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Discussion Starter #1
Hello All, can someone let me know if it is possible to swap the 260mm front discs on my vulcan for 320mm discs? I know this will impact the calipers et al but I would like to know if 320mm discs from another kawasaki match the same bolt pattern as the vulcan's?

Grateful for any advice.

Mike in the Channel Islands, not in California but near France!
 

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Not sure about the bolt pattern, my gut says no.

The real question is ...Why? As in why would you want bigger discs? The two front discs on the bike can provide all the stopping power you'd ever need. Installing braided lines and ceramic pads should provide overkill brakes for this bike.
 

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IMO, the stock brakes are overkill for this bike. 40,000 miles ago, I completely removed the right disc, caliper, and hose. The left brake is completely stock. Bike stops just fine, wheel can be locked up at will, much easier to modulate, and surprisingly, even to me, the left brake is not wearing any faster than it did with both discs. I know this because I put 80,000 miles on another Vulcan 750 with dual discs. Wish I had known then what I know now.
 

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Not sure about the bolt pattern, my gut says no.

The real question is ...Why? As in why would you want bigger discs? The two front discs on the bike can provide all the stopping power you'd ever need. Installing braided lines and ceramic pads should provide overkill brakes for this bike.
I am going to go out on a limb here and guess he is wanting a set of those scalloped around the O.D. rotors like Kaws late model sport bikes,more for looks than stopping power or his may be worn and he has found some this size for cheap,...just guessing though :confused:
 

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Discussion Starter #5
My reasons for needing 320mm discs

Hi guys,

I realise that the current 260mm twin disc set up provides adequate braking but I am installing USD front forks on the bike as it is a bobber project. Installing bigger discs is not a question of increasing braking power for me it is more about the controllability of applying the brakes.

Kind regards

Mike
 

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Hi guys,

I realise that the current 260mm twin disc set up provides adequate braking but I am installing USD front forks on the bike as it is a bobber project. Installing bigger discs is not a question of increasing braking power for me it is more about the controllability of applying the brakes.

Kind regards

Mike
Well, according to Jerry, he got more "control" by removing one of the discs. Apparently having less stopping power is what makes your brakes "more controllable" .......

I always just figured it was skill......;)
 

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The way I see it, the Vulcan was simply overbraked. Many much larger heavier bikes have only one front disc, and do just fine. In this case, having less actual braking power DID make the brake easier to control. People don't seem to realize you actually CAN have to much of something. IMO, if you can easily lock the front wheel, then you have plenty of braking power, because there is nowhere else to go. Locking the wheel is overbraking, and if it can be done easily with one disc, then why do you need two? With two discs, the brake was basically on or off. Yes, it could be modulated to some degree, and during normal routine riding was merely annoying. However, in a panic stop, when you want the front wheel right on the verge of lockup, and often have a number of other things to deal with at the same time, putting just the slightest bit of excess pressure on the lever would lock the front wheel, and we all know what happens when you do that. With only one disc, overall braking feel and control is much improved, and there is still more than enough power to lock the front wheel, but you are not nearly as likely to do it accidentally.

Braking IS a matter of skill. At least to me. It no longer requires skill for those who have ABS, just squeeze the lever hard, and let the computer make the decisions. I have ridden bikes that had very little in the way of brakes. I learned how to use what I had, there was no known way to make them stronger. But on the Vulcan 750, Kawasaki made the brakes so touchy that the slightest pressure on the lever would cause the brakes to grab, and could result in an accidental stoppie. Now, if all you had to do while riding was focus on the front brake, they would work fine. But with the hundreds of other things that have to be dealt with, having brakes that require too much attention are dangerous.

I would like to point out that I have never in 35+ years and 400,000+ miles, I have never crashed on a street bike. I would also like to point out that I have 40,000+ miles on this mod, without the slightest problem. The way I see it, I simply fixed one of the Vulcan's shortcomings.
 

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Well. I don't see the Vulcans duel discs as a " "shortcoming"... But agree they are over kill on a 500 lb cruiser. Perhaps my stint as a roadracer has muddled my view on the "beyond needed" front brake system concept.... But in my book there is no such thing as "too much brake." Humans are supposed to be able to adapt and compensate for variances found in mechanical controls. If you find the lever "touchy" you are supposed to learn to compensate.

Spend some time on a bike that actually has more aggressive brakes and you'll find the Vulcans severely lacking.

I'm sorry to say Jerry's view of ABS on current bikes outdated and symplistic. They are pretty much transparent and ONLY keep the wheel from locking up and that is a good thing. In half a dozen close calls the vastly superior brakes on my FJR have done the job without me ever reaching the point of having the ABS kick in.

I have read some real life testimonials praising the ABS system when it did intervene ... Too many tests have shown that even the best expert rider on a non ABS bike will post longer stopping distances than an average rider with ABS on slick roads. On clean dry pristine roads the "expert" tends to win....but where does one find pristine roads?

The idea however of putting even larger brakes on the Vulcan does sound a bit silly. Keep in mind my suggestion to go with braided lines and ceramic pads first is still in my my view the only needed change.

Hhe rear brake on the other hand can really use some help.....
 

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romeobravo172
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Did they ever put a rear brake on the 750?
 

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If only it had 6th gear..
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Do you mean a disc brake on the rear instead of the drum that they all have? No. It's been mentioned here but it's another one of those "not worth it" mods on these bikes. Again, the shaft drive pretty much dictates what you can do to the arse end of these scoots. Since most braking is done (or should be) with the front brake, the really old school rear brake was never a concern for me. Almost never use it. If you romp the pedal however, she'll lock up and give you a fishtail.

I was thinkin about an old mechanic buddy I used to hang with. Excellent wrench and hated anything computerized. So did I then but honestly, I can't ignore the safety and performance improvements that have come along. My Maxima's v6 has so much bawls and top end that it easily rivals a few of the V8's I've tweaked in the past and it's reliable and better on gas, whereas v6's back then were not as powerful, even one I suped with some edelbrock goodies. My point is, although many things are made cheaper and cheaper as the throw away society increases, I've warmed up to some of the advancements that have come along and the newer ABS systems are included among them. Sorry to :blah:
 

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romeobravo172
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No not disk---any at all is what I was saying on the rear!!! First thing I noticed with my 04,928 miles when I purchased it in 7/11 was rear brake was like pushing your foot in a bowl of oatmeal, was not much there! Had that cked real quick, no problem, learned to compensate with both.
 

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Hmm, sounds like something wasn't right then. Maybe some grease got on the drum or the shoe or something. Did they pull it apart when you told them or just tell ya that's the way it is, because the rear brake is not weak. Like I said you can lock it up if you wanted to.
 

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No not disk---any at all is what I was saying on the rear!!! First thing I noticed with my 04,928 miles when I purchased it in 7/11 was rear brake was like pushing your foot in a bowl of oatmeal, was not much there! Had that cked real quick, no problem, learned to compensate with both.
Mine was like mush too,The shoes were well within wear limits and every thing was in spec,I suspect there is a big difference in the compound of the brake lining on the shoes,If you didn't buy the bike new there is no telling what type you have.
I have figured out this much,organic pads suck,I have had better luck out of ebc sintered medal pads,but I may try a set of the ceramic pads to see if they truly are virtually dust free,
You also heed to measure the I.D. of the brake drum too
 

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Sorry, but off the floor the vulcans rear brake sucks. I bought my bike new, and finally after 5500 miles did it break in and actually work well.

This has been documented by almost every owner, the rear works better the more miles you put on it.

The reason is i believe is the design of the brake itself. As only one end of the brake shoe pivots, it just takes time for it to enlarge it's contact area by simply wearing down some.

How much you use the brake will also determine when this happens. If younever use it , it will never break in.
 

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The Vulcan's rear brake will lock the rear wheel easily, if it is functioning properly. If the front wheel is on the verge of lockup, engine braking alone can lock up the rear wheel, due to forward weight transfer. But without touching the front brake, ride in a straight line and step on the rear brake hard, the wheel will indeed lock up.

I am not and never have been a roadracer, but I did race MX back when I was a lot younger, and never on a bike with a disc brake. I never had a problem stopping or slowing down, in fact I crashed a couple of time because the wheels locked up in loose dirt when I applied the brakes. I still don't believe dirt bikes need or should even have disc brakes, because their braking ability is strictly limited by traction, or lack of it, not how much power the brake has.

Locking the wheels, at least on the street, is not a good thing. If your brakes will lock the wheels, you have enough brakes. I have ridden bikes where you couldn't lock the wheels. Everybody complained about those bikes not having enough brakes, and I would have to agree, but not by a whole lot. Soon, brakes became much more powerful, and it became a simple matter to lock the wheels. Now people were crashing not because their brakes were not powerful enough to prevent them from hitting something, but because the brakes had so much power people were crashing because they accidentally locked up the brakes, and went down before they ever reached whatever they were braking for. So, because of these powerful and difficult to control brakes, something had to be done to prevent them from locking up. ABS was the answer. IMO, the answer to a problem that engineers created by designing brakes that had way to much power for the bike, and brake controls that had no "modulation zone", or space between where the brake first starts to apply, and full lockup. I found the Vulcan front brake to have this problem, and fixed it. I have not noticed any problem with the rear brake, it is very linear and easy to control. A little pressure on the pedal, and you get a little braking. A lot of pressure on the pedal, and you get a lot of braking, to the point of lockup. I believe this is how brakes should work, and it is in fact how both the front and rear brakes on my Vulcan now work. Easily controllable, but still with plenty of power. And no electronics needed.
 

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I'd have to ask you Jerry, how many of your VN750s had less than 3000 miles on them when you got them?

Once the rear brake wears in, its OK. Not great, but OK for the bike. Many Vulcans now are at least 5 years old....most are older, and it is likely hard to find one with less than 5000 miles on it. Romeo's bike has under 5k and I totally believe his statement "what rear brake" ?

If you ride HARD... The front system works fine. if you ride your cruiser like...well, a cruiser.... I can see that many might have problems with the front brake. Brakes heat up, fade, and can seemingly feel different if you ride your bike like you just stole it.:)

Again it's still being able to adapt to the system, which from what I have read here , is difficult for many riders.

ABS is NOT something they came up with to solve the issue of "too powerfull brakes" . It is a system that removes human error.... Which without years of training on wet roads , is a problem with even advanced riders. They simply don't spend that much riding hours dealing with low friction surfaces.

Talk is cheap here. Ride your street bike accross a wet lawn and try to stop fast. Don't matter how many years you been riding... The newbie on the ABS bike will still stop sooner. Making bikes safer FOR EVERY RIDER is to me much more important than building a bike to suit one rider.

What did Spock say again? The needs of the many....?
 

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Ok that makes sense about the sucky braking when new. See, I got mine when it had about 11k on it. When a drum brake is new, the curvature of the shoe and un "worn in" surfaces prevent maximum contact and friction. Happens with autos too. I wasn't taking into account the newness if the Romeo's bike so I stand corrected. I use my rear brake enough to keep it working well but definitely the front gets most attention.

Also just reread Knifenaker's post (I sometimes skim over stuff too fast) about the design of the brake and completely agree about only one pivot point taking longer... much longer to wear in the shoe properly.
 

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Jerry I get where you're coming from to a point regarding electronics, but even when you have a well adjusted maintained braking system and good modulation with it, if you were to hit ice, wet leaves, a fluid spill or something like that, even the best un-aided system can lock up, and with most people, me included as I've done it myself, the instinct is to slam the brake and worse to hold it, causing more problems. In a car you can unlock yourself and feather the pedal to regain control hopefully in time, but with a bike... you're probably on your side sliding before that happens. I think I'm a pretty decent rider but I also know that mistakes and fatigue happen. If a computer chip, which can feather a brake faster than any human, could help on an occasion that I may have been "off my game" I just can't say that's a bad thing. I didn't like the early abs systems but now, I don't know they're there most of the time. Peace.
 

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romeobravo172
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As always still learning a lot here,makes sense that my rear is not that great as I just passed the 2k mark, will keep an eye as more miles pass!
 

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As always still learning a lot here,makes sense that my rear is not that great as I just passed the 2k mark, will keep an eye as more miles pass!
Yep, just make sure you get in the habit of using it. EVEN if the front brake provides 80% of your braking, that still means the rear gives you 20%.

Put those figures in feet, and its easy to see that 20% can save your life.
 
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