i converted my EX to SM and with the stock 12/48 the bike was getting very high rpms at low speed, and i mount a 15/47 that is the stock set up for the SM model and the bike feels good, i get better range and more top speed of about 154kmh with gps
for the brakes i choose probably the most expensive but most convenient solution: All stock and the EX set up but a secondary full brake set up on SM... 320mm rotor, wheel spacer, axial to radial bracket, Stark's Brembo Master cylinder and an Accossato caliper, (the Stark brembo caliper doesnt fit, much wider and it touches the spokes even with spacers)
with a secondary full brake set up i "just" need to change wheels, dismount the radial adapter, put the stock one and dismount the master cylinder and caliper together, is very easy, just have to unhook it from the front plateholder
*Funny story*:
When I tried to install the stock Brembo front brake caliper and saw it wouldn't fit, I sanded it but I went too far and broke the caliper. Oil leaked... there's no solution, so I ended up using it as a door handle for my garage door. I've attached a photo jajajaja
