Front Brake upgrade for my '65 Pan question

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Frankenstein
Posts: 328
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Front Brake upgrade for my '65 Pan question

#1

Post by Frankenstein » Thu Feb 26, 2009 2:58 pm

I realize I don't post here often, but there seems to be a Wealth of experience here, and I'd like to tap into it.
Here's a question that I have to all you modern bike experts out there! At least, modern to me :lol: I'm upgrading the brakes on my 65 pan. Presently, I have the early single 11.5" disk and caliper, circa 73-78. It just isn't enough for the bike. The question is, is the Sporty dual 10 inch brake a significant improvement over a single disk 11.5 inch setup? My other option is to modify the parts I have and use two 11.5 inch disks with the 79-83 calipers. In fact, that was my first choice, as with most things, bigger would seem to be better. But, I'd have to make unwanted modifications to my drumbrake wide glide front end to pull that off.
So, if the Sporty dual 10 inch setup is definitely better than a single 11.5, I'd settle for that for the time being.
Keep in mind I have the 10" dual disks, hub and calipers already, and am determined to use at least the hub and calipers. Those parts are a given. If I use 11.5 disks, they will be the 11.5 rear disk from a sporty of that era. I have one already and making it fit would be easy.
Given my prejudices, I'd still like opinions on which way to go... :lol:
Thanks
DD



51Hog
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Joined: Fri May 20, 2005 7:29 pm
Location: Wasilla, Alaska

Re: Front Brake upgrade for my '65 Pan question

#2

Post by 51Hog » Thu Feb 26, 2009 4:21 pm

With duall 10" you should be able to do front wheel stands with the ricers---LOL
I would think that two 10" disks would have more stopping power than one 11.5".
Dale

RussW
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2007 Kaw. Vulcan 2000
Location: Western Mass

Re: Front Brake upgrade for my '65 Pan question

#3

Post by RussW » Fri Feb 27, 2009 1:55 am

Used to be good at math decades ago, not so much now. Checked out some brake theory sites, and this is the way I understand it.
If everything else is the same (brake pads, rotor, master cylinder pressure) then the brake force (torque) changes by the same percent as rotor diameter. In other words, you will only lose about 13% of you braking ability by dropping from an 11.5" rotor to a 10". (11.5- 13% = 10). So if you consider what you have now as 100%, the 10" will be about 87% of what you have, and two 10" will be about 175% of what you are using. Pretty good increase.
Makes sense, I had a single 10" on my pan years ago, and a tech at Performance Machine told me it wasn't worth the expense to go to 11.5" for just a small percent increase in braking power. What made a HUGE difference was to go to a 2 piston caliper on the same 10" disc, then finally a 4 piston setup on 10" for descent brakes with less lever pressure. Not "stopping" (get it?) there, I now run dual 4 pistons on 11.5" rotors. When I switch back to my FXR with stock calipers on dual 11.5" discs, feels like I need to drag my feet to come to a stop compared to the pan.

mbskeam
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Re: Front Brake upgrade for my '65 Pan question

#4

Post by mbskeam » Fri Feb 27, 2009 2:02 am

is your master cyl bore sized right?
or a better caliper
you should be able to lock the front wheel up with a disk...

Frankenstein
Posts: 328
Joined: Sat Oct 08, 2005 2:14 pm
Bikes: 37ULH,46UL,47EL(80"),65FL,61KH-WL-BSA hybrid,56square4,several 50's BSA 500 singles
Location: Interlaken, NY

Re: Front Brake upgrade for my '65 Pan question

#5

Post by Frankenstein » Fri Feb 27, 2009 5:43 am

Thanks for the replies guys. Sounds like stay with the 10 inch and Ideally go to a 4 pot caliper. I'll keep an eye out on ebay for something helpful.
DD

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