trailer tyre wear

[Steve Joyce]

sounds to me like the trailer suspension is sagging causing the wheels to lean in at the top and out at the bottom. The rules are probably different for trailers than for a car and the various angles are probably not easy to adjust or maybe not adjustable at all.
I suppose it would depend on how the hubs are attached. If it has a stub axle bolted to a trailer member you could probably have adjustments made with shims.

You could easily do a test by jacking the trailer up near the wheel to see if the plane of the wheel varies much. an axle stand would help support it whilst making sure no welds have given way or anything else looks wrong. make sure nothing slips off though, wouldn't want to get any extra ventilation where it's no needed.

I got an Indespension trailer which is really well made, and has torsion bar suspension. Everything is bolted together with very few welds.  This also means you can adjust everything to get the best fit, even around the storm's shapely rear end.

[Steve Joyce]

please excuse the poor typing. My ipad touchscreen has been rubbish since upgrading to ios7.

[Graham W]

I think the CLH suspension units look like this http://www.trailertek.com/acatalog/Unbraked_Suspension_Units.html

Not therefore expensive to replace if this proves necessary.

[Steve Joyce]

that looks straightforward enough. I wonder is Julian has incorrectly rated units. There seems to be 4 types from 250 to 750 kg per pair. this could cause the suspension to sag although may not be immediately apparent. They should be marked up somewhere.

[Julian Swindell]

Graham and Steve
This all sounds interesting. I have got Indespension trailing arm suspension units which were fitted as replacements by the AA after I had a hub failure on one of the originals (long story, see below) I presumed they had fitted correctly rated ones, but I don't know. I trailed all the way to Suffolk and back last year on them without any apparent wear. But I did think this year as I was towing her home that it looked like the wheels were splaying out slightly. I thought it was probably just an optical illusion, because they are trailing arms, which in theory should keep the wheel vertical. But I will jack her up shortly on axle stands and will check the suspension units to make sure they aren't working loose or anything.

I hate trailers

[Steve Joyce]

just had a look at mine. the box part containing the springs are now fitted inside the axle box section rather than being bolted on (this is a Indespension coaster swing). Can't see that ever getting out of line.

Hope you get it fixed soon Julian.

[Colin Morley]

Ho Chaps,

I wrote quite a bit about tyre wear and pressures etc in April 2012. Under the heading Trailer tyres.

[Rob Johnstone]

I agree about Ios7 but thought it was just me!

[Brian Robertson]

A little bit off topic, but I do empathise with Julian's antipathy towards trailers.  On a visit to the Oban area this summer I noticed after launching Amy Pearl that the winch post was a bit wobbly - the weld between the post and base plate had torn (see pic)!  This left me in a bit of a quandary as to how I was going to retrieve the boat at the end of my cruise.  Luckily I found a very obliging local engineer who bashed it back in to shape and re-welded the base plate.

CLH have since very kindly replaced my winch post with a reinforced post.  No idea why it should have failed in the first place though.

[Rob Johnstone]

Still slightly off topic but about trailers in general, does anyone know of the "correct" settings on a CLS trailer for height and horizontal positions of the various rollers etc on which the boats sit? 

Vagabond is on the trailer at the moment, hard up against the front post. In this position, one of the rear set of rollers is squarely in the hole for the reverse self bailer that is used to fill the ballast, and the forward central roller is not in contact with the keel. Also, there is only about 15mm clearance between the rear corner of the (awful) steel mudguards and the hull. Despite tight straps, it's clear that these have come into contact on a few occasions.

[Julian Swindell]

Rob, on the original setup for my BC20 trailer, the tank filler was also just covered by a roller. I have shifted the winch post back an inch or so and it just clears it, but I am very light at the tow hitch now, which is not ideal. I am not sure the position of trailer rollers was considered when the location of the bailer was chosen.

[Graham W]

Still slightly off topic but about trailers in general, does anyone know of the "correct" settings on a CLS trailer for height and horizontal positions of the various rollers etc on which the boats sit? 

Vagabond is on the trailer at the moment, hard up against the front post. In this position, one of the rear set of rollers is squarely in the hole for the reverse self bailer that is used to fill the ballast, and the forward central roller is not in contact with the keel. Also, there is only about 15mm clearance between the rear corner of the (awful) steel mudguards and the hull. Despite tight straps, it's clear that these have come into contact on a few occasions.

Rob,

Continuing off topic, the fact that you are not resting on your forward central roller may mean that your forward wobble rollers are too high.  The wobble rollers at the side are only really meant as stabilisers and most of the weight should rest on the keel rollers.  If you winch in too hard, that may also lift the bow off the forward keel roller.  If you sort that out, it may also solve the problem with the mudguard at the back.

To stop the front of my boat see-sawing and generally moving about on its trailer, I tie it down hard to the trailer using the boat stem towing eye.   Plus a ratchet strap amidships, which I think is a legal requirement.

[Rob Johnstone]

Thanks for the comment, Graham. I think your comment about the forward wobble roller being to high is spot on. At the moment, the strop that pulls the boat onto the trailer is about level with the eye on the stem, so I don't think it's lifting the bow off the forward roller but I'll have to watch it after I've lowered the wobble rollers.  When travelling, Vagabond is strapped to the trailer by a ratchet strop just forward of the cabin and one across the forward end of the cockpit. Getting them tight can be difficult because of friction over the gunwales. (?spelling?)

I was chatting to Matt (our beloved leader) about this the other day and got the impression that it's only with the last few BC 23's that Swallow have arrived at a standardised set up for the trailer. He suggests that I move the front post forward so that the boat can come forward on the trailer to clear self bailer ahead of the rear wobble rollers and keep an eye on the resultant change in downforce on the tow bar. The dreaded sway sets in at about 60 (less in a strong headwind and even less if I've forgotten to completely empty the ballast tanks!). So, there's much to play with when I return to Balvicar next spring.

[Graham W]

Rob,

If your trailer is swaying or snaking at 60mph or less, it sounds like the weight at your hitch is probably too low. With my BR20, I use a rough and ready measure - if I can just about lift the hitch off the ground, then it weighs a bit more than 30kg, which is around 5% of the total trailer + boat weight. I haven't had problems with snaking so far (touch wood). For a BC23, if you do yourself a mischief trying to lift the hitch, it's probably about right!

Moving the winch post forward a bit should cure not only the bailer problem but your snaking issues too. I think the lifting effect of over-tightening the winch strap only applies to boats like the BR20 where the bow is quite strongly raked.  The BC23's bow looks fairly vertical.

[Julian Swindell]

These are my worn tyres, one much worse than the other. Both are worn on the inside, and up until the last trip they hardly showed any sign of wear after nearly three years use. I have jacked up and propped the boat now, and the suspension fittings seem fine and solid. The tyres are rated at a maximum load of 375kg, so they are right at their limit. I think my towing weight is pretty well at the trailer's maximum of 750kg. I think that may be part of the problem, plus I was probably driving too fast this last trip. I wanted to get home in daylight and the roads were clear. I shall ask the tyre shop's opinion when I go to get them changed.