Upgrade to dual front disks from XS1100

JVM650 · Full Member Joined: Jun 23, 2008 Posts: 19

I am installing dual slotted disks and calipers from a XS1100 do I need to upgrade my master cylinder and if so what would be the best size bore to use. I like to canyon carve. Any thoughts on this. Size of bore to feel of brakes and the control of breaking.

Thanks

yamaman · Last edited by yamaman on January 30, 2009, 5:27 pm; edited 1 time in total

I'm not sure on the size, but I'd imagine a XS 1100 master cyl would be up for it!
Ratio is the key, are the 1100's twin spot's? What diameter are the pistons?

Valuable info here from MMM:

www.vintagebrake.com/m...linder.htm

wally

Hi

I have the two 1100 discs on my 1982 Special using a master duel cylinder from micks works fine.

XSjohn has them too but only uses one disc

yamaman

eye Wally, but which callipers do you got? Or are the 1100/650 callipers the same?

xsjohn

yamaman
.........XS1100's slotted fronts.are the same as XS650 fronts.....and XS750-850 slotted fronts are the same as XS650 rear..........

Just one slotted on the front of mine....slotted in back.........if I used a decent brake line it would be more than plenty.......duals up front might be overkill for my skinny ass......

xsjohn

wally

My Callipers are standard XS650 special, they work fine

xsjohn

Think the XS1100 calipers were also the same as later 650's..............same with the master cylinder........

xsjohn

Shannon60

I do have to ask why do this conversion, I mean I have on my 81 a stock caliper, disc, and master with a braided line, and the lever feels great and I can skid a pretty sticky tire with surprisingly little effort.

oldskoolcool · Full Member Joined: Sep 08, 2007 Posts: 372

my front brake is terrible on my XS. I bought a new caliper and new pads...maybe try and get EBC pads, new rotor and braided lines i guess.

kingwj

I believe the XS1100 uses a 17mm mastercylinder and the XS650 a 14mm. I have dual discs and use the 650 mastercylinder. Maybe the best thing you can do to upgrade the brakes is new lines. The originals get spongy after 30 years.

xsjohn

Put the slotted front and rear on mine to mainly get rid of the squeel while hoping for better brakes.......that did both...........will put good lines on it front and rear like I should....

xsjohn

xsleo

some of the 1100 calipers are the same as the 650 uses. the specials are different. on my 75, i put the 1100 slotted rotors and have the forks from a 79 650 too use the later style calipers. i have the m/c off an 82 seca. the stock 75 m/c works ok too. they are both the same size. marked 5/8 on the inside where the m/c mounts to the handle bar. 5/8 inch = 16 mm. the 75 used the old style calipers with two pistons in the caliper. the new style use one piston in each caliper. i figured that two - one piston calipers will = one - two piston caliper. i will also upgrade the lines before too long. i also swapped over to a disc brake on the back, with a slotted rotor.

blue900

I have been thinking the dual disks would help the bike stop better by keeping wheel from flexing to the right when braking with just one. 2 should help the wheel stay strait Right?
I feel the forks are flexy they seen especially bad on RR track Crossings.
I want dual disks and a fork brace.

JVM650 · Full Member Joined: Jun 23, 2008 Posts: 19

My 81 has a single disk and it stops, but not as good as I hoped. I switched to the 1100 twin slotted disks (they are the same size as the 650) but they are slotted for better cooling and I think that two looks better and will give me a more touchy brake. Which is what I want. Just wondering if any of you know which master to use and the bore size.

gggGary · Full Member Joined: Jan 07, 2009 Posts: 114

Anyone come up with a better deal than mikes on SS braided lines?
I have yet to have a single disk bike that gave the stopping power I want. I like two finger stoppies may not get that on an XS but it's what I like.
gggGary

jetmechmarty

I have a XS1100. It doesn't stop any too well. It outweighs my 650 by over 100 lbs, but I think my 650 stops better with its single disc. I don't think the second disc and caliper is the way to go considering the extra unsprung weight. Contact Michael "Mercury" Morris at 650 Central. He can make your bike stop!

yamaman

JVM650 wrote:

My 81 has a single disk and it stops, but not as good as I hoped. I switched to the 1100 twin slotted disks (they are the same size as the 650) but they are slotted for better cooling and I think that two looks better and will give me a more touchy brake. Which is what I want. Just wondering if any of you know which master to use and the bore size.

Did you check the link I put up for you earlier? You just need to know your calliper diameter and number of active pistons, the chart will tell you what is the ideal master cyl size
The early XS callipers were the best as they are 48mm twin piston and cast iron bodies, the later ones were 40mm alloy bodys and only 1 piston. Only thing is that you have to revert to the 34mm forks for the old callipers to fit!
I run twin old styles with a 5/8ths master cyl (according to MMM's page should be a 19mm master) and it stops awesome, I do want to take one off for a trial, because I think the weight saving might be worth the reduced (though I bet not much) braking. If I do that, I would need a 13mm master cylinder.
So until you are sure what diameter callipers you want and how many of them as well as how many pistons they have, then you cant pick your master cyl!

thorshammer · Full Member Joined: Dec 12, 2008 Posts: 58

I'm in the process of refreshing a tx 750 front end to put on my 76, it came with dual discs that I'm drilling for better performance. I also have a fork brace and changing over to roller bearings. In my case this was the cheapest fix.

What Happened to 650rider.com?

Yamaha xs650