Guest Blog: Mat Oxley - Can MotoGP's inline fours return to the fore? is delighted to feature the work of iconic MotoGP writer Mat Oxley. Oxley is a former racer, TT winner and highly respected author of biographies of world champions Mick Doohan and Valentino Rossi, and currently writes for Motor Sport Magazine, where he is MotoGP correspondent. We are featuring sections from Oxley's blogs, which are posted in full on the Motor Sport Magazine website.

Can MotoGP's inline fours return to the fore?

Suzuki and Yamaha have struggled to keep up with Ducati and Honda in recent years, so what are their chances for 2019?

Inline-four MotoGP bikes have won two of the last 30 MotoGP races. That’s why some outsiders predict the end of the line for them.

But if you’ve been paying attention you will know that Ducati’s V4 and Honda’s V4 dominate MotoGP for reasons other than engine configuration. Both layouts have their good and bad points; end of story.

First, a little bit of history about the inline-four…

The first inline-four motorcycle engines were mounted longitudinally, which demanded a ridiculously long wheelbase and caused the rear cylinders to overheat.

The first transverse-mounted inline-four was created in 1923 by Italian engineering graduates Carlo Gianini and Piero Remor. Even that engine – a short-stroke, bevel-driven overhead-cam 490cc four – was quite something. It made 28 horsepower, which was more than three times the output of BMW’s seminal R32 twin, launched the same year. The so-called OPRA (for Officine di Precisione Romana Automobilistiche) was bankrolled by a minor Italian royal: Prince Lancelloti.

Remor later designed the Gilera four, which won six 500cc world titles in the 1950s, and the MV Agusta four, which won 10 500cc crowns over the next decade and a half. These machines inspired the mass-produced inline-four streetbikes that have dominated the motorcycle market for decades, all the way from Honda’s CB750 of 1969 to today’s BMW S1000RR, Honda Fireblade, Kawasaki ZX-10R, MV F4, Suzuki GSX-R1000, Yamaha YZF-R1 and so on.

In other words, motorcycling has a lot invested in the inline-four engine; so what do Suzuki and Yamaha have planned to get the GSX-RR and YZR-M1 back to the front of MotoGP?

Read the rest of Mat Oxley's blog on the Motor Sport Magazine website.


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Reports of the death of the inline 4 in MotoGP are greatly exaggerated. Suzuki's i4 seems in rude health that only requires a touch more top end power to be truly competitive. Interesting to read that their 2017 version suffered from corner entry issues with the then heavierheavier cra. Yamaha seem to have the same issue with their lighter crankshaft as mentioned by Vinales who liked the heavier 2019 version.

Maybe the factories are being deliberately vague as usual on these details.

Yamaha's fine tuning issues appear to be the sum of a few things. Weight distribution, frame geometry, ECU management and rider adaptibility to the Michelin tyres.  If Suzuki can solve corner entry and exit issues retaining agile handling with an i4 surely yamaha can too. They should have won a few more races at the end of last season.

It's still the design that allows for the shortest wheelbase and allows for the most optimal positioning of the engine. As for the v4s having an advantage with removable flywheels an i4 can replicate this with the balance shaft and suitable crankcase access.

I look forward to an i4 renaissance this season.