Nope - the breather is a little tiny hole drilled down the center of the speedo cable retention bolt.

This is also where water gets into the gearbox when pressure washing (or just riding a lot in crap weather) and destroys the gearbox bearings...

The hole you're referring to above the gearbox output bearing is actually the breather for the monolever driveshaft INTO the gearbox, which then breathes through the speedo cable bolt. small holes and convoluted but seems adequate. BUT you must keep the speedo cable bolt hole clear, and don't point water at it. One of these days I'll make a proper vent...

The hole above the gearbox output bearing is sealed with silicone seal when used on a paralever bike, as they don't need venting in the driveshaft. http://www.horizonsunlimited.com/ubb/smile.gif

Right, the gearbox breathes through the speedo input. But there is a rubber cap to keep the water from entering the geabox via the speedo cable. Usually this isn't fitting tight enough, so spread a bit of black silicon paste around the bottom and top of this rubber cap and it should be water resistant for quite a while.

Hans

Ah!

maybe this explains why my speedo doesnt return to zero after a ride, but gets stuck at around 80kph, I expect the pressure is building up and affecting it somehow, because if I open the filler plug it drops back straight away...I would look now but its sitting in the rain probably filling up with water...

alec

If so - change your gearbox oil before the bearings go!

On the speedo side of things - take the speedo cables inner part out and clean it. Probably full of junk and that is getting up into the instrument... clean it all up - lube with a LITTLE grease - not too much as that will get into the speedo head.

Once done silicon the cap onto the cable.