BC23 trailer weight

[Martijn]

Riff Raff is ready to get back on the water later this week, so I figured this would be an excellent opportunity to calculate the weight as she's currently sitting on the trailer, using the "bathroom scale method" as described in the Practical Boat Owner.
I was a little surprised by the overall weight as she's nearly empty, and except for the mast and outboard there are no heavy items on board.
I short, the boat weighs 1079 kg, the total trailer weight is 1457 kg. Just short of the rated 1500 kg.

Considering I have replaced the 2 original lead acid battery by a lightweight LifePo4 battery (30kg weight saving) and that the CLH trailers are at least 60kg heavier than my current trailer, I think for most owners it is very difficult to stay within the 1500kg limit.

For those who are interested, the attached PDF document shows details of the calculation including a list of included/excluded weights. Not mentioned in the PDF, but the anchor is not included in the boat weight

[graham2burton65@gmail.com]

Sorry to hear, this is disappointing for you and other possibly other owners.
Is this the standard trailer supplied by Matt?

I was concerned about all up weight when I bought a BC20, I was lucky to purchase one with an upgraded trailer, probably the one you have.

I know that some owners had their trailers upgraded, it might be worth contacting CLH

kind regards
Graham B

[Martijn]

Hi Graham, Not really disappointing, I'm still under the weight limit. I don't have a CLH trailer. When I took over Riff Raff from Rob Johnstone it came with a standard CLH trailer except for an upgraded axle. I failed to get the trailer approved for road use in the EU, but it was weighed in the process. The trailer weight was 453 kg. Add this to the boat weight and you are over the 1500 kg of the standard 1500 kg axle. My new trailer is lighter which just makes the difference

[Graham W]

*&%@#* trailers!!

[Julian Merson]

Martin, I did the same calculation last summer before having my BC20 trailer upgraded with brakes.
When I did my calculations, I wasn't able to roll the boat that far back without the centre of mass moving to the rear of the trailer wheels.  So, the margins of error were consequently rather large.  If, for example, I had  mis-measured the roll-back by just 0.5cm, that would have made a difference in calculated weight of 66kg.

[Graham W]

If the margin for error is that small, it's worth taking the outfit to your local weighbridge.  In Shropshire for example, there's an animal feed mill that charged £5 to weigh car + trailer with boat, then trailer with boat only. I'm sure that there are lots of others like that around the UK.  The Shropshire one was how I found out that my unbraked trailer with boat was almost exactly on the limit of 750kg, having previuosly calculated, based on the then official numbers, that it was significantly less.

[Martijn]

f, for example, I had  mis-measured the roll-back by just 0.5cm, that would have made a difference in calculated weight of 66kg.

Julian,

I know, I read your post, which was the reason why I decided to use 2 movements instead of one. This results in 3 calculated weights (one for each shift and the 3rd for the overall shift) and gives an indication of the accuracy. The largest weight difference was just 10 kg, which corresponds to the accuracy of 1mm of the laserpointer used to measure the distance of the stem to the winch post. The accuracy of the bathroom scale was 0.1 kg.

[Martijn]

You can also conclude that moving the boat 1cm forward or aft changes the towing bar weight with appr. 3 kg.