-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
xskid
xskid
Its funny, all the different opinions... guess i have to try dual disc's and and develop my own opinion lol
Posted via Mobile
Posted via Mobile
voelser
XS650 Addict
Whoops! I seem to have sparked a bit of a debate!
It did actually point something out to me I had not thought about before: as I have the dual setup my discs are 267mm. So, if I convert to a single disc, will I have to get a larger disc or will a 267mm suffice? And if I do, does a larger disc actually fit? Logic tells me no, but I'm a novice anyway!
Discuss....in a friendly manner...haha
It did actually point something out to me I had not thought about before: as I have the dual setup my discs are 267mm. So, if I convert to a single disc, will I have to get a larger disc or will a 267mm suffice? And if I do, does a larger disc actually fit? Logic tells me no, but I'm a novice anyway!
Discuss....in a friendly manner...haha
hi guys ..... i appreciate the thoughts on trying to save weight.... it sounds good if it comes together well and still does everything you want it tooooooooooooo do ... having said that a while ago a kind gentleman in new zealand sent me some working easy to read drawings to ley out solid front discs and drill them out to a pattern.... unfortunately i have forgotten his name ,,,but he was a member of the xs650 clan ,,, and the weight saved drilling out your disc saved alot of origional weight and you retained the twin disc set up .... it could be worth asking who he was ,,,,after all new zealand not a huge country .... and they are easy to talk to .. regards oldbiker
You'd better measure the diameter of your discs to be sure. I think the factory dual disc set-up that used the smaller discs also mounted the calipers lower (closer to the axle) on the fork legs. If you wanted to switch to the larger single disc, you might need a different fork leg as well.
weaselbeak
XS650 Junkie
I adapted an entire XS750 front fork set for that very reason. Smaller discs take a lower mounting of the calipers. It would be easier to just use 2 larger discs, maybe drill them for the weight gain problem.
The larger disk will mount but the caliper mounts are lower on the fork so the disk will be to large for the caliper. Don't see why a bracket cant be made to suit an after market Bremco caliper though
a couple of brochures showing the difference between where the Euro caliper mount for the smaller disk is lower on the fork.
First brochure, (pic), showing the Euro small, twin rotor, lower caliper mount point, on the forks. Second is the US larger rotor and higher caliper mount point on the front fork.
a couple of brochures showing the difference between where the Euro caliper mount for the smaller disk is lower on the fork.
First brochure, (pic), showing the Euro small, twin rotor, lower caliper mount point, on the forks. Second is the US larger rotor and higher caliper mount point on the front fork.
Attachments
xskid
xskid
Hugh's got a printable pattern for it on his website.
Posted via Mobile
Posted via Mobile
xskid
xskid
Its on his website, in the 650 tech section, looks pretty cool too. Im not sure if its in his blog. Oh and yea there's only one pattern, that i've found so far.
Posted via Mobile
Posted via Mobile
I did not find it on Hughs site but did find the one with the choice of holes.
http://www.xs650.com/forum/showthread.php?t=12671
http://www.xs650.com/forum/showthread.php?t=12671
The Larger XS's like the 750, 850 1100 had dual disc brakes. The standard models used the 11.7 inch, 298 mm rotors, They used a conventional front fork. The Specials used the leading axle forks and used the 10.5 inch, 267 mm rotors.
The standards used the same calipers as the XS650, the specials used a different caliper.
Some of the XJ bikes used the same bolt pattern rotors. Some are 7 mm thick, some 5 mm thick. Some are solid, some slotted.
I have a set of 7 mm slotted rotors on the 81, the 75 has 5 mm slotted rotors. I don't notice much difference in handling I can say is from the brakes. The 81 has stock forks. The 75 has Minton modded forks with Harley springs. These effect the handling as much as the brakes.
Shop around for Yamaha rotors on Ebay. Ask about diameters and thicknesses.
Leo
The standards used the same calipers as the XS650, the specials used a different caliper.
Some of the XJ bikes used the same bolt pattern rotors. Some are 7 mm thick, some 5 mm thick. Some are solid, some slotted.
I have a set of 7 mm slotted rotors on the 81, the 75 has 5 mm slotted rotors. I don't notice much difference in handling I can say is from the brakes. The 81 has stock forks. The 75 has Minton modded forks with Harley springs. These effect the handling as much as the brakes.
Shop around for Yamaha rotors on Ebay. Ask about diameters and thicknesses.
Leo
Tomterrific
XS650 Junkie
Tips on brake drilling.
The last disk I drilled was for the rear brakes on my autocross Miata. The first was for my 1971 Norton with the production racing disk set-up (in the winter of 1973!!!). I went about the pattern the same way. I measured the outer diameter of the rotor and used a compass to draw the pattern on paper. I used free paper from my local home center store (Lowes). Big rolls of free paper are at the exit, just tear off a sheet.
Start with the rotor face and draw the inside and outside with the compass. You will have a dot in the exact center. Use a cheap plastic protractor to draw lines through the middle of the rotor face in equal degrees. Say, 18 points at 20 degrees each or 36 points at 10° or 72 at 5°. You are going to play with your very own pattern. Start from the outer edge and set the compass a fraction of an inch, say 1/4" or 3/8" and start scribing circles down the rotor face. Where these circles cross the lines radiating from the center are where you will drill the holes. Blacken in the drill points the diameter of the bit to see what it looks like. You may find every other point is a better pattern. Cut the pattern and glue to the rotor face. I did a couple of patterns while watching TV with the wife and kids. Better the family see me do this rather than farting and drinking beer in my underware (which is what I usually do).
I used to center punch the rotor where I wanted a hole but the last time was more professional. My drill press has a table that rotates when a clamp is loosened. I clamped the rotor to the table but first I used the bit on the edge of the rotor to get it centered. I then drilled a circle of holes following the pattern by spinning the table to the next hole, then I would loosen the arm and bump the table to the next round of holes. By using the table as a rotary table I was able to keep the drilling balanced from the center.
On your initial pattern you could try drawing archs across the radial lines or a V pattern. It's paper so you can be creative with your pattern before the rotor is ruined. {8^p
Tom
The last disk I drilled was for the rear brakes on my autocross Miata. The first was for my 1971 Norton with the production racing disk set-up (in the winter of 1973!!!). I went about the pattern the same way. I measured the outer diameter of the rotor and used a compass to draw the pattern on paper. I used free paper from my local home center store (Lowes). Big rolls of free paper are at the exit, just tear off a sheet.
Start with the rotor face and draw the inside and outside with the compass. You will have a dot in the exact center. Use a cheap plastic protractor to draw lines through the middle of the rotor face in equal degrees. Say, 18 points at 20 degrees each or 36 points at 10° or 72 at 5°. You are going to play with your very own pattern. Start from the outer edge and set the compass a fraction of an inch, say 1/4" or 3/8" and start scribing circles down the rotor face. Where these circles cross the lines radiating from the center are where you will drill the holes. Blacken in the drill points the diameter of the bit to see what it looks like. You may find every other point is a better pattern. Cut the pattern and glue to the rotor face. I did a couple of patterns while watching TV with the wife and kids. Better the family see me do this rather than farting and drinking beer in my underware (which is what I usually do).
I used to center punch the rotor where I wanted a hole but the last time was more professional. My drill press has a table that rotates when a clamp is loosened. I clamped the rotor to the table but first I used the bit on the edge of the rotor to get it centered. I then drilled a circle of holes following the pattern by spinning the table to the next hole, then I would loosen the arm and bump the table to the next round of holes. By using the table as a rotary table I was able to keep the drilling balanced from the center.
On your initial pattern you could try drawing archs across the radial lines or a V pattern. It's paper so you can be creative with your pattern before the rotor is ruined. {8^p
Tom
Jeeter
XS650 Addict
I've been goofing around with front end component weights and such. For instance a stock Yamaha 2001 R6 caliper weighs 2 pounds 3.6 ounces, and the stock rotor fromt the same bike weighs in right at 3 pounds +. So just removing the caliper and rotor pulls five pounds from the front end, all of which is unsprung weight. After you include all of the rest of the changes (single vs double brake lines, the extra rotor bolts, the extra caliper bolts, the added brake fluid, and so on) it comes out to roughly six pounds removed from the front end, with at least five of those six pounds being unsprung.
I think I've come to learn that if you can afford to upgrade only one part of your braking system, it should be the master cylinder. That said, if you want to upgrade your brakes with the least spent ....
** upgrade to a Beringer master cylinder.
** perhaps an EBC rotor of the most suitable compound.
** the most suitable brake pads (there's bazoodles of them out there, ask someone other than myself which type is "best").
** stainless brake lines (Speigler, others.)
** go to the single disk setup and save six pounds (as well as saving quite a boatload by buying half as many of the components since it is s single rotor system).
As was mentioned, a single rotor setup put together with some good modern stuffs will be leagues better than anything mass produced mid 1970s tech has to offer. Duals, singles, triples, everwhat.
I believe ... myself ... that one can put together a really strong front brake system with one decent two piston caliper (four piston preferred), the right rotor, a modern radial master cylinder, stainless lines, and well bought pads. But that's just me, and I may be totally wrong.
I think I've come to learn that if you can afford to upgrade only one part of your braking system, it should be the master cylinder. That said, if you want to upgrade your brakes with the least spent ....
** upgrade to a Beringer master cylinder.
** perhaps an EBC rotor of the most suitable compound.
** the most suitable brake pads (there's bazoodles of them out there, ask someone other than myself which type is "best").
** stainless brake lines (Speigler, others.)
** go to the single disk setup and save six pounds (as well as saving quite a boatload by buying half as many of the components since it is s single rotor system).
As was mentioned, a single rotor setup put together with some good modern stuffs will be leagues better than anything mass produced mid 1970s tech has to offer. Duals, singles, triples, everwhat.
I believe ... myself ... that one can put together a really strong front brake system with one decent two piston caliper (four piston preferred), the right rotor, a modern radial master cylinder, stainless lines, and well bought pads. But that's just me, and I may be totally wrong.
So the euro XS650 dual front disks are the same smaller size as an XS650 rear disk & the fronts on an XS750/850.
Well, you learn something new every day if you ain't careful.
I converted to twin disks years ago and decided to drill them.
(At that time I didn't know about the slotted XS11 disks)
First, the pattern is all in your mind, so long as the disk stays balanced and the holes sweep all of the pad face the brake don't care.
Vulgar patterns or rude words even, if that's what you fancy.
Now the drilling.
The XS disk material is as tough as old boots.
If you don't have a "bro with milling machine" you'll need a bench drill, starter size and finish size cobalt steel drill bits, and a big jug of cutting oil.
Mark out the hole pattern and make effin' great centerpunch marks for each hole.
Bench drill set to it's lowest speed, reef down hard on the feed lever and keep the cutting oil flowing.
Well, you learn something new every day if you ain't careful.
I converted to twin disks years ago and decided to drill them.
(At that time I didn't know about the slotted XS11 disks)
First, the pattern is all in your mind, so long as the disk stays balanced and the holes sweep all of the pad face the brake don't care.
Vulgar patterns or rude words even, if that's what you fancy.
Now the drilling.
The XS disk material is as tough as old boots.
If you don't have a "bro with milling machine" you'll need a bench drill, starter size and finish size cobalt steel drill bits, and a big jug of cutting oil.
Mark out the hole pattern and make effin' great centerpunch marks for each hole.
Bench drill set to it's lowest speed, reef down hard on the feed lever and keep the cutting oil flowing.
Jeeter
XS650 Addict
Additionally, (re:1 vs 2 disks) while a person may be able to "lock the front wheel with one disk" and a mighty mighty pull, the notion of being able or not being able to "lock up" the front wheel with a single disk is not even anywhere near the point.
Two disk setups provide a better response ... or "feedback curve" .. for the rider when riding near front wheel traction limits, aka "threshold braking". Sure, a single disk can lock up the front tire easily enough, but the difference between "wanting just a tiny bit more braking power" and eating major shit resides on this tiny itsy bitsy little sliver of a response curve.
Twin disk setups make that "touch and go" zone on the brake lever much longer, the graduations of braking force are sortof "reverse exponential" (not sure that's even a thing, I just kinda made that up). If anyone reading this is experienced with electronic components, the twin disk setup is sortof like a reverse log potentiometer ("reverse logarithmic" vs "log", or "logarithmic") where the most touchy portion of the pot's curve is at the end of the sweep, instead of at the beginning of the sweep or instead of being "linear" or having a straight line response). The closer the brake gets to it's locking point, the LESS sensitive it becomes. The response curve of the brakes actually becomes flatter, not steeper, towards hydraulic locking pressure (the point where the pads grab the rotors better than the tire grabs the road) and face meets asphalt.
With a single disk setup the brake lever is less forgiving, the point between braking and locking is touchier, more sensitive than dual disk systems. That hyper critical area of the response curve is much steeper, things happen much sooner with less time to react.
As well as the advantage of shedding heat far more efficiently, which is great for riding two-up with your not tiny significant other when coming down that mountain pass that you took all morning to climb and enjoy the ride. Speaking of under engineered brakes, I got into a spirited ride down the front side of Sunshine Pass (near Jacumba close to San Diego). A six thousand foot drop covered in about 45 minutes on two Harley FXRs (my dad and I, my wife on the back of my FXR). Well, long story made very short, the undersized (but cool looking! oh brother) dual disk front brakes of that HD were about worthless by the bottom of the run. My dad commented on a pass I made on him at about 105 mph while entering a left turn marked at 50mph. I didn't want to tell anyone that I had little choice in the matter since when I grabbed the front binders to check up going on that particular turn I had basically nothing but a handful of overheated brakes. The bike weighed 650 wet, add the passenger with her gear/helmet/leathers and that put the entire machine at about 850 pounds total less me. Wrestling with an 850 pound HD with hot brakes and a severely overheated sense of competition with my dad down that mountain was a ride I'll never forget (I haven't even bored the hell out of you with the part about how we caught a group of sporties on new Interceptors, those guys totally freaked out when we saw them later ... "you guys are on HARLEYS?!?!?" Heheh....) Anyhow, I just acted all macho, like I did it all on purpose (I'm sure no one here has ever done that before ... yea right!). Days of youth.....
So anyhow, that more forgiving braking curve is another thing going for the dual disk setup. Then again the single rotor system is, after all, at least five pounds lighter. Hmmm ... much to think about for someone stuck in this position.
Presently my choices are being dictated by money, or more accurately the lack of money. Used sportbike stuff is pretty cost effective sometimes. So for now until more of the dead presidents show up I'm kinda going with whatever stock stuff I can afford.
But man oh man can I bench race with the best of them!!!!
Two disk setups provide a better response ... or "feedback curve" .. for the rider when riding near front wheel traction limits, aka "threshold braking". Sure, a single disk can lock up the front tire easily enough, but the difference between "wanting just a tiny bit more braking power" and eating major shit resides on this tiny itsy bitsy little sliver of a response curve.
Twin disk setups make that "touch and go" zone on the brake lever much longer, the graduations of braking force are sortof "reverse exponential" (not sure that's even a thing, I just kinda made that up). If anyone reading this is experienced with electronic components, the twin disk setup is sortof like a reverse log potentiometer ("reverse logarithmic" vs "log", or "logarithmic") where the most touchy portion of the pot's curve is at the end of the sweep, instead of at the beginning of the sweep or instead of being "linear" or having a straight line response). The closer the brake gets to it's locking point, the LESS sensitive it becomes. The response curve of the brakes actually becomes flatter, not steeper, towards hydraulic locking pressure (the point where the pads grab the rotors better than the tire grabs the road) and face meets asphalt.
With a single disk setup the brake lever is less forgiving, the point between braking and locking is touchier, more sensitive than dual disk systems. That hyper critical area of the response curve is much steeper, things happen much sooner with less time to react.
As well as the advantage of shedding heat far more efficiently, which is great for riding two-up with your not tiny significant other when coming down that mountain pass that you took all morning to climb and enjoy the ride. Speaking of under engineered brakes, I got into a spirited ride down the front side of Sunshine Pass (near Jacumba close to San Diego). A six thousand foot drop covered in about 45 minutes on two Harley FXRs (my dad and I, my wife on the back of my FXR). Well, long story made very short, the undersized (but cool looking! oh brother) dual disk front brakes of that HD were about worthless by the bottom of the run. My dad commented on a pass I made on him at about 105 mph while entering a left turn marked at 50mph. I didn't want to tell anyone that I had little choice in the matter since when I grabbed the front binders to check up going on that particular turn I had basically nothing but a handful of overheated brakes. The bike weighed 650 wet, add the passenger with her gear/helmet/leathers and that put the entire machine at about 850 pounds total less me. Wrestling with an 850 pound HD with hot brakes and a severely overheated sense of competition with my dad down that mountain was a ride I'll never forget (I haven't even bored the hell out of you with the part about how we caught a group of sporties on new Interceptors, those guys totally freaked out when we saw them later ... "you guys are on HARLEYS?!?!?" Heheh....) Anyhow, I just acted all macho, like I did it all on purpose (I'm sure no one here has ever done that before ... yea right!). Days of youth.....
So anyhow, that more forgiving braking curve is another thing going for the dual disk setup. Then again the single rotor system is, after all, at least five pounds lighter. Hmmm ... much to think about for someone stuck in this position.
Presently my choices are being dictated by money, or more accurately the lack of money. Used sportbike stuff is pretty cost effective sometimes. So for now until more of the dead presidents show up I'm kinda going with whatever stock stuff I can afford.
But man oh man can I bench race with the best of them!!!!
Similar threads
