boat were to sink or get nicked from the harbour, he'd have a nice trailer, ready for the 7-7.5 m replacement .........unless, of course, someone nicked the trailer while the boat was sinking...........

Now that scenario would only enter the head of a chap whom lived in the Swansea or possibly Mersey areas.I was thinking more along the lines of he'd have to buy a new trailer to sell with a used boat and then have to put a new boat on a used trailer?

[Downhilldai]

Originally Posted by Mollers

.......a chap whom lived in the Swansea or possibly Mersey areas.

I'll have you know I have no association with either of those places. Not that there's anything wrong with Merseyside

[Neil Harvey]

Originally Posted by Hugh Jardon

to be honest my trailer is a bit long as well and when i picked up the trailer i was of the thinking that i should shorten it by 24-30 inchs

however

over time i have come to realise this is a huge bonus for me as it means the car is that much further away from the water

attached is a pic of it so you can see how this compares to yours

personally i feel it is a big benefit for me....and....i can upgrade to a 7 - 7.5m boat and keep the trailer

Bet that's not what you thought at Camber Dock a few weeks ago

[Neil R]

Here's what happened in practice.

In the end I was amazed that B&Q has some suitable steel tubing, well actually I bought two lengths; one a nice tight fit in the other to give at least 2mm wall thickness. Bought a 16mm drill at the same time - to match the largest o.d.

I wanted this round tube to go right through the square tube, to provide extra bearing area on the bolt to square tube interface, since the main loads will be in the 'towing' direction. Which is also how original was done.

Drilled the holes and all proved to be a nice friction fit. Centre punched in 3 places around the o.d. of the short cross tube to stop it rotating - my thinking being that any rotation should be in the bolt only. The seam seemed to be on the top by the way.

Applied some protection, and tidied up / de-rusted the underside of the complete hitch assembly whilst access was easy. Was slightly embarrased to find a third grease nipple on the brake lever pivot point well hidden underneath - in six years I'd not noticed this before. But I bet I'm not the only one!

Still to check the hitch weighting, but the hand-lift test suggests I might get away with it - I think I was set up to be on the light side of the declared range because the old car used to look stupidly down at the back when all loaded up.

Overall pretty pleased, and in the end not as difficult as I thought it might be.

Hugh - there will be the odd occasion where I'll admit I'll regret losing the extra length. But I'd begun to realise that the existing length was becoming almost a showstopper for me taking the boat on hols with us - ever since one of the neighbours had a right moan about how much car park space we were taking. The trailer was simply backed into our normal car space against the perimeter wall, and to be honest I was also always worried that it would catch some other neighbours driver / car out and cause damage. Even with the prop bag hung over the hitch to give it extra visibility it just seemed too much like an accident waiting to happen. It probably still will be, but at least my conscience is as clear as it can be.

No the existing square tube wouldn't slide backwards. It has a slight downwards bend aft of where it meets the side frames, before it joins the first cross-member.

[jwalker]

Originally Posted by Neil R

I wanted this round tube to go right through the square tube, to provide extra bearing area on the bolt to square tube interface, since the main loads will be in the 'towing' direction. Which is also how original was done.

Drilled the holes and all proved to be a nice friction fit. Centre punched in 3 places around the o.d. of the short cross tube to stop it rotating - my thinking being that any rotation should be in the bolt only. The seam seemed to be on the top by the way.

Neil, I don't understand this, are you saying that the ø16 tube is taking the crush load and this is only held to the square tube by the centrepunch dots?

[bedajim]

Originally Posted by jwalker

Neil, I don't understand this, are you saying that the ø16 tube is taking the crush load and this is only held to the square tube by the centrepunch dots?

My understanding is that he's drilled the box to so the tube passes through then centre punched on the join of the tube and box to work like a key and stop the tube from spinning

James

[Neil R]

Confirm James (bedajim) has understood what I meant. The bolt (which is horizontal by the way) and side plates of hitch assy itself prevent any end-float of this crush tube, the centre punching stops the 'crush tube' from rotating with respect to the square tube (unlikely I know), which I think is the best means of ensuring that any wear due to the bearing-loads happens in the right place.

The centre punch technique is something I vaguely remember from a dim and distant past - possibly a means of retaining bearings in housings?