Disk versus Drum

D

Disliked23

Been Around the Block
Picked up a cl450 for parts for my cb450, and the cl of course has the drum on the front. I would really like the clean look of not having a master cylinder and all the extra stuff on the bars and around the headlight that that entails, but I'm worried about how much braking power I'm losing by getting rid of the disk. Worth it? I'm not brave by any means on my bike, so I'm not super worried about having a ton of stopping power, but safety is safety.
 
Is that drum a single or double leading shoe style? If it's a double you are in luck as they can be set up pretty strong. my 360 had a 2ls that would stand it on it's nose without a lot of effort.
You'll want to have the hub trued (assure that it's nice and round) then have the shoes freshened up with new performance type liner. The guy that does them over at caferacer.net (go to the vintage racing section) seems to be pretty good at it adn will turn the fresh shoes to match your hub.
Punch out the sides for ventilation and you're dialed!
 
If by double leading shoe you mean the opposite ends of the brake shoes (180° from each other) are pushed out against the hub, then yes. Well at least my '72 K5 is. However, I find the capability of my front brake to be lacking. I definitely have to use both front and rear to bring my bike to a stop in a hurry. Of course, mine may not be adjusted/setup properly. On my old CB400t with front disc, I barely used my rear brake. I haven't ridden the CB450 with the disc up front.

I let a friend who races a 600 Ninja ride my bike after I got it running. He said the lack of front braking power scared him since the bike was so heavy. Of course he is used to racing his machine and rides a BMW on the street.
 
Yeah my buddy rides an sv650 and we swapped for a day and he freaked out about my front brake. I personally don't seem to have any problem and I can't lock it up, but I also stop pretty damn fast. On his SV it seemed like it would be super easy to go over the bars if you hit that brake too hard, and that feeling sucked more for me that needing an extra couple feet to come to a full stop. Aren't you supposed to try to evade first then brake? That's what they said in my MSF class, and that you shouldn't brake hard unless you're in a straight. Really, I rode that SV for a good couple of hours and didn't feel any safer because of brakes. If anything it was nice to not hear any rattles or vibration (but I kinda like getting the crap vibrated out of me on an old bike ;D) .
 
I think migrating from an old bike to a modern machine takes some time and you gotta be careful. My first ride on anything newer than 25 years old was a 2008 Ducati GT1000. Needless to say I could lock up the front wheel with my pinky finger on the lever. In stark contrast to the brakes on my BMW R75/6 or any of my old Honda CB's over the years.

I'm still working on my XS650 project, which will have a 2LS Yamaha front brake. I'd love to score a 4LS hub from a GT550/750 or the like, but they go for gobs of money.

If you tune them right, maintain them and ride within their limitations, drum front brakes are fine. But then again, if you ride within the limitations of your equipment, riding with no brakes at all would be fine - just drag your feet.

Would mean riding at 2MPH and never within 100ft of another vehicle or obstacle, but you'd be safe :)
 
the biggest problem you're going to get with a front drum is that when it gets wet, or hot, it loses stopping power fast... even if it's dialed in right, it's not as good as a disc... I guess you have to sorta pick between performance and looks, and I think any cafe racer back then would give his left nut for a front disc to replace his drum
 
/\ more or less the state of things, I will say however that with the proper vented drum, good performance oriented liners that are cross cut with slots you can do quite well. I got to spend a summer on a BUILT T500 running a Grimeca drum up front and it could do stoppies all day long, never faded enough to worry about (and I don't ride gently) and it sluffed moisture quickly in the rain.
Now, keep in mind that the 'big G' is a $1000+ drum and it had probably $500 worth of work done to it beyond that.

In the realm of the everyday dude on the street........get yourself a set of ebc pads and some braided lines and you'll be good for pretty cheap.
 
now here's an idea... I think this one came from hondachoppers... you could take the drum lever from one bike, run the cable to a concealed master cylinder, and run the hydraulic line to the disc! ;D ::)
 
thinking, thinking........

That's actually a cool idea. I don't think the work is worth not having that master cylinder on there, though. I'm not planning on doing a complete teardown until this winter. For now, it's just paint, exhaust, seat, bars, and tearing things off the bike I don't need.
 
BMW Airheads have the master cylinder under the gastank. There's a cable running from the brake lever to the MC, and then hose from there to the brakes.

So if you wanted to do this, a BMW R75/R90 etc. MC would be a good option, as it's already set up for cable actuation.
 
Ya know I kinda dig that idea. It'd be one more way to clean up the clip-on.....Hmmmm
 
rockcitycafe said:
now here's an idea... I think this one came from hondachoppers... you could take the drum lever from one bike, run the cable to a concealed master cylinder, and run the hydraulic line to the disc! ;D ::)
Click to expand...


^^^^^^^^^^^^^^^^

This is exactly how you do it.
 
the cb350 that Im building came with a front disk, but it wasnt working. So I got the idea to just steal the wheels (which are much cleaner) from the bike that Im not yet building and it has front and back drums. After looking at more and more bikes, I decided that dual drums look awesome anyways.

That being said, when this bike is done, the first thing Ill start into is probably going to be rebuilding the disk brake for use on one of the two bikes.
 
If you want a drum that's goign to stop like a modern disk, find yourself a Suzuki GT750 (the old Water Buffalos aka Kettles) front hub. That is one monster drum.

Just about as good is the 2LS Triumph/BSA front brake (69-70, NOT the comical, er, conical hub jobs from 71-72). They're fairly easy to find.
 
Syke said:
If you want a drum that's goign to stop like a modern disk, find yourself a Suzuki GT750 (the old Water Buffalos aka Kettles) front hub. That is one monster drum.

Just about as good is the 2LS Triumph/BSA front brake (69-70, NOT the comical, er, conical hub jobs from 71-72). They're fairly easy to find.
Click to expand...
what is entailed in using this setup? I have a disc for my 74 cb450, but I have to rebuild the caliper and get some other things to go along with it. Aesthetically, drums look better to me...but if using a drum from another bike entails lots of other minor changes then it's just a headache.
 
If you can locate a decent GT750 drum, you'll want to have it re-machined so assure that it's round, then you'll need to send the shoes out to be relined, preferably with a very aggressive material. IIRC someone here used forklift brake liner material to good effect. Once the shoes are relined, you'll need to have the entire assembly (shoes, backplates and actuators in place) turned to match the refreshed drum.
Once you're here you'll need to make stout locating straps that'll keep it from spinning.
Now you'll need to have it laced to your rim with new spokes.

Now that you're monster drum is in place on on you'll have brakes that'll stop a Chevy Impala that look cool.
Keep in mind, they are heavy so expect some handling trade-offs, especially on rough pavement.
 
Disks beat drums any day.

The stopping power is not even comparable. Sure, you could run a gt750 drum, but those things can run you a couple hundred dollars nowadays and good luck finding them.

That drum is HUGE- not to mention the fact that youll get very sluggish handling because of it. I mean really; A huge drum just to get almost the same amount of stopping power?

Really guys- a master cylinder doesnt look all that bad on your bars :-[
 
Heh.....
You're the highschool kid right? What you say mostly true though your vehemence is a little over the top.
It's about performance AND style. In the case of most guys here (and on caferacer) these aren't bikes that are really going to get pushed to race pace. With that in mind and an eye to homage and history, there are some tradeoffs that are regularly made.
Don't sweat it too much, different strokes and all that.....
 
You must log in or register to reply here.

DTT Light or Dark

  • DTT Light

    • Spread the Love

    Back
    Top Bottom