Is Direct Drive Really Better?

I've been reading and hearing more and more about the superiority of direct drive because it drives the platter rather than dragging it along by belt. It actually makes some sense if you think about cars. Belt drives rely on momentum from a heavy platter to cruise through tight spots. Direct drive actually powers the platter. Opinions?
Direct drive, idler wheel, belt drive. There are good and bad implementations of all of these, just like suspended and non-suspended tables.

BTW, your car analogy is a bit flawed when you consider what the engine's flywheel is designed to do. A stock car will have a heavy flywheel from the factory which helps get the car going from a standing start. When I used to drag race one of the first things we did was to lighten the flywheel just enough to help get the rpm's up quickly. Too much and you had trouble getting the car off the line.
Above a certain price point, direct drive is the superior technology. But designing and building a good direct drive unit costs a fair bit of change, which is why it was generally only attempted by companies that could amortize that cost over a large number of units--esp. your larger Japanese makers. And they're largely out of the turntable market now, save for a few really low-end units--belted, of course. The most obvious exception is the Technics 1200.

For smaller makers, belt drives are much easier to build well, so that's what they do. At the same time, they've spent the last couple of decades trash-talking direct drive, so a lot of audiophiles have heard that direct drives disappeared because they were inferior. Not so.
Is this a joke?
It is too bad that so many shoddy, cheap, direct-drive tables were churned out in the 70s and 80s. Many truly sound terrible and have given this drive system a bad name. Regrettably, most people have not had the opportunity to hear a properly set-up Denon DP-6000, or an SP-10. As these were motor units, the choice of plinth is quite critical. Feast your eyes on the direct-drive museum,
here you will see numerous examples of correctly implemented direct-drive tables. Sonically, they offer a very different set of strengths and weaknesses than traditional belt drive units. I own both belt drive and direct-drive tables, but my Micro Seiki MR-711 really brings me a lot of joy as did my Denon DP-6000 and Micro Seiki DDX-1000 before it, and that's what it's all about. No joke.
I would agree with Pabelson.

When you consider that some of the vibrations on a record groove are measured in the billionths of an inch, the importance of keeping motor vibration out becomes critical. It would seem to me that the cost and engineering of doing this with a direct drive would be prohibitive compared to a well implemented belt drive.

It's interesting that some CD player manufacturers, like CEC, use belt drives on their units.
What I remember about the rise of belt drive at the expense of DD was the feud between Ivor of Linn and Michael of SOTA. It went on for years to the delight of the audio press. It seemed to be staged in much the same way as the WWF feuds. It caused audiophiles to choose sides concerning which suspended table they preferred. VPI and Oracle were also both ascending and the unsuspended direct drive tables were forgotten. A few years later, digital took over.
Now that the belt drives are all going unsuspended, we're again looking at direct drive and seeing that they actually outperform even the most prestigious belts.
This is what I felt when I asked the question but I was wondering what sort of agreement or controversy I might find. So far, I have 1 noncommittal, 2 agreements and someone who thinks I'm joking. What's your opinion?
I think digital belt drives are high end snake oil, but I as most could never find a direct drive table within reason that could compete with a mid priced belt drive table.
Direct drive TTs and belt drive digital: my ticket to high end salsa music reproduction. My KAB modded Technics 1200 and Modwright modded Parasound belt drive transport are great performers in any league.

Curiously enough, I ran into my father's friend who introduced me to high end when I was in high school. I was telling him about my KAB modded Technics 1200. He had to admit that selling his Technics SP-10 for a SOTA vacuum was a mistake.

I have to admit I love my Technics SP-10MKIII. I also have a Linn LP12, Micro Seiki 1500FVG, Teac TN400, Dual CS5000, Empire and a few others laying about. I use the Technics most but the Micro is great too.
Actually, idler-drive rules. There's a reason why the Audiogon thread, "Building high end 'tables cheap at Home Despot (sic)" has over 3,100 posts and grows daily. Go all the way to the end of it and read the most recent post by Johnnantais. This is no joke.
I find it intigueing that Brinkman, who make one of the finest belt drive tables out there, recently introduced a DD model. Interestingly, they are also the US importer for the Norma-Hylee-Tech modded Thorens TD-124 idler-drive tables. Grand Prix also just started showing the new Monaco DD table, which appears to be out of of prototype form. Do we have a trend beginning? Can I get a witness?
Marty - trend or no, superior technology or no, there will always be a response to a buzz. Audiophiles start talking about and yearning for DD's and idlers? One-man shop guys and DIY'ers getting good results on the cheap? Companies will never let that stand. Exisitng manufacturers or new ones (just wait) will leap into the fray with claims that THEY have the secret to unlocking the very best of whatever technology is currently sexy. Of course, as an example, only the finest titanium shafts turned on gold-plated lathes using ceramic tools whose paths are greased by the sweat of nubian maidens will do. And, by God, that costs money. Money they would just love to cleave from your wallet. Soon you have a 1200 in a $25,000 package. Just wait!
Good to see that you wandered over here from the Vinyl Asylum. I am in complete agreement, though I never claimed that any technology was superior; I am more interested in fun than superiority. Oh, and I will need to be a beta tester for that nubian maiden sweat, BTW.
Oh, I've been saving their sweat in jars in anticipation of a future windfall. Such is the soundness of most all of my investment strategies...

Naw, I really could not care less which technology is used - only about what my ears ultimately hear.

You are on VA, too. Another person who uses a separate name? That's damn confusing, I say. :-) My name over there is 4yanx. You can call me 4yanx. :-)

"the sweat of nubian maidens".

NOw, I'm FINALLY interested in analog playback!
Exactly the type of response which is routinely preyed upon...:-)
A native of Nubia.
Some good info before the thread veered sharply downward. I'm going to conclude from this meager participation that direct drive is a better performer than belt and few people are aware of the fact. And at least one person thinks that rim drive is better yet. I wonder.
Macrojack, I question your conclusion. I think a better read is that both belt and direct drive can work wonderfully, but it really depends on the implementation. One is not really better, each simply has a different set of compromises.
I own a Denon DP59-L direct drive.. and a Dual SC7000 belt drive.
Both are nice tables that sound good enough to my fussy ears. And both have 'lift at end of play' devices, and start cueing too. So my drunken ham-fisted mitts do not destroy the LP or the stylus.
But then I am only a common audionut.. and not a full blown Audiophile wacko.
(only because I am relatively poor.. If I was a billionaire it would be a different story)
I think the best course of action is to buy a turntable on the basis of the quality of sound it produces versus its cost to purchase, and to forget belt versus direct versus idler.

If you want to buy a sports car do you buy on the basis of the engine configuration (V8 versus turbo versus supercharged, versus rotary) or do you take the cars for a drive ?
In that case, Seandtaylor, there's only one winner - my Lenco GL75 idler wheel tt from the 60's cost me $200 after making a heavy CLD plinth for it. I sold my well set up Garrard 401, and Thorens TD160 belt drive as they were substantially worse in every way (though I wonder if the gap may have been closer with the Garrard if it had a heavy plinth also). Then I read an article in Hi Fi World magazine in which David Price (editor) trumpetted the 401 over his favorite belt drive Michell Orbe (at $5000). Heavyweight knockout or WHAT????!!! i am still amazed by my tt and endorse everything that johnantais says in his last post on the Building high end tt's at home despot thread.

I think it would be unwise to make such a conclusion based simply on a number of responses on this thread. The almost universal employment of belt drive in high end tables is more than just a mere coincidence.

A poster indicated that the use of belt drive is mostly due to cost, rather than outright sonic performance. That may very well be true, but I then would have expected to see a few more direct drives available considering the tens of thousands of dollars some tables retail for.

Regards Paul
"...home despot thread" pretty funny, what kind of table does Baby Doc Duvalier use at home?
Goldmund made a direct drive table and I've heard that the final version of the Rockport was DD. A poster above mentioned the Monaco turntable that appears poised to surpass all existing turntables in measurements and sonics. The Technics SL 1200 must by now be one of the best selling tables of all time. All these things point toward a degree of superiority.
I think we were led astray by the audio press when we started to prefer belt drive categorically. I'll be interested to see if a cost no object rim drive appears. Or the long rumored Bose chain drive diesel table with direct reflecting mirrored platter mat and Gabriel suspension. And long overdue -- they intend to offer a left handed tonearm with organic butter damping.
I can't wait to see Fremer gush over that one.
Is butter a better lubricant than nubian maiden sweat? Or is that only on left handed tables, and is it true that if you take them below the equator that they spin the other way? Whoa, dude, that would be like CDs!
CDs actually spin the same direction as LPs they just play from the inside out. But when you think about it, wouldn't it have been better if records played from the inside out? It would make a tonearm lift unneeded. The arm would just fall off the record when it got to the end.
likely not. equal perhaps. the goldmund was dd but at what cost? somehow i dont think the 1200 is nearly a goldmund nor an SP10.

aka hifitommy.
unfortunately, this thread has turned into a joke as cwlondon predicted.
More like a series of jokes. Sort of like the turntable with the schtick shift. And I didn't get ole CW making a prediction. He came across to me as condescending, as if my question had no merit.
4yanx, as usual, provided a cogent observation. This time it was his comment about buzz. I have sensed for a while now that there is a definite revival of direct drive in the works and I was fishing with my question to see who, if anyone else, had the same sense. Seems like there are a few.
Just because we kid a bit in some threads, hardly negates the excellent information posted. Some of us like a little sugar in our tea, some not. Perhaps some are a bit constipated and could use some Immodium.
Lighten up, or wash the blood out of your shorts geeeeez!
I have sensed for a while now that there is a definite revival of direct drive in the works

Guess who's one of the main characters...yours truly!

I've reread my last post repeatedly in search of the comment that triggered the Immodium and bloody shorts remarks.I guess I'm going to need an explanation.
Immodium is for the control of diarrhea not for relief of constipation.I looked it up.
As for blood in my shorts -- is that a gender driven slight? If so, you are addressing the wrong gender.
And if you want to find a direct drive turntable that can beat a medium priced belt drive, I can help you with that and it appears that Psychicanimal can as well.
What is it about this thread that is causing you boys to giggle and smirk? Where are the observations about the relative merits of DD versus belt? How about establishing some of the trade offs between the two. Someone earlier stated that there are definite trade offs. What are they?
Have your fun, if you must but I'm looking for more than jokes. I already know how clever some of you can be and I enjoy the repartee but must it be either or? Aren't you deft enough to intermingle the humor with useful contributions. 4yanx does this well and Viridian typically splays adroitly.
No one has seen fit to comment on my suspended tables theory. Doesn't it seem in retrospect that the entire consumer market has been swayed by a little postulation and a lot of press on more than one occassion? Do you think that Harry Pearson has done more harm than good?
yes...if you're grandmaster flash.
I posted in haste before and did not get my point across. I love the joking as much as anyone and don't mean to sound like a curmudgeon.

"I'm going to conclude from this meager participation that direct drive is a better performer than belt and few people are aware of the fact."

This seems more like a statement of what had already been accepted by Macrojack as fact. Since he is so quick to come to this conclusion I'm getting a sense that the point of starting this thread is something of fishing expedition, otherwise known as trolling. I'll stick with my original thoughts. That is, there trade-offs with all 'table designs. None is inherently better than the others, but the proof is in the implementation. There are good and bad examples of DD, idler, belt-drive, suspended, non-suspended, etc., and to dismiss all others for the sake of a chosen "golden" theory is short sighted, IMO. Kind of like the debate about whether or not digital is worth doing.
I understand fully well that any approach can be mishandled or compromised by price point considerations, sheer ineptitude or misdirection. Let those units go. They are not intended to influence this discussion.
Taking the best efforts in each of the various turntable drive options into consideration, do you believe any drive system to have an inherent design superiority. Is belt slack and take-up an insurmountable obstacle? Is there magnetic influence on the cartridge from the motor as your arm nears the center of the record on direct drive tables? Wouldn't it be better to rely on constant drive of the platter rather than requiring momentum for speed stability? How the heck can an idler wheel not transfer rumble? Is chain drive really dead? Can analysis be worthwhile........?
"constant drive of the platter "

The platter is still driven by a motor, and that motor is still subject to noise or vibration. One could argue that a belt filters motor noise.

Why would a lighter platter directly driven by a higher torque motor produce a more constant rotation with less noise than a massive platter driven with high inertia by a low torque motor ?

To me it is not obvious that direct drive has any advantage over belt drive.
I'll chip in a bit here. I've been using an LP12. It was enjoyable even though it wasn't maxed out. I now use a Mitsubishi LT-30, which is both DD and with a linear tonearm. The Linn provided a more spacious soundstage and great rhythm (toe-tappin'). The LT-30 sounds more emotional to me and my wife.
Please understand that I am not an engineer. What I pose here is speculative and lay in the extreme.
Consider that your stylus is being driven through obstacles such as a narrowing of the groove or some groove pattern of exceptional complexity. Or it is being dragged through by a belt with the aid of momentum. It seems that at the point of immediate resistance a mass no matter how great will hesitate slightly when confronted with the aforementioned obstacle. I imagine that a large motor directly driving the platter would not hesitate at this time. Further it seems that at take up a belt would stretch a bit momentarily.
As for vibration, I remember from my 1970s era audio sales days that higher end DD tables had rumble figures unimagineable to the belt drive units.
Idler-wheel drives anyway (and big DDs to a lesser extent) clearly demonstrate, in comparisons, that mass/inertia alone does not overcome stylus force drag in belt-drives. Big DDs such as the SP10 MKII and big idler-wheel drives, such as the Garrard 301/401 and the Lencos, are clearly superior to belt-drives in terms of bass depth, power and speed, and no one disputes this. This underlines a weakness in belt-drives: regardless of the mass of the platter, stylus force drag is exerting a force which is never entirely wiped out in belt-drives, only mitigated to a certain extent, which brings with it other problems, such as loss of PRaT, rhythm, timing, gestalt. This means it takes torque, an active force, a bigger motor, to combat stylus force drag, that simple mass is quite simply insufficient. Now what is clearly audible and demonstrated in comparisons between belt-drives and idler-wheel drives or big DDs - first and foremost in the bass - MUST be audible across the frequency range, and it is: dynamics and speed and attack are clearly superior, again something which most would not dispute. Now this difference in attack and dynamics is less large between belt-drives and big DDs than it is between idler-wheel drives and belt-drives, showing that idler-wheel drives go further down the road to perfect speed stability than either of the other two formats. I and others in my area (and around the world) have done repeated tests using a very high-mass Technics SP10 MKII vs various Lencos and a variety of high-end belt-drives. And no, rumble is not audible from such more highly-developed idler-wheel drives as the Lencos. Anyway, I posted reasons on "Building high-end 'tables cheap at Home Despot":

"So in a nutshell here's why I believe idler-wheel drives are simply superior (apart from the actual empirical testing which clearly demonstrates this so far ;-)). Belt-drives have belts, and these stretch and contract, and if they are not stretchy, then they slip. Not only that, but they use dinky little motors which spin at relatively low rpms, so they have neither the torque nor the speed stability of the high-rpm idler-wheel motors. Now, belt-drivers claim that simple mass in the platter wipes out stylus force drag, but since both good idler-wheels and good DDs clearly show superiority in the bass, then this quite simply shows this is not true, else belt-drive bass would be as good as that from Garrards or Direct Drives, kapish? This MUST also be audible across the frequency range, and it is, as a relative softness and lack of attack and dynamics as compared with both DDs and idler-wheel drives. The turntable with the best speed stability in practice should, given a decent platform, quite simply be superior, but belt-drives show weaknesses in all kinds of areas, therefore they are at the bottom. The finger demonstration shows this clearly ;-).

Direct-drives are saddled with low-rpm motors. Therefore, while they have superior torque and so are less susceptible to stylus force drag than belt-drives, they are at the mercy of the motors (and their imperfections) to a far greater extent than idler-wheel drives or belt-drives. The platter mass serves to counterbalance the very slow and jerky rotation of the DDs, and in comparison with idler-wheel drives, there is a consequent "dryness" and dynamic constriction of the sound which is clearly audible (the Lenco and Garrard sounding quite a bit more liquid and dynamically open).

Idler-wheel drives have motors which spin at roughly 1500-1800 rpm, meaning that the very high speed serves itself to smooth out its own speed imperfections. But when securely coupled to a flywheel-platter via the idler-wheel, the platter regulates the motor's behaviour, smoothing things out further, while the powerful high-torque high-speed motor pushes the platter through all the passages, so that stylus force drag is truly eliminated, by a combination of brute force and elegant flywheel effect. Idler-wheel drives were created specifically to combat stylus force drag, from the days when cartridges tracked at 10 grams. The largest consequence of idler-wheel drive superior speed stability?: there is simply more magic and vigour in vinyl spun on idler-wheel drives. The rest, detail, bass slam, etc., is all there, but the ability of a Giant Lenco, for instance, to draw one into the music is downright spooky, incredible, amazing. It transcends the equipment, all the way down the line. Since music is the #1 consideration in reproducing music, then the most potent music maker is the best 'table/system, the end (and yes it is superior as well with respect to detail etc. yadda-yadda). I am still agog.

The issue of whether or not one system is superior to another can only be settled by testing. With high-end designers getting into the Lenco game, then expect to see rebuilt Lencos begin to appear at high-end audio shows, and perhaps one day, me along with them."

And to corroborate this, some independent published findings at

Endlessly trumpeting that all systems have compromises ignores the degree and number of compromises, and assumes that each compromise is equivalent to another, such as, for instance, speed stability has equal importance as silence. Wrong: speed stability is the single most important aspect of vinyl playback, and how can it be otherwise? Records are engraved at 33 1/3, and must be replayed at 33 1/3 to get the full intended result. A compromise here outweighs every other consideration, which can be addressed anyways by a variety of means, such as mass-loading idler-wheel drives to eliminate noise (the traditional approach), neither difficult nor especially expensive. Belt-drives, however, will always have belts, and yes, you're right Macrojack, much was made of the isolation from motor noise of belt-drives, but the much cheaper manufacturing costs of belt-drives (at least in the old sensible days), and thus increased profits, were not trumpeted. Plus, when the Linn first came out, it had more measured rumble than a Lenco by a significant amount, and yet the press trumpeted its increased silence, on "principle."
"This means it takes torque, an active force, a bigger motor, to combat stylus force drag, that simple mass is quite simply insufficient."

How does the stylus know the difference between a high torque motor and a large mass with a large polar moment of inertia ? I cannot understand how a large polar moment of inertia is any less capable of overcoming stylus drag than a high torque motor.

Do you feel a difference between being run down by a car (being actively driven by a motor) or a large rock rolling down a hill ? I would say that both will crush you equally, one using its motor, the other a very large inertia.
Do you feel a difference between being run down by a car (being actively driven by a motor) or a large rock rolling down a hill ? I would say that both will crush you equally, one using its motor, the other a very large inertia.

Sure, Sean, but you're asking the question from the wrong perspective. What if you wanted to run somebody over, which would you use? Seems to me that "direct drive" would be the right tool for the job!
With high-end designers getting into the Lenco game, then expect to see rebuilt Lencos begin to appear at high-end audio shows, and perhaps one day, me along with them."

The ironic juxtaposition of high-end designers with you along side them notwithstanding, do you or does anyone think that high-end designers will be satisfied with trotting out rebuilt Lencos at high-end audio shows?! Please. While they may allow this initially as a co-opting exercise to further whet the market's appetite and bring recalcitrants into the fold, the high-end designer is "high-end" by definition of being high dollar, not necessarily high performance. They won’t make diddly rebuilding Lencos and they will do NOTHING that won’t make them diddly. In their hands, the idler wheel will soon be a titanium/graphite composition coated with rubber from first-growth virgin Indonesian rubber trees, the platters of some exotic ceramic, and the plinths made from only the very rarest hardwoods taken from the deepest, most dangerous African forests and assembled in finished using strictly proprietary, superior (though unproven) methods. Why? Because ONLY with these combinations can you bring out the very best performance. And, we all want the VERY best, right? Old song, new verse. The only other way for them to profit at the levels they will expect will be to sell it as a super cheap alternative with the hope of totally cornering the market for those looking to spin a few oldies and not wanting to spend more than a couple hundred. Yeah right, THAT’s going to happen, that market demands good sound.

Clearly, the idler wheel tables have A LOT going for them, especially when thoughtfully and effectively restored and when compared against much higher priced tables. I’d even say that idler wheel tables have the ultimate edge on belt drives. Of course if one is happy with what they hear from their own table, who can argue? I, for one, do not really care which technology is used, provided joy is attained through listening. This hobby is FULL of folks wanting you to believe that “you haven’t heard your music till you’ve heard it on this”. And, that’s where dough gets separated from wallet. The beauty of some of the latest idler wheel and DD units and restoration efforts is that nearly equal, equal, or even better performance can be attained at a lower cost - which allows either more money in the jar or more money to be spent on music. I am not holding my breath that high-end designers will be promoting that ethos – now or ever.

Macrojack, I’m not sure if this is cogent, but it is heartfelt and well considered. :-)
This is an excellent topic and discussion! What I find so intriguing about the resurgence of interest in DD and idler wheel designs is the retrospection it is prompting abou how the high-end has developed. Do you all remember Harry Pearson's first review of the Linn LP in which he described it as something that appeared to have been built in a Bronx garage? He took huge flack for that. He had been an SP-10 enthusiast, but gradually shifted in other directions as DD lost favor in the high end. Art Dudley's latest S'phile column acknowledges that he (and most of the rest of us) may have bought into a certain way of thinking about turntables that we perhaps we need to re-consider. This is fascinating stuff, don't you think?

Seveeral of the threads here about the Technics SL1200 (w/ KAB mods) compare it to belt-drive tables in the same price range. Okay, so it's serious competition to Regas and Music Halls. But tell me, Psychic and others, is it serious competition to the next rung up in belt drives: Linn, Nottingham, Basis, VPI, Kuzma, etc.? Forget about the Walkers and Rockports even, but in the segment around $2K - $4K do the DD's compete? David, (4yanx), am I right that you moved from a Nottingham, which you were very enamored of as I recall, to a DIY idler wheel TT? Has it been an unequivocal step up?
Assuming nothing about relative sizes of car and boulder, and knowing nothing about polar moments (sounds like a phrase from a travel brochure) I would surmise that the boulder would be slowed somewhat by your body since it was coasting whereas the car which is actively powered could be completely unaffected by your presence in its path.
What I'm imagining here makes perfect sense to me but that does not mean I'm sure it is supported by physics. Does someone out there have a background in physics and an opinion on this matter?
I appreciate your contribution here. It's more like what I was seeking when I asked about this topic. I'm aware of your Despot thread but it's so huge now I can't even find the end of it.
What do you think about the Thorens 124? I took an interest in that until I found out it has an iron platter that attracts cartridge magnets. Is that a valid concern?
Your observations registered on this end as both wonderfully incisive and appropriately cynical.
I think that the Chinese idler wheel turntable might appear if Schifter or Nudell or someone of that ilk finds the demographics are there to support such an endeavor. Perhaps we'll be seeing the Johnnantais Signature Model with the new Lega arm.
Drubin, there has been a lot of buzz, in my opinion at least, for a couple of reasons. One, people love to argue what they like and/or know best. OK, true, but not the main reason. There are valid reasons for promoting idlers and DD's and for questioning why belt drives currently dominate the scene. Inquiring minds want to know if it is because they are superior or just good enough that one can't really tell much difference or because of some nefarious or market-driven reason. IMHO, when in doubt, bet on the market. That is why I am HIGHLY skeptical of the "high-end designers" sudden interest in idlers. Clearly there have been idler advocates for quite some time - the restored Garrard projects go back quite a ways. Only a matter of time before folks started using similar tables to similar ends. Kudos to Jean for trying it with the Lencos but, by his own admission, it isn't a novel idea. But, with all the current buzz, Garrards, Lencos, Rek-O-Kuts, Russcos, etc., etc. this is beginning to look like something that audiophile will BUY! Thus, perhaps, the apparent "suit" interest.

To answer your second question directly, yes I loved my Spacedeck. It is still in service, however, with one of my sons. I still have a Hyperspace and it is a great table. However, we (another son and I) have built now six Lencos. All sound terrific, frankly. The best of our efforts will compete with turntables costing many times more, and we have friends that can attest to this fact. I some ways, they sound better, especially in the lower end and in that indefinable “pleasure” factor. I am neither an engineer nor a psychologist so I will not try to explain the “boogie factor” these tables seem to have. They are good but, on the other hand, not everyone has the time, patience, skill, or whatever to rebuild one. Also, if not done RIGHT, they can be loud, rumbling messes (whether anyone who has built one wants to admit that or not). In other words, proper implementation is crucial. I have had MANY folks write to me wanting me to build them one because they like our plinth designs and because they want to do the comparison but don’t have one or more of the necessities listed above. Again, this will pique the interest of those wanting to cash in. We, ourselves, have deferred except to make a couple for friends. Given recent improvements in my back, this may change quickly, though, especially if we can help a few folks before these old ones are all gone and you can only find one from a high-end designer at a high-end price. Ha! :-)
"I would surmise that the boulder would be slowed somewhat by your body since it was coasting whereas the car which is actively powered could be completely unaffected by your presence in its path."

I think you'll find both are slowed. Cars are slowed by headwinds, even though they are powered. A car is slowed when it hits a tree, even when it's powered. A large rock rolling down a hill can smash to splinters a tree that would stop a car dead in its tracks. Even if the incline is very slight, such that the gravitational force acting to roll the rock is very small the rock carries a lot of energy in its inertia.

All I'm saying is that I cannot see any way in which high torque/low inertia is inherently superior to high inertia/low torque, for purposes of speed stsbility.