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MTB ADVICE!! with Team Robot - ANSWERS #2 20

Stack height, rogue trail building and pedal kickback are the subjects of another tantalizing injection of MTB ADVICE!!

MTB ADVICE!! with Team Robot - ANSWERS #2

Our email servers have been upgraded to handle the tens of thousands of mountain bike-related questions for MTB ADVICE!! with Team Robot #2. As one of one of mountain biking's most *respected* internet commenters, Vital MTB sold the corporate Yaris and used the funds to wine-and-dine Team Robot so he would present his bedrock of two-wheeled wisdom. This is the best mountain biking advice column on the internet.

Team Robot's algorithm processed and discarded the onslaught of feeble, fruitless queries to consume, digest and excrete answers to three partially-palatable ponderings worth a robot's time and CPU resources.

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


Got stack? Greg Minnaar does, but he's a better rider than you.


A body position question. I would love to run a higher stack height as it does feel nice when riding steep stuff. Unfortunately at this higher stack height, I wash the front tire more than normal in corners or just get a vague feeling when I'm going to initiate a turn. To counteract this I find I have to keep telling myself to get forward of my normal neutral position. Problem is, I have trouble doing more than one thing at a time, and when I start thinking about body position, things like line choice, looking ahead or breathing go out the window.

Should I just try and relearn a new more forward neutral position? Or just do more pushups so I can hold on with a lower stack height?

Thanks!

Matt

Team Robot: Ideally, your bike should be set up so you don’t have to consciously think about your body position at all when riding. I’m a huge fan of pushups for bike riders, but I don’t think more pushups is ever the answer to a bike fit problem. The benefit of doing your pushups is at the tail end of a long and draining race run, or at extreme peak-impact moments like overshooting a road gap or hitting a massive hole. You shouldn’t be dependent on push ups to sustain your body position in normal riding conditions. Being in plank position 24/7 makes you tense. Tense is exhausting, but it’s also slow, because you’ll get bounced around by bumps instead of smoothly flowing over them. Instead, your bike should put you into a neutral & relaxed position when you get on it. So how can we get you into a good, neutral, relaxed position on the bike?

There are lots of potential variables we could change to try to give you the riding position you need and, luckily, you’ve already tested one variable. Because you’ve noticed considerable drawbacks to running your bars high and running them low, we can rule out handlebar height as the source of your problem. Here are three alternate suggestions.

Stiff like Gwin?

Run your fork stiffer. If you’re running 30% sag on your fork, that’s your problem. Soft forks dive on steep sections of trail, and as a result your body weight shifts forward on the bike and drives weight onto your hands. Scary! If your fork is too soft, that would also explain why it’s hard to weight on flat turns with tall bars. With tall bars, you lack the leverage to weight the front tire with your hands, but you shouldn’t be trying to weight your tire with your hands in the first place. Like I said above, your center of gravity should be positioned in such a way that your tires are properly weighted from a neutral riding position. If your fork is too soft, it will dive when you use your feet and hips to shift your full center of mass forward. That fork dive is gonna feel sketchy and vague, so you’ll be tempted to keep your body weight back on the bike and manually weight your handlebar with your hands. This is bad, and can be fixed with a stiffer spring rate in your fork.

Check your shock sag. If your rear shock is too stiff, it won’t absorb the bumps it’s supposed to and instead will drive compressive forces onto your fork. This overloads your fork, creating brake dive, weight shift, sore hands, and a host of other problems. Check your shock sag and see if you’re actually in the 30-35% range. If not, try going down a spring rate on your shock and see if it gives you a more squatted, settled rear-end.

Big bike.

You might have a Pole Problem. Last but not least, your bike might be too big. You probably don’t actually ride a Pole, but if your bike is too big for you, you can still thank Leo for making it seem like a good idea. If your bike is too long, you’re gonna have a hard time putting weight where you want it. You’ll have to make big, exaggerated movements to weight your front tire, and you’ll end up in something akin to the plank position trying to keep weight on your front tire. This body position is, obviously, horrifying on steep sections, which will lead you to run a shorter stem and higher bars, which will compound your problem by making it even harder to weight the front tire.

So either you need to spend five minutes with a shock pump, or you need to buy a whole new bike. Good luck.


The Post Office trails weren't sanctioned when they started.

Would enjoy your opinion on rogue trail etiquette.

-Tom

Team Robot: I’m going to assume you’re asking about building rogue trails, because the etiquette for riding rogue trails is pretty simple. If you know the first rule of fight club, you know the rules for riding rogue trails. My etiquette for building rogue trails is that you should definitely do it, but probably not where you imagined building and probably not the way you imagined it looking.

Rogue trails can be great for mountain biking. Lots of land managers will turn a blind eye to trails that they can’t or won’t give a written and formal “yes” to. For land managers, the formal approval process for downhill trails, jumps, or even bike trails in general can create risk and paperwork, along with the risk of more paperwork. But lucky for us, land managers are often able to ignore unsanctioned trails that *pop up* on their land, and unsanctioned trails can sometimes stay open for decades despite not having legal status. For instance, did you know there are only two mountain bike trails at UC Santa Cruz? Yup, I checked the local trail maps and that’s it.

Hiding in plain sight.

In some rare cases, unsanctioned trails can even be grandfathered into legal protected status. For instance, most of the sanctioned downhill trails I’ve ever ridden were unsanctioned when they were originally built and then were grandfathered into the existing trail system years later. This is great news because many of our officially sanctioned trails suck. I know it can hurt to hear, but a lot of the trails that MTB advocates bled and died to get built aren’t all that hot when you ride them. Sanctioned trail builders face a whole host of requirements and complications that don’t exist in the unsanctioned trail building world. Sometimes they emerge victorious from the red tape battle, sometimes they don’t. Other times, the guy who’s great at wading through the bureaucracy on behalf of mountain bikers isn’t as great at driving a mini-excavator.

So, if you’re sold on the idea and you’re ready to build an unsanctioned trail, here’s what not to do.

Don’t build somewhere that already has trails. That narrows it down a bit, huh? Sanctioned riding areas are a bad place to build new trails because your stupid new trail jeopardizes everything else that’s been built. The mountain bike advocates in charge of your sanctioned local riding areas have worked for years- and in some cases decades- to build good relationships with the land managers. Don’t be that person who takes a steaming dump on all their hard work and trust. Illegal trail building gets legal riding areas shut down all the time, and it can make new, sanctioned trail building politically impossible. Similarly, don’t build at someone else’s secret spot if you haven’t received a personal invite from the head trail boss to do so. Just like with legal trail spots, your misplaced enthusiasm can ruin other people’s hard work. Don’t be that person. When in doubt, build somewhere else.

Don’t be that person who takes a steaming dump on all their hard work and trust.

 

Don’t build something that’s going to age like bread. Just because it’s “super sick” when you’re skidding down the forest floor’s original duff layer, doesn’t mean it’s going to be sick in a year or two when your rear tire has excavated everything down to the mineral layer of hard-packed soil. If your trail alignment is too steep and unsustainable, your trail is never going to be legal and it’s going to be higher on the priority list for shut down. Land managers don’t want to see troughs and trenches going down the fall line. Similarly, if you’re going to build a jump or berm, don’t build it with logs, sticks, or trash, and don’t use garbage dirt that’s full of forest floor duff. Build it the right way so it’s not a hazard to the next rider. Dirt should be 100% dirt, and logs are only acceptable on the outside of berms and jumps as an erosion control device. Build a trail that’s worthy of respect.

Trinidad, Colorado, DH trail - around for over 20 years.

Ask someone smarter than you. The first time I built a downhill trail, I asked for help. Over 10 years later, I still think of the advice I got every time I’m working on a trail. Invite someone in who’s done this before, especially someone whose trails you’ve ridden and enjoyed, and you’ll probably learn a thing or two. Learning is cool.

And lastly, as a representative of an actual trail organization, I have to officially say that you should never build illegal trails anywhere because they’re bad.


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If you think of pedal kickback and products like Ochain built to combat it, surely the best, most expensive hub you can get with the most engagements is also the worst one?

Should I get a DT 240 and downgrade the ratchet system to 18 engagements, but not tell anyone so people still think I’m cool and like me?

Thanks,

Fionn

Team Robot: Here’s a quick test for you, Fionn- do you remember that time you took a lap on someone else’s bike with fancy high-engagement hubs and thought, “Pffft, my feet are getting destroyed out there!”

You don’t remember that because it never happened, and it never happened because freewheel-induced pedal kickback is not actually a thing. The claim being made by pedal kickback theorists is that our hubs are micro-engaging hundreds (and potentially thousands) of times per ride while coasting downhill, and this is creating suspension feedback in our feet. I rode fancy high engagement Chris King hubs for years, and last year when I switched to cheapo no-engagement Stans NEO hubs I didn’t suddenly thank Stan for removing pedal kickback from my life. Similarly, I know what my hub sounds like when I pedal hard enough to get the audible “THUNK” from the pawls engaging, and I’ve never heard that sound while coasting, certainly not in rapid succession. Have you ever heard that sound in a Vital RAW? Neither have I.

 

Now, it is true that flat pedal riders feel more input at their feet through the pedals, but that’s due to a widely studied phenomenon called “hitting bumps.” With feet carelessly positioned on flat pedals, hitting bumps can knock your shoes loose from the pedals. This sensation can be remedied by a simple adjustment called “dropping your heels.”

Insert picture here of Mr. Heeldropper himself, the one and only Sam Hill. (Here are 15 more, too.)

2003. Heel dropped.


Clipless riders still experience the sensation of hitting bumps, but they aren’t affected by it as much because their feet are bolted to the pedals. Whenever I switch back to flats, I have to consciously remember to rock my feet back and drop my heels through rough sections, and I have plenty of scars from forgetting to do this. Watch Sam’s feet through a rock garden sometime and you’ll begin to appreciate why he’s Sam Hill and you’re not.

 

Right now you’re probably wondering, “Wait, if freewheel-induced kickback supposedly isn’t a thing, what’s the deal with Ochain?” You may recall this very website did a test of Ochain a few months ago and came away with a positive impression. Neko Mullaly tested it and said he felt a difference. Reece Wilson won World Champs with Ochain. What Ochain claims to do is prevent freewheel-induced kickback. I’m dubious of that claim, but I don’t think Ochain does nothing.

Canyon
DisConnect

Ochain definitely allows freer movement of the chain during suspension events, which probably has benefits. With most suspension designs, as the suspension goes into its travel, it typically sees chain growth as an effect of the rear axle moving farther away from the bottom bracket. For every centimeter the effective chainstay length grows, the chain needs to grow two centimeters in length to compensate. Swinging derailleur cages accommodate the need for chain growth during suspension compression and they allow for chain slack to be reeled in during suspension extension. However, without Ochain, only the bottom half of the chain can move because your feet are holding the cranks, chainring, and top of the chain in a static position. With Ochain, the top of your chainring is able to move during impacts, which allows the top and bottom of your chain to freely move your cassette and chainring as needed during movements. What exactly is the performance benefit of this movement? What’s the performance cost of using a normal chainring and preventing this movement?

Uhhhh emoji.

I don’t know, but I know it has nothing to do with your stupid hub. I’d say additional research is required into the effects of chainslap and chainstay growth on suspension for bikes running a traditional drivetrain, but in the meantime buy whatever hub you want. Your hubs have nothing to do with your suspension.

Other factors to consider:

Clutch derailleurs. They resist the motion that Ochain allows, and likely exacerbate suspension harshness in bikes with high anti-squat values. Are they a net positive? A necessary evil? Or should we go back to loud bikes with no clutches? Ask Chris Porter what he thinks.

Chains are heavy and made of steel. When they slap up and down and back and forth, that takes a lot of energy. This energy has to come from somewhere in the system, meaning chainslap is acting as a damper of sorts on your suspension movement. Don’t trust me, ask Steve from Vorsprung.

 



If you have a question about mountain biking for Team Robot, now is the time to ask.

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