Momentum Wins: Scrap the Downhill Rider Yields to Uphill Rider Rule

Dear Lennard, I hate the IMBA trail rule to yield to uphill riders

Dear Lennard,
I hate the IMBA trail rule to yield to uphill riders. I think there would be fewer problems on the trail if uphill riders yielded to downhill riders.
What do you think?

Dear Frank,
I agree. Most of IMBA rule number four is reasonable, but that sentence is not. In fact, I find it a bit irritating that it is never questioned and that people can become self-righteous about enforcing such a senseless rule. What I find particularly irritating is when I myself become self-righteous about it and belittle somebody for not knowing the rule. While I personally would rather not have to stop my uphill progress because somebody is coming down, it makes way more sense for me as the uphill rider to stop than the rider coming down, and I’ll tell you why.

Ever notice how people who are new to mountain biking and don’t know this cardinal rule tend to stop when they’re going uphill and somebody else is coming down toward them? That’s because it makes sense to do it that way.

Here are some reasons why:
1. The rider coming down has way more momentum and requires much more braking to stop than the rider going up.
2. The downhill rider may not be able to stop, if he or she is coming around a corner fast and doesn’t expect come upon a rider there. The uphill rider can essentially always stop easily, though.
3. If the rider going up doesn’t get out of the way, both riders could be seriously hurt by the downhill rider’s momentum being transferred to the uphill rider.
4. Stopping the downhill rider’s bike is much more damaging to the trail than stopping the uphill rider’s bike.
5. The uphill rider is forewarned of the coming of the downhill rider, but the reverse is not true. The downhill rider’s bike is making a lot of noise, and the uphill rider’s bike is not. What little noise the uphill rider is making cannot be heard by the downhill rider over the racket of his bouncing bike.
6. The downhill rider will get by a lot faster and clear the trail sooner than the other uphill rider would.
7. A critical skill in mountain biking is being able to start up on a steep pitch. Reversing the IMBA rule would give riders more opportunity to practice this essential skill.

Claro Brasil Ride 2011
Claro Brasil Ride 2011. Stopping suddenly on a downhill has consequences. Photo: IvanPadovani

We tend to justify this nonsensical rule with the argument that it is easier for the rider going down to get going again than it is for the rider going up. While that is certainly true, I’m cynical enough to believe that it probably was never thought out in this way when it was established, but rather was inherited from other rules of human activity. I think that the downhill-rider-yields rule might have originated from rules for horse-drawn (and ox-drawn) wagons; it would be very difficult to restart a fully-loaded oxcart, carriage or Conestoga wagon on an uphill. On the other hand, I don’t know how the downhill cart would back up, whereas it seems that the uphill one could do so more easily. It reminds me of a theory for why riders usually dismount on the left side of the bike and why the derailleurs are on the right side. I think it’s because horses are usually mounted and dismounted on the left, and that became customary because soldiers (presumably right-handed) wore their sword on the left and didn’t want it to get tangled up with the horse when mounting.

In the California Driver Handbook – Laws and Rules of the Road, it says:
“On mountain roads, when two vehicles meet on a steep road where neither vehicle can pass, the vehicle facing downhill must yield the right-of-way, by backing up until the vehicle going uphill can pass. The vehicle facing downhill has the greater amount of control when backing up the hill.”

That makes sense to me, but that argument doesn’t apply to bikes.

I tend to begrudgingly adhere to this senseless downhill-yields rule, since it’s useful for riders to have some sort of understanding about what the other one will do, even if it’s misguided. However, a buddy of mine says, “When I’m coming down, they’d better get out of the way. The only time I would yield is if the guy coming up is cleaning something super hard, and by that I mean something that is really hard to clean (i.e., not just something that a good rider can clean relatively frequently).”

He says that he can even predict if a guy is the type to not get out of the way based on what bike he is riding and what he is wearing. That rider holding his ground may be in the right based on the current rule, but he could end up dead right.

Another buddy of mine, after stating the it’s-easier-for-the-downhill-rider-to-get-going-again argument for the existing rule, says he approaches it with pragmatism. “If a guy is flying down toward me all padded up like a football player,” he says, “you bet I’m going to get out of the way!”

I think it would be ideal if riders banded together to change this rule by general consensus. In practice, it’s hard for the masses to change a rule that’s been in place for so long, but IMBA could take the lead and reverse its policy. Failing that, if riders were simply to yield whenever they can and approach each situation with an open mind on a case-by-case basis, it’s much safer than uphill riders blindly adhering to the current rule and not budging for downhill riders. Somebody can get hurt that way.

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Technical writer Lennard Zinn is a frame builder (,
a former U.S. national team rider and author of numerous books on bikes and
bike maintenance including the pair of successful maintenance guides
Zinn and the Art of Mountain Bike Maintenance” – available
also on DVD, and “Zinn
and the Art of Road Bike Maintenance
,” as well as “Zinn
and the Art of Triathlon Bikes
” and “Zinn’s
Cycling Primer: Maintenance Tips and Skill Building for

Zinn’s regular column is devoted to addressing
readers’ technical questions about bikes, their care and feeding and how we
as riders can use them as comfortably and efficiently as possible. Readers
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appears here each Tuesday.