After many years of riding with one brake (the rear one since as a kid I once went over the handlebars using a front brake on a mate's bike), I've decided - at any price - to find a solution that allows me to control two brakes with my one hand.
I use the bike for London commuting (have done for 20 years) and some long distance. Building a new bike from the ground up based on the Pipedream 29er Skookum frame (internal Alfine 11 gear, belt drive)
I've read the forums and there are a number of solutions - the one that most like (and still allows independent operation of the two brakes) is to stack two levers on one side, operating one with two fingers and two with the other. I would like a more elegant solution and am looking at two alternatives and would value opinions (especially from those who understand the mechanics (physics) of brakes/braking and those who've experimented.
The first is to use one of the dual cable levers (e.g http://www.bikecare.co.uk/product_info.php?id=443) and to channel the two cables into the independent ports of a 'cable to hydraulic' converter (best one seems to be:http://www.hopetech.com/page.aspx?itemID=SPG343) which connects to the two brake callipers.
The second is to use a single hydraulic lever one with a splitter that sends fluid (50:50) to both brakes. To pump enough fluid I'd need the largest possible piston size and the calipers with smallest piston size (e.g. the Hope 'tech evo with 2x X2 calipers'). Even then I'm told that I'd need to replace brakes pads frequently in order to minimise piston travel.
Both have drawbacks of course. Not sure how serious and perhaps there are workarounds.
The main problem on both is the danger of transmitting equal power to both front and rear - with the possibility of locking the front and sending me into a front wheel skid or over the handlebars without applying optimal force to the rear (thus not being able to brake hard if I need to). To combat this I'm thinking about ways of building in a differential 'power' to the two brakes. The trouble is I'm not sure whether there is any 'best' ration and whether the three alternatives I've found/invented would work. Here they are:
1. Different pads size front and rear (does this lead to different braking power under different pressure - not an obvious answer).
2. a device that lowers pressure on one of the hoses (you can buy these but they look very bulky, heavy and 'inelegant')
3. If using the cable option (the first option above) then split the sheath and insert a very stiff spring in the gap which compresses under strain (thus modulating the pull on the respective chamber and thus reducing power.
That's as far as I've got.
My first post so sorry to be asking before contributing. Have read all previous posts on the topic though so hope I built on, rather than repeat, the discussion.