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Mechanical Drum vs. Hydraulic

20K views 57 replies 24 participants last post by  kickstarts 
#1 ·
I know neither is as good as a disc. That said, here’s my situation.

I am collecting parts for a period correct ’55 Panhead project, in a ’48 wishbone. I have found both a mechanical drum(would still need to find the plate, shoes, etc.) and a complete hydraulic rear brake. This bike was run before with a juice drum, so the cross shaft for the mechanical has been cut off. I have another tube and shaft I can put on there. Will not have a front brake. I know the mechanical will look a lot cleaner, so I’m leaning that way, but how much better will the hydraulic stop? This bike will be mostly for show and cruising around, no high speed blasts on the freeway or lane-splitting in heavy traffic.
 
#2 ·
On the '56 I had a drum in the back and ( later ) a sportster drum on the front . It stopped pretty well , considering it was a stroked and very fast motor , with only the rear break . I did a lot of freeway fast riding and lots of light to light terrorizing and never had many situations that I thought " boy I sure would like to be able to stop better " .

Obviously I never needed it so it was never a problem . Hard to say when you're going to need it though . I'd say if you only plan on round town cruising and putt putting , either should be fine for you . The juice would be a little more effective by design , but probably not noticeably so . I'd say either would do what you want them to do in the end .
 
#5 ·
my pops has the juice brakes on his 65 pan and they stop much better than the mechanical and in my opinion look just as well on a period correct build as a mechanical brake does
 
#7 ·
I am collecting parts for a period correct '55 Panhead project, in a '48 wishbone.
Period correct? What period are you talking about! Juice on a rigid is a '70s thing. Never saw one set up that way before. I did one in '73 and people thought it was weird!
Robbie
 
#9 ·
From Richards other threads, it is a 70's style scooter--raked, twisted springer, molding, etc. Looks good to me.

If you've got the juice brakes and the bike is set up for them then use 'em. Here's mine, but it has some modern stuff on it. Most folks don't notice.

Mid 70's would more than likely use a Wagner style master cylinder.
Larry T
 

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#12 ·
Advantage of disc: Won't fade, easy to modulate the point between braking hard and locking up.

Advantage of juice drum: Easy to modulate the point between braking hard and locking up.

Advantage of mechanical drum: Simplicity, clean looks, still stops really well.

I use mechanical drums on my chopper.

-Craig
 
G
#13 ·
Advantage of disc: Won't fade, easy to modulate the point between braking hard and locking up.

Advantage of juice drum: Easy to modulate the point between braking hard and locking up.

Advantage of mechanical drum: Simplicity, clean looks, still stops really well.

I use mechanical drums on my chopper.

-Craig
That's a good point on fade. I have mechanical brakes on my Pan and Knuckle. If you hear the back wheel locking up, back off the brake a little bit -- it works real good, just like juice. I've never had my mechanical brakes fade if they are set up right. I live where there are a lot of mountains and curves, and I ride up people's ass all the time with late model bikes. Haven't had any late model disc brake bike pull away from me yet. I'll take a mechanical over a juice drum any day, and personally I think a disc looks stupid on a rigid Pan or Knuckle bike unless it's an S&S motor - that's different if you're building a look-alike.
 
#17 ·
I don't think there's anything wrong with the juice brakes. It's like running a flathead; you KNOW it's not gonna beat a Ninja, so you "ride accordingly".

I really, really like my juice brake. If you've got all of the parts (INCLUDING the correct drum bearings and the seemingly elusive internal spacer), I think they're a good compromise between mechanical coolness and disc stopness. When I actually think.
 
#20 ·
I think the juice drum brakes work as well as some of the early single pug banana disk calipers.
+1 with what Trent said about shoes arched correctly, my 67 front aren't (maybe fallen arches?!) and it's no bueno on stopping.
Are you runnin a front brake?
 
#21 ·
What's the best way to modify a rigid frame for a juice set up?
I've seen a tab in the bottom of the axle plate or modify the drum itself for the tab to fit between the legs... In the second option, how do you adjust the chain? Does it become a pain in the ass?
What your opinions and experiences on this? (pictures welcome...)
My rear axle plate have already been molested by previous owner:
Photobucket
 
#22 · (Edited)
I'm running a hydraulic drum (juice) on my rigid shovel. It's the later mid-star hub version with the bearing in the drum. Real solid set up with good braking and a nice feel to the braking action. I use the Wagner master (the cast looking one), it fits the look of the bike better than squared-off billet looking type. If you don't have a tab on your frame for the brake plate anchor you'll need to add one. You can either fabricate the tab or buy one and weld it on in the proper location at the bottom of the left axle plate.

For elekvins: the tab for anchoring the brake plate has a slotted hole to allow for chain adjustment

Regards,
Geo.
 
#24 ·
For elekvins: the tab for anchoring the brake plate has a slotted hole to allow for chain adjustment

Regards,
Geo.
Thank you Geo, yes i know that from my swing arm set up.
My question was if you put the tab between the legs instead of below the axle plate, does it make chain adjustment a problem?
Is it in the way of the adjuster, or there is enough room for the adjuster and the tab?
 
#25 ·
Elekvin, on the D.Allen bike the brake plate is rotated clockwise compared to the stock installation which would put the brake anchor bolt to the front. It's a little hard to tell from the angle of the pic. It also looks like he used a hard line all the way from the master to the wheel cylinder which will give your brake a better feel than the fat soft ones (as long as you use steel line).
 
#55 ·
It also looks like he used a hard line all the way from the master to the wheel cylinder which will give your brake a better feel than the fat soft ones (as long as you use steel line).
To get all the air out, you'd have to bleed the wheel off the bike , with the wheel cylinder at the 12:00 position, and then install it without breaking any of the line connections.
Must be a little complicated with hard lines if you have to rotate the drum every time you need to bleed...
Is there a trick or I'm missing something here?
 
#34 ·
It's the right type. Unless you are certain that its all good, a rebuild kit is pretty cheap. That way you can be sure you've got the right guts in it so that valving is correct for a hydraulic DRUM brake with a wheel cylinder.
 
#33 ·
I just went out and took a look at the difference between the my pan and shovel. It looks like you could make a modified spacer for the juice plate anchor so it would fit in the slot for the stock mechanical brake anchor. You might have to trim the length of the juice brake anchor stud a bit as well so it will clear the axle adjuster. Set up in that fashion, it would probably help to remember to bleed the lines with the wheel cylinder horizontal, like stock.

Regards,
Geo.
 
#38 ·
There has been lots of discussion about this before.
Both work great if they are setup right! Both will skid just the same or work like crap, you have to know what you are doing...
As someone who as a '58-62 juice drum setup apparently like dick allens in a rigid frame using the stock brake stay... if i did it again i would do a mechanical brake for simplicity...

But those early juice drum backing plates have a bolt on brake stay and you can take it off and easily modify it to do what ever you want.

Arcing the shoes to the drum helps a lot with ANY drum brake.
 
#40 ·
The best "profile" shot I have....hey, it's not like we can get Dick to take any additional photos for us. You can see the shortened pin located in the mechanical brake slot on his frame.

Sidenote: Also notice that Dick's rear footpegs are actually bolted through the rear of his horseshoe tank. Joe Hurst has that oil tank now....

 
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