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General Category => General Discussion => Topic started by: Kane on August 26, 2022, 11:34:20 PM
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Been looking at loop frames and I know that the front disc 850 Eldorado is very popular, but there are a lot of lovely earlier drum brake bikes around that I like. So how are the drum brakes on the earlier loop frames, Eldorados and Ambassadors? Are they good enough to live with for regular riding? I am not planning on doing any track days, and I like the way the front drum wheel looks on an older bike. Are they good enough or is it a bad idea for a regularly ridden bike?
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No…
They’re a back breaker. :sad:
The way I see it these days, it’s dangerous enough out there without knowingly going partly equipped.
When you say…are they “good enough…”?
I guess if you’re happy to potentially collide with a turning vehicle in front of you at 30 mph instead of stopping 2’ short then yes…
They are “good enough…”
The acid test regarding good enough is the same as tyres, lights, helmets, handling…etc.
They are never “good enough” but, they can be deemed “acceptable”.
The latter term is when you roll the dice with a hearty meal versus a wheelchair post ride and decide the odds are worth it.
Jam tin brakes are a known weak spot on any bike, if you can engineer your safety buffer every time you’ll never have a problem.
But you have other drivers actively taking a part in your destiny..No thanks.
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Huzo, that doesnt include postie bikes does it :azn:
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Just like any vehicle you ride it and learn what it likes.
I've rode my 1958 R69 46k miles and have never had a problem stopping in time.
Every few thousand miles check and adjust the cables, levers, and cams and you are good to go and stop.
But you will probably crash and burn for lack of ABS on that old bike.
Don
Edit: https://www.youtube.com/watch?v=JzTpAELS1HE&t=346s
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I have an early Ambassador and it does fine. You do have to think ahead.
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My Ambassador schooled me on how to ride mountain roads as fast and smooth as I could within the brakes' limits. Best riders training I could ask for.
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But you will probably crash and burn for lack of ABS on that old bike.
It does have ABS..
You can squeeze the lever like Dwayne “The Rock” Johnson and it will never lock.
The “ABS” is for Absolutely Bloody Shocking…
It’s not all bad though, the heat from the glowing front drum can be ducted up to the handlebar ends by copper strap, as a jury rigged heated grips mechanism….
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(https://i.ibb.co/jRrKTYY/IMG-0191-1.jpg) (https://ibb.co/jRrKTYY)
Why ask us, there will never be a straight answer, take one for a ride and judge for your self. Disc brakes can be adapted to a loop, after all that's what the factory did in 74, easily enough done, do some research on Greg Benders site. I adapted a dual disc system on my 71 Ambo-Vert using the proper fork tubes and T3 or Convert wheel, rotors, callipers etc. Easily done for affordable cost. DonG
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My 72 Eldorado has twin leading shoes, they are quite adequate, I have no intention of upgrading to disks, that would spoil the experience IMHO
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With well over a quarter million miles on drum brakes on old Ambos and Eldos I can say they are suitable for an alert rider. Learn how to ride..don't go racing up to the stop sign, watch your traffic lights and be aware of your surroundings. I've ridden in Houston, TX Chicago, IL and even hilly San Fran, CA with drum brakes. Even rode up Pikes Peak when it was gravel.
Realize that drum brakes wont stop you on a dime and drive accordingly.
If all drivers had to drive a semi pulling a tanker they'd learn how to drive.
Buy one and enjoy it.
Tex
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My Ambassador schooled me on how to ride mountain roads as fast and smooth as I could within the brakes' limits. Best riders training I could ask for.
This has always been my way to approach drum brake performance. Realize that in the Ambassador days, brake lining material was still asbestos, which has the best friction coefficient, compared to the composites that are standard these days. When I was working on my son's Eldorado, equipped with the single front standard leading shoe system, he wanted me to install a new brake cable and shoes on the front. The new shoes, even if not asbestos, had good friction, but the new cable just stretched too much for an adequate lever pull. The original Guzzi one was much stiffer and worked better.
But, overall drum brake performance will never be as effective as discs, but you just adapt to the limitations.
As a Vespa owner myself, in Vespa circles we are fond to state that "Vespas don't stop, they just decelerate"....
And, I am grappling with the same issue on my front Vespa brake myself through a series of improvements.
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I have bikes with drum brakes. Sure, they don't match the performance of the modern discs but you are riding vintage machines that fail that test on other criteria as well. I have those 2LS on my 500 Falcone and I've ridden it on The Dragon without running off the road or into anyone. Most of the time there, I was feathering the drums to slow down for some kid lagging around on a crotch rocket in front of me! lol
I like the looks of the drums- on vintage bikes. Try it. Just ride like a sane person on an old bike.
One note, I once had a beautiful Guzzi 850GT with the famous 4-leading-shoe brakes. I spent a lot of time setting up the brakes, getting all shoes to free-trail just right. That sumbich would stop much quicker than the disc brakes that followed them on that era of bike. The self-servo effect of the 4LS would almost throw you over the handlebars if you weren't prepared. I, as others have done, backed of the precise adjustments a little to soften that dramatic snatch down those huge brakes could create.
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As others have pointed out, the drum brakes can be perfectly adequate........... .if they are set up correctly. The geometry of the levers on the brake plate is very often incorrect, check out photo's of Loops on the web. Go to Greg's brilliant website where all will be revealed. The lining material needs to be correct too, take advise from brake lining specialists. My two Loops, one with a TLS brake and the other with a 4LS brake stop very well but they will never be as good as a modern disc setup. Ride accordingly. :thumb:
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I just re-did the front brakes on jumpmaster's lovely Eldo. Before, they performed only average despite new aftermarket shoes (Newfren) arced to the drum and a quality Barnett cable. I had a pair of NOS Ferodo "green compound" shoes in stock, so we decided to try those.
I mounted them to the backing plate, used the axle as an arbor along with spacers as needed. Slipped an .020" shim between the cam and shoe and then turned them in my big lathe to the drum's inner diameter (8.660"). Huge improvement! Initially, they were too good - at low speeds they were grabby and began to squeal. Great at higher speeds though. I tapered back the leading edge of the lining approx. 1/4" and now they're perfect - powerful, controllable, no squeal.
(https://i.ibb.co/KmyXgtp/John-s-Eldo-005.jpg) (https://ibb.co/KmyXgtp)
(https://i.ibb.co/N34shpc/John-s-Eldo-006.jpg) (https://ibb.co/N34shpc)
As mentioned, lever angle and proper link rod adjustment are very important.
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It does have ABS..
You can squeeze the lever like Dwayne “The Rock” Johnson and it will never lock.
The “ABS” is for Absolutely Bloody Shocking…
It’s not all bad though, the heat from the glowing front drum can be ducted up to the handlebar ends by copper strap, as a jury rigged heated grips mechanism….
Agreed. Never been a fan of ABS equipped bikes. A "somewhat mushy" front brake seems to be part of the package. Even on the high dollar sport bikes I have rode.
That said, first time I ever crash due to wheels locking during braking, I'll probably change me mind.
But how would one ever know if ABS saved your butt? You had ABS, neither wheel locked up, you didn't crash.......?
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(https://i.ibb.co/jRrKTYY/IMG-0191-1.jpg) (https://ibb.co/jRrKTYY)
Why ask us, there will never be a straight answer, take one for a ride and judge for your self. DonG
Well said.
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I just re-did the front brakes on jumpmaster's lovely Eldo. Before, they performed only average despite new aftermarket shoes (Newfren) arced to the drum and a quality Barnett cable. I had a pair of NOS Ferodo "green compound" shoes in stock, so we decided to try those.
I mounted them to the backing plate, used the axle as an arbor along with spacers as needed. Slipped an .020" shim between the cam and shoe and then turned them in my big lathe to the drum's inner diameter (8.660"). Huge improvement! Initially, they were too good - at low speeds they were grabby and began to squeal. Great at higher speeds though. I tapered back the leading edge of the lining approx. 1/4" and now they're perfect - powerful, controllable, no squeal.
(https://i.ibb.co/KmyXgtp/John-s-Eldo-005.jpg) (https://ibb.co/KmyXgtp)
(https://i.ibb.co/N34shpc/John-s-Eldo-006.jpg) (https://ibb.co/N34shpc)
As mentioned, lever angle and proper link rod adjustment are very important.
VERY SLICK Charlie.
Back in the good ole days, we did the same by sanding the high spots off the brake shoes with 60 grit paper.
It several disassemblies and took a lot longer....
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My Ambassador schooled me on how to ride mountain roads as fast and smooth as I could within the brakes' limits. Best riders training I could ask for.
Good point. Back in the day, Motorcyclist had an article about riding at "The Pace."
Short version, ride as fast as you want on twisty roads using only engine braking.
It is often surprising how fast you can ride by riding a gear lower than usual and only using engine braking.
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depends also on the riding you do,
if your riding is mainly in heavy traffic i would not want drum brakes.
if you live in the countryside it might be possible to adjust your riding.
personally , after running , and working on the front drum of my V7sport for 25 years i fitted disks after a accident that could have been avoided with better brakes.
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All great points above - I put 100K miles on my Eldo with front drum, and while I would have liked a disc the drum worked like it was supposed to. I did have to pump them in the rain to clear them so they would work adequately though.
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But how would one ever know if ABS saved your butt? You had ABS, neither wheel locked up, you didn't crash.......?
Take a modern ABS bike and go do a full-on panic stop in the rain. You'll know!
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Huzo, that doesnt include postie bikes does it :azn:
No Ray.
The postie bike will stop as well as the Norge or V85 due to the light weight.
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I have friends and acquaintances that ride nothing but no front brake, rigid frame choppers, and ride them like the devil is chasing them. Most of them have crap rear brakes also, and goes without saying that helmets are nowhere to be seen in this crowd. Sketchy as hell to put it mildly. Not one of them is capable of a controlled panic stop. The weird thing is, they don't seem to get killed off more frequently than the AGATT, ABS guys. Not sure why they haven't all perished by now.
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I just re-did the front brakes on jumpmaster's lovely Eldo. Before, they performed only average despite new aftermarket shoes (Newfren) arced to the drum and a quality Barnett cable. I had a pair of NOS Ferodo "green compound" shoes in stock, so we decided to try those.
Huge improvement! Initially, they were too good - at low speeds they were grabby and began to squeal. Great at higher speeds though. I tapered back the leading edge of the lining approx. 1/4" and now they're perfect - powerful, controllable, no squeal.
As mentioned, lever angle and proper link rod adjustment are very important.
:thumb: on Charlie's assessment of the improvement after his work! I'm now in the process of relearning how to stop smoothly with the new & improve front brake. I don't know how long the improvement will last, & I doubt that my brake adjustment work in the future will be as good as his, but the front brake now feels like I could lock it if I tried - but I won't, of course. Before, it felt like I could squeeze to the point of breaking the cable & it still wouldn't lock.
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:thumb: on Charlie's assessment of the improvement after his work! I'm now in the process of relearning how to stop smoothly with the new & improve front brake. I don't know how long the improvement will last, & I doubt that my brake adjustment work in the future will be as good as his, but the front brake now feels like I could lock it if I tried - but I won't, of course. Before, it felt like I could squeeze to the point of breaking the cable & it still wouldn't lock.
That's good to hear! When in the hands of a master like Charlie, it is amazing how good the "old. outdated" equipment can function!
Is that a double leading shoe front brake?
IIRC, a few bikes came with Four Leading Shoe front brakes and two front brake cables. Setup was crucial.
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That's good to hear! When in the hands of a master like Charlie, it is amazing how good the "old. outdated" equipment can function!
Is that a double leading shoe front brake?
IIRC, a few bikes came with Four Leading Shoe front brakes and two front brake cables. Setup was crucial.
Yep, mine is 2LS front. Some on this forum have said that a properly set up 2LS front will just about match the stock 4LS or single disc front brake, but I have no exprience on either of them.
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Yep, mine is 2LS front. Some on this forum have said that a properly set up 2LS front will just about match the stock 4LS or single disc front brake, but I have no exprience on either of them.
The way Charlie did it is brilliant. You get to see all the improvement after one machining/adjustment operation.
The way we used to do it (no lathe) you might feel a small 10-25%? improvement each time you sanded the shoes to get a better match with the drum. In those situations, I think human nature always dominates and it is easy to delude yourself that the improvements are more significant than they really are, cause of "your skill" and "TLC."
IIRC, way back in the day, one of the big technical sellings point of the early disc brakes were that they were "self-adjusting!"
I think every modern trials bike on the market today has a hydraulically actuated clutch for that reason.
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I roadraced a BSA B-50 with the widely maligned 2LS conical front drum brake. It had Ferodo shoes, and the only other modifications were 1/2" longer arms on the cams and a clutch lever and perch on the handlebars.
I could easily stand the bike on the front wheel coming into the pits after a practice or a race, but I had to tighten the cable DURING the race and loosen it when I got off the bike in the pits.
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I have friends and acquaintances that ride nothing but no front brake, rigid frame choppers, and ride them like the devil is chasing them. Most of them have crap rear brakes also, and goes without saying that helmets are nowhere to be seen in this crowd. Sketchy as hell to put it mildly. Not one of them is capable of a controlled panic stop. The weird thing is, they don't seem to get killed off more frequently than the AGATT, ABS guys. Not sure why they haven't all perished by now.
Wow, I didn’t know there were still bikers like that. Like a Dave Mann artwork come to life! All of the Harley guys around here, including the local badass M.C. guys I see, are riding Road Kings and the like. All newer bikes (with disc brakes from bow to stern). But I live in L.A.
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My Ambassador schooled me on how to ride mountain roads as fast and smooth as I could within the brakes' limits. Best riders training I could ask for.
Agreed!
Biggest thing you need to know is you will ALWAYS apply front and rear brakes on a loop in tandem.. not like on modern bikes where I use the front only about 75% of the time.
The brakes arent super great, but they arent exactly rubbish. They fit the power of the Ambo fine. You are talking about a bike that wont- or will just barely- crack the ton, it's not a rocket ship.
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You can always get safer. Some wont ride with single disc, some without ABS, frankly even a bike itself should not be ridden, and we need to all get in our Volvos. No denying that twin front discs will stop you much faster in most cases. Discs will self adjust. Discs wont fade as bad in high heat use. A disk brake will work better in the rain.. But like anything, you need to adapt your use to the equipment shortcomings. No doubt discs are better. But for the right bike, at the right price, that fits your planned use? Sure I would ride a bike with drums. Just need to adjust your riding style to match the performance level of the machine.
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In addition to addressing the mechanicals of the brake-- the choice of cable and its routing can make a difference. After using both the switched and un-switched cables available from MGCycle I ordered the "custom" cable available directly from Barnett ($70). Using this stout cable eliminated much of the elastic feel and improved the response. The cable is routed straight from the perch over the bar clamps then down through the cable stay at the triple-tree and then through the cable stay at the fender. Although the triple-tree stay is sometimes not used I think it's effective.
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Sounds like "we" have successfully settled the issue!
Serious fiddlers can make drum brakes work well enough!
We should move on to either carbs vs. fuel injection, or what's the best engine oil?
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YEAH! What's the best oil to use?????
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YEAH! What's the best oil to use?????
Where? On your skin? In your hair? For cooking? Etc., etc., etc. :evil:
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Where? On your skin? In your hair? For cooking? Etc., etc., etc. :evil:
They make different kinds of oil for different applications?
Used motor oil in your hair can save a lot of money on hair dye (Guzzi content)!
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The main trouble I had with the drum brakes was the inconsistency due to humidity. Most of the time they worked ok but dampness sometimes made them not so good and inconsistent. I learned to heat them up a little at the beginning of a ride. That’s when they would squeal. It actually saved me once when about a half mile from home as I was setting out to go somewhere, a car on my left started to pull out in front of me. The front brake didn’t slow me much but the squeal was louder than most horns and the car stopped. I put new shoes on after that and the squeal went away.
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I own some bikes with late drums and some with 1st gen disks. Some 1st gen disks weren't much better than late drums on some bikes. My 70 ambo had a barely adequate front drum until I spent some time shimming, adjusting, sanding and more tweaking to get the front TLS working right. It's still not up to modern standards but I keep my distance from other traffic and it's fine for me, I love riding that old loop!