World Superbike Favoring Four Cylinders Over Two?




Echoing the belief that twins in WSBK (basically the privateer Ducatis), are not evenly paired with the inline/V fours of the Japanese and Europeans, Checa said that “unfortunately there was an obvious difference in acceleration between us and the four cylinders and we weren’t 100% there with regard to the rideability of the bike,” explained the rider after the conclusion of Race 2 at Assen. “Anyway the overall balance was not bad when you look at my results. We have a good package but we are lacking acceleration and speed compared to the four cylinders. I couldn’t do more than I did but I’m still fourth in the standings, in what will be a long championship.”

That’s a fairly modest description, but Althea Ducati boss Genesio Bevilacqua took things further though and saying that “today we saw the difference in speed between us and the four cylinders. I believe that with the current regulations it is almost impossible to do more with regard to acceleration and, above all, with regard to top speed. The rules penalise the twins.”

The data would seem to support Althea Ducati in some respects, as the top speeds from Assen show a strong skewing of four cylinder machines on the maximum speed listings. This theory of course is partially debunked by the factory Ducatis, which rank 3rd and 4th in the top speeds seen at Assen, and let us also not forget Althea Ducati’s win at the WSBK season opener at Phillip Island.

While the common wisdom has been that twins exchange top-end horsepower for tractability and low-end torque, the races to-date may suggest that this trade-off is an even bet, as Ducati’s have been seen running up front on more than one occasion, and top-speed is not an end-all predictor of race outcomes.

With evidence supporting both sides of the argument as to who has the upper hand (let’s not forget who finished 2nd and 3rd in last year’s World Superbike Championship), this debate would seem to close for A&R to call. So we’ll leave further debate for the comments section below. Have at it.

Top Recorded Speeds from World Superbike at Assen, Netherlands:

1. 289 km/h – Max Biaggi (Aprilia), Sylvain Guintoli (Suzuki).
2. 288 km/h – Cal Crutchlow (Yamaha)
3. 286 km/h – Jonathan Rea (Honda), Leon Haslam (Suzuki), Leon Camier (Aprilia), Michel Fabrizio (Ducati), James Toseland (Yamaha),
4. 285 km/h – Troy Corser (BMW), Noriyuki Haga (Ducati)
5. 284 km/h – Tom Sykes (Kawasaki), Max Neukirchner (Honda)
6. 282 km/h – Jakub Smrz (Ducati), Shane Byrne (Ducati), Lorenzo Lanzi (Ducati), Chris Vermeulen (Kawasaki)
7. 281 km/h – Carlos Checa (Ducati)
8. 279 km/h – Ruben Xaus (BMW), Broc Parkes (Honda)
9. 278 km/h – Luca Scassa (Ducati)
10. 275 km/h – Matteo Baiocco (Kawasaki)
11. 273 km/h – Roger Lee Hayden (Kawasaki)



  1. Marshall says:

    Here’s something I don’t get regarding the debate between 2 vs. 4 cylinders, or more specifically, 2 cylinders vs. a 4-cyl. with a cross-plane crankshaft.

    Motorcyclist recently published an issue where they talked about the benefits of Yamaha’s “crossplane” crankshaft engines as well as those of some V twin or V4 bike (I forget if it was a Ducati, the RSV4 or the new VFR). In the article about the Yamaha, they mentioned how the Yamaha motor improves tractability by “spreading out” the power strokes of the 4 cylinders 90 degrees apart, so that the power is applied more evenly to the rear rubber and traction is increased. In the article about the twin, they said something like “the engine gives the rear tire enough time between torque pulses to regain traction.”

    How can one engine improve traction by spreading the pulses out, and the other improve traction by lumping them together? Maybe I’m missing something, but it sounds like a case of reading off different manufacturers’ press materials without noticing the contradiction. All other features of the engine, bike and rider aside, one ignition scheme must be better than the rest. Which one is it?

    The fact that rear wheel traction isn’t a matter of “on or off” certainly complicates things.

  2. monkeyfumi says:

    The article you ask about has it wrong.
    A “big bang” engine like the R1 (technically a long bang, there is a difference) groups the combustion pulses together, giving a longer duration of rest for the rear tyre.
    So yes, traction is improved by lumping the pulses together instead of evenly.

  3. Marshall says:

    So the R1 is a long bang and a V-twin is a big bang?

    If the advantage of twice (or 4x) the “tire rest” outweighs the disadvantages of twice (or 4x) the torque pulse, then why do people seem to think that the cross-plane crankshaft in the R1 is an improvement over the traditional crankshaft design? If a big bang twin engine is at one end of the spectrum and the long bang crossplane I-4 is at the other, the traditional I-4 must lie somewhere in between.

    Maybe the answer has something to do with the tire/wheel/torque damper system’s response to different torque pulse frequencies. All these bikes seem to share very similar rear wheels and tires, so I’m curious if the “big bang” engines require significantly softer torque dampers in the drivetrain.

  4. georGe aka-VintageWrencher says:

    Maybe Checa-chuka needs to leverage the factory to give Althea the “good oil” since Corse seems to be lacking now that Tardozzi(sp?) took a hike to the other side of the Alps.

  5. TT says:

    So what. Look back to the 750 era… Ducati gradually petitioned for more capacity until the only bikes winning were Ducati’s… then Honda made the 1000cc SP1/2 V-Twins and there were two manufacturers winning races… it’s the age old debate, how much ccm to ‘give’ the V-Twins over the 4’s. At the end of the day, some tracks will favor the 4’s, some will favor the twins. The hard part is understanding how much advantage that drive from the V-Twin out of turns will give the rider.

    Marshall, think about these engines as ‘even firing order’ Vs. ‘uneven firing order’. Even firing order does not give the tyre time to recover, meaning it will spin (lose traction) easily. Uneven firing order give the tyre a break from drive, allowing it to recover some traction. Remembering we are talking about complex load on the tyre… that is, the tyre is suffering side loading from cornering then having power applied.

    When considering the difference between ‘even firing order’ engines, it’s simple… a twin will fire each cylinder once per 4 rotations, that is one cylinder will fire per 2 rotations. A 4 will fire with the same 4-stroke design, but this means one cylinder will fire every rotation. This means less force per explosion (smaller cylinders), but a more constant load to the rear tyre, = less drive out of turns. A cross plane crank, or big-bang engine uses smaller cylinders (better piston velocity) and allows the smaller explosions to be grouped together to mimic that big-bang drive. It’s like the best of both worlds.

  6. World Superbike Favoring Four Cylinders Over Two? – #motorcycle

  7. Eagle6 says:

    Ducati already are running 1200cc engines and piston mods the other teams can’t use.
    So what next? Just keep upping the odds in favour of Ducati until they rule the world again?

    My original thoughts in previous years when they were allowed bigger engines were “I thought this was a 1000cc capacity championship?”

    Ducati cried to the Italian owners of the series and they backed down and let them have what they wanted. Now they’ll do it again.
    Does anyone run in MotoGP with a 990cc engine just because its not as strong or has as many cylinders as an 800cc?
    Ducati: If you can’t compete on equal terms ….. goodbye.

  8. Voodoovaj says:

    This is a ridiculous argument from Ducati. They have a (more than) capable 4 cyclinder engine. Their reluctance to put it into a sport bike beyond the desmosedici is their choice. Adding to that, I’ve been watching the races and the Ducati’s have been running well. I think the largest disadvantage the factory bikes have is the loss of Tardozzi (and BMW’s gain). Finally, the Ducati privateers are doing better than any other privateers and they are consistently at the front.

    Maybe FIM will allow 1600cc air cooled twins and Harley can race too :p

  9. georGe aka-VintageWrencher says:

    Marshal and Monkeyfumi(is that a VR46 reference :)- Here is a good article on the firing order subject. I am not responsible if it makes your head hurt. lol

  10. hoyt says:

    I agree with some of the comments above (history repeating itself with twins getting this or that in order to to be “competitive” w/4s). I’m a big fan of twins, btw.

    Why don’t the racing sanctioning companies put more effort on the track selection/track configuration instead of engine differences? Establish the same cc limit for all engine configs. and put more effort into equal amount of tracks that favor twins and multis. (and a couple tracks that are in-between). There doesn’t seem to be many tracks with multiple “S” corners back-to-back & short straights.

    Wouldn’t the track configurations then help demonstrate the fantastic differences across motorcycle engineering? This is a sport not only about rider & team skill, but engineering talent at the factory and privateer garage.

    Erik Buell helped explain the level of complexity that goes into racing in his John Burns interview. Whether you agree with Buells running with 600cc is not the point, but that racing is very complex. In fact it is so complex that it makes you wonder if racing sanctioning bodies should simplify engine rules and let the rules of the road (pun intended) dictate more of the success.

  11. georGe aka-VintageWrencher says:

    Sorry I zoned out and forgot to add the link:

  12. Sean Mitchell says:

    A&R, I love you guys, but this is another non-story. You’re blowing one quote from Checa out of proportion.
    Haga won a race last round on a Ducati. Checa’s been toward the front all season. There has been no belly aching from the factory Ducati team about rules favoring 4 cyl. Ducati was incredibly competitive last year. You haven’t sited any rule change from last year, so what’s the big deal now?

    This “story” just drums up more of the 4cyl vs twin argument. The point is moot.
    Twin’s put down power differently than 4 cylinders, twins aren’t going anywhere, so quit bitching about it.

  13. Rob says:

    Simply put, engines with less cylinders should be allowed more displacement or more race oriented components. With less cylinders there is simply less surface area for valves to flow air and therefore less power. So for Twins or Triples to be competitive with 4s, they deserve more displacement or less weight or something similar. This is what makes the racing not turn into a bunch of Inline4s racing against each other with nothing interesting on the grid

  14. Marshall says:

    What if the bikes were held to fuel efficiency or component cost limitations rather than complicated rules regarding displacement and component types?

    Things might be interesting for a couple years, then one type of bike would probably prove to be superior and the rest would drop out.

  15. Ry_Trapp0 says:

    I see it time and again, bike fans complaining about how it’s “unfair” for the V-twins to have more displacement, or say “well, that’s their choice to run inferior equipment”. Guys, this is NOT spec class racing, so these arguments have no merit at all. If the weakest in the series doesn’t get a handicap, then no other make in the series should, leaving the strongest to just dominate every race.
    As a big sports car/touring car fan, it just shocks me every time I see this stuff, when touring/sports car racing has been running relatively problem free(nothing is perfect) for decades upon decades. We’re talking about front engine/V8/RWD Ford Mustangs, front engine/turbo I5/AWD Volvo S60Rs, and rear engine/F6/RWD porsche 911s all racing equally, I4/FWD Mazda3s, turbo F4/AWD Subaru Imprezas, and I6/RWD BMWs all running competitively. I’m failing to see how balancing a V-twin and an I4 is such a huge issue.

  16. hoyt says:

    Top speed is only one aspect of road racing (arguably the most boring part of road racing).

    What if there were an equal # of tracks that emphasized a rider’s skill (& chassis capability) to handle directional changes as there are tracks with long straights?

    I’d love to see a track that didn’t have a straight away, but replaced it with more chicanes.

  17. RT @Asphalt_Rubber World Superbike Favoring Four Cylinders Over Two? – #motorcycle #WSBK #Ducati

  18. Ape Factory says:

    The fly in the ointment for Ducati is the fact that another Italian manufacturer, Aprilia, is doing well in the series. Notice all the airtime the bike gets. Ducati will have to build a more competitive bike and personally I think the factory is sand bagging to get more favorable rules. Hell, Haga won a race from what, 14th place on the grid? Just look at which bike has won more championships since 1988. After watching last weekend’s second race, the Flamini brothers would be stupid to change a thing.

  19. Morpheous says:

    Maybe Ducati just need to come forward to the modern Engine era. Ducati’s V-twins, (like Harley’s) are a novelty, old tech, not competitive, and need to be dropped from the evolutionary tree. Heck, even BMW have moved on from the old Opposed twin. The euro-Harley must die.

  20. emd says:

    Maybe something along the lines of airbox and intake restrictions could get looked into for WSBK. They are heavily regulated at the moment

  21. hoyt says:

    morpheous – hold on.

    BMW still makes and sells a ton of boxer-based motorcycles for valid reasons on and off a racetrack. The formidable HP2 Sport streetbike did awesome racing in Daytona in its 1st season.

    Ducati’s engine is Not an opposed twin. Even it was, it will be difficult to find an engineer who does not find the boxer engine config. very worthwhile (modern Porsche or Subaru engines run great).

    Ducati’s 90 degree twin runs incredibly well and is still a contender.

  22. Jaybond says:

    V-Twins should stay in WSBK, because one of the main attraction/spectacle of the series is 4 cyls dicing with the Twins. Perhaps the organizer should look carefully within the next few races to see if Ducati really suffers alot due to the restrictions, if yes then probably some adjustment’s needed. WSBK needs to maintain the engine variety, as its unique feature againts Grand Prix class, and maybe perhaps to consider allowing rotary engined-bike (Norton) to compete in future!

  23. faster1 says:

    Total BS! What happened during the Bayliss days. It’s all a full cycle.. Ducs dominate for forever and the fist time they don’t, it’s unfair? Sure there will always be tracks that favor one configuration over another. Three races into the season there is NO conclusion to be made. Work harder Ducati and give Haga and Fabreez a decent bike! They basically didn’t change a whole lot from last year and they are surprised? Be serious! For the first time in a long time there is equal parity. This is the most entertaining WSBK year ever!
    Ducati,, go change your panties and get on with it.

  24. Scott says:

    the manufacturers willing to race a twin should bare the consequence’s, they already got a 200cc extra (and a little added weight) if you’d ask me 1000cc is 1000cc if you’re wiling to construct a v10 1000cc go ahead you wanna compete with a 1000cc single its your call but don’t go and cry @ ur mothers when the guy with the v10 kicks ur ass.

    It’s already an emberasment that the twins get 200cc extra. so ducati stop producing those retardedly sounding v-twins and come out with a triple or a v4 (triple’s can have 1100) ;-).

  25. Jaybond says:

    WSBK = 4 Cylinders vs Twins vs Rotary :-) , the winning selling formula!

  26. Jaybond says:

    Plus triple cylinders

  27. lalaland says:

    The SBK Commission is not playing favorites.

    WSBK machines have a wide variety of engine specifications yet all of them make roughly the same top speed. Everyone claims this is the result of the tires, but Ducati run the same tires as everyone else so why add weight and air restrictors? Why have capacity limits at all if the tires control the performance?

    The sport is rev limited, hence the overly complicated performance controls for 1200cc twins. Rev limits don’t work across multiple capacities. It’s too bad InFront and the FIM don’t tell people how FIM homologation really works, but I guess they are afraid people will stop watching.

    No reason to take sides. The sport basically guarantees equal engine performance to all participants. Ducati should have built a 100cc 4-cylinder racebike to avoid the performance indexing problems, but they chose 1200cc instead. Begging for more performance is the price they have to pay. The SBK Commission will get things sorted.

  28. Norman says:

    Why not Ducati built a 1075cc V3 instead of mourning their endless misery?