The World Cup Circuit is back in Mont Sainte Anne, Canada, for the first time since 2019. The track is looking fast and the weather is dry for now.
As always, Ross Bell, Andy Vathis and Nathan Hughes have been keeping an eagle eye on the riders and mechanics as they prep their bikes for a track that could hardly be more different to the last round. Here's the cream of what they've spotted so far.
Tech RandomsCustom alloy bits on Ben Cathro's Santa Cruz V10 to increase the chainstay length (they're the ones that Greg Minnaar used for his experimentation in the past).
The Track
Holy crap, we’ve been doing it wrong all along.
As I understood it, they're actually the same bits the GOAT was using but Greg preferred the stock length, so the Giraffe was able to half-inch them. About a 470mm chainstay length! Or at least that's what was said in the bike check earlier this year: www.pinkbike.com/news/ben-cathro-santa-cruz-v10-sea-otter-2022.html
Umm, yeah sure, "bare". Except for that stupid internally routed brake hose just hanging on there. Even pro mechanics, who can likely do a bleed in their sleep, don't want to open hoses unless they absolutely have to. Shit, that one runs interally for a grand total of like 4 inches through the chainstay! There will be more hose outside the chainstay than inside when it's built. Which marketing wanker over in Wales insisted that had to happen? So dumb.
This one is also one of the worst offenders of internal routing just for the bullet point of "full internal", in that it only goes internal for a fraction of the actual run along the chainstays. All the effort wasted to design 2 ports, and then actually route it, for 4 whole inches of internal out of like 12 inches from front triangle (also silly, but at least it's a significant part of the run) to caliper? So dumb!
I do think that internal routing has to be done right for it to be worth considering. Better to not bother if it isn't fully guided on a simpler frame.
If there is any chain growth through the suspension travel, then the freewheel acts like a brake and stiffens the suspension; the O-Chain reduces that.
Regardless of debate on how much of an issue things are or not, I decided to try an Ochain and it’s kind of nutty how noticeably smoother things are underfoot
It’s a rad feeling!
www.vitalmtb.com/features/MTB-ADVICE-with-Team-Robot-ANSWERS-2,3031
I've posted the math several times in the past, so I'll just summarize this time:
• When coasting without wheel lock-up, there is no realistic ratio of shock shaft speed to wheel speed that will produce any kickback, let alone problematic kickback. I base this statement on actual telemetry data. Only a trials rider using rear suspension - Akrigg, Macaskill, and the like - would produce such a scenario when landing a drop with nearly zero forward movement. Typical riding on any commercially available bike cannot produce any kickback while coasting without wheel lock-up.
• When coasting with wheel lock-up, some kickback is likely. Not the maximum possible amount, mind you, as that requires a 0% to 100% stroke impact while the wheel is locked, with zero hub driver rotation. The total kickback is a function of the fraction of the travel used, reduced by any float prior to engagement from the hub or O-Chain.
• When pedaling, a sensation of kickback is unavoidable, and neither a low-engagement hub nor the O-Chain will help. The O-Chain float bottoms out by design while pedaling to avoid a "rubbery" pedaling feel, so there's no remaining float to take up the kickback. The cranks don't actually rotate backward when pedaling, there's just a momentary disruption of the rotation that can feel like they went backward.
Regarding the other points:
• Clutch: The effect isn't literally zero, but it's small. Use a finger push on your derailleur's control arm and compare the breakaway force to the force of an impact - especially the forces World Cup DH racers put into the chassis. The clutch breakaway force is tiny.
• Chain inertia: Again, it's small. The upper run of chain is usually constrained by contact with the chainstay, and can be constrained further with an STFU Bike or similar.
Steve at Vorsprung is one of the brightest and most sensible people in the entire bike industry. This topic is the only time I can recall that I've disagreed with him, and I believe he and I agree in principle, differing only on an error in the calculation. If I recall - it's been a couple years - he compared the unsprung mass of the chain to the unsprung mass of the rear suspension and wheel, in which case the effects of the chain are not trivial. Instead, the inertial forces of the chain should be compared to other unsprung masses and the sprung mass, which will show the total unsprung mass effects are moderate and the chain effects are small, compared to the total impact force - and the whole picture gets fuzzy when we try to account for how the chain moves during impact events.
If someone wants to call it "kickback", fine. I call it brick feet. On a single pivot (assuming no idler) vs a multi-pivot (FSR, DW Link, Maestro, etc) it feels like your feet turn rock hard because the drivetrain/chain/cranks/suspension all engage intensely and every bit of what you are whacking gets sent back through your feet.
All that's really happening in the simplest form is that your feet and body weight are trying to turn the cranks and make that bike move forward with an amount of force you couldn't normally generate while rolling/stomping on the pedals. The suspension cycling, the angle of the rock/root/hole you just hit is so square...that even the full weight of your body isn't enough leverage to push the crank down and make the bike move forward in the gear you're in.
All O-Chain really does is dampen that harsh feedback. It's enough feedback on a single pivot/high pivot, that if you're wearing any flat shoe other than a full on Five Ten Impact...you can get your feet bounced off the pedals. Really amplified when wearing Vans. Multiple square hits or a braking bumps and that lack of forward movement of your pedals combined with the chain yanking on the hub/suspension & heaven forbid the brakes are on....and the best way to describe it is definitely kickback.
Maybe the cranks aren't actually jumping into reverse....but you can't tell anybody's feet that.
Has anybody tried at the wc pits to get some free, barely used bearings, brake pads, tires, maybe even marginally dented wheels?
Tires sure...but not much else.
He had a pic of Remi's race run rear wheel from Andorra a few years back. It was practically an octagon but you'd never notice it without the close up pics.
At the last day of Snowshoe, you heard him stop at each pit and say the same sentence loudly, clearly and without a hint of sincerity. Just like a robot: "Do you guys have any...FREE...USED....DOWNHILL TIRES?" followed by "Nope" and a sincere "Ok. Thank youuuu."
And on to the next pit.
People all loved that kid, signed for him without hesitation but he only got so many free used downhill tires.
It can get similar to UK mud if it's actively raining or just had a downpour. But that's way better than the chonky pottery on top of scree rock and roots it dries out to be so quickly.
Honestly, if you want to make fun of how much easier to ride someone's dirt is when wet, it's Whistler. The wettest day at Whistler I had was the grippiest wet dirt I've ever ridden. I didn't get to go out of bounds to get to the organic stuff though.
PS - my comment above was completely in jest. I'm sure there are a lot of places with decent slope - it's just the UK complain about it the most.
5 riders in the top 12 is even more proof.
I think a pseudo-scientific Pinkbike article on who has the slickest mud would be interesting- data on soil clay, silt and sand composition is pretty available (at least in the US), as is number of rainy days and annual temps/precipitation/humidity.
Vermont (especially Mt. Snow) is the home of "Mystery Rock". BOOM!!! in the middle of a beautiful, calm, smooth grassy meadow. And your bike melts like butter!!!
Sounds strange to say, but the slickest place I've ever ridden was Deer Valley. That deep, steep sand on the slopes at 35mph headed into pitch black pines and you're just a passenger with no brakes or steering. Just death surfing.
Pretty sure PB itself told us that those are the same bits that Greg actually used...
Those were the truly exciting days. Blurry...no context...boatload of rumors...no confirmation from the companies. Just mystery and 20 pages of bad CAD and/or paint drawings guessing what was going on.
I miss forums.
Link, yes.
I wonder if many have practice bikes and race bikes. Having two or more in the mix saves downtime. Anyone have insight on this?
Stopping MoMo may be impossible at this point, but I'd say Bruni, Finn, Loris, and the GOAT all have a decent shot. I'd be pretty pumped if Bernard put down a heater as well. So close last time.
I think Finn's got all the tools as well, and it's great to see him to starting to dial in his consistency and get the mental game sorted.
I know every enduro frame nowadays has a big ass hole in it and specialized even does it with alloy .... but does drilling holes into your frame not impact the fatigue strength of your construction ? A sharpe notch like that has to be terrible for the structural integrity doesn't it ?
Also if that's the solution for shock adjustment, it becomes obsolete as soon as the shock change because the dials and knobs are in different spots
ever seen wing uprights on a touring car racecar?
I do wonder how they'll accomodate other shocks though (assuming this prototype ever makes it to production, lol).