lastminutepanic

If this was said in the video I guess I missed it: I'd be surprised if weight was the most important force on unsprung mass. Even if you save a few hundred grams, I'd think that another force resistive to movement would be more important. And this force has nothing to do with belt drives or gearboxes; it's connected to the extra security you can create when you only have a single front and rear cog. If you have two cogs with a wall on each side, perhaps what you don't need is the resistive force of the clutch, which adds both sprung resistance and a bit of stiction that weight doesn't. With tall enough cog walls, if you can eliminate the derailleur clutch and tune the belt/chain tensioning device with a minimal spring, you get that much closer to the "chainless" feel. For a chain setup, perhaps you'd go narrow-wide on both front and rear cogs. Maybe this is done already in single speed; I don't know the parts in that universe. It certainly seems like you could go even further with tooth profile, like using hooked teeth, if you never had to worry about the chain making its way up and down a cassette. If I'm off on this, please share why! I'd love to know more about it. I know what the chain looks like when you see mid-ride suspension oscillation - how it flails around, and retention is an issue. Is a belt any better? If it is, it could be a big benefit in a sport where suspension movement is much more important than pedaling efficiency.

@nickfranko: you’re saying taking the inner aluminum portion of a shimano ice tech rotor and making it part of the hub is heavy? Even if you move the fixing bolts to where the rivets are now and eliminate the rivets? And even though the hub will get larger, which means the innermost portion of the aluminum will now be hollow for a bigger opening? I don’t see how that makes sense. Right now you have a small diameter for the hub and then a bunch of material to get to the 180, 200, or 220mm diameter of the rotor. In every situation where a manufacturer tries to save weight, they don’t go with small tubes and lots of material. It’s always larger diameter which means more strength, and thin tubing which is less weight. A bigger hollow hub with ice tech style spider arms cast in is not heavier. And the only weight that is moving out from the center vs an ice tech rotor is that the bolts go in the position where rivets would be. That’s such a tiny change that I can’t believe it would be a point of contention. If this wasn’t the optimum setup for strength and weight, we wouldn’t have crank spiders with a relatively large bcd. We have direct mount cranks for versatility and because we don’t put large cogs as part of a triple on a mtb anymore. I argue that the creators of the 6 bolt standard never saw rotors growing to their current size, and they would have had crank style arms from the start if they did.

I saw the proprietary rotor and thought "great, another new standard". Then I thought about it a bit more, and a new rotor mounting standard could be really useful. Not necessarily this one, but maybe a 6 or 8 bolt standard that has a much wider interface. Rotors are so thin and the mounting point is so close to the center, and it's a real challenge for them to stay perfectly true. It would make sense to have a mounting standard with a diameter wide enough that it just barely fits on a 160 rotor so there's not nearly as much metal to bend. I know that higher end rotors solve this problem with an aluminum center section that's riveted onto the steel braking track. If this is effective, why not just have a larger aluminum shell/spider as part of the hub standard, both for rotor bending resistance and better heat sinking, and then all rotors could be relatively cheap steel rings? And if you do this, the non-drive-side shell diameter could grow and then there's plenty of room for things like non-drive-side hub internal power meters and drive rings.

@EvoRidge: And yet, we commonly have video coverage (not shot by Pinkbike, but still) of talented groms ripping up bike parks. Maybe this is a controversial viewpoint, but the "highest level" is not inherently interesting, when it comes to competition. A year where the top man or women slaughters the rest of the field is interesting as a show of talent, but it's not competition. Great competition is talent plus rivalry.

If major media won't cover the epic junior rivalry, maybe Pinkbike can? We have this amazing head to head between Jackson and Jordan, and it's the kind of drama media should dream of. They're not fast for juniors; they're just plain fast, and it should make for exciting coverage.

If this is 12 speed Deore, isn’t the cassette a microspline 10-51?

I feel like the release of Deore m5100 throws a wrench in the cheap drivetrain market. A shimano engineered 11-51 setup for cheap is pretty great unless you’re specifically looking for 9 speed with the big gap at the low end. You can get the chain-shifter-cassette-derailleur combo on eBay for $145 ($160 from an American seller). Ratios are a really reasonable 11-13-15-18-21-24-28-33-39-45-51

Thanks to everyone who answered my question! I think I’d like to focus on either weight shift or manualing off the edge because: 1) what if the landing is really steep? If I just throw more speed at the problem, a 5ft drop becomes a 15ft drop, and maybe that’s not what I want (it’s definitely not) 2) what if there’s very little space after the landing? Maybe the landing rolls into a sharp turn quickly, and I’ll be in the trees if I fly off the drop. I was just watching Ben Cathro’s coverage of the snowshoe World Cup, and he spend some time analyzing exactly this kind of drop. I’ve seen Friday fails where people have the opposite problem - they loop out on the landing, so it must be possible to manual/shift weight to stay neutral off the drop, even at slower speeds. I don’t know how to manual so I’m pretty limited in the tools I have so far. It’s on the winter list of skills to acquire. There’s a section of a local trail where the edge of the trail has a steep drop off and in one spot it’s open so you can ride off it. Essentially this means making a 90 degree turn mid trail and going off maybe a 3ft drop with a steep landing and not much room before you have to make another hard right to rejoin the trail. The entrance to it doesn’t allow you to carry much speed because of the initial sharp turn, and the exit would punish you if you did carry this speed. It’s these sort of “short cuts” that I’d like to be able to handle. I mentioned compression before launch because that’s what I’d use to pop off the lip of a tiny jump (something like a 1ft tall dirt mound in the trail). I can see how it’s less effective without the lip. I’ve never tried pushing the bike forward off a drop. Gotta experiment with that.

This drop is something I wouldn’t know how to handle, so I watched the video for what went wrong and how her technique created that issue. Because of slo mo in the video, it’s hard to tell what speed she dropped at. It looks like she shifts her weight down and backwards just before going off the edge. It doesn’t look like she pushes the front end down - more like the front drops and pulls her arms straight (unbending her elbow) and forward. I’ve never gone off a flat drop off anywhere near this high but this technique of weight back, arms not locked out, sometimes compressing the suspension before the jump to use the rebound to unweighted the bike, works ok on the small stuff. Of course, lots of wrong stuff works ok on small stuff. So I can practice good technique, what should she have done to keep the bike mostly level?