Feels lighter vs IS lighter is an interesting point. Weight is always the enemy, but where that weight is on the bike is more important when splitting hairs. Having the weight give the best possible distribution, center of mass, inertia effects etc is what we’re really after. Sent from my iPhone using Tapatalk
The V4 engine is roughly 5lb heavier than the 1299 unit. But if that mass can be placed farther forward in the chassis (it is), then it’s not a huge detriment. Couple that with the fact the V4 rotates in the opposite direction, the inertia effects felt by the rider are less than the Superquadro Sent from my iPhone using Tapatalk
At some point lightness becomes detrimental. At a recent track day I saw the frame snap in 2 places on a shiny new V4 Pani from a minor lowside.
The V4 has a perimeter style frame that terminates at the rear cylinder head instead of continuing down the rear behind the engine and supporting the swingarm a’la RSV4 et al. Also, lightness is never a detriment. No engineer is trying to make a frame that crashes better. The lighter the bike is the less force that’ll be exerted on its components in a crash and therefore the less likely catastrophic failure will occur. This is why 125s crash ‘so well’, there’s much less mass to really fuck things up. Sent from my iPhone using Tapatalk
Lightness is a detriment when durability is affected and parts become fragile. The 125s crash well because the whole thing is light, not just certain components.
If they told you the frame couldn’t be damaged in a crash if it was 60lbs heavier would you want it? C’mon, modern frames and motorcycle parts are very extensively engineered for a specific purpose. You can’t start pouring resources into making the thing perfectly straight after it tumbled down the asphalt at 150mph Sent from my iPhone using Tapatalk
I never said I'm expecting it to survive a 150mph tumble. In my specific example it wasn't a tumble or anywhere near 150mph, it was a simple low-side. I'm not talking about it not being straight. It straight up snapped in two separate locations.
I assume, this is the Grattan bike? I’m in a small FB group that guy and mutual friends are in. Everyone is miffed as to how a frame could break in-two, when all the bike supposedly did was slide. I wasn’t there, but, several witnessed it.
No, this one was at another track. The owner got online to search and found a number of people with the same outcome on various forums.
60 lbs is a stretch for a frame that weighs what, 20 lbs, but 5 lbs, for sure. The fatties are giving up way more than that anyways.
That is certainly an odd failure. The bike just low sided on the left and slid on asphalt and resulted in that? Sent from my iPhone using Tapatalk
Yes. That’s the claim by everyone. I’m no engineer, but, where it broke looks awfully thin for a casting. Broke on both sides. Crash trucks are going to have to start carrying ample ratchet straps to hold these things together, if this is going to be status quo.
I don't know how they're built but is the engine only mounted at that point? Aren't there normally 2 points of connection? (upper near the head and lower near the crank)
I'm sure it's that thin for flexibility or lightness or both. That being said, again, I'm sure no engineer designed that for lateral shear loading and impacts. Gotta take the good with the bad when searching for ultimate lightness and such. It is a shame though and you'd rather it not happen obviously. Hopefully a replacement frame section can be found for not too much money.