Dear MOby,

It would seem (pardon) that DCTs have much more applicability for production motorcycles than seamless transmissions as used in MotoGP racing, and therefore would be of more interest to the manufacturers to better leverage their racing investment. Doubly true these days, as manufacturers struggle to make motorcycling more accessible to a wider audience as us boomers are, er, “aging out,” so to speak.

Walter Barlow


Dear Walter,

Stop making sense. As near as I can figure, the FIM banned dual-clutch set-ups in MotoGP because the FIA had banned them earlier in Formula 1 (where they showed up more than 10 years ago). The FIA banned dual-clutch boxes because CVT gearboxes aren’t allowed (constantly variable transmission) – the rationale apparently being that since there’s zero lag time as gears are shifted in a dual-clutch transmission, a DCT is in effect a CVT.

With a seamless transmission, there’re still a few milliseconds between one gear and the next, and the rider still has to instigate the shift with his foot – which gets around the MotoGP reg prohibiting “purely electronic means of gearchange”. (Also since nobody at first understood how Honda’s new seamless gearbox worked in 2011, nobody was able to come up with a reasonable sounding reason to ban it.) Another stated reason for not allowing dual-clutch systems was to keep complexity and costs down, which seems to have backfired since Honda’s seamless gearbox work-around is reputedly way more costly than a DCT.

Seamless gearbox

This image is from formula1-dictionary.net, where there’s a pretty good explanation of how seamless gearboxes work.

I’m with you: I’m a big fan of the DCT in every Honda I’ve ridden so equipped, and it’s a must-have for all riders whose feet or legs or left hand don’t work so hot anymore, if at all. Not only does Honda’s DCT work great, they’ve also gotten the price down to where it’s only an extra $700, for example, on the Africa Twin. Another drawback to the DCT on a MotoGP bike would be weight and a bit of bulk: Honda says the Africa Twin DCT weighs 23 pounds more than the manual gearbox version.

Honda Africa Twin Shootout: DCT vs Manual Transmission

The seamless gearbox remains somewhat mysterious, but various sources report they’re not only expensive to build, but also require constant servicing by dedicated mechanics – partly because they’re mechanically finicky, partly to maintain secrecy. All of it seems like a lot of effort to shave what most sources say is around 0.2 to 0.3 second per lap, which is a big deal in top-level racing but wouldn’t seem to be of much benefit at all to the average street rider.

Then again, it probably won’t be long before the World Superbike people decide they need that extra 0.2 second, and after that camel’s nose is in the tent, well… you never know. Today’s exotica is tomorrow’s Craigslist beater.

Here’s a great video to explain how the seamless gearbox actually works.


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  • Donnie

    Just think how much motorcycle development has been stifled because of the FIM’s arbitrary rules. Aerodynamic gains, more than 6 speed transmissions, material advancements… The list goes on and on.

    • Old MOron
      • mikstr

        I’d ride the rider but not the “bike”…

      • Michael Howard

        My name is Nobody.

        • Old MOron

          Oh man, great movie. Now I want to go home and watch some Terrence Hill and Bud Spencer reels.

    • Goose

      I wish I could up vote your statement more than once. Bad decisions by the FIM have haunted motorcycling for decades.

    • azicat

      Same goes for the UCI and cycling, where fundamental bicycle design is trapped in the 20th century. Disc brakes have only just been approved “on trial basis” this year.

      Admittedly it’s not an easy task – these governing bodies are trying to find a balance between human sporting skill and engineering innovation.

  • BTRDAYZ

    I would like to see DCTs in Maxi-scooters like the BMW C650, Yamaha T-Max and even the Vespa 300 GTS, complete with thumb shifters.

    • Campisi

      I’d rather Vespa focus on cracking that thirty-horsepower barrier for now. Hell, since we’re pretty much dreaming anyway, put a manual transmission in a version of the Sprint 150.

      • BTRDAYZ

        Actually, the Vespa GTS 300 has 33 horsepower, and is on par with other single cylinder bikes of the same displacement with more sporting intentions, like the BMW G 310 R with its 34 HP.

        • Campisi

          “The Vespa GTS has no rivals on today’s market. Its 300 cc engine can deliver maximum power of 22 HP at 7,500 rpm and maximum torque of 22.3 Nm at just 5,000 rpm, ensuring quick throttle response and extremely brilliant performance in general.”

          http://www.vespa.com/en_EN/Vespa-Models/gts/gts-300.html

    • Stuki Moi

      Honda sells such a best in Europe, I believe.

    • Kevin Duke
      • mikstr

        Please, make it stop!!!!!!!!

        I thought posting about “it” (the NM4) was against the Geneva Convention….

  • mikstr

    Why not just go with CVTs and be done with it? Much lighter, simpler and cheaper than a DCT if you really must democratize riding. Give us a single brake lever too while you’re at it, the complexity of two brake activation points is intimidating to the neophytes. Oh, and add a third or fourth wheel too… Joan Claybrook lives again!

    • Mark Frumkin

      Weight, CVTs are weak. To make one work at over 150 bhp it would be large & heavy.

      • mikstr

        They work quite well in snowmobiles, where power is often much above 150 hp and the stress is light years ahead of what it is in a bike, so getting them to work in bike would be a piece of cake.

        • Kevin Duke

          I’d guess the stress is less on a snomo, as a track is more likely to spin slightly in snow. Hooking up a sticky tire to a grippy road might be tougher. Also less likely to overheat a belt in Minnesota in January than in a motorcycle in Arizona in July.

          • mikstr

            what about oval racing and drag racing sleds, which are graced with hundreds of studs and definitely hook up better than any bike? For that matter, look at the pavement drag sleds and look at the surface of the track on the pavement, and they use CVTs and belts too. Want to talk heat, how about a snowmobile which uses up about 50% of its power just turning that track? There’s a recipe for heat problems, especially when you look at how insulated the cabs/engine compartments are on modern sleds (to meet sound emissions). Look at mountain sleds which spend considerable amounts of time at full throttle clawing up long slopes (with hardly any airflow). Sorry, but CVTs are more than up to the job. Seems many around here would benefit from exploring the world of technical marvels that are modern snowmobiles… DI two-strokes that run cleanly and economically, turbocharged triple four-strokes pumping out over 200 hp….

            here, read this for a quick sample of what’s out there: https://www.snowtechmagazine.com/2017-ski-doo-pdrive-primary-clutch/

            FYI, the (stock) sled this is used in pumps out just shy of 110 lb-ft of torque, so it should easily handle the 80 or so of a modern-day literbike….

          • john burns

            I keep thinking Polaris has to have some kind of radical Indian up its sleeve based on this stuff… you have to think the only thing holding them back is the size of the hardcore sportbike market lately?

          • mikstr

            I would tend to think they would fear “tarnishing” the Indian brand; you know how image sensitive the cruiser market is, wouldn’t want to ruin the brand by making, God forbid… a sportbike!!!!!!

            I can’t believe that BRP haven’t brought the Can-Am brand back to its two-wheel roots/origins… A light and clean DI two-stroke sportbike with CVT would simply annihilate everything on two-wheels in any kind of performance measure…

          • Old MOron
          • Kevin Duke

            Well, perhaps they could be made to function in a bike, but packaging such a system might be more challenging than on a sled. Plus, some of us still like the way a moto engine sounds going thru the gears. Reading about the CVTs in your link, I got to this part and started tuning out: “it is amazingly consistent at holding rpm.” The thought of a Panigale or RSV4 holding rpm like a scooter makes me nauseous.

          • mikstr

            The challenge in a snowmobile application is to maintain consistent peak rpm under full throttle in varying conditions, and this is what the author of linked article was referring to. This is not the case on a bike. One thing CVTs do exceedingly well is to jump to peak rpm as soon as you give it lots of throttle, maximizing acceleration in the process. If you think a Pani accelerates hard now, put a well calibrated CVT on it and stand back.

            I am not necessarily a proponent of CVTs in bikes as I quite like the idea of shifting through gears (is an integral part of the magic of two-wheels for me). HOWEVER, in a world where complex DCTs are deemed desirable, why not go whole hog and go CVT.

          • Kevin Duke

            As fancy as the new DI two-strokes in snowmobiles are, we still haven’t got anyone credible confirming that such technology can meet EPA or Euro 4 standards. Please let us know if you have different info, as I’d love to see a new two-stroke motorcycle!

          • mikstr

            I wonder the same thing. However, KTM has been making a lot of noise and loud claims about their new FI two-strokes and how they supposedly meet Euro 4. Bear in mind these are “merely” semi-direct injection (as they are called in the snomo biz) two-strokes, a full generation and a half behind the latest DI two-strokes (ie. Rotax E-TEC mills).

            More reading for you: https://www.ski-doo.com/technologies/rotax-850-e-tec-engine.html

          • john burns
          • mikstr

            Kevin Cameron is God (or close to it) in my book. His article, as always, is pretty spot on and gives a good general overview. The only “error” or oversight is that he states that four-strokes do not have to deal with fresh charge exiting out the exhaust (due to separate strokes). The reality, however, in a high performance four-stroke is that such an event can occur anytime there is valve overlap (a necessity for high rpm engine breathing). This, in fact, is one of the reasons for the move to DI in four-strokes too.

            To sum up, modern DI two-strokes are worlds removed from the smokey, ring-ding smokers of years past. They remain lighter and more powerful, have less mechanical drag and pumping losses, and (can) actually use less fuel than four-strokes as a result. Sadly, the world has gone four-stroke and most are unaware of these advanced and exciting mills.

            On a final note, when high performance four-strokes were introduced into the snowmobile world (Yamaha’s FZ1-based four-stroke 4-cyl. mill in the 2003 RX-1) many were quick to predict the end of two-strokes. Enter 2017 and sales of four-strokes have not only plateaued at about 25% but are actually shrinking as snowmobilers increasingly sample and return to new, clean and economical two-strokes.

            Don’t you love happy endings?

      • Stuki Moi

        The best argument ever for allowing them in prototype racing…….. Those guys are pretty much in the business of solving large/heavy/weak conundrums.

        • mikstr

          No need for it, the technology already exists… see below

  • therr850

    What did he say in the video? I’m pretty sure he used ten of the seven words banned from TV.