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Previous Next Up Topic Public / Dune Buggy Build Advice / brake upgrade (4686 hits)
By Kirt M 1177 Date 2009-09-14 15:02
Greetings guys n gals
   61 street buggy on full length pan with link pin and swing axles. Original wide 5 bolt drum brakes front and back, wheel adapters, 15" aluminum wheels with Chevy bolt pattern. I want to put disc brakes up front and keep drums rear. Been looking at many kits from several companies. Thought I would get some input before I lay my money down.

1) "If" I want to keep my wheels and adapters and convert to front disc only, will a wide 5 disc kit make my wheels stick out? Is it bad to do this?

2) Is it better to convert to 4 bolt drums and disc and replace my wheels? $$$$$

3) Will 4 bolt drums and disc fit my 61?

4) Get a wide 5 front disc kit and get wide 5 wheels ( get rid of wheel adapters ) ?

5) Get 5 or 4 bolt disc front and back?

What are the pros and cons? Or is there a better option? Do tell...

Buggy Bro Kirt
By ManxRob Date 2009-09-14 16:59 Edited 2009-09-14 23:17
Hi Kirk

My experience with Disc brake conversions is with the later ball joint front suspension, and GM bolt pattern wheels on a buggy. Your link pin front may be a little different.

I too wanted to use (readily available) GM patterned wheels, but did not want the additional offset provided by wheel adapters as they push the wheels/tires too far out to provide fender coverage. The solution for me was to use rotors and drums drilled for the GM pattern. I purchased my drilled/studed rear drums from SO-Cal Autoparts. They are drilled blanks, rather than re-drilled stockers. They may be available from other suppliers as well.

The results are that my 16 x 8.5 Chevy IROC wheel/tire combo 'just about' fits under the fenders of my Manx. The IRC wheels have a 'non-standard' backspacing. The wheels I'm using in front have 5 " backspace, the wheels in the rear have 4 " backspace.



I installed Karmann Ghia front disc brakes that came installed on a used front beam. The rotors had been drilled for the GM pattern in the early 1980's. I also installed a new, stock VW Karmann Ghia disc brake master cylinder, which has a larger bore designed for the front discs. When I went for my first test drive I found the front brakes provided wayyyy to much of the buggies stopping, locking up before the back wheels. I solved the front/rear brake proportion by installing VW front wheel cylinders in the rear per the "Brakes" section of this article:
http://vwhelp.com/
I used the 68 & later backing plates (with wider brake shoes) on my 1966 short axle/SA. It worked great! Stopping is now quick & controlled, with the rears doing their share of the braking.

The only problem I have is keeping the rear brakes adjusted. As the pads wear the car develops a tendency to 'pull' to one side when brakes are applied. The front disc brakes are essentially auto adjusting.  I'm currently replacing the rear drum brakes with discs (with the ebrake option) since I'm to lazy to keep the rear drums adjusted. I will use the new '4 wheel disc' master cylinder from SO-Cal when I do the switch.

Rob
By Jeffrey P 655 Date 2009-09-14 17:23
Get a disc brake kit that will fit your front link pin and get rotors drilled for the chevy pattern. Solved your problems. No need for new wheels and you can ditch the adapters....or sell them to offset the cost.
By Kirt M 1177 Date 2009-09-14 19:41
Rob,

   You have a lot of meat on that Manx... Looks good. I called So-Cal and Frank looked for a Chevy pattern disc brake kit for my link pin front. But all the kits he could come up with have a 2-1/2" drop spindle with the kit. Even the Chevy pattern rotor for that kit will not fit my link pin spindles. Do you have the dropped spindles on yours? The link vs. ball fronts may have some other differences ei. height etc. I have low profile tires up front. If I put 235/75 up front (like the rear) to get some height back, I think they could hit the fenders. So-Cal did not have the blank rotors to fit mine either.

   I may take the tip from Jeffery and have them re-drilled. The guy at the VW shop here did not like that idea... said they might warp in use. But the drop spindle kit comes drilled for Chevy and Ford. So the wheel flange must be strong enough for 10 holes. But then I think it uses the "L" shaped rotor where as the one that fits mine would have an "H" shaped rotor and flange... Jeffery, Did you do that to a link pin buggy?

   There is only one thing better than going... that's stopping!

Buggy Bro Kirt
By Jeffrey P 655 Date 2009-09-14 19:52
What about www.mooreparts.com

XAC407091 KING PIN FRONT DISC BRAKE CONVERSION KIT ( 5 LUG CHEVY PATTERN ) INCLUDES ROTORS, CALIPERS WITH PADS, CALIPER MOUNTING B... $230.00   
By Kirt M 1177 Date 2009-09-14 20:58
Jeffery,

   Groovy man! They have everything I need... I like the price too!

Kirt
By Kellison Jim Date 2009-09-14 21:59
I used Lovin Buggies for my front disc brake kit
http://lovinbuggies.com/index.php

http://lovinbuggies.com/product.php?cat_id=258
"This is a complete king pin disc brake kit with the Chevy 4.75" 5 hole pattern that will fit directly on the stock king pin spindle. This kit comes with rotors, calipers, brackets, seals, caps, and special bearings for stock application. A true bolt-on application with no alterations or spindle changes needed. NOTE: If you are converting from a stock ball type bearing setup you will need two (2) LR-40-5017 bushings for the conversion to roller bearings in this kit.
Price : $179.99" 

Your front will be 1" wider.
Kellison Jim
By Kirt M 1177 Date 2009-09-14 23:44
Jim,
   I checked it out. Like they say on the radio, the hits just keep on coming. Thanks Jim!

Kirt
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