Welcome to the forums, Nick - I see you have been around a while, but as an 'observer'.
Oops - the thread is about 6 years old and we haven't seent eh original poster for about a year. I ownder if he went ahead and did this conversion. Not a good idea though.
I can't let your comments go unchallenged though as they contain some inaccurate information. Just for the sake of anyone else tuning in and thinking the same thing.
I think you will be able to do it very easy, the front brake operates the 2 outer pistons on the calipers, hence when you bleed them you do the top bleed nipples
That is correct. Outer pistons on botht he left and right caliper.
I can’t see why you can’t put a bolt in the middle banjo to plug the smc,thus fluid won’t be able to pass out
That is not correct. If you put a normal bolt through the Banjo on the middle piston of the front left caliper, it will stop fluid flowing into the front left centre piston, but it will not stop fluid flowing through to the SMC and to the circuit that feeds the rear caliper outer pistons. That Banjo has two tubes attached to it - an inlet and an outlet, so fluid will flow around the outside of the bolt to the outlet.
... on the rest (rear ?) caliper again the 2 outer are pistons operated from the rear pedal, so a bolt in the middle banjo would plug that
The two outer pistons on the rear caliper are operated by the action of the SMC in normal use. In the garage, they are operated by the rear brake pedal.
I think that you are suggesting plugging the banjo on the centre piston of the rear caliper. That banjo is served directly from one of the lines from the Rear master cylinder, and the piston is operated by the brake pedal.
the only other problem I see is you may need a single banjo on the rear master cylinder but I think it should work,I’m about to strip my smc due to sticking back brake,don’t mind a seal kit but I’m not paying sill money from Honda to sort out this common problem,best part of £300 smc,£550 proportion valve etc etc
The bike has a very well balanced braking system which is extremely effective at bringing a third of a ton +passengers to a rapid, controlled stop. it needs to additional controlled stopping power prvided by the linked brake system. When you apply the front brake lever only, you have 6 pistons providing the braking force.
The complete SMC is £242 inc VAT. And for an older bike is probably an essential item to replace. The problem isn't with the SMC, it is with the people who have not maintained them properly. Buy a used bike, you can expect to have to replace this component.
The Proportional Control Valve is not something that I have heard much about in terms of failing, or needing replacement. Who said that you needed to replace that ?
Take a bit of time looking around - there are other things that could be causing the rear brakes to drag. Caliper slider pins, badly fitted pad springs, too much grease, after market pads, faults on the front calipers, incorrectly installed front wheel, ....
If you need to be careful with the funds, then don't go wasting it by throwing at at something that isn't the cause of the problem. You don't want to be spending money on the SMC if it turns out that someone has not tightened the front wheel bolts in the correct sequence.
And before you think - that wouldn't affect the rear caliper ? Oh yes it can.
Take a look at the Articles / ST1300 section. 'Avoiding the pitfalls' is a good place to start.