in my experience this brake works fine, even on a relatively heavy machine like a Trident. In the end it all depends on the correct setup of the brake.
In my experience - now 33 years with at least one T160 and four years with a T150 with the earlier drum brake - the drum brake 'works fine' if you don't use much of the triple's performance, don't carry a passenger or much luggage and stay away from twisty roads if they also go downhill for many miles. And, as I say, this is with a pre-conical drum that has had much collective experience lavished on it - drum checked for ovality, matched linings, top-quality cable, yadda, yadda.
Otoh, any half-competent diy mechanic can improve the disc brake - single to double, floating and/or 12" discs, four-pot calipers, etc., etc. - until it's other cycle parts that invoke the law of diminishing returns.
Bottom line is even a kick-start triple is a near-500lb motorcycle when filled with fuel and oil. Fitting them in 1968 with standard cycle parts also used on the contemporary twins was simply short-sighted - the CB750 always had a disc, even though Honda made some very good tls drums; the GT750 had a 4ls for just a year before Suzuki acknowledged the inevitable, etc., etc. Then quite how BSA arrived at the collective conclusion that what their top-of-the-range models really needed was the drum brakes replaced by different drum brakes of the same sizes is likely to remain a Marie Celeste-type mystery, I suspect.
Originally Posted by Peter R
These brakes can be upgraded by fitting 1-inch longer brake lever arms,
... at the expense of longer handlebar lever travel.
Don't get me wrong - if it's what you want, either BSA/Triumph drum brake can give reasonable performance in modern traffic conditions; just, for similar effort and expense, even the '73-on Triumph/Lockheed disc will always reward with greater performance. Also, once disc brakes are done, their performance will deteriorate almost unnoticeably even if never maintained; otoh, maintaining peak performance with either (any?) drum brake requires regular fiddling and fettling.
Hard to argue with, there is a reason they went to discs on nearly everything. Even with a well set up drum you only get a few stops before fade. How the bike ends up being set up will depend on how much I like driving it. All my daily drivers have three discs and it might well be necessary to upgrade this bike for traffic, if so I'd retain all the original bits as we are only temporary custodians.
Stuart has some interesting points indeed, however I still insist that the conical hub type brake is a good stopper, and I feel safe at any speed on my Trident. This can not be said of the Lockheed disc setup on my Commando, which felt outright scary, (and has long since been replaced by a modern Grimeca unit). Modifications like a sleeved down master cylinder were also offererd to improve the standard setup.
Of course disc brake technology has come a long way, and I am convinced of the superiority of a modern disc brake setup. I only would like to point out that the first generation of disc brakes, offered only a marginal improvement over the drum brakes they replaced. Even in the 1970's the first generation of disc brakes were often critisized for their "wooden feel", and their failure to brake at all under wet conditions -the latter applied in particular to Jap bikes-
I do not disagree that a drum brake needs more fettling to make it work at its optimum, and that there is a good reason why modern bikes all use disc brakes.
Peter. 1974 Commando 850 1972 Trident T150T 1961 Goldie DBD34 1969 Benelli 250 sport special
This can not be said of the Lockheed disc setup on my Commando,
Ah, I think I see where you might be coming from ... thankfully, the disc brake Triumph used has absolutely nothing (major?) in common with the one Norton used on the Commando; apart from those caused by neglect, you wouldn't have any similar problems with the Triumph disc. This is also why, if you utilise all the available experience on Triumph drums and discs, if even a single disc isn't noticeably superior to either drum, you've done something wrong.
Originally Posted by Peter R
Modifications like a sleeved down master cylinder were also offererd to improve the standard setup.
On the Triumph discs, my personal jury is still out on this. Some other owners I know who've had the mod. done like it; otoh, my T100 has the standard 5/8" i.d. master cylinder with single disc, my T160's started out like that but have 7/10" i.d. master cylinders with twin discs, I've tried triples with twin discs and 5/8" i.d. master cylinder and didn't like the brakes at all.
Sorry for the lack of updates but do to bad weather and work I've had little time for anything bike relate, but I do have a couple photos to share.... This is The Garage of my new Home, the Trident was the second thing I moved in...That's only because the Norton was in the way....Hopefully I'll be able to get into cleaning it up this spring once I'm all moved in...