Front brake disk hole

Just noticed one of the holes in my front disk is bigger than the rest. What's thaft all about?

I believe it is so your disk will not get too hot when brakes are applied IMO

Generally the holes are to help heat dissipate, to clear water and gas build up.
What I'm asking is why one hole is larger than the rest. Most likey just a manufacturing glitch, but it a one off or do we all have one?

A padlock ?

Often here in UK city's people drill one bigger for a disk lock. If you do 3 equally round the disk and a small notch in line in the rim with white paint it makes it easier to find one when parking.

I really do find that hard to believe that when it's far simpler to choose a disc lock with a locking pin size that fits through all of the holes of your motorcycle/maxi scooter brake disc (17mm on the Silver Wing) rather than go through the rigmarole of drilling through a thick steel brake disc (11mm on the Silver Wing) to enlarge a few holes. Then having to mark out where they are, and that's just if you already have a good drill and the correct size drill bits to do the job.


I've a unused 19mm pin disc lock in the garage, it doesn't fit the holes on the Silver Wing's disc so why would I try to make it fit. A good thing about a maxi scooter is the underseat storage, and the heavy duty locking Abus chain I keep there aces any disc lock.

Disc locks are a nuisance anyway, probably ever rider that's bought and fitted one will have at least once forgotten about it and moved his bike/scooter off it's centre stand with it still fitted. Or even worse tried to ride off with it in place. That's why they sell those hi-vis plastic reminder cables you tether to the disc lock and handlebars.

A bike lock sounds logical but how about balancing the disk? I don't know dip squat about it but that's what popped into my mind.

I'm with Meldrew on disk locks, they are the work of the devil!
Rev, bang, crump, expense...

The larger holes may be made to balance the disc. Kinda similar how crank shafts are drilled for balancing. My 2¢