Hi guys, I'm ordering some new brake rotors. They are offering two options:

1.- 11.5" one piece rotors

2.- 12.5" two-piece rotors (floating)

Now my question is: can I fit either one of those with my stock calipers??? Is there enough room for the 12.5" ??? They say I could even fit a 13" w/o problems, is this true??? My ride is a '99 Fatboy (stock on the brake sytems).

Which ones would you get and why? The price is almost double for the 2-piece against the single piece ones.

Thank you for any info on this,

Mimo.

 

Mimo,
Hi guy looks like your not getting any answers. So I'll toss in my .02 cents.
Its my understanding that the stock rotors are 11.5 and if you want to go bigger you need to add an adaptor that moves the caliper out 1/2" for 12.5" rotors and 3/4" for a 13" rotor.
If your looking to get better brakes the bigger the rotor better, it gives the caliper move leverage, just look at a Buell sometime, and 2 piece rotors are better than one piece. They cool better/faster and because they are not solidly attached to the centers or hubs the braking surface of the rotor can move to stay in contact with the pads even if they are warped a bit.

 

I have seen you around for a while so here goes. There is no such thing as a 12 1/2" rotor. The one you may be referring to is 12.6" which is 320mm rotors. Yes you need an adapter. I am not sure on a 1999 fatboy but are they not two piston? I do know FL's so I will not try and trip over facts.

I do know that the 1999 & 2000 sliders are interchangeable as you have a Fatboy which has 41 mm forks. You may wish to dump the lowers and upgrade as brand new takeoffs are like $25/pair unchromed. You could upgrade the calipers cheaply as they require a 2000 & up caliper mount on a 2000~current lowers (sliders). Go to my site for the How-To to let yourself know what you are getting into. Look in the DIY section or under FL's, they are the same forks.

It would be counterproductive using 1999 calipers IMO when you can buy better calipers cheaply. If you still wish to buy a 320mm rotor go HERE and take a look of what is required. Look at the top and you can see the adaptor.

The next this is your wheel. If you wish to purchase an expensive oversized rotor think about what it can only fit. It can only fit a 3/4" axle non-sealed wheel which your rotor register is 2.00" and the sealed bearing 2000~current is 2.20". Hope I did help you and give you something to think about. If you ever change bikes to a newer year, you can always take the parts with you. Use organic pads and the rotors will last forever.

Forgot, the only way you can put anything more than a 11 1/2" (stock) is to use an adapter or change sliders and purchase a Brembo with a 300mm rotor. Youu also need to change wheels as the rotor register is 2.20" on all the new rotors using 300mm.

 

Thank both of you guys for steppin' in...

This is the deal, I'm putting on a new set of spoked wheels (50 spoke fat daddy's). In the rear the overall diameter of the rubber won't change because I'm increasing the wheel's diameter from 16" to 18" but reducing the tire's so it will stay the same.

The front is a different story. Yes my '99 has 11.5" stock rotors, since I'm putting a 21" wheel in the front, I believe an increased brake power would be needed. I'm considering either one of this:

1.- Putting on a 6 piston PM caliper with the 11.5" rotor, or

2.- Increase the diameter of the rotor to 13" and use a 4 piston caliper

Which one would you go for?

Mimo.

 

I would stick with the stock sized rotor for exactly the reasons FastHarley cited. There are too many what fits what issues to suit my taste once you start fooling around with the much larger than stock rotor sizes. Especially when you add aftermarket wheels into the mix.
Given the question of bigger caliper or rotor. I would opt for a direct replacement six piston progressive style caliper along with a good floating rotor. Its a combination that will improve the brake system with virtually no part size guessing.
If there is a drawback, its that neither option is going to be really cheap.

One thing that always makes me a little Leary of going to some of those really big rotors and big calipers is the possibility (however remote it may be) that you could actually put together a combination that's powerful enough to accidentally overpower the tires traction limits. I crashed my first bike by locking up the front wheel in a panic stop a long time ago that way and have NO wish to repeat that little disaster.

 

Very valuable information Sir Frank that is something certainly to consider. Thank you for taking tha time.

Mimo.

 

"Sir Frank"? You OBVIOUSLY have not been talking with my wife. Her names for me would be quite a bit less 'flattering'.

As for 'valuable information, that's questionable as it was "my opinion", and opinions are like butt holes, everyone has one and they all stink.

Don't sweat the time as a friend your worth it. (we need better smilies)

 

[QUOTE=Citoriplus;3991329]"Sir Frank"? You OBVIOUSLY have not been talking with my wife. Her names for me would be quite a bit less 'flattering'.

QUOTE]


LOL, Got it. Thaks anyway brother.

Mimo.

 

Mimo, I want to see those Fat daddy's on your bike when your done.They look Fackin Amazing !

 

Citoriplus, I for one need to say I can not stomach flattery or any other crap. I would hate to 100% agree with you on the 21” thing and loosing traction as I did that on my 1975 dual disk girder in 1975. The only thing that saved me was I had a set and the wheel held steady whereas with a single rotor your front tends to twist. As far as “I crashed my first bike by locking up the front wheel in a panic stop” is not a remote (see I am arguing here) possibility as it happened to me.

Mimo, as far as customizing your bike I could care less as not everyone has the same taste in motorcycles as I, no matter how foolhardy I may think they are. But than again I would loose my Ferrari red FXR in Wally Mart in a sea for red FXR's if the world was a perfect place. The end of the disclaimer.
You may wish to consider a few things before doing whatever you do anyhow as your heart is set. Please think about:

• Think about the added inertia you would receive when adding additional diameter to your front wheel.
• Think about the added weight of the fat spoke wheels you are adding to your bike. Google Newton’s 1st law of motion (It may be seen as a statement about inertia) than get an online calculator and figure out how much your weighs at speeds you will use. Your 20 pound (static weight) wheel and tire will weigh roughly 4 X that weight at 40mph. It gets heavier the faster you go and not in direct relationship with speed, it is logarithmic. The bigger the hoop the heavier it gets the faster you go.
• Think about the decreased sidewall and why we use to use 16” rear tires and spoke wheels with 25 lbs on hardtails. Some things do not change.

A few more points to consider that do not cost more:
There is many, many 21's on Softails with great results. Good brakes are really good thing so knowing your bike and learning the feel of a new brake is a good thing and can overcome locking up your wheel.
Before investing in expensive wheels, first make sure that you can put a 1.227” axle wheel spacer in the hub for a 1” axle upgrade at a later date or increased resale value. Make sure they are a 2.220” rotor register as said before. Any late model (2000~current) has the same hub width if you choose a dual flange (6.320” +/- 0.01”) “Bagger” hub and you can put a Softail hubcap over the second flange hiding it if you ever change bikes in the future. Again, I am fully understanding you should do what you want but if you do your research in the bathroom you are less likely to be asked to do another “Honey-do” by the wife.