JohnD Posted October 22, 2021 Report Share Posted October 22, 2021 Postman, Quote "Drilled discs are generally more prone to heat checking and thermal cracking if used consistently at extremely high temperatures." https://www.racetechnologies.com/article/how-do-disc-face-types-affect-brake-performance And that is the website of a company selling brake discs! To widen your experience, please read: https://www.carthrottle.com/post/the-pros-and-cons-of-different-brake-disc-designs/ Quote, "those holes can become stress points, potentially leading to cracking during heavy braking." Just because you haven't heard of it doesn't mean that it's not true. John Link to comment Share on other sites More sharing options...
postman Posted October 22, 2021 Report Share Posted October 22, 2021 Yes, obviously JohnD. The above is pretty much a description of race conditions where almost every component is tested to it limits and failures go with the territory. A clue in the company name 'Race Technologies'. I said it's not happened to me which is rather different to 'haven't heard of it'. Of course a drilled hole 'can' become a stress point, no argument. Incidentally I've drilled my own discs in the past (only a couple of times, as they've never failed) and put a shallow countersink on each hole. Down to personal choice as is engine tuning, suspension tuning etc. If you desire improved performance there is likely to be a downside. Link to comment Share on other sites More sharing options...
SpitFire6 Posted October 22, 2021 Report Share Posted October 22, 2021 Hi,"Drillings are complete borrocks" Wrong & incorrect. Fitted to my 206CC & now when I brake in the rain at motorway speeds my car slows down as intended. "Slots are complete borrocks."Wrong & incorrect. I have 10mm thick Disks fitted to my Spit6. They are 1mm deep. Would be foolish not to have them in my case. Iain. 1 Link to comment Share on other sites More sharing options...
ahebron Posted October 23, 2021 Report Share Posted October 23, 2021 What is interesting with brakes these days is that discs are almost as consumable as pads, 2 or 3 sets of pads to 1 set of rotors. Drums go on forever! Link to comment Share on other sites More sharing options...
Clive Posted October 23, 2021 Report Share Posted October 23, 2021 11 minutes ago, ahebron said: What is interesting with brakes these days is that discs are almost as consumable as pads, 2 or 3 sets of pads to 1 set of rotors. Drums go on forever! I reckon 2 sets of pads does it. But with pads lasting 40K that isn't pad. My record for wearing a set of pads out was on my vitesse, locally supplied from a motor factor, they lasted about 4k of everyday driving, and were not very good either. That is when I started using NoS pads, probably mid 1990s. They last well and don't seem to wear te discs. Saying that, my spitfire does get driven hard (trackdays, some alpine adventures, Stelvio is very hard on brakes if driven enthusiastically) and the ds2500 pads are less than half worn in about 20K, (capri vented) discs still look new. Pads are over £100 a set though! Link to comment Share on other sites More sharing options...
Anglefire Posted October 23, 2021 Report Share Posted October 23, 2021 2 hours ago, ahebron said: What is interesting with brakes these days is that discs are almost as consumable as pads, 2 or 3 sets of pads to 1 set of rotors. Drums go on forever! Thats a fair point- my daily - a Skoda Superb - has done nearly 52k miles and is on the same pads and disks - and it is the rear disks that are going to need replacing in the not too distant future - pads are actually ok - though obviously would be changed at the same time. My disco would generally do two pad changes to one disk change. Fronts I got down to 1 1/2hours for a full disk and pad change from starting to getting the tools back in the garage - about 1/2 that for a pad only change. Rears took another 1/2 hour or so as the handbrake needed cleaning and adjusting to avoid issues. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 23, 2021 Report Share Posted October 23, 2021 modern discs as softer to get the grip and pads more aggressive to get the braking and abs stopping power demanded these days not like old discs that can last 50 years as many have found i would be interested in how reducing the swept area with holes and grooves makes any use in normal conditions its not a idea promoted by many modern manufacturers cars Pete Link to comment Share on other sites More sharing options...
Anglefire Posted October 23, 2021 Report Share Posted October 23, 2021 The rear brakes in mine being the "worst" ones are due to the active cruise control - it uses the rear brakes apparently to slow down if reducing the power is not enough. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 23, 2021 Report Share Posted October 23, 2021 2 hours ago, Pete Lewis said: I would be interested in how reducing the swept area with holes and grooves makes any use in normal conditions its not a idea promoted by many modern manufacturers cars But heavily promoted by motorbikes and even bicycles as 'sporty'... looks like a lace doily but might explain why bicycles never stop at red lights or junctions? 1 Link to comment Share on other sites More sharing options...
NonMember Posted October 23, 2021 Report Share Posted October 23, 2021 The bicycle one is done entirely for lightness. Cyclists - especially those who need "disc" brakes instead of rim ones - are obsessed with lightness. Link to comment Share on other sites More sharing options...
rlubikey Posted October 23, 2021 Report Share Posted October 23, 2021 Colin, I think you'll find that the "little perforations" (was that a tea-bag advert?) are for lightness. Disc brakes on bikes are still heavier than rim brakes. But whereas they give reliable braking off-road in muddy conditions, I believe they're just being needlessly pushed into the on-road market by the manufacturers. They want us to buy new bikes - this years model - and make it more likely we'll throw the bike away when something small fails. Cheers, Richard - who DOES stop at red lights (bike and car) Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 23, 2021 Report Share Posted October 23, 2021 That's a Kawasaki 250F front disc... it really must eat pads. I've got discs like that for the angle grinder... 2 Link to comment Share on other sites More sharing options...
Chris A Posted October 23, 2021 Report Share Posted October 23, 2021 4 hours ago, rlubikey said: believe they're just being needlessly pushed into the on-road market by the manufacturers. They want us to buy new bikes - They are becoming more and more common at professional level, the Tour de France is one case, this is despite the fact that changing wheel due to a flat takes more time. Marketing or real advantage ? 1 Link to comment Share on other sites More sharing options...
Patrick Taylor Posted October 23, 2021 Report Share Posted October 23, 2021 The economists would tell us that this is technology push, not demand pull... Link to comment Share on other sites More sharing options...
Chris A Posted October 24, 2021 Report Share Posted October 24, 2021 12 hours ago, Patrick Taylor said: The economists would tell us that this is technology push, not demand pull... I agree. Amateur economist, Normandie 🙄 1 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted October 24, 2021 Report Share Posted October 24, 2021 12 hours ago, Patrick Taylor said: The economists would tell us that this is technology push, not demand pull... You mean like EVs?? (thread drift alert - he's doing it again!!) Link to comment Share on other sites More sharing options...
Chris A Posted October 24, 2021 Report Share Posted October 24, 2021 2 hours ago, Colin Lindsay said: You mean like EVs?? (thread drift alert - he's doing it again!!) Just because it is thread drift doesn't mean it isn't valid. If this thread drifts enough it could 'collide' with the other and they would disappear in a puff of electric blue smoke 🤔 Link to comment Share on other sites More sharing options...
Badwolf Posted October 24, 2021 Report Share Posted October 24, 2021 Further drift alert.... Wasn't 'Electric Blue' a dubious magazine from the 70's, or just a line from a Bowie song? Link to comment Share on other sites More sharing options...
Chris A Posted October 24, 2021 Report Share Posted October 24, 2021 1 hour ago, Badwolf said: Wasn't 'Electric Blue' a dubious magazine from the 70's, I've no idea but you seem to have . . . Link to comment Share on other sites More sharing options...
Badwolf Posted October 24, 2021 Report Share Posted October 24, 2021 Just something that I heard about in my youff!!! Probably the precursor to Doug's other site?? Link to comment Share on other sites More sharing options...
PeteH Posted October 25, 2021 Report Share Posted October 25, 2021 Does sound a bit like something from a 60`s Danish (Ahem) "naughty" film.? One Ship steward had a nice line in 8mm Scandinavian film stock. His other "venture" was Lunch time picture shows in the Crew Mess for the Dockers at 2/- a head. One might say very entrepreneurial?. Pete Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 25, 2021 Report Share Posted October 25, 2021 11 hours ago, Badwolf said: Wasn't 'Electric Blue' a dubious magazine from the 70's, or just a line from a Bowie song? The tiny grey cells have joined the dots and come up with Electra Glide in Blue, a not very good film, but more importantly a Harley Davidson. Doug Link to comment Share on other sites More sharing options...
Chris A Posted October 25, 2021 Report Share Posted October 25, 2021 Oh look, that Harley has drilled discs front and rear. I wonder if they are any good at . . . No, seriously though - they fitted them to save weight. 🙄 1 Link to comment Share on other sites More sharing options...
ahebron Posted October 25, 2021 Report Share Posted October 25, 2021 I do wonder if motorbikes and pushbikes have holes in the discs because of the thinness of the discs and metallurgy. I recall my old BMW with solid discs would warp the discs but my newer BMW has holes in the discs and dont warp as much. Might be barking up the wrong forest here Link to comment Share on other sites More sharing options...
JohnD Posted October 25, 2021 Report Share Posted October 25, 2021 "warping". How did that show itself? Was there actual run out at the rim of the disc, or was it more a sensation of vibration or grabbing? The second is due to brake material being imprinted into the disc surface. Usually caused by sitting with the brakes in when they are hot, and the alloy of the disc affects how likely it is to happen. John Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now