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drilling inboard disc
Posted: Sun May 01, 2011 5:41 pm
by mickdale
will drilling the disc on an inboard lambretta brake help stopping ability?
if so does anyone know what size / spacing of holes works well?
what are the best pads to put in as ive heard std arent too clever?
cheers
mick
Re: drilling inboard disc
Posted: Mon May 02, 2011 12:13 am
by corrado
I wouldn't recommend it, the heat of drilling may warp the disc or potentially weaken it leading to stress fractures.
Under certain conditions where the disc gets very hot gasses are created between disc and pad that push the pads back leading to reduced braking, holes or grooves can help disipate the gasses and improve cooling under those circumstances but if the brake isn't very efficient from the off then the holes and grooves are unlikely to improve things. Sintered pads may help but the Lambretta disc is a pretty flawed design and probably only converting it to hydraulic is going to give you a decent brake.
Re: drilling inboard disc
Posted: Mon May 02, 2011 12:23 pm
by RICSPEED
i have done it but they are avalible new in a vented/drilled style
Re: drilling inboard disc
Posted: Mon May 02, 2011 1:49 pm
by mickdale
rally season has started so limited funds - can get it drilled at work so didnt want to buy one
cheers
mick
Re: drilling inboard disc
Posted: Mon May 02, 2011 2:25 pm
by RICSPEED
ok ....what i did was this .....get a peice of mdf (about 6mm thick)
get your self a compass ,ruler and a protractor ,
measure the disc diameter and the depth of the disc face ,and draw on the board ,so a circle within a circle
then divide the distance between them so you have 4 more circles within the first two
still with me?
now get your protractor and divide into 10degree segments
then mark where the line intersects on the bottom line -
after making four holes go back to the bottom line and repeat
this should work out so the last hole you mark will be a top one ("should" as i did this 20yrs back)
screw some wood to the mdf to keep your disc in position and drill through the mdf into the disc with a small drill then remove pattern and you can then use progressively larger drills till you are happy with the size
but given corrados advice i leave it up to you ...ok

Re: drilling inboard disc
Posted: Mon May 02, 2011 2:52 pm
by mickdale
top man ricspeed - just what i was after
thanks
mick
Re: drilling inboard disc
Posted: Tue May 03, 2011 7:21 pm
by joey
...only time it's worth drilling is when you get brake fade from overheating...but that would only really happen in extreme circumstances....on a road scoot i think its good to get a bit of heat into the brakes...use the copper coloured pads all other pads are s**t other than citreon bx rear pads but these are dangerous when worn down!

Re: drilling inboard disc
Posted: Tue May 03, 2011 7:40 pm
by mickdale
thanks joey
are the copper coloured ones the "sintered" ones?
Re: drilling inboard disc
Posted: Tue May 03, 2011 8:43 pm
by joey
...there on ve uk race sintered...
Re: drilling inboard disc
Posted: Wed May 04, 2011 3:19 am
by mickdale
joey wrote:...there on ve uk race sintered...
oh
