850T Master Cylinder Swap

[swooshdave]

I'm getting tired of the rock hard brake. I don't think it really needs dual disks so the cheapest option is a new master cylinder.

I was going to order from MG Cycle but I went with Bevelheaven as they are closer and a few bucks cheaper on the Brembo stuff. It shipped on Friday and I got it today. Not bad.

The actual swap won't be until later this week. Going to take a venture for some InNOut tomorrow. Not on the Guzzi. Too far for that bike... for now.


12mm

[swooshdave]

Installed the new master cylinder. It makes a huge difference. What felt like squeezing a brick now feels like a brake. It does pull back nearly to the bar which might mean more bleeding or maybe that's the way it will be. I have the lever clamped back tonight to see if that helps.

It's now a one or two finger brake with excellent modulation. I don't think for most riding a second disk would help. That being said if I add a second disk I'll just put the original master cylinder back on.

[canuck750]

if you are interested in selling the original master cylinder please let me know,

thanks Jim

[Mark Dasher]

if you are interested in selling the original master cylinder please let me know,

thanks Jim

Jim,

Check your PMs

--Mark

[swooshdave]

if you are interested in selling the original master cylinder please let me know,

thanks Jim

I'm going to hold onto it in case I ever put a second disc on the front.

[Britcheflee]

I changed mine out some years ago now - was kinda sorta thinking of rebuilding it and putting it back for originality but after your comments I think not.   Does your off/on/off switch next to that work?   Mine does not and I use the key - also the ignition key does not start the bike when turned far right - have to just switch it on and use the button.

[Britcheflee]

Here is what I put on - works great -



BTW what are those grip you have?  I have the old waffle style and it kills my throttle hand - makes it hurt to keep the throttle open on longer trips.

[swooshdave]

I changed mine out some years ago now - was kinda sorta thinking of rebuilding it and putting it back for originality but after your comments I think not.   Does your off/on/off switch next to that work?   Mine does not and I use the key - also the ignition key does not start the bike when turned far right - have to just switch it on and use the button.

On/Off/Start all work although switch is falling apart.

I believe the ignition switch on the 850T doesn't work with the starter but it did with earlier bikes. I suspect it can be modded but I haven't looked into that yet.

[swooshdave]

BTW what are those grip you have?  I have the old waffle style and it kills my throttle hand - makes it hurt to keep the throttle open on longer trips.

The grips say DURY on them. They are pretty soft. Seem to work ok. Still trying to find out why they used such stiff throttle springs. I assume so your right arm would get as big as the left because the clutch is a pain too.

I'm going to look into getting lighter springs or bigger arms.

[Mark Dasher]

Here are some pics of mine after I modified my handlebar controls, switches and master cylinder last winter.  Parts were purchased from MG Cycle.  I sent the new switchgear to Greg Bender who cut the wires to length and installed the correct molex connectors.  Perfect fit!  And much more functional.

The master cylinder is a 12mm unit and coupled with braided steel lines, F09 caliper and HH pads.  It's now a truly one or two finger brake with great modulation - a joy compared to the old one!

[Mark Dasher]

if you are interested in selling the original master cylinder please let me know,

thanks Jim

Jim,

You can have mine for shipping cost.  I know it'll go to a good home!  Send me a PM with your details...

--Mark

[swooshdave]

Here are some pics of mine after I modified my handlebar controls, switches and master cylinder last winter.  Parts were purchased from MG Cycle.  I sent the new switchgear to Greg Bender who cut the wires to length and installed the correct molex connectors.  Perfect fit!  And much more functional.

Nice!

Where did you get the handlebars?

I have some of those mirrors which will need to go on soon.

[Britcheflee]

About to ask the same thing - love the handlebars (kinda look like the ones which were on my Ballabio) - where did you get the mirrors and how do they work for you?
Lee

[bobdar]

Possible combinations of calipers and masters, area ratios:
 
38mm F08/15mm master:  6.42 (original)
38mm F08/12mm master:  10.03
48mm F09/15mm master:  10.24
48mm F09/12mm master:  16.00
(2)F08's/15mm master:      12.84
(2)F08's/12mm master:      20.06

I suppose (2) F09's is possible but might run out of lever travel.  Lots of ways to improve upon the original "rock hard" setup.

[swooshdave]

About to ask the same thing - love the handlebars (kinda look like the ones which were on my Ballabio) - where did you get the mirrors and how do they work for you?
Lee

KAWELL® Universal Round Bar End Convex Mirrors For Inceased Vision For 7/8" Handle Bars Fits Most Harley Davidsons, Suzuki, Honda, Kawasaki Cruisers, Touring Bikes, Sport Bike, Cafe Racers, Electric Scooters side rear view mirrors motorcycle https://www.amazon.com/dp/B002GTKAHQ/ref=cm_sw_r_cp_tai_ggXXxbXZH8NGC

[swooshdave]

Possible combinations of calipers and masters, area ratios:
 
38mm F08/15mm master:  6.42 (original)
38mm F08/12mm master:  10.03
48mm F09/15mm master:  10.24
48mm F09/12mm master:  16.00
(2)F08's/15mm master:      12.84
(2)F08's/12mm master:      20.06

I suppose (2) F09's is possible but might run out of lever travel.  Lots of ways to improve upon the original "rock hard" setup.

http://www.vintagebrake.com/mastercylinder.htm

[Triple Jim]

The grips say DURY on them.

They say OURY on them.  http://www.ourygrips.com/

[rodekyll]

I've used that chart and thought it calls for smaller than optimal m/c bores by a half-size or more throughout -- I seem to prefer one-half to one mm larger for all the combinations I've tried.  I'm sure there's personal preference involved, but the OP's report of the handle coming almost to the bar is one of my gripes.  That gives me the inconfident feeling that I'm not going to get full brakes on the first stroke -- and sometimes if there's a slight bit of mushy in the lines, I don't.  Yes, you get 2-finger action.  Yes, you get a LOT of lever travel to modulate.  But if you reach the end of the stroke and still can't stop, what did all the good 'feel' do for you?

$0.02

[Mark Dasher]

I've used that chart and thought it calls for smaller than optimal m/c bores by a half-size or more throughout -- I seem to prefer one-half to one mm larger for all the combinations I've tried.  I'm sure there's personal preference involved, but the OP's report of the handle coming almost to the bar is one of my gripes.  That gives me the inconfident feeling that I'm not going to get full brakes on the first stroke -- and sometimes if there's a slight bit of mushy in the lines, I don't.  Yes, you get 2-finger action.  Yes, you get a LOT of lever travel to modulate.  But if you reach the end of the stroke and still can't stop, what did all the good 'feel' do for you?

$0.02

Yeah I agree there is some more lever travel, but careful bleeding took care of most of it.  I don't think I'm in danger of losing enough travel on my setup as there is about 1/2" left when fully applied.  Took a little while to get used to the new brake function...

[Mark Dasher]

About to ask the same thing - love the handlebars (kinda look like the ones which were on my Ballabio) - where did you get the mirrors and how do they work for you?
Lee

The handlebars are Emgo Superbike bend. I got them from one of the big online retailers (Bike Bandit, Revzilla or Motorcycle Superstore, I can't remember). They are just a tiny bit wider than the Euro bend bars they replaced.  They also have enough room for the new mc, switches and throttle/clutch assemblies.  Very comfortable! 

The bar end mirrors are el cheapo (Guzzi-like) eBay items (queue snapping suspenders). Think they are less than $20 pair and work well.

[swooshdave]

They say OURY on them.  http://www.ourygrips.com/

http://www.ourygrips.com/road-street-grips/

They sure do. Isn't that's what I said? 

Wife bought me reading glasses for my birthday. I refuse to use them. 

[swooshdave]

Yeah I agree there is some more lever travel, but careful bleeding took care of most of it.  I don't think I'm in danger of losing enough travel on my setup as there is about 1/2" left when fully applied.  Took a little while to get used to the new brake function...

I clamped the lever back last night and the travel is shorter. I can't get the lever to the bar now. I may still have a little air in the system.

That being said the brakes are now fantastic and I could probably get the rear tire in the air if I squeezed hard enough.

According to the chart it's at 20.06 which is a little lower than my Norton at 24.01. I'll take either one of those over the stock ratio at 12.84 (stock is 15mm, right?). For the single F08 I suspect an 11mm master would be ideal.