Drilling brake rotor

[Mikep328]

I have a spare CB 400 front brake rotor and am thinking about having it drilled. I COULD do it myself but the measuring/marking out/drilling the holes is more fiddly than I prefer to deal with!    Can someone recommend a UK shop that does this? 

[DomP]

If you have a pillar drill I'd go with plan A, I found print out templates for my xs disk online.  Low speed/cutting oil and go up through drill sizes stating at around 3mm and its easy, centre punch all holes first for a nice accurate start.

[Mikep328]

I decided that, although it looks cool, drilling the rotor was too much trouble/effort for what is just an "appearance" thing.  I can spend more "bike time" doing more useful work!  Today I'll be checking out the clutch and neutral switch mentioned in a different thread.

[TrickyMicky]

I decided that, although it looks cool, drilling the rotor was too much trouble/effort for what is just an "appearance" thing.  I can spend more "bike time" doing more useful work!  Today I'll be checking out the clutch and neutral switch mentioned in a different thread.

  I agree with you wholeheartedly re the "appearance" thing.  The idea of drilling holes into a possibly 50 year old brake disc beggars belief.  The invisible damage that could be caused to the metallic structure of the disc doesn't bear thinking about. A shattered brake disc is a frightening prospect.  I think with the choice of pads available now, the old problem of wet weather braking has been all but eliminated.   The number of holes I have seen in some discs must have surely reduced the amount of braking surface area, and as for "cooling", we are talking about vintage vehicles on public roads, what sort of riding is required to get the brakes that hot?  Maybe we should start drilling through the rear brake drums as well.  Good luck with the clutch switch, a solution to a much more everyday problem. Stay safe.

[ST1100]

https://4into1.com/ sell drilled SS repros of the P/N 45120-374-700 rotors...

https://4into1.com/stainless-steel-drilled-brake-rotor-honda-cb450k-72-74-cb500-550/?searchid=3556121&search_query=45120-374-700

seem the safer option over DIY drilling... but I don't know about about import VAT and/or other trouble arising in the strange times we currently live in...

[Mikep328]

Looks pretty nice but not worth the price to me just for appearance and for probably reducing the braking ability due to less surface area for the pads to grab.  As I've stated in a thread re brakes, mine now work very well and I don't want to do anything that reduces their effectiveness. 

FWIW though not directly related to this thread, I tried five different pad brand/compounds and broke in each set.  Vesrah VD 102 pads were clearly more effective than any others.  Interestingly, they were the only pads that come with a bevel/chamfer and they were the only pads that didn't (don't) squeal.  All the others did sometimes - though not always.  Since beveling seems to be a common recommendation, it seems to me the Vesrah might have actually tested the pads on a CB400F!!  Additionally, they are the only pads of the 5 sets that allowed "two finger" braking on my bike!  I don't think they make the VD102 pad for the 400 any more but they are still available from suppliers.  I never heard of Vesrah until I became a CB400F owner two years ago! 

[DomP]

The purpose of drilled discs is to dissipate heat and the hole edges sweep the pad theoretically keeping it refreshed as it were