MTB ADVICE!! with Team Robot - ANSWERS #1 27

Team Robot, one of mountain biking's most iconic, honest and sardonic internetters, has teamed up with corporate giant, Vital MTB, to bring you the most  resourceful and thorough MTB advice column found anywhere in cyberspace.

So many questions came in for this first round that the email server initially crashed and additional exabytes of storage were required for processing. Sifting through the avalanche of pitiful questions yielded three possibly-acceptable inquiries worth a robot's time and insight.

Answers stated by Team Robot do not necessarily (but most likely) reflect Vital MTB's stance.

Dear Robot Team,

What year is the gearbox going to be a thing, like when is it going to be a decision we all need to make?

-Chad

Never. Sorry Chad, maybe on e-bikes because there’s more power available to overcome the efficiency deficit, but gearboxes are never going to happen for a mainstream audience for general use human-powered bicycles. A chain drive is always going to be more efficient than a comparable gear drive, and that efficiency is important because humans are not powerful engines. In his glory days, Nathan Rennie could put out close to 3 horsepower in a sprint. In terms of endurance, top road guys can produce something like 1/2 a horsepower for an hour. For comparison, a 2019 Honda CRF450R with a gear-driven transmission puts out something like 57 horsepower. The benefits of a gear-driven gearbox are real, but for most users they’re outweighed by the mechanical drag.

What’s the cause? Gears. Gears have to mesh together, and that’s a lot of contact, force, and friction on a relatively small surface area. Especially if you have multiple gear drives working in series, which would mean the inefficiencies stack on top of each other. By comparison, chains are marvelous. Here’s a link to a great video if you want to see how a motorcycle’s gear-driven transmission works:

It’s not a crazy amount of watts lost, somewhere between 2-13% less efficient compared to a chain, but that’s not nothing. Imagine if I let 10 psi out of your tires before the start of every ride, or took the grease out of your bearings, or if your brakes were always dragging. If you were a 454 Chevy big block engine, you probably wouldn’t notice, but you’re a person who probably produces somewhere in the ballpark of 1 to 2 peak horsepower. You’re going to notice.

Here’s a great home test from a very German-sounding online magazine called FahrradZukunft, comparing drivetrain efficiency between gearboxes. Their findings indicated that the Rohloff Speedhub is pretty darn efficient, especially compared to the abysmal Nuvinci shifting hub. The Pinion gearbox and Shimano Alfine geared hubs land somewhere in the middle- they’re less efficient than a chain, but not terrifically so. If you ever rode a Truvativ Hammerschmidt crank, you’ll probably remember that it was okay-ish when applying low to medium force through the pedals, but had awful drag when you sprinted. Unfortunately for Truvativ, high-power pedaling is pretty important for technical climbing and technical descending.

Efficiency isn’t the only hurdle for gearboxes, and it isn’t even the biggest one. You also have to figure out how to get your customers to pay more for a bike that’s now heavier and slower. I’m not saying that’s an impossible sales pitch, but I am saying that’s a harder sales pitch than most bike brands want to attempt. “Oh by the way, the gearbox shifter feels weird and unfamiliar.” Sure, rear derailleurs are weak, vulnerable, and temperamental, but it’s taken 15 years for bike brands to admit that short chainstays kinda suck, so I’m not holding my breath.

For now, the likely applications for gearboxes will be anywhere pedaling speed isn’t a major concern, or where extra horsepower is available. Right now that means bougie commuter bikes, e-bikes, and downhill bikes. Or maybe bougie downhill commuter e-bikes.

-Team Robot

I'm having a hard time cornering in clips. On flat pedals I have no problem getting the job done, but when I clip in I just can't fully commit to fast, loose corners. I've been riding and racing for awhile, and feel pretty confident otherwise. I know that if I can get dialed with clips I can unlock some speed, but what's your advice on getting over my fear of really leaning it over and committing? Cornering drills with cones on grass (sounds like a kill-list activity)? Say screw it and stick with flats?

In need of some help.

-Daniel

Great question, Daniel. You’ve captured the fundamental problem facing all clipped-in riders: How will I ride slippery sections of trail?

Ideally, the best thing you could do is put on your big-boy pants and start committing to turns, clipped in and feet up. I don’t know whether you humans would call this “confidence” or “manifesting your reality,” but typically if you keep your feet on the bike, things just seem to work out. For example, I think I’ve seen Troy Brosnan clip out two times in my whole life. Clipped in and feet up seems to work for him.

Unfortunately, as you’ve discovered, you’re not Troy Brosnan. You’re wracked with fear and trepidation and your brain is trying hard to avoid falling down. Luckily, you’re already headed down the right path with your cones-on-grass idea. You want to find a low-consequence arena to test and train your low-traction bike handling skills. I’m a huge fan of cones on grass, and Amaury Pierron showed the world how useful grass cornering skills can be in his now famous winning run in Les Gets in 2019, but for your purposes I wouldn’t recommend starting on grass. Underneath grass is dirt. Dirt is hard, and falling on hard things hurts, so I think the best place for you to start working on this skill is bark dust or wood chips. Falling on bark dust isn’t scary at all. If you can find one or two good bark dust turns to destroy at a local park, you’ll be able to go bananas with your feet clipped in, sliding sideways, with minimal fear of injury. Pretty soon you’ll get comfortable on the bike, figure out what body position works, and learn the benefits of committing to turns with your feet up. Don’t forget to use a rake to undo the bark dust damage when you’re done.

If you practice that drill enough, here’s what you’ll discover:

Taking your foot off doesn’t help you go faster through a flat turn, but! Knowing you can get your foot out will make you feel safer in clips, and feeling safer really does help you go faster. You can create that peace of mind by shifting weight to your outside foot and letting your inside foot come up as you’re entering the turn. Imagine your pedals coming to the 6 o’clock and 12 o’clock position in the corner. By shifting weight to your outside foot, you’ve effectively unweighted your inside foot and left it free to clip out and dab if things go too sideways. This allows you to have your cake and eat it, too. You’re not unclipped, but you can unclip in an instant if you need to.

Lastly, weight creates traction. You want your front wheel to grip in loose turns and if your bike is going to slide, you want that slide to occur at the rear wheel. You can use your weight to help create traction where you want it. Lean forward aggressively on the bike to shift weight onto your front tire. Leaning forward is the opposite of what your brain wants to do as it’s headed into danger and uncertainty, but your brain’s hardwiring is actually pretty useless for mountain bike physics. On slippery surfaces, leaning forward can save a slide and keep your front tire gripping and ripping.

In summary:

• Ride like Troy Brosnan
• Practice on bark dust
• Weight your outside foot
• Don’t take off your inside foot
  
• Shift your weight forward on the bike

Why do mountain bikers suck?

Thank you

-Garrett

P.S. make trails rough again

Garrett, there are so many layers to your seemingly simple question. I only have so much time and space, so please allow me to hone in on one particular dimension of why mountain bikers suck.

First, let’s be clear about who we’re referring to when we’re talking about “mountain bikers.” I’ve played basketball a few times, but I’m not a basketball player. Jeff Bezos has two feet and two hands, but he isn’t a human being. In the same sense, most people who mountain bike are not “mountain bikers,” especially when you consider the recent bubble in the outdoor adventure world and the crushing outdoor traffic created by Covid-19. When we say, “mountain bikers suck,” we’re not referring to new riders or casual riders. That would be unfair. How would they know our local surf-spot etiquette or not to wear ankle socks?

The people who suck are the ones who’ve been around long enough to know better, but don’t. The people who simply cannot be bothered to pick a downed tree branch up off the trail after a windstorm. The people who never turn off their Strava, even when they’re riding a secret spot. The people who blow up the shared parking lot with trash and loud music, or speed by the neighbor’s houses and get the spot shut down, or blast by walkers and equestrians and scare the shit out of everyone. The people who always tell the local trail builder they’d love to come dig sometime, but when the trail builder says, “I’ve got a shovel right here,” they suddenly have an important meeting to get to or a kid to pick up from soccer practice. The people who straight-line the turns in a public trail to shave a few seconds. The people who constantly talk about “shredding” and “loam” and “getting so sick,” but don’t shred, who don’t know what the word “loam” means, and who don’t show any interest, curiosity, or respect toward older, wiser, newer, or faster riders. And don’t forget the entitled pricks who got the most popular mountain bike trails in Vermont shut down by yelling at the property owners for riding horses on their own property.

So what makes these people suck? There’s more than one way to suck, but one notable theme between each of these awful people is arrogance. They think their shit doesn’t stink. Their bike, their riding, or their time is more important than everyone else. That attitude sucks, and what these people need is better riding friends to help sort out that shitty attitude and put them in their place.

For any of you still confused about this, allow me to be that better friend and help clarify something: You will never, ever be cool because you ride a mountain bike. Nothing you do on your mountain bike will ever be important, at least not important enough to warrant being a dick about it. Trust me, your riding is not that interesting. I guarantee your own mother doesn’t want to watch your GoPro footage. I’m sure there are other redeeming and valuable qualities you possess, and I’m sure your life has some important purpose, but I’m 99% sure ripping our local lunch spot and terrorizing dog walkers is not your life’s raison d'être.

So try to be more of a team player out there. You humans are all on the same team, after all.

P.S. Don’t tell me what to do. Go make trails rough again, yourself.

-Team Robot

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