rear caliper 4 pot upgrade. pics :-)

[fattyJr]

Finally got sick of the crap wooden feeling rear brake on my ulysses. Read up on the common "hidden" brembo caliper upgrade but wanted matching nissin calipers.

Was looking on ebay and managed to buy a NOS 4 pot front left caliper off a triumph trophy. Nice thing it said "nissin" on the side and not "Triumph" like it does on my other bikes. Came with new pads and stainless bleed, so bargain for £110 delivered.

Took the old single pot unit off, took some measurements and got a billet of aluminium that I machined up. I have got the measurements wrote down if anybody wants them.

First impressions are brillant. Lot more feel and lot more power. The caliper has two 30mm pistons and two 34mm pistons.

 

[34nineteen]

Interesting conversion. I’m actually surprised the master cylinder could move enough fluid to activate the 4 pistons. On paper, it seems like it shouldn’t work.

 

[Cooter]

Actually, thats probably why it does work. I hate the rear Buell brake so much I never use it. Ever You get the 'wooden' feeling from a MC that is much too big in relation to the caliper piston size.
You could get a better feel with the stock caliper by using a smaller rear MC. An easier conversion for sure, as most rear MC...MC's (haha) bolt up the same.

Good job OP, let us know how it works long term

 

[34nineteen]

I wonder if it can lock up. Maybe that’s some of the magic is that the cylinder runs out of fluid to push before the caliper can generate enough force to lock up the brake? It could lead to a feel that is a bit more modulate-able.

I’d be curious to hear how this works out in the long run on the road. Just be careful until you get the “feel” figured out.

Keep us posted!

 

[njloco]

So, has any one tried changing out the rear MC for a smaller one to see if it improves the performance ?

 

[fattyJr]

Been out for a few short runs to bed things in and it's getting better all the time. i prefer to use my back brake while riding in traffic. I did try swapping out the pads on the rear for ferodo sintergrip which helped, but still didn't lose the wooden feel.

There was a thread on here https://www.buellxb.com/forum/showthread.php?51067-Rear-master-cylinder-upgrade that did a bit of in depth research about the rear master size.

he went for an 11mm bore master combined with a brembo hidden caliper. You can get them in 11mm that match the setup on the buell.

I could probably got up to a 13mm bore master if i need to, but it's not much bigger.

I do have a brand new ztl2/EBR caliper to go up front. cost me $150+ shipping back to the uk. Also have a 19mm radial master too.

 

[Cooter]

How did I miss that thread? Awesome work by AZ:up:

Thanks for the link fattyJr!

 

[pur pony]

nice job! Ive been running a 4 pot Brembo on my X1 for several years now. Love it

 

[fattyJr]

Been riding the bike to work and the new caliper on the back is working flawlessly. you can rest your foot on the pedal and feel the initial bite, then just ease on the pedal. very progressive. Reccommended upgrade.

 

[GregoXB]

Rear brake not important, only 10% of stopping power. Stock is acceptable.

 

[Chicknstripn]

I did the brembo, hinden caliper mod, and it’s much better than stock.

Nice work on conversion. To me it looks a bit bulky for a minimalist ride like an xb.

 

[lowkey]

Nice work OP!:up:

 

[MakingPAIN]

Cool set up. That’s a lot of brake power on the rear.

I see that a lot people saying they don’t use the rear brake or just very little once and a while.. I must be a weirdo I use my back brake every stop every time. And I have noticed over the years of dirt and street riding that from high speed throttle chops If I apply my rear brake before my front the bike will settle down and experience less dive sensation while really throwing the fire off the brakes.. not saying it’s the right thing but it feels good and I like things that make me feel good lol

 

[optomist]

one really important function of a back brake, to me, is going downhill on a dirt trail. The bike washes out really easily with the front brake but the rear brake keeps everything tidy. Talking about my Uly here

 

[Cooter]

MakingPain: If you keep you arms loose and grip the bike with your thighs like you're supposed too, it won't dive like that.:up:

Try it back to back at stop lights using only the front brake, you'll see what I mean.

 

[GregoXB]

Yea for the amount of stopping power the rear brake is gonna offer you, the stocker is more than up to the task.

 

[MakingPAIN]

Mr Cooter you are correct with the loose arms and tight thighs to bike. What I meant by “settle” the bike down is, your coming from a loaded torqued out frame and suspension to a relaxed motorcycle in a split second and applying the rear before the front will bring the bike into a smoother deceleration. Instead of sinking the front end down right out of a throttle chop with the front only..

I picked that up from a factory Kawasaki racer from the 80s my buddies uncle that now designs dirt bikes for Kawasaki.

 

[fattyJr]

I must be one of the werid people in the world that like good brakes both front and rear. I like nice progressive brakes that are not like a switch. No point having good front brakes and mediocre brakes on the rear. Now weather has calmed down, I'm out to try the 8 pot on the front

I had a similar discussion/arguement with a friend of my fathers. He's got a total stock 883 sportster with the usual cheap tack stuck on it like headlight covers etc. He said his brakes are totally adequate. Then He saw the sportster I purchased that had a buell rotor upfront with a 6 pot tokico and a 250mm rotor out back with a 4 pot on the rear. My father rode both bike when he took them for their yearly inspection. He rode mine and the brakes were great. He rode his mates and after he stuck his man vegetables on the wheel, he finally stopped.

 

[njloco]

That is a funny way of putting it, his man vege's on the wheel !

P. S. To me, that kind of looks like a sportster version of a Buell STT.

 

[GregoXB]