Brake rubs on 1/2 of a wheel rev

Forum rules
Please do not start new topics here, but here: New Panhead and Flathead topics
Post Reply
awander
Site sponsor
Site sponsor
Posts: 1241
Joined: Fri Sep 21, 2007 3:03 am
Bikes: '52 FL
'64 FLH
Has thanked: 9 times
Been thanked: 53 times

Brake rubs on 1/2 of a wheel rev

#1

Post by awander » Sat Oct 18, 2008 4:26 am

The front brake on the '52 FL has been getting less effective, so I figured I'd adjust it. I also noticed it was making a "shoosh=shoosh" sound when applied at low speed. sounding like it was making contact only on half of the front wheel revolution.

So I put the bike on the lift, and then loosened up the pivot stud nut, the axle nut, and the axle sleeeve nut. Next, I adjusted the front cable/tube it until it was very tight(holding the brake on), and then tightened the 3 nuts. Readjusted the brake cable to a point where the wheel would rotate with no application of the lever, and it still rubson 1/2 the revolution of the wheel.

Tried again, 2 or 3 times, trying different sequences of tighteningthe 3 nuts. No change.

So I pulled the wheel and the drum, and decided I'd try a new set of shoes. When I took the old shoes off, pieces of lining fell out-from the ends, broke right at the rivet holes closest to the cam end.

Installed the new shoes, re-centered, readjusted....still rubs on 1/2 the revolution of the wheel.

Do I have an out-of-round drum, or am I overlooking something simple?

And what is that slot in the end of the pivot stud for?



VT

Re: Brake rubs on 1/2 of a wheel rev

#2

Post by VT » Sat Oct 18, 2008 6:06 am

Probably out of round drum. Cast iron drums will warp (sitting on a shelf at least).
Try a dial indicator set up with the wheel turning and see how much deflection there is. If you want that drum turned, contact "Mercury" Morse at http://vintagebrake.com/

Panacea
Posts: 1867
Joined: Fri May 24, 2002 1:00 am
Bikes: 64FL 99FLHR 01FXSTD
Location: Mpls. MN.
Has thanked: 14 times
Been thanked: 57 times

Re: Brake rubs on 1/2 of a wheel rev

#3

Post by Panacea » Sat Oct 18, 2008 6:53 pm

Awander, I sent my front drum to Vintage Brake where Michael Morse re-lined the shoes with a new friction material, turned the drum, mainly to remove the chrome, and arced the shoes to fit the drum. There was some improovement in stopping but not nearly as much as I was hopeing for. I've come to accept the fact that this is a fifty eight year old bike, and may not perform as well as a state of the art Brembo, Mike

108
Posts: 180
Joined: Sun Aug 06, 2006 8:12 pm
Bikes: 1948 FL 74in Panhead Chopper , 1958 Zundapp Citation 500
Location: Indianapolis

Re: Brake rubs on 1/2 of a wheel rev

#4

Post by 108 » Sun Oct 19, 2008 2:40 am

You might try repositioning the drum on the hub. Clamp the axle in a vise and fabricate a pointer from wire, etc. nearly touching the inside of the drum and spin it to test for which of the 5 positions gives the least runout . I fixed a .025 rear drum/sprocket runnout that way a few months ago.

awander
Site sponsor
Site sponsor
Posts: 1241
Joined: Fri Sep 21, 2007 3:03 am
Bikes: '52 FL
'64 FLH
Has thanked: 9 times
Been thanked: 53 times

Re: Brake rubs on 1/2 of a wheel rev

#5

Post by awander » Sun Oct 19, 2008 2:53 am

Thanks 108, I will try that. I had another repo drum on the shelf and installed it-same results.

Ya' know, I never noticed before that the front drum doesn't have the dowels like the rear one does, to mate with the hub.

Post Reply

Return to “Brakes”