no more back brake problems for ever

Pretty extreme decision ol mate I certainly don't use mine very much..but does come in handy at times! As piss poor as the brake is, it stops the back end trying to pass the front end under heavy braking. Good luck with it all, but take care mate.

i must admit, i've thought about doing that from time to time, but there have been times when i need to tighten a line, and didn't want to touch the front brakes. man, that's when i'm really glad i've got that rear one on there.

if you're is really that bad, why not look into an aftermarket replacement? get some brembo or AP hotness on there :yumyum

-:banana

what about MOT???????

agreat1 said:

what about MOT???????

Click to expand...

Never mind MOT. What about the eagle eyed cops who're doing their normal routine bike checks.Ooh illegal can/number plate sir, and er where's your back brake?
Mine just sat there useless but at least it looks legal.

do bembro do an after market replacement, possibly even a large ratio master cylinder to give a good brake.:dunno

Yes, RSVR.net do an larger bore Brembo rear brake master cylinder and a bigger 34mm piston Brembo rear brake caliper for £96.50 plus vat including new rear brake pads

cheers legs might be the way to go:thumbup

what about MOT?

Click to expand...

Not sure they have an MOT equivalent in Canada squire :dunno

Not a popular thing to say, but if you had the time and patience to take it off, you could of spent that time altering and repairing it instead......do I need to start running yet? :lookaround

crashtd said:

.... but there have been times when i need to tighten a line, and didn't want to touch the front brakes. man, that's when i'm really glad i've got that rear one on there.

Click to expand...

another very good reason to have it indeed..when you run in a little hot and as said need to bog it into a tighter line but keep a throttle on and definately no front brake...it will do enough to achieve this ok

That aftermarket Brembo sounds like it might be worth investigating for that price...not too costly a price for a nicer back brake if thats the outcome. :thumbup

Just ordered mine...cyl and caliper..and heat guard to be on the 'safe' side.....hope it fixes the prob..

Exclnt mate..plz post up how it all goes..is looking like the only way to get a rear brake that performs.

I have been giving these upgrade bembro items alot of thought, but am at work and can't look at my bike at the moment. can someone remind me if the rear caliper is single or twin piston.

I have been throwing some figures about with regards rear break efficiency.
standard hydaulic ratio is 8.46:1 (with STD 11mm & 32mm items), regarding multiplication of pedal effort to caliper force. i.e 10Kg of pedal force equates to 84.6Kg of caliper force.

Now if you use both the upgrade master cylinder and caliper (13mm/34mm) the hydraulic ratio falls to 6.84:1. this would have the effect of requiring more pedal effort.

it appears, if my calcs are correct, that the best combination appears to be STD master cylinder with upgrade caliper (11mm/34mm) this appears to give a hydraulic ratio of 9.55:1

does this make sence or have i got the wrong end of the stick, and talking bollocks. await any of you qualified engineers to give the definative answer.

I've not looked into the pro's and cons of the upgrade yet. The lack of a decent back brake is down to where Aprilia decided to mount the rear brake master cylinder. Excessive heat, due to the close proximity of the front cylinder exhaust pipe, boils the brake fluid causing the spongy pedal feel. There are numerous fixes about. Either remount the master cylinder on some expensive rear sets such as sato's. Another fix is to fit the revised 45 degree 4.5mm ( up from 3mm ) plastic black brake unions as per Aprilia service bulletin 23-2004. This helps the self bleed function of the master cylinder expell air up to the rear brake resevoir buy doesn't reslove the excessive heat issue. Personally my back brake gets a little spongy every 600 miles or so. All i do is put the bike on the rear paddock stand and hang a 5 litre container of oil using a cable tie off the rear brake pedal overnight. This has the effect of forcing any air in the rear brake system up to the fluid resevoir and so vent to air. The fact that the bike is canted forward slightly as it's on the rear paddock stand helps the self bleed procedure. It's not a particularly engineered solution but it works and the pedal is firm with plenty of bite to the rear brake

The brake caliper and master cylinder upgrade should give more rear brake performance as more fluid is being forced rearwards and is acting on a larger piston for more brake pad pressure. The problem of the heat acting on the master cylinder remains. Wrapping the exhaust with heat proof wrap will help protect the master cylinder as will a small heat shield mounted behind the master cylinder itself

ye seen all the mods legs. been following them for some time. my rear break is very firm, dosn't appear to have an air ingress, spongy problem. mine just has very little breaking effort, feels like the pads are made of wood.
Am considering a better quality pad with a higher coeficient of friction, like EBC HH. i have heard all the things regarding disc wear, but have used these to good effect in the past on previous bike with no problem, and the breaking effect was much more agressive. i will also change the fluid for a higher spec dot4 racing fluid as mentioned by others, with a higher boiling range.
i wrote some time ago about degassing your break fluid before you use it, as all fluids retain an enormous amount of air in it, removing this prior to use means that it will not be there to boil out later.
my earlier post was with regards improving the amount of breaking pressure which is applied to the rear pads with a good solid (no air) pedal.
it all has to do with hydraulic ratio. the ratio of one piston diameter to the other, and i think the way to get the greatest caliper pressure, is to use the std small master cylinder, and the modified larger caliper. this gives the highest hydraulic ratio.
however before i spend out on a new caliper i am going to try the new pads, and change to fluid for a higher spec which has been degased.

Sounds like a good call Hero, be interested to hear how you get on.

I'm using Gilles rearsets with the original caliper and M/c and it's superb, will lock the back at will if i want it too 3000 miles after fitting.

That tells the story that it's not the parts that are the problem but the way they are implemented by Aprilia. Even if you solve the air issue in the standard setup it is still totally wooden and without power for the most part.

MV went the same route as Aprilia on the f750 and never solved it properly. On the F1000 the M/C is mounted on the rearsets.

It's an expensive option as to my knowledge only Sato or Gilles offer M/C relocation but it's a 100% fix.

The stock system is fine. It just requires a thorough bleeding and then monitor it. If you ever tip it over it will need bleeding. Mine and a friend's Mille R are fine after a few thousand miles after bleeding per the Service Bulletin and all is good. The rear brake components are top notch Brembo kit, why chunk it when you can easily and cheaply correct it? Also the fluid should be a high quality fluid, and the most critical aspect is to adjust the 1 to 1.5 mm play in the pedal. Good Luck.

thankfully,still not had a problem with mine in 3000miles in the last 2 months.
half expecting it to happen tho.lol