I did the math and it's not even close... Ratio for the 6 pot and 14/15RCS was in the low teens compared to about 28:1 for the 19x18 and M4 Brembo.
Leverage ratios are simple hydraulics in a perfect system. Ratios of fluid transfer have nothing to do with the ability to disperse heat. Which is exactly what a brake system has to do. Ratio express feel, at a static point, independent of how heat effects the system. Brake systems change a lot during operation, particularly in race applications. What is needed for a specific application is another consideration, mass and potential energy is underlying force here then heat transfer and its ability to dissipate it. So, why would you need a 6 pot single (small area) disk with a small MC volume?
Single Nissin 6 pot caliper (30,27,22mm) total piston area- 3319 mm^2 Brembo 14RCS piston area- 154 mm^2 caliper piston area to MC pitson area ratio- 21 with the 15RCS the ratio drops to 18 Dual Brembo M4 caliper (34,34mm) total piston area- 7263mm^2 Brembo 19x18 MC- 284 mm^2 Ratio- 25.6 According to the hydraulic ratio, my 14mm Brembo RCS with the single Nissin caliper should feel wooden with minimal lever travel compared with the 19mm Brembo MC with the dual M4 calipers. It's simple hydraulics... However, in actuality, the 14mm RCS is barely adequate @ the 20mm setting and unusable @ the 18mm setting. There is too much lever travel. The 19x18mm/dual M4 caliper combination is braking combination heaven... I'm sure there is a reason, but it escapes me. I'm not sure what you are asking with your question...
I shouldn't say that the 14mm RCS is completely unuseable at the 18mm setting, I just have to let out the lever adjuster pretty far for it not to reach the grip. I've done about 50miles (this is a street bike, though) after the switch and immediately feel the power having come from a hugely oversized 19mm MC which was basically the definition of wooden brakes. Little lever travel, no power, required huge grip and even then it didn't seem to slow the bike down. After the switch, more lever travel, much better power at lower grip pressure. And yes, I previously tried a couple brands of sintered pads. Currently using Ferodo. Used Nissen in past.
Small update vid from this weekend, nothing major but did have some fun at the end. I pulled the trigger on a mostly complete R6 front end so I'll be able to mock things up soon. I also did some wheel research, including getting some crude (Bathroom scale) weight measurements of some of the wheels I have on hand and I'm surprised at how light generic supermoto wheels are, I was originally all gung-ho about finding some forged mags but... unless I fall into a set of BST Carbons regular spoked supermoto wheels will do just fine.
You can get some very accurate digital postal scales on ebay for less than $50. I purchased a pair of 550 pound versions that are only 1-2" high. I can slide them in and out under the tires when on stands.
I might look into that, but for the moment this is 'good enough' data for me to compare costs to gains on the wheel front. Those may come in handy when it comes time to compare total before and after build weights though... hrmm...
Just remember that a tube will add a pound or two to the assembly unless you get tubeless spoked wheels. However, the lack of cush drive on the rear might offset that weight, but the front might be a wash for weight with tire mounted.
Yup, I'm including that in my mental calculous. This has me leaning towards Alpina wheels, about the same weight as my normal spokers, but tubeless and not crazy expensive. In the same bracket are Warp 9 forged aluminums but they weigh a decent chunk more than spokers, so without knowing how the weight is actually distributed (Don't you wish mfgs would list the Moment of Inertia numbers?) I'm not leaning towards them yet.
Got 90% of an R6 front end to play with now, just short wheel spacers, fender and clipons. If I get time this weekend I'm going to do a weight comparison between the KTM front end and R6 setup. The last tricky bit before I can have a functional enough roller to test on track will be rearsets, I don't know if it makes more sense to make the full bracket around say Woodcraft pegs/levers or just make stub brackets I can bolt a common rearset assembly to? Either way is going to require some mill work as I will likely have to reuse the stock peg mounts as one of the two attachment points, no just drilling some holes in flat stock for this one.
I race a 450 supersingle bike. I think that it helps to run a cush drive when converting these bikes to roadracing. I actually had a Marchesini hub come apart on me a couple of years ago, bolts sheared right off. Galespeed makes 4.5 and 5 inch rims that work well (WR250F or DRZ400 fitment) with very minor modification, mainly new spacers. Something to think about when you're looking at supermoto wheels. For rearsets, I like Vortex. You can get a set that are close and then you just need to make new adjustable mounting plates to fit your required frame attachment points.
I didn't think to look at DRZ400 rear wheels, so Gale Speed is an option, thank you for the tip! I wonder how their wheels weigh compared to Warp9's forged units?
I don't know about Warp9, but the weight is within a pound of the marchesinis. With the cush drive, for me it is a no-brainer. Cheaper too.
Ended up going with a Warp9 rear wheel, FedEx was supposed to have delivered it Friday but... yeah. I'm working out of my RV in my driveway so I can face the road at all times, no chance of them claiming they tried to deliver but I wasn't there. I think I want to try and adapt a Warp9 front to the R6 forks, single rotor for more weight savings, have to do some more math on that to see how much of a PITA that could be, also curious to see how hard it'd be to redo the cush drive assembly to accept a smaller rotor in back for larger tracks, more math down the road. In the mean time, front end is getting adapted, I've got workable wheels, I still need to settle on a brake master, and design up and get machined some rearsets. Is there anyone besides Woodcraft and Vortex I should be looking at to source pegs/levers off of for my rearset design? I prefer the old style Woodcraft stuff, simple, minimal part count, etc but I also don't want to base off kit they're going to stop making soon.
So... not a damn thing has happened since... turns out the machinist that was tapped to make an adapter stem to fit R6 clamps to the KTM frame had external issues that prevented him from doing the work well into winter... so I gave up and got my parts back with the goal of just putting the KTM back into dirt trim, cleaned up for a quick sale? I also ended up buying a KTM 150SX to learn dirt on and... well it'd be in sumo trim if I hadn't ordered wheels from Italy at the start of the year... So, seeing as I've suddenly got no racing to look forward to in the near term, a bike partially torn down in my garage, a bunch of R6 bits without a home... I need a distraction and wrenching is a great one. Anyone want to adapt an R6 clamp set or make a bespoke set of clamps to mount R6 forks on my project? The other, likely worse idea I got was to get one of those Tianda TDR300 'pre moto3' chassis to base the build around instead, 27hp four stroke replaced with an 80hp two stroke, what could go wrong? I'd assume it'd need to be reworked to accept wider wheels running a 120/160 setup given the power but maybe skinny Moto3 tires have more grip than I thought?
I need to sit down and try and design a working stem too, KTM uses smaller ID bearings at both ends, going to end up being a stem and custom top nut setup I suspect.
Bearing can be changed. For sv I make bearing needed because you can't buy it. Ends up easier and more cost effective than making stems.
