Swallow Yachts Association
Swallow Yachts Forum => Technical => Topic started by: Julian Swindell on 28 Sep 2013, 18:35
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I have just towed my BC20 home from Poole, about 120 miles. All very easy, but I noticed that one trailer tyre has worn down on the inside to almost no tread in that distance. Does anyone know if that is a sign of under or over inflation, or something else. I had them pumped up to 35 psi, which I thought was the correct pressure, but maybe it's not. I don't actually know why I thought that was correct.
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Hi Julian,
I have not got my BR20 at home so cannot check but am pretty sure that I keep my tyres at about 35psi as per the instructions here:
http://www.swallowyachtsassociation.org/?page_id=557
As far as I can remember this was consistent with the tag on the trailer.
I have not noticed any wear at all on the tyres but have only made two long trips Salisbury to Falmouth plus Wales to Salisbury and annual trips to and from Poole. So I cannot help you with the tyre wear but it does sound as if something isn't right. I am sure I remember someone else mentioning tyre wear as a problem a few years ago.
Colin
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More info here: http://www.swallowyachtsassociation.org/?page_id=17&URL=http://www.swallowyachtsassociation.org/smf/index.php/topic,559.0.html
Just scroll down to pics of worn tyres.
HTH,
Colin
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Julian,
Are you saying that your tyres wore out in 120 miles, or that you only noticed it for the first time when you got home? And are your tyres the original cross ply ones?
I keep my repacement radial tyres at 36psi and have covered about 3,500 miles on them so far without noticeable wear.
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They are the original tires and this tread wear happened only on this last trip. I had noticed that they still looked almost me when I checked their pressure last week.
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If they are anything like my original trailer tyres, they are not of the highest quality. Even so, sudden wear shouldn't happen over so short a distance. In the previous thread on this subject, an AA man had blamed something similar on under-inflation of the tyre. Unless they were rubbing on something on the way home, I can't think of other explanations.
Anyway, it's an expensive opportunity, not a problem! You can now upgrade to some decent radial tyres, either the same size or (if you upgrade your wheels at the same time, which perversely can sometimes work out cheaper), something with a larger diameter, which would spread the load a bit and give you better ground clearance. Reg Barker was looking at doing this, having seen someone else at the Bala rally (Matthew P?) with 13" wheels on their BR trailer instead of the standard 10" ones. I don't know if the standard mudguards would also need changing to accommodate a bigger wheel.
Trailertek in the UK have a wide range of replacement tyres and also complete wheel assemblies. If buying the latter, make sure that you specify the correct PCD size to fit your hub.
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I am beginning to wonder if the tyres are just overloaded. Looking on Trailertek's website, they recommend a maximum load of 350kg for the tyres I have got. I must be pretty well up to that in total if not more. I will do a bit more research over the next few months. I also wonder if I just drove too fast. I was on motorway all the way and tried to keep to 60mph, but I am sure I was over that quite a lot as the roads were quite clear.
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That's 350kg per tyre, plus 30kg on the trailer coupling (say), giving you a limit of 730kg. A bit faster than 60mph shouldn't make much difference.
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Hi, Julian.
Graham's right. The original tyres are not "of the best quality" . I would put it more strongly and say that they are barely "fit for purpose" as they never last for more than a few thousand miles - even at 36psi. Swap to better quality radials ( don't forget the spare) before they start shedding lumps of rubber on the motorway, as mine did. Make sure that the different tyre profile will fit the chassis.
I can't imagine that loading is a problem but I do think that the suspension geometry is responsible for some of the scrubbing. The rubber torsion arm gets a proper workout on even smooth roads at the legal limit. Tracking is suspect on many trailers, too. If you get the chance, follow your boat as someone else tows it. You'll soon see how much stress the suspension is putting on the tyres! (.....and if you can see it, you know it's bad!)
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I'm very pleased to see some focus on trailers as it's a neglected area (I admit, it's not so exciting though). For information, the tyres supplied with our CLH trailer (purchased spring 2011) are 13 inch with a tyre width of 145 mm. The recommended tyre pressure as stated on the outside of the tyre is 46 psi. This sounds high, I know, but I did double-check it with the supplier who confirmed it's correct.
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Julian
Recently had to replace trailer tyres and spare to radial. The fitter was very helpfull in helping make the right choice based on boat and trailer weight and the speed i was planning to tow at. If you punch in tyre code into wikipedia it explains the code you see on the tyre wall. My original radial tyres had quite severe cracking on the walls but plenty of tread so they needed changing. It was pointed out that the 10" wheel is not used on cars any more so the price of these tyres and availability is getting higher and more difficult to get hold off. Please see the code image below from wikipedia hopefully it will help along with the other information on wikipedia.
So if my old tyres were rated at 350 kg, the boat emty weighs 450 kg the trailer i'm guessing at 250 kg, assume 25 kg engine and 50 kg of other bits we keep in the boat it soon puts the tyres on the limit.
http://en.wikipedia.org/wiki/Tire_code
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My experience is very similar to Graham's. I have a CLH trailer, supplied in 2010, which has done over 4,000 miles with no significant visible wear. It has 145 R10 radials which I keep inflated at the recommended 35PSI. I have to admit that this relatively low pressure makes them look very squashy and they do run hot on long journeys, but they seem to be standing up well. The squashiness has the advantage of damping some of the buffeting on rough roads.
Julian, the incredibly rapid deterioration of your tyres does suggest major tracking problems. Overloading shouldn't cause such rapid and uneven wear.
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I'm suspecting it is an alignment problem but not sure how I will check. I will jack up and prop the trailer soon and have a look at the offending wheel in detail. The other side looks a bit worn on the inside as well, but nothing as serious.
I hate trailers
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I was wondering how you check it too. I came across this on t'Interweb:
1. Connect the trailer tongue to your vehicle's hitch. Park the trailer on a level surface. Lower the trailer tongue jack stand to level the trailer, if necessary.
2. Attach the fishing sinker to the end of the fishing line. Tie the fishing line to the bottom threads of your vehicle's tow hitch, allowing the sinker to hang. The fishing line and sinker should be hanging directly below the center of the trailer tongue ball hitch coupler. This will provide a plumb line for assessing your wheel alignment.
3. Remove the hub caps on your trailer's wheels, if necessary. Screw an axle extension tube to the center spindle on either wheel.
4. Measure and note the distance between the plumb line and the tip of the axle extension tubes on either wheel. Compare the distances from the plumb line to the right wheel and from the plumb line to the left wheel. If the distances deviate by more than 1/8 inch, your wheels are likely misaligned.
5. Measure and note the distance between the front wheel and rear wheel on either side of the trailer, if your trailer has a second axle. Compare the distances between the right wheels and the left wheels. If the distances deviate by more than 1/8 inch, then the rear axle is out of alignment with the front axle.
Alignment
6. Inspect the leaf spring assembly, which suspends and protects your axles. Replace the U-bolts and retainer brackets that hold the springs to the axle, if they appear loose or cracked. If cracked or bent, replace the front and rear shackle brackets that secure the leaf spring ends to the undercarriage. Replace the leaf springs if they are sagging, cracked or twisted.
7. Inspect the conditions of the wheels and tires. A bent wheel rim, low tire pressure or worn treads may interfere with the trailer's handling. Depending on the extent of the damage, a bent wheel rim may require professional attention, and possibly replacement.
8. Inspect and replace the same components of the rear axle, if applicable.
If this all sounds too complicated (it did to me), Mr Kwik-Fit probably has lasers and stuff that can check the alignment quickly.
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The problem at the moment is that I have a 20 ft boat sitting on the trailer which makes taking it anywhere for the next 6 months a bit of a chore. I had meant to get it serviced over the summer, but the weather turned out too good to spend tome doing that. I shall have to meditate on it all for a while
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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.
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please excuse the poor typing. My ipad touchscreen has been rubbish since upgrading to ios7.
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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.
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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.
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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
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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.
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Ho Chaps,
I wrote quite a bit about tyre wear and pressures etc in April 2012. Under the heading Trailer tyres.
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I agree about Ios7 but thought it was just me!
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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.
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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.
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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.
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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.
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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.
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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.
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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.
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Julian,
These tyres look quite like the ones that Tony had trouble with, although his problem was under-inflation http://www.swallowyachtsassociation.org/smf/index.php/topic,559.msg3280.html#msg3280
They may also be the same as my old ones, although they were so prematurely worn that it's difficult to tell http://www.swallowyachtsassociation.org/smf/index.php/topic,559.msg3636.html#msg3636
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Just an update on my trailer tyres. I have had new ones fitted at a local tyre shop. They just looked at them briefly and got me a new pair, with no specification from me. What they have provided turn out to be radials, looking much better quality, and the recommended pressures are 68psi rather than 36psi, which is quite a change. The maximum load per tyre is 475kg, giving a total of 950kg, which is way more than the towing weight of 750kg. Costs were £55 each, fitted. So they look much better, I will just have to see how they last next year.
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Julian, at 68 psi you will also notice that the fuel consumption will be much lower and the comfort in towing/driving improved. I have my radials at 58 psi ( 4 bars ) and drove on rather long distances (1000km) with no sign of abnormal wear .
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Catchando Bay (BR#48)
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Just to wind up this old thread, I think I have discovered the root of my trailer tyre wear problem. As usual, human error (stupidity). i still have my original spare tyre, which matched the worn ones, but has never been used. I looked again at the moulded notes on the side of it and they said 30 PSI fully laden. Then I looked more closely with a decent light, and it doesn't say that at all. It says 3.0 BAR, which is completely different, and equates to about 45 PSI. So I had been driving grossly under-inflated all the time. So check your tyre instructions in a good light with your glasses on!