drilling bigger holes in rear discs

[02GF74]

... just an idea. most bikes have 160 mm disc front and rear (I'm alking shimano and do know they come in bigger sizes for the front).

anyways, we all know the brunt of the braking is taking pace at the front.

so how about making the holes in the rear disc bigger to not only save a couple of grammes in weight but to balance the brake pressure needed on the both levers?

anyone tried this?

and why is it such a bad idea?

 

[tyred]

Several things spring to mind. The disks would probably be very hard to drill in the first place. It would probably increase the risk of the disk cracking. You would also need to really take the time to finish the job properly as any burrs/rough edges would tear the pads apart in a very short time and possibly cause stress risers.

 

[spandex]

+1

 

[gbb]

Several things spring to mind. The disks would probably be very hard to drill in the first place. It would probably increase the risk of the disk cracking. You would also need to really take the time to finish the job properly as any burrs/rough edges would tear the pads apart in a very short time and possibly cause stress risers.

Forget it, i don't think you'd ever be able to drill them...full stop.

 

[spence]

save a couple of grammes in weight

Five feet up the first trail and the extra mud will counteract that. Better still, don't eat the extra muffin in the cafe beforehand.

 

[dodgy]

1995 called and they want their crazy ideas back.

 

[PapaZita]

Why not try a 140mm disc at the back? They don't seem to be very common, but they are available. I use one with my BB7s, because a 160mm disc wouldn't fit between the chainstays. Can't say I've ever noticed the weight saving, or any difference in the front/rear brake balance though.

PZ.

 

[GilesM]

Why not try a 140mm disc at the back? They don't seem to be very common, but they are available. I use one with my BB7s, because a 160mm disc wouldn't fit between the chainstays. Can't say I've ever noticed the weight saving, or any difference in the front/rear brake balance though.

PZ.

I use a 140mm disc at the back on my hardtail, braking's fine, many XC bikes do. As for drilling the disc, a tad hard I think, and it would/could weaken the disc, don't really fancy braking a disc, could end in tears.