MV Rear Brakegreenspun.com : LUSENET : MV Agusta F4 : One Thread
There is an issue which has been raised a few times on this forum, which always causes me to furrow my brow and worry for the brother who made the statement. The issue is that of MV rear brake performance. My credentials on the matter are as an ex production bike racer (Ducati) a one time riding instructor, and a survivor of around 35 years of road bike riding. Many of you are probably much more skilled and experienced riders so I apologise if the following is like telling you how to suck eggs, but for some……
I have seen several people complain that they just cant pull their bike up on the back brake, that it fades etc…. I can only suggest that those people go out to the garage and have a good look at that brake, and for that matter the rear brake on just about any big bike made today. Small isn’t it…How on earth would you expect a brake that size to pull up 250kg of bike and rider from virtually any speed. You wouldn’t put a brake that size on a modern 250, it would be totally inadequate.
That brake is not supposed to stop that motorcycle…. It is only there to give some balance to the braking, so that the rear wheel isn’t trying to overtake the front. It is there to help control the bike during a full lock U turn or negotiating a difficult park or a hill start, where your brake hand is otherwise occupied. If you are fading your rear brake, then you are not using your brakes the way they are designed to be used.
Compare the front brake with the rear one.. At the front you are supplied with two enormous discs, with a total of 12 hydraulic pistons working on them. You can hardly see the front wheel for brake disk. The brakes on your bike are configured that way for a very good reason. You are supposed to use the FRONT brake for stopping. I have seen statistics somewhere, (cant put my hand on them at the moment) which said that in a considerable percentage of motorcycle accidents the rider could have avoided the accident if he had used his front brake. Even if your rear brake can lock the rear wheel (which I don’t think the MV rear is designed to do) your stopping distance is enormously increased compared to using the front.
I suggest that those of you who in your secret heart of hearts, when reading this recognise that you are a closet rear wheel braker, change your ways. If you don’t want or cant afford to do a motorcycle braking and cornering training course then at least.. Put on your best protective gear, take yourself off to a deserted car park or road, and from a slow speed, practice using your front brake. Try squeezing gently in the first instant, then harder , but not suddenly, always smooth. You should practice this for hours, till it becomes second nature. Until you can feel the front wheel just beginning to lock. If you do feel that locking then that ease the pressure off, then on again..gently…. If you combine that with a very light foot on the rear brake, not so much that the rear wheel locks, then you are getting the best out of your brakes, and you will have a much better chance of avoiding that truck that just pulled out in front of you.
If you go back another time when its been raining, and ever so gently and carefully practice the same thing, you should be a lot safer in the wet too. Back wheel brakers will know that the rear locks up real easily in the wet. If you don’t believe you should use your front brake in the rain, try watching Valentinto Rossi, he gets his back wheel off the ground he brakes so hard. I’m not suggesting you try that hard, god knows I don’t. I hope this helps, I’m not trying to be a smart ass by writing this, I just hate the thought of my fellow bikers endangering themselves, through bad habits. Ian.
-- Ian Sylvester (firstname.lastname@example.org), August 30, 2004
More fuel to the fire ive owened a f4 for 3 years ,if my back brake even faded i,d e be happy . You said all its supposed to do is hold me from rolling back at traffick lights well it can,t even do that ive had Itallion bikes for 20 years ive had the bike in 3 times to fix said problem and the best solution is ive got to pump the lever 20 times then it might work . Saying that though its probably the only bad thing on this bike I absolutley love it and have no intention of buying the new 1000
-- michael phillips (email@example.com), August 30, 2004.
Appreciate the post, Ian. I think you too own a Brutale and maybe the rear brake on it is a tad better than the F4's, although I rather doubt that.
My rear brake certainly performs well in the way that you suggest it should be used. I had to brake quickly this past weekend from speeds of around 80 mph and I applied both brakes to come to a very fast, stable stop. I think I lucked into it but was pleased that neither tire locked up. My fear in applying the front brake is that I will use too much force and lock up the front and fly over the handlebars. I don't know how justified that fear is, however.
-- Tom Solimine (Tsolimine@amph.com), August 30, 2004.
Yo! FU**IN SHI* YOU MEAN TO SAY YOUR SUPPOSE TO USE THESE DAMN REAR BRAKES TO STOP THESE DAMN BIKES????? Ha ha ha ha it's a joke & I could only agree with you more on what you have written. I was laughing my hearts out everytime I hear them complain about rear brakes & why is it not functional. I seldom use them myself specially for stopping the bike, you say bye-bye to your bike if you use 'em instead of the front brakes. Even the local dealer tried to con me about these rear brakes & told me that I need to spend about $600 to fix it. Imagine, fixing a non-worthy problem and costing me a whole lot of money (I keep my mum shut so not to offend this poor bastard). C'mon, doesn't anybody has any common sense on just by seeing these brakes & comparing them why it is so? If you don't analyse them very carefully & never ever wonder for an answer, better leave your bike inside your garage & leave it to it's peaceful solitude.
"Bike Lesson #1: one has to understand the bike to actually learn to ride" "Bike Lesson #2: always have a buddy when riding. safety is a precaution" "Bike Leeson #3: keep reading this thread, you might actually pick-up & learn something new"
Cheers to everybody & keep posting! Have a safe ride......
-- AJ (firstname.lastname@example.org), August 30, 2004.
I sometimes let certain individuals do all the talking but when I hear that the rear brake on an F4 does not work its just amazing ...I guess all those man hours the engineers spent on saving weight and looking for ways to make the f4 more agile were just a waist of time ...guess what ,lets just remove the rear brake assembly ,pedal ,hoses ,caliper, rotor ,nuts bolts and now we have saved Mv a fortune in parts and the saving will go to the customer ...gentlemen...lets get serious ...the rear brake works the way its designed...its the owner/rider that needs to have some common sense and knowledge how these marvelous motocycles r to be used. One more thing (I cannot resist)...do u think the engineers that developed the front brakes (they work don't they )(I hope)need help developing the rear one ? hummmmmm?Yes I agree when the rear wheel is in the air the rear brake still works but is not so effective on slowing the bike down...I guess maybe we r being a little 2 silly here (maybe just me)but if the fronts ever fail (not likely)I plan to use the rear brake until there is no tire left or the soles on my boots wear out... I feel much better now...maybe...one more thing ...if u have to pump them a few times... maybe just maybe u need to bleed and totally change the brake fluid...u have changed the brake fluid every so often haven't u ? Well now I think that should work...may u all use the front brakes to its outmost profiency but don't forget the rear ...also extremely important... To those that have become insulted or puffy or turned a shade of red from my comments I did not in anyway meant to do so 'but just in case check your blood pressure ...to those that think I meant well all along ...smile ...its still free...
-- Rui C Gomes (email@example.com), August 30, 2004.
If your rear brake works when you pump it--more than likely it has a stubburn air bubble in it. Remove the caliper and hold it high to bleed it. Make sure the master cylinder is not bad.
-- martin (firstname.lastname@example.org), August 30, 2004.
The reason the pedal is long is due to the heat transfer from the exhaust overheating the fluid in the master cylinder, I changed to a good fluid and the pedal has been consistent ever since. Use something like Castrol SRF/AP 600/Endless 650
-- Richard Thompson (rthompson@NRRT23.com), September 01, 2004.
Geezz.. Ian.. Could you be any more condescending? You act like the rest of the poor schmucks out there can't tell the difference between a good rear brake and a bad one..I've got a clue for you, Mein Furor... Most MV owners can. Obviously you haven't ridden any other brand motorcycle on the market lately or you'd AGREE that the MV F4 rear brake is a piece of Italian shite...I also guess that you don't read reviews from professional journalists that say the same thing.
While our credentials are similar, IMHO.. the rear brake on my 03 Evo is simply the worst I've seen on any non-American motorcycle.. ever..
Agreed that it will work fine for "our" needs and I don't use mine often, but that doesn't justify poor design and/or function on a high dollar bike. MV designers simply missed the mark with it and should offer a free solution.. or better yet.. fly a sexy young Italian vixen with pouting firm breasts to our respective garages to do the fix., IMHO...
I'm taking the advise of a few others who have changed to a better fluid.. whenever I get around to it.. Not a pressing issue to me.
and that's all I've got to say about that..
-- Pirate (Pirate@acelink.net), September 04, 2004.
Pirate: I did try to apologise in advance for appearing a smart ass. I can see why experienced and skilled riders may see my piece as being condescending, and I agree with you that if the rear brake master cylinder on an F4 is poorly positioned with regard to the exhaust, then we should be complaining long and hard to MV.
I do not have that problem on my Brutale. The rear brake is perfectly adequate, I have in fact had a few very minor rear wheel lockups during hard braking. (due to weight transfer to the front wheel)
When I started reading in this discussion group, people complaining about the rear brake I had to go out and consciously try it. If I don’t touch the front, my Brutale rear will just lock up the rear wheel if I press really hard. I have ridden a few other modern bikes, and haven’t noticed any difference with the rear brake performance, probably because, as you would know as an experienced biker, most of my braking is on the front wheel with the rear making only a relatively small contribution.
I found an research paper by the British Royal Society for prevention of accidents at http://www.rospa.com/pdfs/road/motorcycle.pdf page 25 item 7.4.2
According to their study over 30% of motorcyclists only use the rear brake… and they estimate that 30% of motorcycle accidents could be avoided by the correct use of the motorcycle brakes.
You may be correct, perhaps all MV buyers are well trained skilled riders who use their brakes correctly, call me sceptical, but I kind of doubt it…I suspect that we are most likely a pretty representational group of riders, and that over 30% of us do not use our brakes correctly..
I am not writing this to blow my own trumpet, I am not someone who likes to stick his neck out, but if my bringing this issue up helps even one person to avoid an accident which may have hurt or killed them then its worth the discomfort at being criticised.
-- Ian Sylvester (email@example.com), September 06, 2004.
Ian, While agreeing with your initial statement about worrying for the brothers,I feel you missed the reason these posts were made,namely,a lack of mechanical apptitude to recognise that the brake needs bled. The F4 brake when bled is no worse than most other sport bikes on the market. I think most requests were not how to use it, rather how can I make it work or why is it not working? And yes MV should have sorted it out for us but they havent,I think the new bikes now have the reservior relocated under seat. As the guys said use High temp fluid,some have wrapped insulation around lines . Its a pyhsical mechanical problem like engines stop when they dont get fuel and brakes dont work when they dont get fluid. ian.
-- Ian paterson (firstname.lastname@example.org), September 06, 2004.