Why might I want to buy MTB clothing, rather than use road cycling kit that anyway seems exactly suitable for both sports?

Question

Road Cycling

There is a very strong case for tight-fitting clothes on a road bike:

1. Wasps (I'm listing the reason that firmly converted me first.) A wasp entered my shirt while driving, and I momentarily lost control of the car from agony at the moment it stung me. A wasp sting on a bike would be a rather dangerous event.
2. Crawling sweat On climbs or when the wind is so stale it doesn't evaporate one's sweat fast enough, cycling in street or baggy clothing results in the creepy feeling of drops of sweat crawling on one's back, chest, and under one's arms. Tight special fabrics quickly wick sweat, spread it to a larger area, and evaporate it without the cyclist ever feeling the moisture.
3. Rain During drizzles or even downpours, there is really no reason to seek shelter unless there are thunderstorms. Cycling in the rain is thrilling (and, as an aside, the "casquette" helps a lot with keeping most of it away from glasses). Here tight-fitting clothes and their special fabrics also help significantly. They magically somehow keep one warm.
4. Rashes If you've ever ridden a long distance with baggy shorts, you will have noticed inflamed skin where the hems touched you. Lifting then lowering the legs tens of thousands of times will do this. Tight-fitting hems solve the problem.
5. Aerodynamics As long as one is riding with a leisurely group at 15-20 km/h, wearing sail-like clothes could sometimes be pleasantly refreshing. But ride over 20 km/h and the clothes will move up your limbs, and the sail-like clothes become irritating, not to mention that they will make it harder for you to keep up with a faster group.
6. Fitting in Road cyclists typically do wear tight-fitting lycra. Concerns of lack of modesty quickly disappear with a group, and as a bonus one fits in.

Mountain/Trail Cycling

By comparison I see no reason to acquire specialized clothing for MTB, and all the reasons above still apply, except that aerodynamics matters more or less depending on speed, still as with road cycling.

Sports stores are of course happy to tell us that the pockets on tennis shorts make them unsuitable for doubling as soccer shorts.

Can you suggest any advantages to MTB's baggy clothing, besides "fitting in"?

Related

Wear fabrics that do not hold much water

This question has been edited to make its focus distinct from a similar question.

Answer 1

As someone who has been around long enough to have seen at least some of the early days of the MTB, I would have to surmise that the reasons for the baggy MTB attire can be one or more of the following (in no particular order):

1. The perceived relative comfort of a looser fitting shirt and shorts. This could also be due to inexperience regarding how comfortable snug cycling clothing can be.
2. Possible separation to establish an identity different from the "roadie" look. The perception of "no rules" MTB vs. the strict regimen that road riders had, and still have (not necessarily bad regimen, just a bit too rule-ridden for the free spirit MTB crowd). MTB riders are the "rebels," and therefore dress differently.
3. If a rider's first foray into cycling is via MTB, and they don't have other clothing, then the use of just shorts and a shirt (baggy) seems natural. They are just riding a bike, not going for fashion points. Plus, they may not have taken time to invest in cycling-specific clothing yet, and are comfortable looking similar to their fellow MTB'ers.
4. If a MTB rider is biking to a location where they may extend their adventure on foot (i.e., hiking), then the cargo shorts/t-shirt option serves that better than tighter-fitting clothing, and the cargo shorts would have plenty of pocket storage.
5. The aerodynamic advantage of snug-fitting clothing used for road riding is not as much a factor at relatively slower speeds while mountain biking.
6. Being a little self-conscious about wearing snug fitting clothing. It does reveal more than baggy clothing would.

There has to be additional reasons not listed above...

Answer 2

One advantage is in the robustness of materials used.

For example on a wet muddy/gritty ride the spray coats the saddle with dirt which acts as a grinding paste. Given the nature of MTB riding, there can be a lot of small movements in the saddle due to the bumpy terrain. This can cause lycra cycling shorts to wear extremely quickly.

To combat this, MTB shorts often have a more robust material like cordura in the seat area.

Answer 3

One fairly important aspect of MTB clothing is indeed the visuals. I think the other answers have elaborated on the psychological and social explanations of this very well already. I just wanted to bring up an interesting piece of supporting evidence: in competitive DH racing, the baggy clothing is mandated by UCI regulations! When casual riders see their heroes wearing a certain clothing style, they are naturally drawn to replicate that look.

Found in this document (UCI Regulations, Part IV: Mountain Bike), the section concerning DH racing says this:

4.3.011 All lycra-elastane based tight-fitting clothing is not permitted. (p. 25)

I didn't write the rulebook so I can't say exactly why this is, but I would imagine it has to do with the culture and optics surrounding downhill riding. Interestingly enough, modern DH outfits appear to be pushing this rule as much as possible by being tight-fit while still non-stretchy. The aerodynamic benefits of tighter clothing are undoubtedly significant when average speeds are often in excess of 45km/h. Take Loïc Bruni for example (2021 image):

This rule regarding clothing does not apply to XC races, and so as expected, everyone is wearing skintight lycra there.

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As a somewhat related side point, here's the rest of the clothing specification section:

4.3.012 A full-face helmet must be worn properly both when racing and when training on the course. The helmet must be fitted with a peak. Open-face helmets may not be worn.

4.3.013 The UCI strongly recommends that riders wear the following protection:

• back, elbow, knee and shoulder protectors made of rigid materials;
• protection for the nape of the neck and the cervical vertebrae;
• padding on shins and thighs;
• broad full-length trousers made from rip-resistant material incorporating protection for the knees and calves, or broad-cut shorts made from rip-resistant material plus knee and calf protectors with a rigid surface;
• long sleeved shirt;
• full finger gloves.

(p. 26)

While not as clear-cut as the lycra ban, I think all these recommendations do contribute to creating an overall theme for what DH racing looks like.

Answer 4

I mix and match road and mtb stuff, often wearing road jerseys on trails, but sometimes mtb-specific or even hiking kit to ride.

In terms of sweat running down, it doesn't make much difference. MTB clothes move around enough that almost any covered area comes into contact with fabric pretty soon, while even my close-fitting road jerseys leave plenty of places uncovered to get sweaty. Most mtb and a lot of hiking or general outdoors kit is as good at wicking sweat as road kit.

Baggy shorts are often worn over close fitting liners anyway.

The snag hazard is more of an issue - on some trails - while on others you never get near the vegetation.

Plenty of mtb riders do wear road jerseys, but the pockets can't always be trusted to retain their contents in hard landings; the pocket contents can also clash with hydration backpacks.

Answer 5

As far as I'm concerned, there's one practical reason: on some trails you get flogged with brambles, thistles, nettles, etc. The spines absolutely poke through tight cycling shorts.

Baggy shorts offer much better protection against this, mostly because they're a bit further away from the skin, so the spines don't take off a chunk of meat. They're also thicker, which helps.

For the same reason a shirt with slightly longer sleeves that are not skin-tight is a plus.

I also need pockets. Usually I'll be using a Camelbak, so I can't use the traditional pocket at the back of the cycling t-shirt, because the backpack would rest on it. It's nice to have pockets with zippers in the shorts, so whatever I put in them doesn't fall off.

Answer 6

I wear baggy mountain bike shorts to protect against branches, bushes, crashes, etc. The thicker material is more durable, and because it is less stretchy it tends not to snag as much. It can't be too tight or else the thicker, non-stretch material would be hard to move around in. If I am on a trail with little possibility of crashing and not a lot of plant growth on the sides of the trail I will often just wear road bike shorts.

Answer 7

Cross country riders have clothes that are very close to the ones of roadies. Maybe a bit reinforced, but 'tight with some sponsors written of them' is common.

Baggy clothes have an advantage when one wears padding and special protections: a branch/stone between a protection and yourself can be very uncomfortable. They are more likely to come back at the right position: with tight clothes, you may end with a gap between the protection and the short.

I also haven't tried it personally, but for the sections that look closer to what you might have in enduro/downhill, it's much more of a "static effort" kind of exercice rather than the dynamic one with wind that you might have in road/cross-country. I think that baggy clothes are more confortable for this kind of effort, especially to evacuate the sweat: they create an illusion of wind, rather than having clothes staying tight.

Answer 8

Durability, protection from the terrain and plants. Especially if you're not just riding well developed trails. I think a lot of the other less practical reasons kind of developed out of that over time.

One other consideration would be footwear. You might need to do a fair amount of hiking in some cases in addition to just riding. Having some shoes/boots that are comfortable to use off the bike with a good tread can make a big difference.

Answer 9

A very minor answer: whatever the styles in various sports, by this year there are very good fabrics that wick away sweat, tight-fitting or not. And I can vouch that they really do work. And, in heat, they do function to make evaporation "through" a shirt more effective. In cooler weather, where it is often the case that evaporation-cooling is not desired, and does not occur, the effect is not so much "cooling" as just getting the sweat away from one's body. So, actually, more comfortable if it's chilly.

But, as I've always said, my book budget is based on what I save on my clothing budget. :)

Answer 10

I wear Mtb clothing whether on trails or roads. Why? Because I primarily ride mtb and like the Sam I don't see any good reason for buying two sets of kit. I find the reasoning for buying just road cycling gear a bit suspect.

• Wasps The anecdote is driving. Do you now only drive in tight clothing? I have yet to be stung on a bike. I'm quite certain a wasp could sting you through lycra or a tight jersey if motivated enough. Getting into clothes is a rare situation period. Weird way to start that this was the deciding factor on road attire. No wasp could sting me through my winter baggies from the outside and if they got under they'd have liners to content with. Wasp stings are rare, with an estimated frequency of one sting every 15-20 years. The recommended clothing to prevent wasp stings is it being light in color and full coverage. If you look at what bee keepers wear to prevent bee stings you'll find it's white, full coverage and loose fitting.

• Crawling sweat I have never experienced this, mind you I wear proper jerseys that wick sweat not cotton t-shirts. Maybe it is happening but I've never noticed it. With loose clothing you are also not relying 100% on the fabric's ability to wick sweat which some may find more refreshing. I know some mtbers that wear tight, some loose, some it depends on what they are riding (e.g. xc vs enduro). Sweat isn't the reason why.

• Rain I'm in the PNW, I ride in the rain and temps down to 4c/39F. I'll conceded that I will wear a tighter fitting cycling jacket made of jersey material. While it's snugger there is no way it would be mistaken for road gear. I wear sports specific compression socks for warmth but with water resistant baggies and on the rare ocassion cycling pants. I also love cycling in the rain whether trails or road.

• Rashes I've never had this issue, but I wear liners. I tend to have more issues with knee pads with unshaven legs. The solution is shaving.

• Aerodynamics Got any numbers on "harder to keep up with the group"? I really doubt there's a big enough difference for that, sounds like an excuse if anything. Concern with aerodynmics often seems to be the worry of people on casual rides who would gain more from losing some weight than a tighter jersey. I'll definitely conceded that if you race then shaving 10ths of a second are a true concern, but for your average rider on a casual ride (even a fast ride) you are choosing the road gear to fit in than anything else. Personally I've never had a jersey ride up because it was loose, quite the opposite.

• Fitting in Who cares about fitting in? Wear what's comfortable for you. You might get looks for showing up in jorts, but will definitely get some respect when you keep up (apparently Handup the glove maker makes cycling jorts, I have not tried them but I'm tempted).

All jesting aside, there are different clothes for different type of riding for actual functional and performance reasons. Other posters have covered those. For casual riders you can wear pretty much anything (though I'd strongly recommend sports clothing that properly wicks sweat and doesn't chaff). If someone is starting out riding I'd suggest wearing workout clothes or jogging clothes rather than buying specific and often expensive cycling specific clothing.

Answer 11

There is no reason, it is just fashion and the fitting in. Unless you do stuff where you need extra protection like full face helmets and the spine thingies, or hardened layers against thorns and scratches, you are fine with lycra on an MTB.

Many mountain bikers do no want to associate themself with the road bikers, or worse MAMILs. At least in some countries. However XC racers use lycra clothes that very much look like the road ones just fine. And around here many cross country mountain bikers wear the same lycra that road cyclists wear as well. The must-wear baggies attire you see, e.g., in GMBN vs. GCN is not too prevalent among the local general cycling enthusiasts who mix XC, some trails and roads and often use the some clothes on all their bikes.

Example photo from the official gallery of a czech amateur XC series Kolo pro život. These are the average ranks, not the top racers and they (most people like them) wear similar clothing for their normal rides too.