Why can’t anyone agree on MTB trail difficulty ratings?

I can’t tell you how many times I’ve finished a ride with friends, cracked a cold one, and then proceeded to analyze the new trail that we’d just ridden. Inevitably, the conversation turns to technical difficulty.

“Is that really a double black trail? All of the difficult features had easy ride-arounds. I think a double black has to have mandatory features,” one person would quip.

On a different trail, “that trail was rated a black, but it only had one black section in it, and 99% of the trail wasn’t a black.”

Or the conversation might go, “All of the difficulty ratings around here are overblown! The blacks are blues, and the blues are greens. The riders here must not have a clue what they’re doing.”

We all love to debate trail difficulty ratings, the gnarliness (or lack thereof) of various features, and how we performed on the toughest sections of trail. But I began to wonder: how do these trail difficulty ratings get assigned in the first place? Where do the blue squares and black diamonds come from?

Why can’t anyone agree on how to rate trail difficulties?

For this article, I interviewed eight different people on three different continents and consulted at least a half dozen more. The sources in this article include authoritative organizations such as the International Mountain Bicycling Association (IMBA), innovators like the International Trail Rating System (ITRS), land managers like the Bureau of Land Management (BLM), and more. In addition to these sources, I’ve drawn on my experience traveling the world with my mountain bike for the past 20 years.

As I interviewed sources and asked several of the same questions over and over, I talked to many people who were adamant about how trails should be rated. For instance, one authoritative source was adamant that a trail should be rated based on its single most difficult feature.

But then another authoritative source would say the exact opposite — that you can’t rate trails based on one feature and must instead assign difficulty based on the overall character of the trail. In this view, one really difficult section wouldn’t warrant a difficult rating.

For seemingly every single topic I asked about, the sources I interviewed disagreed. Should trails be rated on a local/regional level, or should they be assigned scientific ratings based on quantifiable criteria that can be used all around the world? Who should be assigning these trail difficulty ratings in the first place? Should trail difficulty ratings be posted at all?

On the one hand, the lack of agreement from these authoritative sources was startling, but on the other, it made sense — this is precisely why we debate trail difficulty ratings after a ride. Even among a group of friends that ride together often, each person has a different perspective on the various technical features that each trail contains. Subjectivity on the topic is rampant.

I tried not to let that inherent subjectivity stop me — I continued to dig a little deeper in an attempt to figure this mess out.

One thing we all can agree on: new trail construction.

For the most part, all of the sources that I interviewed agreed that when a new trail is built, the intended trail difficulty and the features included in the trail should all be laid out and agreed upon before construction begins. It is then the contractor’s job to build the trail to those specifications.

“From a Trail Solutions point of view, the way we implement things is when Josh [Olson]’s team are building a trail after we’ve designed the trail, that trail, the whole length of it, is representative of the first 200 feet,” said Mike Repyak, IMBA Trail Solutions Director of Planning and Design. “We’re not throwing a double black diamond section in the middle of a green trail. That’s just wrong to do that. We’re consistent throughout the trail segment that you’re on from sign to sign, and our signage provides information that riders can make an informed decision — not just the green, blue, black, but the trail is this length, the trail has these aspects/characteristics to it, the trail’s at this average grade.”

If the project specs are clear on the front end and the contractor does their job properly, the trail difficulty rating is known before the builder even breaks ground.

Trail difficulty ratings still don’t align from one region to another.

However, even within the world of professional trail building, there’s still subjectivity inherent when assigning the rating after the trail is complete. Riders will often notice a certain degree of variance in trail difficulty from region to region: a black diamond on their home trail system won’t be the same difficulty as it is in a different area.

It used to be that Midwest riders heading to the Rocky Mountains (for example) would get beat down because the trails out West were so much more difficult. But now, that experience of being under prepared for a trail’s technicality can even occur in a much smaller area. I’ve spoken with trail builders in the Midwest who see riders coming from the southern Midwest to the rocky, rugged trails in the Upper Peninsula of Michigan or on Minnesota’s north shore that are entirely unprepared for what they find.

Just because you can ride a black diamond trail in your hometown doesn’t mean you can ride one in Whistler or Moab.

“What you’re seeing is that they want to provide the differentiation even inside of the region,” said Josh Olson, IMBA Trail Solutions Director of Construction and Operations. “Everybody wants to have a green, blue, and black and needs to explain their terrain. You don’t just say everything in West Virginia is blue, even though they may not have terrain that gets to Colorado black. So you’re gonna see those ratings from different regions, and they kind of represent the local topography and everything else.”

Furthermore, even though a professional trail builder may be handed detailed specifications for the trail that they’re contracted to build, they generally aren’t responsible for assigning the difficulty rating after the trail is complete. That’s up to the local land manager or the local club.

Some land managers don’t assign difficulty ratings at all.

While the ultimate decision on how difficult of a rating a trail should receive rests with the land manger, it turns out that many land managers don’t rate their trails at all. I spoke with the director of a local advocacy group who mentioned in passing that their group doesn’t post trail difficulty ratings on their trails because neither the BLM nor the Forest Service in their region post difficulty ratings. I personally found this surprising. To get to the bottom of this issue, I interviewed three different people at the BLM — two in Colorado and one in Utah — and learned that even within the BLM, the approach to trail difficulty ratings is inconsistent.

First, I spoke with Dave Jacobson, The Travel & Transportation Lead for the BLM Utah State Office. Prior to moving up to the state level, Jacobson managed the recreation in the Cedar City area, which is home to the professionally-designed Iron Hills mountain bike trail system with fantastic trail signage — including trail difficulty ratings. Other districts that now fall under his purview, such as Moab, also have extremely detailed trail signs.

In fact, some of Moab’s trail signs feature trail difficulty progression scales, ranking each trail against the others so that riders can slowly work their way up in difficulty. This system is utilized by bike parks like Whistler and Trestle, but it’s rare to see it on multi-directional trails on BLM land. Moab also breaks down their trail difficulty ratings much more granularly, including sub-ratings such as green/blue, blue/black, and more.

However, the BLM Tres Rios district in Colorado — which covers the entire southwestern corner of the state, including the town of Durango — doesn’t assign trail difficulty ratings to any of their trails. I was under the impression that even if the ratings weren’t posted, the US Forest Service (USFS) and BLM had trail management objectives (TMOs) that governed how they maintained and managed each trail. In fact, one of the first controversial articles I ever wrote for Singletracks was about a terrible rebuild of the Bull Mountain Trail in Georgia, which purportedly was done to bring it back in line with the TMO for the trail.

TMOs essentially outline the specifications that the trail is built to and how the trail will be maintained in the future. These objectives identify how wide the trail is, how big the drops are, how steep it is — all of the factors that go into a technical difficulty rating. As trails fall out of line with their TMOs over years of use and erosion, they’re often then rebuilt to bring them back in line with the TMO. Sometimes those rebuilds are viewed as “dumbing down the trails” by uninformed mountain bikers, but other times, the maintenance can go the opposite direction. For instance, if there is unauthorized trail work that makes a technical trail easier than it should be, that also goes against the TMO. In this case, the cheater line would be removed to make the trail more technical.

But after speaking with Jeff Christenson, Outdoor Recreation Planner Lead in the Colorado BLM state office, and Jason Byrd, Supervisory Outdoor Recreation Planner for the Tres Rios field office, I learned that many (if not most) BLM districts haven’t had the time to develop TMOs for all of the trails that they manage.

“TMOS are, in a perfect world, developed for all of our trails,” said Christenson. “In reality, I only know of one field office that’s actually had the staff and the time to develop them, maybe two.”

“The Grand Junction office in Colorado has been able to have the staff and time to set TMOs for their trails as they develop and maintain them,” said Christenson. “Other offices […] haven’t had that staffing and time luxury.

“Jason, how much staff you got?” asked Christenson.

“It’s me and one — well, now two park rangers,” said Byrd. “We’re stretched pretty thin. So yeah, it’s pretty hard to do. Luckily, we have partners that help us get the trails and maintain them and stuff like that. But yeah, that kind of idea — it’d be nice to be able to do that kind of stuff. But we’re just trying to stay afloat, essentially.”

If nearby regions don’t follow the same system, forget about different countries.

If two regions located just a few hours apart managed by the same government agency (albeit two different districts within that agency) don’t follow the same process, what hope do different countries have? I spoke with Edoardo Melchiori and Mischa Crumbach, co-developers and managers of the International Trail Rating System (ITRS) based in Europe, to understand how rating systems differ from country to country.

According to the ITRS website, Melchiori and Crumbach developed this new system because “in 2020, there were at least 14 different trail rating systems in Europe alone to describe the ‘difficulty’ of mountain bike trails and routes, whereby ‘difficulty’ did not always evaluate the same aspects.” When I spoke with them, they mentioned that the number is now at least 20.

In other countries, even the nuts and bolts of how ratings are shown to riders differ. For instance, the IMBA scale in the USA goes: green circle, blue square, black diamond, double black diamond. The system in most (but not all) European countries goes: green circle, blue square, red triangle, black diamond.

I also spoke with Ryan Hunt, President of Mountain Bike New Zealand, and learned that the trail rating system there utilizes a number scale. In New Zealand, Hunt said that they have “national trail guidelines,” which follow a number grading system from one (easiest) to six (hardest). Even within the small country of New Zealand, the system isn’t applied evenly, echoing the same difficulties seen in the USA and Europe.

While discussing the efforts of the ITRS is outside the scope of this article, be sure to read my dedicated article on the topic.

Ultimate responsibility falls on the rider.

Posted trail difficulty ratings serve many purposes. At their most fundamental, they allow riders to choose trails based on their perceived ability levels. Posting trail difficulties also acts as a risk management tactic for land managers. But at the end of the day, the responsibility for riding a trail within one’s skill level falls on the rider — and nobody else.

“Riding mountain bikes — it’s inherently risky,” said Olson. “If you would like to assume zero risk, you should not ride mountain bikes, you should stay at home. I mean, everything in life has a bit of risk associated. It’s just being informed and evaluating your risk levels and taking responsibility as a rider to ride within your abilities and use the signage to inform that.”

We all ride mountain bikes for the challenge of it. If all we sought was fitness, we’d be riding on the pavement. At the end of the day, trails need to be difficult, even if that means that some riders might get in over their heads and get hurt.

“The worst outcome of this would be that you would want to take all of the different trails with all the different variety and try to dumb it down to the lowest common denominator,” said Olson. “People want to have technical trails. People want to take that risk and assume that risk.”

“I think the goal would be to not necessarily dumb down the trails to reach the most common, lowest common denominator, but to just be able to provide that information as accurately as possible,” Olson concluded.

Will we ever agree? Probably not.

My foray into the murky world of mountain bike trail difficulty ratings was exciting, but unfortunately, it didn’t yield any clear answers to the questions. When even the professionals disagree, what hope is there for the rest of us mere mortals who are just trying to avoid eating shit on an unexpected ledge drop?

After talking with a slew of experts, I doubt that trail difficulty ratings will ever be standardized across different regions, much less different countries. It seems prudent to consider trail difficulty ratings as mere “guidelines.” If you’re traveling to ride a new trail, proceed with caution until you get a feel for what that region has to offer.

If we leave our egos at the trailhead and approach new trails with a healthy dose of caution and humility, we’ll be able to safely test our mettle on the technical challenges inherent in this beautiful sport.