Thomas Morsellino is a French freelance journalist and photographer, with keen eye for the technical details of MotoGP bikes. You may have seen some of his work on Twitter, where he runs the @Off_Bikes account. Peter Bom is a world championship winning former crew chief, with a deep and abiding knowledge of every aspect of motorcycle racing. Peter has worked with such riders as Cal Crutchlow, Danny Kent, and Stefan Bradl. After every race, MotoMatters.com will be publishing a selection of Tom's photos of MotoGP bikes, together with extensive technical explanations of the details by Peter Bom. MotoMatters.com subscribers will get access to the full resolution photos, which they can download and study in detail, and all of Peter's technical explanations of the photos. Readers who do not support the site will be limited to the 800x600 resolution photos, and an explanation of two photos.
Maverick Viñales' seat
Peter Bom: An old trick, seen a lot in 125s and Moto3: The rider can move their butt up by sliding backward. The advantage of this on most bikes is that it reduces wind resistance. The air flow stays attached to the rider's back for longer, making the rider's wake smaller, and reducing drag. Maverick Viñales gains more from this, as he is shorter than Valentino Rossi, so lifting his rear puts his back into the same spot as Rossi's without the seat pad. There is a downside to using this on a MotoGP bike: support in hard, low-gear acceleration is less.
Carbon swingarm on Pol Espargaro’s KTM RC16
Peter Bom: In terms of shape, this swingarm is identical to the aluminum version. The advantage is primarily weight, of course, but also that you can modify stiffness in multiple directions quite easily. You do that simply by laminating in a different direction, by placing the layers of carbon at different angles. We can expect to see KTM bring a lot more carbon swingarms now. The initial investment is very high for the first version; making a mold to lay the carbon up in is expensive. But because you can create swingarms with different stiffnesses by changing the way the carbon is laid, it is much less expensive in the long term.
Carbon swingarm on the KTM RC16, interior view To see the technical explanation for this photo, sign up to be a site supporter.
Aluminum swingarm with carbon cover on Johann Zarco's KTM RC16 To see the technical explanation for this photo, sign up to be a site supporter.
Rear wheel cover on Michele Pirro’s Ducati GP19, left hand side To see the technical explanation for this photo, sign up to be a site supporter.
Rear wheel cover on Michele Pirro’s Ducati GP19, right hand side To see the technical explanation for this photo, sign up to be a site supporter.
Rear wheel cover and swingarm attachment on Danilo Petrucci's Ducati GP19 To see the technical explanation for this photo, sign up to be a site supporter.
Carbon discs, calipers and front wheel covers for the Ducati GP19 To see the technical explanation for this photo, sign up to be a site supporter.
Aprilia RS-GP swingarm attachment To see the technical explanation for this photo, sign up to be a site supporter.
Special livery for Pramac at Mugello on Jack Miller's Ducati GP19 To see the technical explanation for this photo, sign up to be a site supporter.
Moto2 rear wheel speed sensor – relocated at Mugello, as up until Le Mans, it wasn't set up correctly To see the technical explanation for this photo, sign up to be a site supporter.
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Comments
Swingarms
I was very surprised when very well respected sources in the paddock attributed the recent driveline failures to swingarm flex. The flex needed to derail a chain would be steering the bike from the rear and feel similar to a deflated tyre to a rider I would imagine.
A more likely explanation would be a failure of the countershaft sprocket, torque sensing gizmo or the chain itself. I recall Yamaha having 2 similar failures at a French GP? recently, solved by reverting to their original type of sprocket.
This is why
I am a site supporter!!! Thank you David for the best GP site on the planet. Great pictures and commentary.
Swingarms
I was very surprised when very well respected sources in the paddock attributed the recent driveline failures to swingarm flex. The flex needed to derail a chain would be steering the bike from the rear and feel similar to a deflated tyre to a rider I would imagine.
A more likely explanation would be a failure of the countershaft sprocket, torque sensing gizmo or the chain itself. I recall Yamaha having 2 similar failures at a French GP? recently, solved by reverting to their original type of sprocket.
This is why
I am a site supporter!!! Thank you David for the best GP site on the planet. Great pictures and commentary.