Does MUni impact the trail more than MTB?

I’ve seen some photos here of people doing the MUni on very-muddy trails.
Around here that is a big no-no.

Please consider your impact on the trail.

Does a Municycle have more or less impact on the trail than regular Mountain Bikes?

For downhill I would think MUni does not skid as much so we are better for the trail in that regards.

In tight turns/switchbacks though, the single point interface with the trail may mean you grind up a bit more dirt in tight jerky turns. The MTBers might flow through tight turns a little easier.

I’m sure some areas of the country may not consider their impact on the trail as much. (Widening trails, double-tracking, shortcuts, deepening trails, erosion etc)

In higher alpine environments it takes years, if-ever, for a trail to be grown over and repaired. Much of the damage caused by MTBs, Hikers and horses tend to be almost permanent. Horses IMO seem to be the worse.

I do admit I have never gone and volunteered for a trail maintenance day. I may change that this next summer for trails I use a lot. It’s only right.

Your thoughts?

The impact of riding in the mud varies greatly depending on the soil. There are places in the Bay Area where the trails are essentially two feet deep in redwood duff. The mud’s too soft and loose to hold any form; the trails easily repair themselves as the trees drop more litter. There are also places where the soil is bay mud that sticks and cakes onto everything; riding on those can definitely cause damage. (There are two mitigating factors: one, those trails are basically impossible to ride when they’re wet, so people don’t, and two, most of that land also allows cattle grazing, which has so much more impact it’s not even worth worrying about.)

The environmental impact of trail use, in most environments, is generally overstated by alarmsts wanting to keep bikes off trails. All trail use has some impact, but almost all major trail damage occurs from natural processes of rain and erosion that we don’t control or effect. An exception is an environment like Moab, where we can damage the cryptobiotic soil that forms the basis for the local ecosystem.

IMBA and its local affiliates are good organizations to get involved with, for trail maintenance and advocacy. They work to extend opportunities for off-road cycling (and are working right now with the national park service on opening up some trails in national parks), and do a lot of work to keep our existing trails available and fun. Keep singletrack single.

Road damage is proportional to the 4th power of the axle load. A MUni has one axle, a bike has two. If the MUni and the bike weigh the same, and the riders weigh the same, the MUni will do 16 times the damage to the trail that the MTB does.


I’m sure some areas of the country may not consider their impact on the trail as much. (Widening trails, double-tracking, shortcuts, deepening trails, erosion etc) IMBA has guidelines for how to “tread lightly” and what to do/not do to make trail wear & tear worse. Off the top of my head the major ones I can think of are:

  • Stay on official trails (don’t make unauthorized trails)
  • Don’t cut corners or switchbacks
  • Ride it, don’t slide it (no skidding)
  • Don’t widen the trail around puddles. See a puddle? Go through it!

Like Tom said, there is the actual trail wear & tear we cyclists cause, and then there’s the exaggerated “damage” we do as reported by people who want us out of the parks and public lands. This is always especially humorous when it is pointed out by equestrians, who generally do a lot more wear & tear due to the vastly heavier weight of their vehicles. Also, I’ve yet to see a cyclist take a dump in the middle of the trail. :slight_smile:

I am a member of, and have, participated in trail work with my local mountain bike group, which is an affiliate of IMBA. It’s been a while, but I have to avoid certain areas because clearing brush, when it may contain poison oak, is very bad for me.

Certain trails in my area (Sierra Nevada Foothills) are closed during wet weather due to their tendency to wear fast under tires. People are supposed to stay off them during certain times of the winter. It’s up to us to be responsible trail users, even if our impact is minimal.

Is that trail, or road? I think that figure is related to hard pavement, though we definitely put more weight down per square inch of tire coverage. I would venture to say that our non-braking impact on the trail is perhaps a little larger than that of a bike, especially with our fat tires, that displace a lot of mud and leave wide indentations behind.

That is road or hard pavement.

If I’m not mistaken, the weight per square inch we put down is more or less equivalent to the tire PSI. So since we run at lower pressures than bikes, we actually put down less weight per square inch of tire contact. In exchange, we have larger contact patches.

The trails in Chico’s Upper Bidwell Park, where I do most of my riding, close for at least three days after significant rainfall. I always adhere to the trail signs, and have been known to get pissy at bikers I see out when the trails are marked as closed. I’ve done trailwork with the parks department, and it’s a fun way to help out. We have a recurring trail day the 1st Saturday of each month, and it’s a nice way to make a positive impression on a variety of trail users. Many of the people who show up to help are hikers or equestrians, and it’s good for them to see cyclists helping out.

I think in simple riding from a-b we do simular trail damage, good arguements with our PSI vs their dual wheels for weight distribution. I only disagree with your statement on tight turns, since mountain bikers take these turns at a higher rate of speed they would have to apply the brake often times causeing to slide creating burms in the track. I know from my experience in mountain biking that I spend alot of time hitting those turns with a roost to maintain my speed, or just for fun :D. On a uni when you do a switch back you are allready pretty much being forced to take it at the appropriate speed(slow), unless you are rockin a guni or 36, in that case your just crazy.

As Tom said, the situation varies greatly depending on the type of soil and other local factors. There are trails in the Seattle area that are rideable year round, even during the Seattle wet season. There are also other trails in the area that are not rideable in the wet season due to causing trail damage and due to the type of mud.

A nice thing about the Seattle area is that if you are very serious about riding you can manage to ride trails year round.

I believe unicycles cause less trail damage than bikes. Unicycles don’t spin the tire trying to get over roots and obstacles. You can’t spin the tire on a unicycle because if the tire slips you fall off. Not so on a bike. Unicycles also don’t skid when slowing down. Unicycles also tend to take a different line around turns (a unicycle can take the inside line of a corner that a bike could not manage). So while the bikes may be chewing up the outside line in a corner a unicycle can take the inside line.

Riding in the wet does require some special trail etiquette. If there is a puddle across the trail you should ride through the puddle rather than skirting around the edge of the puddle and widening the trail. Trying to ride around a puddle or riding off the trail to get around a puddle causes trail damage. Stay on the trail.

If staying on the trail applies to riding skinnies our group effort at etiquette leaves a great deal to be desired.

That rule does not apply to urban Coker rides.

The 1-axle thing might increase our theoretical damage, but I think the slower speed thing makes it actually much less.

As others have mentioned, cycle damage to trails is often just a yelling point used by other groups who don’t like mountain bikes on trails because they go so fast and can more easily run into hikers or spook horses. Since unis go slower, and more interesting to watch, I expect anti-cycle-folks shouldn’t be as hostile towards us.

No one should be hostile toward us. We’re better than other people. We’re clowns.

Assuming that road damage is indeed a 4th power function ( care to explain why?) …should that not therefore be 8 times the damage? Each MTB wheel causing 1/16th the damage?


This kind of stuff is really interesting coming from over here in the UK. Most of our trails are just bridleways, originally old tracks for people to get places on horses, or walking. Because of them being for transport as well as just fun places to ride, it’d be ridiculous to close them in the wet (not to mention that not riding for 3 days after rain would mean not riding for 6 months of the year). Some trails aren’t worth riding in the wet, because they get super muddy, but that’s just a choice thing. Some trails get a bit damaged, and need to be fixed, but if they become not so fun, people just go ride somewhere else.

Part of the thing is that because there’s so many trails compared to many other countries (in England and Wales there’s something like 40,000 miles of legally rideable trails, 140,000 miles of legally walkable but often rideable trails) that people are spread out a lot.

The purpose built trails here are designed for all year riding, there’s a lot of work into drainage.

Interestingly, one of our local areas now has a designated ‘casual riding area’, in which making of random trails, riding off the trail etc. is officially allowed. It does change shape a bit every year, new trails appear, old ones disappear, but it doesn’t seem to cause any problems, the undergrowth just grows back where the trails have gone out of use.


No. But here is one of many references.

Yes. My ability (or willingness) to divide by two has diminished with age.

There are some excellent MTB trails about 5km’s from my house, Tokai Forest, against the side of the Steenberg mountain in Cape Town. As it’s so close I go there very often. Having spent the last year riding there, including through a very wet winter, I have noticed how dramatically trails can get damaged.

In order of damage done:

  1. Rain/water errosion
  2. Horses
  3. MTB’ers
  4. MUni

The first is a given especially when you have steep trails. We had a very wet winter for Cape Town and the damage on the trails by water could be seen weekly.

I get so annoyed by the horse riders taking their horses down the single tracks completly ripping up the trails with a single horse doing more damage than 100 MTB’s. I noticed this a lot during the winter months when the damage would be even greater due to the muddy/loose soil.

The MTB’ers here also tend to take the easiest line, or rather making easier lines by just riding a new path on an existing trail, particularly around some drops and turns. I put it down to pure lazyness and an inability or unwillingness to actually ride the existing trail. This obviously causes more erosion during the wet months of the year. It seems that a large number of MTB’er do not care about the trails they ride on and have personally seen a number of them just locking up their rear wheels while going down some sections instead of riding them properly, going around obstacles rather than over them widening the trails.

MUni would do damage to the trails but I believe that the damage is far less than an MTB. I also ride the trail and don’t go bundu-bashing because I can and damage the areas around the trail. I ride the drops and whatever else is on the trail. I mean that is the point… isn’t it ?

I would actually like to get involved with the trail building and restoration in my area for 2 reasons. The first is because I ride the trails I would like to contribute to maintaining them. Secondly, some trail restoration that has taken place lately in Tokai Forest has really “dumbed down” some of the trails, making them much easier for the “everyday” MTB’er taking away some of the trails technical points which is a little frustrating. I believe that if you can’t ride the trail… don’t … or at least practice so that you can. Don’t “dumb-down” the trail because you’re to lazy to increase your skill level. (rant over) :slight_smile:

I don’t agree with that. My (fairly typical) xc mountain bike had 1.9" tyres running at about 40psi. My (fairly typical) muni has a 3" tyre running at 18psi. Although the muni tyre is carrying the entire weight of the cycle and rider on one tyre, a low pressure tyre with a big contact patch will put less weight per square inch of contact than the narrower, harder bike tyres.

Also, the fact that you have to ride smoothly on a unicycle in order to keep balance I reckon means we probably do LESS damage than the average bike.

But (apart from idiots locking back wheels all the time) a rolling wheeled machine does FAR less damage than a horse rider, who seem to think it’s the cyclists that are the evil ones.


It is counter-productive to blame one type of trail user for damage more than any other. Quantification attempts in this context, like harper, are silly.

Use it? Help maintain it.

My post wasn’t really intended to point blame, although it did come across that way (horse riders are given a pretty free rein round here, while cycle-legal trails are becoming more and more limited due to perceived damage caused, which annoys me).