Four different mainsheet systems are shown below, and there are many more possibilities. Which one you choose just comes down to personal preference. If you are using a spinnaker then you will need a mainsheet cleat, otherwise that is also optional.
Purchase should be 6 to 1 on a Mosquito. If you can be bothered to make one, a tapered sheet works well at reducing the friction in the system.
Internal systems have been tried with limited success.
QUESTION:
I note that you and Gary appear to have strops (?). If so, what are they made of and what length? Jeremy
ANSWER:
They are the same 3mm stainless as the sidestays, but some people are now using Dyneema (or similar) strops. The length depends on the setup of your boat. The rake, the mainsail cut, and the size of your mainsheet pulleys all affect it. What you have to do is rig the boat, put on the maximum mainsheet tension you ever use, measure how far the pulleys are from each other (including the becket) and then make up a strop to close that gap. Remember to allow for the extra shackle you will need to attach the strop and make it 3 or 4 cms too short so you can always get that extra little bit of main tension when you need it. The other way is to use some rope to tie the lower pulley to the traveller and keep adjusting it till it’s right (that’s blue rope in the last of the pictures below, now replaced by a wire).
Why bother? Well you end up carrying around a bit less mainsheet (not much) and I suppose there’s marginally less windage, but the best part for me is that when the traveller is centred my tiller extension doesn’t bang against the mainsheet blocks. It only touches the strop which allows a bit more freedom of movement. Tim
All on the rear beam, with the cleat & ratchet block fixed in the centre.
All on the rear beam, with the cleat & ratchet block on the traveller.
Ratchet and cleat mounted forward on the centre beam. If sailing sloop rigged it wouldn’t be so far forward.
Ratchet mounted forward on the boom, sheet led straight from the boom.