Morning all. have any of you guys fitted wavy rear discs ? if so, which make ? i ordered a galfer one from bikehps last week which arrived on Friday. It is supposedly the right one for the mts, but it has metal sensor bobbins (for 1098) rather than threaded holes for the phonic ring that our bikes abs needs. just wondering if these unscrew or something, if anyone else has experienced the same, or possibly has the right part number to order. by the way, brake tech in the USA do a lovely floating rear disc, but they won't actually manufacture it for our bike until there is demand. So come on guys, get your orders in cheers John.
This ^^^. The last owner of my Fireblade hack fitted these, pointless tat, no proven benefits, in fact surely less meat on the disc due to the cut out shape would increase the metal temp ultimately increasing the risk of warping.... Time will tell. Best get some red anodised bolts while you are there
Why what - why replace with a wavy ? well the simple answer is why not mi had a wave disc on my st4s and it improved brake feel / performance. thought it has to be worth a try on the mts too. After all we have tried most other things !
Srad, thanks for the suggestion on the bolts. from experience wave discs DO work. I don't spend money for the sake of it, only where there is an improvement to be had. yes they have less contact patch, and it seems the perceived increased surface area is a red herring, but the existing disc is shite, so anything has to be better. I am not saying you should all do this. Only those that (potentially) want a working back brake for more than 5 minutes need apply
This is the bit I can't work out. Less material for the same amount of heat to dissipate means it must run hotter, not cooler? Less surface area for the same friction coefficient = less heat generated, but also less braking effect? However, provided you don't exceed the heat capacity of the system this shouldn't be a problem per se, and all the leading edges of the wave disc will give extra initial bite. I had a read of the Galfer and Braking websites and all the marketing blurb seems to insinuate solutions to problems that shouldn't exist on a properly designed and maintained braking system. :frown:
Wavey discs came from the the dirt bike world Reason been a wavey disc will clean its self (better than a standard disc) of mud and crap, scraping away the braking surface of the pads of all the goey stuff! I can therefore see the benefit of such discs in the off road world, but not so sure for the tarmac..?
The main benefit is due to it being a better material. the standard discs have a high chromium content in the stainless. This stops them from corroding, but also reduces their friction coefficient. bikehps advocate using brembo gold front discs, for the same reason as above. the reduced efficiency of the wave pattern on the rear is far outweighed by the better material.
Unfortunately, when it comes to physics and materials while you can bend the rules there are basic principles that do not change. As such there are then some major flaws in your argument above - for example when calculating heat dissipation a larger surface area is better. For heat capacity a larger volume can store more energy (in this case heat) for the same rise in temperature. However, as I have better things to do than sit there working out the thermal transfer coefficients, specific heat capacites and so on, I shall leave my disagreement here.
Where does all the weight go when you brake? but more importantly where does it leave what is allready a very small contact patch........why do you only have one very small disc on the rear with an even smaller calliper, but two mahoosive discs on the front, with even bigger mahoosive callipers?
ah now, there in lies the flaw in your argument. Your argument applies to all vehicles, so on that basis nothing should have rear brakes. Now consider a car. Its back brakes have a load balancer. When there is a load in the back (possibly people) then the rear brakes activate more proportionally than they did when empty, because there is more load to maintain that contact patch. This is exactly the same for riding two up. Lets not forget that when two up there is the added weight of the pillion. Use the rear brake and you essentially get the equivalent of more engine braking without the significant weight transfer and associated fork dive, that also affects steering geometry. It also pre-loads the rear suspension, and doesn't pitch the pillion about so much.This works even when solo (except pitching the pillion - that would be a marvelous trick if it did :tongue. For those of us that like to make the same progress when two up as when solo, a working rear brake is more than just a nice to have. As I said above I am not saying everyone wants to do this, its a riding style preference just the same as hanging your arse off the seat, or covering the levers. Personally I'd rather spend money on increasing the performance of something sensible I use than on carbon... :wink: Arthur, if only I could do the same ! :biggrin:
So on this basis you will improve the performance of it with a cocking wavey rear disc........please..
No... i will improve it by fitting a disc that has a better friction coefficient than the crap ducati one... The fact it is wave shaped is incidental, and outweighed by the better material, as I said in #10 above. I mentioned the brake tech purely because it is a floating rear disc of exceptional quality (like their fronts). If you don't like it, so be it. i'm not looking for approval. If you read my first post you will see I was looking for advice from those that had tried other discs. Since I assume you haven't, I'll also assume you have nothing further of any value to add :smile: I guess I got my answer, as well as discovering none of you lot value your back brake. I therefore won't bother to share my experiences once its done either since no one is interested.
