Cafe Racer Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
229 Posts
Discussion Starter #1
Hi All.
since i was not very happy with my XJ550R front brake capabilities, i have decided it is time to improve the entire front end.
i bought a new model Yamaha R6 front end including the triple tree, suspensions, clipons, master cylinder and calipers.
i would like to keep the original XJ550 wheel and i know i will probably have to make some bushings for it.

my question is - are there any floating rotor disks that will fit the XJ550's front wheel?
what is the bolt pattern to look for?
i saw that the wheel have rotor mounting holes on both sides, so dual disk brakes are in order.
what rotors should i look for in order to work with the R6 calipers? if i wont find the right radius, i can make an adapter to relocate the calipers.

any help and advice will be appreciated.
Thank you.
Raviv.
 

·
Registered
Joined
·
1,537 Posts
YOu will, likely have to make adapter plates to mount the rotors to the wheels to space the rotors out, since the forks will be wider than the original. If I were doing this exercise, I would use the R6 rotors for the front end you plan to use. That will avoid needing to space the calipers out to a different radius. The R6 wheel is probably wider than the XJ hub where the rotor would mount, so here's how I would go about finding my starting point for my spacers:
1. Figure out my axle, first. I am sure the XJ axle is smaller than the R6, so where the axle enters the wheel will need to be smaller than where it clamps to the forks. This makes my head hurt, and I will let you figure that out by yourself..;) You have the machining expertise to do that, I am sure.
2. Assemble the front end, calipers plumbed and bled, with the rotors unbolted to the wheel.
3. Insert the rotors between the brake pads where they would ride, if they were connected to the wheel.
4. Squeeze the brake lever and use a zip tie to lock it down.
5. Now you can measure the offset to the hub on each side...hopefully they will be the same. They should be, I would think. This gives you the thickness that the spacers need to be.
6. You will need to figure out the bolt pattern to mount the spacer to the hub, and drill and counter bore the holes to accept bolts that will be flush when mounted.
7. Another bolt pattern of drilled and tapped holes needs to be made to bolt the rotors to the spacer

That's just how I would do it. Someone else may have a different method.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #3
Hi 8Ball , these are some good suggestions.
i wonder what route should i take -
1. use the XJ550 rotors (EBC have a floating ones for it), these will bolt on directly into the wheel, and then move the calipers (inwards at both axis) to accept these rotors.
2. use the R6 rotors, and manufacture an adapter that will bolt into the wheel (with the XJ bolt pattern), and will have the proper offset and outward bolt pattern to accept the R6 rotors and placing them inside the calipers. (generally - 8Ball great suggestion)
i wonder what will be the more efficient and correct way to go, looking at parameters like unsprung weight, durability and safety.

unfortunately, using the R6 wheel is not an option since the bike is licensed with a 19" front wheel, and the R6 is 17" ... i will not be able to pass the needed DMV test.

did anyone made a similar conversion? would sure love to see some pics or information.
now i need to decide if i buy a set of XJ550 rotors or R6 rotors...
 

·
Registered
Joined
·
1,537 Posts
What version R6 front end did you acquire? The 1st and 2nd generations had conventional forks and the way the calipers bolted on, would allow you to fab a plate that could relocate the position radially, and move them inboard. The 3rd generation (and the 2005) models, with inverted forks, have radial mounted calipers, that can easily adjust for a larger disc, but not so easily moved inboard, and not for a smaller diameter disc.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #5
it is the 3rd generation R6 front end (inverted).
the R6 front rotors are 310mm, the XJs are 298mm.
do you think or know if i can get a 310mm rotors with the XJ's bolt pattern ?

R6Frontend.jpg
 

·
Registered
Joined
·
1,537 Posts
No idea. I think that would require reaching out to someone like EBC, directly.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #7
already done that, haven't heard from them yet... will probably give them a call tomorrow..
thanks a lot for the great suggestions
 

·
Registered
Joined
·
5,780 Posts
I think the FZR600 discs may work. I will be able to check in the next couple of weeks when I get back to my bikes. I have an XJ wheel and FZR discs sitting around somewhere in the garage.

I think somewhere on this site:
The FZR Forum (Powered by Invision Power Board)

or this site:
? Index page

There is a listing of Yamaha compatible discs.

I am too busy to look for it right now.

I also believe that you can get the right wheel bearings with the OD to match the XJ wheel and the right ID to match the R6 axle. The R-6 bearing may fit the XJ wheel. I have done that on most of my front end wheel swaps.

Ken
 

·
Registered
Joined
·
290 Posts
Maybe this is too late, but the bigger Seca front end would have worked. My XJ550R had dual-disc, but I got it that way so I don't have all of the details on how they got it to go. The fork bottom doesn't normally have a mounting boss for the caliper so I would guess that they took the forks, too.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #10 (Edited)
kenessex,
you are the man, thank you for the information... if you can look around your shop and provide some insights based on experience, it will be fantastic!
will look into the FZR rotors.

dielectric,
my SECA came with a single rotor, but are some additional caliper mounting holes on the other leg...
the wheel have rotors mounting holes on both sides, currently there is a plastic cover on the side that is not in use , i need to take it off and have a look.
The R6 front is on its way, and i am set on using it... i know it wont be as simple as bolt on, but this is what its all about.

meanwhile, i got some information from EBC, which were great...
ebc.JPG
 

·
Registered
Joined
·
6,587 Posts
Can I just ask why you are wanting to run the 550 wheel instead of an R6? Seems like a lot of hassle to take a bit of a backwards step.
 

·
Registered
Joined
·
1,537 Posts
Can I just ask why you are wanting to run the 550 wheel instead of an R6? Seems like a lot of hassle to take a bit of a backwards step.
He answered that earlier:

.....unfortunately, using the R6 wheel is not an option since the bike is licensed with a 19" front wheel, and the R6 is 17" ... i will not be able to pass the needed DMV test....

Remember, he is in a country that has very specific rules for vehicle registration. That discussion was part of what he could and couldn't do to his KZ.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #15
hillsy, 8ball.
Thanks, that is right, The Israeli DMV rules are pretty strict, as a general rule, we are unable to change anything on our own vehicles (ridiculous, i know)...
one of the most highlighted things is the wheels and tires size, as these sizes are written on the vehicle's license (similar to a "title")... in case that the dimensions doesn't line up, the vehicle will not pass the DMV test and will not be approved for the road.
beside it being illegal to drive an uncertified vehicle on public roads, a more important aspect is the lack of insurance... you can actually find yourself behind bars in case of a serious accident... not to mention the lack of medical bills coverage.
so, i try to stay in reasonable area, where i keep the wheels size but change the suspensions, i will be able to pass the DMV test and insure the bike.

meanwhile, will continue looking for some information, and any idea is much welcomed.
once i get the front end, i will start measuring and fitting it with new steering bearings, and look for the best way to fit the rotors (not sure which ones to go with).

Brad,
Thanks for the info, it sure helps.
 

·
Registered
Joined
·
229 Posts
Discussion Starter #16 (Edited)
So, i need an advice on how you think would be the best way yo proceed, here are the options -

1. option number one is buying the R6 rotors, and machine an adapter plate that will bolt onto the XJ550 wheel and on it will bolt the R6 rotors, the adapter thickness will be determine according to the needed offset, what material should i use?
the main concern is the added unsprung weight, there will be two of these, made of iron (or should i use aluminum?), it will be rather hefty, below you can see a solidworks model i designed based on the XJ660 and R6 rotors.

brakeadaptor.jpg


2. second option is buying a 320mm disk with the correct bolt pattern for the XJ550 wheel, my question - will the Yamaha R6 caliper position will accept a 320mm disk? the original is 310mm ...
i will need to make a simple adapter that will move the rotors outwards (offset) so they will fit the R6 calipers position...

img1-10986.jpg

Any help and idea will be much appreciated.
pictures of similar things would also help alot.

Edit -
Hy 8ball, you mentioned something about the ability to adjust the R6 calipers to accept a larger diameter rotors, can you elaborate on that ?
Thank man.
 

·
Registered
Joined
·
5,780 Posts
If the calipers are radial then you only need 5mm spacers to move the caliper out to use the 320mm discs. If they are non radials then you need to make plates that will allow you to move the caliper radially 5mm. If you choose to make adapters to use the stock R6 discs, make them out of aluminum, steel is unnecessary.

Does the Israeli DMV really know what the oem front wheel width and diameter is for every 30 year old bike? Can't you just show them that they com with 17" front and rear?
 

·
Registered
Joined
·
1,537 Posts
What Kenessex said. However, with the 320 mm rotors, you will likely still need to make an adapter for the hub to get the offset....but it would only need one set of holes, and they wouldn't need to be threaded.

With either hub spacer, I would use AL, not steel. The rotor carriers are AL, as is the wheel. No reason to use steel, but I would use something like 6160
 

·
Registered
Joined
·
229 Posts
Discussion Starter #19 (Edited)
The DMV doens't know nothing, just a bunch of overpaid people with too much power.
the thing is, the Israeli law doesn't allow the owner of the vehicle to change anything, especially the tire size... so in order to do that, they written down the tire size on the vehicle's license (title), so when you go to the annual exam, the tester checks if your tire size is as written in the title.
that been said, i checked again and my title only states the rear tire size, the place where it should say what is the front size, is empty... this is actually very good, since now i can actually go with a 17" wheel (R6).
i know, the entire thing is just ridiculous...

on the other hand, the XJ550 wheels are rather nice, and it would be great if i could keep them (especially the front) as at looks better then the ordinary R6 front wheel... correct me if i am wrong.
wouldn't it be better to stay with the 19" wheel? wouldn't the 17" will look too small, almost like a supermoto bike?

As for the brakes, they are radial, getting a 5mm spacer shouldn't be a major problem.
$_57.JPG
 

·
Registered
Joined
·
5,780 Posts
2012-06-08 09.24.58.jpg

Here is my XJ550 with 17" wheels on both ends. I will look for a better picture of the front, but I think it looks balanced. Maybe the answer is to run R-6 wheels except when you take it to the annual inspection. I think the original 550 wheels are ok looking but they are narrow. They are a WM2 front and WM3 rear as I recall. You would be stuck with a 110 or 120 rear and a 90 or 100 front width the swingarm will easily handle a 150 - 17 rear, that is what I use, or possibly a 160 rear.
 
1 - 20 of 29 Posts
Top