How good can the stock front drum brake be made to work?

[Jeeter]

Really stupid wording there in the topic. What I'm wondering is how well the stock XS650 drum brake can be made to work? I see a lot of restorations and resto-mods of XS650s that use the stock drum up front. Having zero experience with the stock drum brakes up front on the XS, I do not know anything about it's design (some drum brakes are better than others by design).

I'm just toying with the idea of using one, doing the research on it. It would be purely aesthtics, and a bit of ~romance~ (longing for the past) mixed in with it.

Take a look at Mike Kidd's Yamaha (attached pic, circa 1981). The drum brake looks great on it (not to mention the DT tank, I'd been wondering what a DT tank would look like with an XS engine, now I know! May just have to go that way.)

So, are there aftermarket upgrades for the stock front hub/brake? Can it be made into a reasonably good brake? I am of the mindset that one good way to assure you have enough brakes is to slow down. I lived in the Los Angeles area for several years, and it's easy to get used to having six inches between you and the vehicle in front of you. Where I currently live I can count the cars on one hand in the spread of twenty minutes on the nearby freeway. I think differently these days. The "S" on my chest has faded away quite a bit, and I no longer change clothes in a phone booth. And I've learned that I am NOT bulletproof either. Just sayin' y'know?

 

[jd750ace]

Drum brakes always work at least as good as dragging a whitewood 2 X 4 on the ground to stop the bike. A real treat when they are wet! There's a reason drum fronts went away.

 

[XSLeo]

I might suggest calling MMM over at 650 central or Vintage brake, Same guy runs both.
Michael "Mercury" Morse has been riding these things forever and has lots of good advice.
Leo

 

[Jeeter]

Drum brakes always work at least as good as dragging a whitewood 2 X 4 on the ground to stop the bike. A real treat when they are wet! There's a reason drum fronts went away.

Yup, marketing

(Kidding, kinda) Sometimes older tech can be improved upon by modern materials and other upgrades. This entire forum is proof of that, I mean, "there's a reason air cooled carbureted engines went away..." (to use your own logic) and yet here we all are, in this forum, working on and riding a bunch of old tech pushed around by old engine designs. I'm not even sure you can buy a new modern bike that isn't fuel injected, and air cooled engines are mostly for entry level machines or niche market bikes (cruisers and so on). But here we are nearly worshipping these 40-odd year old carbed air cooled bikes, even though there is a reason they went away decades back. So the idea of the stock drums may not be as obviously ridiculous as it may at first seem. Like someone in this forum already said about this project, "after all it IS a rigid framed street tracker with no more than 60HP on narrow tires (by today's standards)". I have to wonder if the stock drums may be enough. If not, then so be it, I'll move on with disks.

Much has changed over time, and I am new to the XS650 format. That said, I didn't know if there were some decent improvements on the stock drums over the years (exactly as there have been enormous strides in the engines of these bikes over that same time). Hence, this thread. Worth asking, y'know?

So, any of the owners of restored or resto-mod XSs have anything to say about their drum brakes? I know they're not Brembos, but this isn't a 600cc sportbike, either.

Thanks.

 

[Jeeter]

I might suggest calling MMM over at 650 central or Vintage brake, Same guy runs both.
Michael "Mercury" Morse has been riding these things forever and has lots of good advice.
Leo

Thanks for the helpful direction. I'll check that lead out.

 

[Jeeter]

(added the Mike Kidd picture to post #1. I had to totally shut my computer down and reboot, Microsoft decided to do another update and my system was hanging until I let them install the upgrade. All is well now.)

 

[Jeeter]

I think the drum brake may be something calling to me from way back. I know the enduro tank certainly is. Pics are of my first ~real bike~, 1971 Yamaha JT-1 Mini Enduro. I raced it six months after I got it, first race was at Deadman's Point where I took like 374th place or something out of twelve of us. Hey at least I beat that kid that was riding around with his choke on!

After awhile it got set up better for the many TT and scrambles tracks that littered Southern California in 1972 (Indian Dunes, Corona, Adelanto, Deadman's Point, Perris, Saddleback, wherever!), man there were SO many, not to mention the MX tracks that were anywhere/everywhere. Racing on Wednesdays nights, racing Friday nights, racing Saturday nights. It was a very nice time to be alive and involved.

It ended up with a cut rotary valve, corked lower crankcase, better rubber (Carlisles?), Hooker chamber, foam air filter, milled head, rider-accessible fuel enrichment setup, strutted rear end, removed Autolube (premix). It was a pretty fast little bike. Fast enough for me to break all five metatarsal bones in my left foot in a nasty getoff at Perris. I was closing on the guy ahead of me, a planned pass at the end of the long straight. I was closing on him, taking advantage of some momentum when he suddenly seazed solid and locked up. Before he could pull the clutch in and before I could react I squarely hit him pretty hard. We both went down. I had just recovered from a mid-air collision with another rider at Deadman's Point a few weeks prior. We sold that little demon machine soon afterwards. Dad called it the "little neck breaker".



Anyhow, I'm still knocking this drum thing around. Just thought I'd share a silly set of anecdotes here.

Funny what lurks in the back of our minds, what shapes what we like and dislike.

Thanks.

 

[jayel]

a drum can be quite effective it's just they tend to fade quicker with hard use, one stop you're good, next couple it starts going away as it heats up

 

[neanderthal]

i had a 66 harley with drum from and rear. 900 cc it stopped fine. yes disc are better, but you should be fine with a drum. hell its better than those running a spooly up front.

 

[TwoManyXS1Bs]

Only `70-`71 XS's had that front drum brake. That's my world. Finding shoes and other parts is difficult. I'm now a sedate rider, and they work fine for me.

In the early `70s, as front brakes were transitioning to disc, there were some uncomfortable teething pains. Disc brakes had hydraulics, considered as additional messy maintenance by some, godsend by others. Prices for pads were at least 4x what shoes cost. You had to be meticulous about adjusting caliper position (Hondas), or they'd drag and squeal. Many squealed anyway. Various anti-squeel kits were offered, questionable success. If caliper wasn't adjusted correctly, and allowed to drag, the caliper would heat-up, drag some more, heat more, and eventually refuse to properly retract, requiring rebuild or replacement ($$$). Mechanics caught a lot of flak over this, I still have combat scars. Many of us were convinced this new braking system was an insideous method to scalp the customers.

However, in proper condition, discs were/are quite superior to drums. And, we're well past those early days, the bugs have been worked out, pricing has become more reasonable.

That same early period was probably the zenith of drum brakes. They were quite effective, if setup properly. But that may become lost knowledge as they disappear.


Drum brakes points to ponder:

Braking energy goes into the iron insert of the drum casting, heat disipates thru the aluminum casting. The heat expansion cycles on 40+ year old drum brakes introduce a risk factor. Couple posts here show signs of separation (rear hubs).

Get 'em wet, they don't work very well.

Turning drums is nearly a lost art. Normally just replace the hub, if you can find one.

Fitting shoes is nearly a lost art. Factory shoes had the proper thickness and circular form to match the drum. Aftermarket shoes seem to have thinner material and don't match the drum diameter. Aftermarket shoes are expensive and difficult to find.

The shoe pivots at one side and expands on the other. With a too-small radius, the expanding end of the shoe is the main contact area. Reduced contact area, and braking load now biased toward the actuating cam, not good. In severe cases, some brake designs will chatter in this state, and risk breaking the actuating cam. Breaking-in the shoes doesn't really fix this. We used a shoe grinder to form-fit rebuilt/rebonded oversize shoes for specific needs. Properly fitted, you could expect to get almost full contact of shoe to drum. These performed quite well.

Properly adjusted mechanical brake shoes don't drag. Less heat, more mpg.

Drum brakes generate brake dust (*cough*).

The XS1 front drum brake is, in my eyes, one of the most attractive and advanced front drum brake designs out there. The twin leading shoe gives better stopping power than the leading/trailing design. If needed, the vent cover and rubber plugs can be removed. My rubber plugs are quite hard now, so I'll just leave 'em in there.

Hope this helps...

 

[fredintoon]

- - - What I'm wondering is how well the stock XS650 drum brake can be made to work? - - -
So, are there aftermarket upgrades for the stock front hub/brake? - - -

Hi Jeeter,
compared to what? Compared to the bacon grease lined 7" SLS drum of my Ex WD Royal Enfield 350 it works like a vise.
Compared to a modern 4-pot dual disk set up, it's kinda pathetic.
But cleaned up, tuned up and with the right linings, the XS650 stock front drum will work well enough to be safe unless you start bumper-hugging.
Upgrade the stock drum brake? I doubt it but you could swap in a better class of drum brake.
The double sided 2LS drum from an early Suzuki GT750 worked as well as the disk brakes of that era.
And just recently I saw an aftermarket dual 2LS drum on a BSA 750 Triple.
It was so effin' big that the spokes that laced it to the wheel rim were no more than 3" long!

 

[JP50515]

"...there's a reason air cooled carbureted engines went away...I'm not even sure you can buy a new modern bike that isn't fuel injected..."

Royal Enfield disagrees.

http://royalenfield.com/motorcycles/bullet-500#!technical-specification

 

[XSLeo]

I have a Honda CM400 with a front drum brake. I was very surprised at well how it works. It does take a bit more effort to use than the dual disc set ups on both my 75 an 81 XS650's or the Harley.
The bike only weighs 370 lbs. though. The extra 90 lbs. or so of an XS650 might be a bit much for that brake but as I mentioned earlier MMM should point you in the right direction.
From reading his Vintage Brake site he has several lining materials to fit to your shoes. They are extra thick so after they get mounted to your pads he mounts them in a special lathe to turn them to the correct diameter to match your drum. A bit costly but this makes the brake work very well.
Leo

 

[jayel]

i had a 66 harley with drum from and rear. 900 cc it stopped fine. yes disc are better, but you should be fine with a drum. hell its better than those running a spooly up front.

I had a 61 900cc it didn't stop fine, first big bike I wrecked, of course that highway commission mower tractor pulling out in front of me at 70mph didn't help heck of a difference between a skinny single leading shoe brake and a double leading shoe brake, did a front wheel stand with one of those once avoiding a left turning car, still pissed me off enough to chase them down and kick in a door for them

 

[neanderthal]

I had a 61 900cc it didn't stop fine, first big bike I wrecked, of course that highway commission mower tractor pulling out in front of me at 70mph didn't help heck of a difference between a skinny single leading shoe brake and a double leading shoe brake, did a front wheel stand with one of those once avoiding a left turning car, still pissed me off enough to chase them down and kick in a door for them

yeah different front brakes...out of all them the 66 had the worst brakes yeah, but i never shit my pants. sorry to here about your crash man, thats aways a bummer and a 61...You should post some pictures if you have any. id love to see it.

 

[TwoManyXS1Bs]

...From reading his Vintage Brake site he has several lining materials to fit to your shoes. They are extra thick so after they get mounted to your pads he mounts them in a special lathe to turn them to the correct diameter to match your drum. A bit costly but this makes the brake work very well.
Leo

Fantastic info Leo! I'll be checking into that for mine! Thanx!

 

[jayel]

yeah different front brakes...out of all them the 66 had the worst brakes yeah, but i never shit my pants. sorry to here about your crash man, thats aways a bummer and a 61...You should post some pictures if you have any. id love to see it.

oh that was back in 1968, long ago and far away had the first set of Branch heads in Iowa on it, 12:1 compression XLCH it was way to fast a bike for the "slows" (brakes) it had on it

 

[Jeeter]

There's a service that Racetech offers that's known as "re-arcing". They make the arc of the shoes match the arc of the drum in a more efficent manner.

That, and that the Yamaha stock drum is a twin leading shoe (200mm diameter x 40mm wide) makes "today's" drum a bit better than yesterday's drum. Couple that with the targetted 350 pound wet weight, as well as this bike being a rigid frame (meaning it has speed limits kindof built in to the design) and the drum brake might be well enough.

Will they compare to a four/six piston disk? OF COURSE NOT. DUH. But that does not mean that the drum won't be enough. As was mentioned previously by another member, the drum works great for your basic e-stop. But for racing where you're beating the living piss out of it 15 times per lap, then yea, the disk is the obvious winner there.

It comes down to being honest with yourself. What do you need vs what do you want.

Will a drum brake designed for a 450+ pound bike work safely enough to be considered for use on a <350 pound bike? I really don't know. But I don't think I'd be afraid to try it.

 

[Jeeter]

Only `70-`71 XS's had that front drum brake. That's my world. Finding shoes and other parts is difficult. I'm now a sedate rider, and they work fine for me.

In the early `70s, as front brakes were transitioning to disc, there were some uncomfortable teething pains. Disc brakes had hydraulics, considered as additional messy maintenance by some, godsend by others. Prices for pads were at least 4x what shoes cost. You had to be meticulous about adjusting caliper position (Hondas), or they'd drag and squeal. Many squealed anyway. Various anti-squeel kits were offered, questionable success. If caliper wasn't adjusted correctly, and allowed to drag, the caliper would heat-up, drag some more, heat more, and eventually refuse to properly retract, requiring rebuild or replacement ($$$). Mechanics caught a lot of flak over this, I still have combat scars. Many of us were convinced this new braking system was an insideous method to scalp the customers.

However, in proper condition, discs were/are quite superior to drums. And, we're well past those early days, the bugs have been worked out, pricing has become more reasonable.

That same early period was probably the zenith of drum brakes. They were quite effective, if setup properly. But that may become lost knowledge as they disappear.


Drum brakes points to ponder:

Braking energy goes into the iron insert of the drum casting, heat disipates thru the aluminum casting. The heat expansion cycles on 40+ year old drum brakes introduce a risk factor. Couple posts here show signs of separation (rear hubs).

Get 'em wet, they don't work very well.

Turning drums is nearly a lost art. Normally just replace the hub, if you can find one.

Fitting shoes is nearly a lost art. Factory shoes had the proper thickness and circular form to match the drum. Aftermarket shoes seem to have thinner material and don't match the drum diameter. Aftermarket shoes are expensive and difficult to find.

The shoe pivots at one side and expands on the other. With a too-small radius, the expanding end of the shoe is the main contact area. Reduced contact area, and braking load now biased toward the actuating cam, not good. In severe cases, some brake designs will chatter in this state, and risk breaking the actuating cam. Breaking-in the shoes doesn't really fix this. We used a shoe grinder to form-fit rebuilt/rebonded oversize shoes for specific needs. Properly fitted, you could expect to get almost full contact of shoe to drum. These performed quite well.

Properly adjusted mechanical brake shoes don't drag. Less heat, more mpg.

Drum brakes generate brake dust (*cough*).

The XS1 front drum brake is, in my eyes, one of the most attractive and advanced front drum brake designs out there. The twin leading shoe gives better stopping power than the leading/trailing design. If needed, the vent cover and rubber plugs can be removed. My rubber plugs are quite hard now, so I'll just leave 'em in there.

Hope this helps...

Thanks TONS for the insight here. I have options open to me on this issue. The girder front end on my project bike can be had with caliper mounts for modern Harley brakes. I have the option of having one side, both sides, or no front brakes. The "Harley brakes" thing implies that whatever aftermarket stuffs fit modern HDs will fit this girder as well.

However...

The drum setup fits with an "era correctness" that's sortof is-and-isn't adhered to with this project bike. You gotta admit there is something very "Friday night" about that picture of Mike Kidd's Yamaha with the drum brake on it (see my post above). Anyhow, it's something I will keep in the middle of my mind, in the event I happen to run across a smoking deal on XS drum stuffs, I won't be afriad to test the idea out. I would, of course, need to add some sort of "lugs" for the drum's backing plate to lock against on one of the girder legs. But that's not too big an issue.

Anyhow, my point here is that I think after what I've read the drum is a viable choice for this project bike of mine. I plan on keeping an open mind to it if some opportunity presents itself to me.

Thanks for the input folks.

 

[Jeeter]

By the way, here's a link to Racetech's drum re-arcing page .....

http://racetech.com/page/title/Brake Arcing