| Author | Message | ||
     Xodot |
comparing a 14mm bore master cylinder to a 19mm. What would the difference be in performance and feel? Any idea what the size of the stock MC is? thanks XO. | ||
| Dcmortalcoil |
Stock m/c 14mm both brake & clutch. Big difference in brake. Harder feel. Haven't tried clutch. | ||
| Dcmortalcoil |
Stock m/c 14mm both brake & clutch. Big difference in brake. Harder feel but greater force applied with your hand. Haven't tried clutch. | ||
| Nuts4mc |
more info here: http://www.oppracing.com/category/40-clutch-master -cylinders/ I use a Hayabusa M/C on my brakes (5/8" dia ( 16mm) I like it better than stock...if you're looking for a better feel with the clutch... a cable may be the only way to go... | ||
| Xodot |
sorry guys, I was referring to the feeling of the brakes - not the clutch. do they come on harder/faster/with shorter pull/more or less precision applying the brake to the exact degree desired?? | ||
| Alaskacr |
19mm master will take more force applied to the lever to stop the bike compared to the 14mm. However, you should also notice the brakes feel more gradual as pressure is applied. Also lever travel will be reduced. (Message edited by alaskacr on October 04, 2011) | ||
| Arcticcr |
Is this a hypothetical conversation? If not, should note that it is unsafe to run a 14 mm M/C on either 1125s; you won't move enough fluid. If you notice, the 6-piston caliper setup on the XB uses a 17 mm, which works well. However, with the 8-piston caliper, you'll run out of level actuation with a 17 mm bore. So I strongly recommend not changing to the 14 mm, best call would be to go with a custom bore around 17.5 mm (I've not tried this, so try at your own risk) or if you can find that setup off the shelf. Jay (Message edited by Arcticcr on October 05, 2011) | ||
| Dcmortalcoil |
Jay, Factory oem m/c is 14mm for 8 piston and (12.5 or 13.5 forget for 6 piston m/c not 17mm. The 14mm brakes work just fine. It's just a issue with the initial free play that many people don't like. | ||
| Dcmortalcoil |
BTW, I tried initially with 16mm Brembo radial m/c. Did not like it as it is too sensitive and travels a bit too much. Also tried 19mm (Brembo RCS) at 18mm leverage setting - 20mm leverage is like a rock too hard. The 18mm leverage is ok, but still requires a greater force. I like Brembo OEM radial m/c (16mm) made for Yamaha R1/R6 the best. Not too hard or too soft. Even though two Brembos I tried have 16mm, Yamaha OEM Brembo feels different (I think) due to the leverage being different. | ||
| Arcticcr |
Dcmortalcoil, The factory OEM M/C bore for the 8-piston is 19 mm and 17 mm for the 6-piston. Maybe I misunderstood what you wrote. Jay | ||
| Xodot |
My question stems from the availability of the Accossato Radial Front Master Cylinder - a forged aluminum radial front master cylinder with a 19mm bore, and an 18mm non folding lever. (from EEBBRR) and the Nissin 14mm Front Master Cylinder. (from American Sport Bike) I am looking to upgrade from stock to my riding level of an intermediate track day guy who rides it on the street too. I have no experience in this type of thing and appreciate your help. BTW - What is a "radial" bore on a MC? | ||
| Al_lighton |
Jay, I'm not sure where you're getting that info, but it is wrong. If using the Nissin RADIAL master (NOT OEM), you would use the 17mm for the 6 pot and the 19 for the 8 pot calipers. But they have much greater mechanical leverage against those large pistons than the OEM masters do. Al | ||
| Arcticcr |
Hey Al, That's what I said 17 mm for the 6-piston and 19 mm for the 8-piston. Jay | ||
| Dcmortalcoil |
Jay, Al said Nissan Radial is 17 or 19mm. Nissan Radial is not stock. Like I said before stock OEM m/c brake is 14mm. Its clearly marked on the m/c: B14 (14mm). (Message edited by dcmortalcoil on October 06, 2011) | ||
| Hellraiser |
Hey Dcmortalcoil, What year Yamaha R1/R6 did you pull OEM radial m/c (16mm)from? Did you have any issues bolting them to the larger bar ends used on the Buell?? I've always HATED  the amount of free travel and initial inconsistency from the front brakes on the 1125R. It seems like you need a couple of applications before they are consistent. I think they are just ok for track days (when your on the brakes quite often) but for street riding it just doesn't cut it. BTW - I'm confidant that there is no air in the lines. I've bleed them "normally" then tried the "back filling" method using a syringe then tried using speed bleeders. Each method yielded the same feel. | ||
| Jdugger |
Hell, It's true... the brakes firm up as they get hot. A new MC will *help* with that, though some of the flex you feel is the caliper halves spreading themselves. It's not just super rigid... | ||
| Smoke4ndmears |
The mounts also show visible flex. | ||
| Nuts4mc |
has anyone tried the caliper "rebuild kit" from EEBBBRR racing? ( $50 - no pix on the site ...assume it's just seals/"o-rings" and pistons??)...since HD went on a cost saving exercise when they built the 1125r...maybe the seals and "o-rings" are not optimal for this application...or the stock ones were meant for "track -like" applications needing some "heat" before they operate at an acceptable level...??? | ||
| Jdugger |
> has anyone tried the caliper "rebuild kit" from EEBBBRR racing? Yea, I use them all the time. In racing applications you go through quite a few sets of brake pads. Certainly far, far more than the typical dual-caliper set-up. So, all that dust clogs stuff up and you need to rebuild relatively more often. The seals and pistons kit makes it cheap and easy to pull the caliper, split it, clean it well, and restore it to a "factory new" performance level. To my knowledge, the seals and pistons in the rebuilt kit are exactly the same as OEM. | ||
| Nuts4mc |
thnx JD ...I'll give them try...less costly than M/Cs and custom lines! | ||
| Jdugger |
Keep in mind it's just a pistons and seals kit. If you don't like the way the brake feels brand new, it's not going to make a difference. |
