In 2008, the UCI banned the use of Lycra-based skinsuits in downhill racing, legislating that riders must wear baggy clothing and full-face helmets with a peak.
The rules may have relaxed in more recent times, and they’ve definitely been bent since, but should the skinsuit make a full return to DH racing?
I wanted to find out, so with a little help from a former World Cup DH racer (my boss, Rob Weaver) and BikePark Wales, we headed to the forest with a speed gun, some timing equipment and an Expedition 68 XL campervan from our sponsor Auto-Trail.
Starter’s orders
Downhill racing is all about setting the fastest time against the clock. It’s a game of speed, where riders stand on the top step by margins of a second.
Technological advances have helped riders go faster every year, with suspension, tyres, brakes and geometry helping the best push the limits. But the rules on baggy clothes, enforced from 2008, have only slowed things down.
Bulkier, baggy clothing flaps around, adding wind resistance, and ultimately slowing riders down.
So, should the UCI rescind its rules, banning Lycra-based skinsuits? Or, is modern-day riding attire just as fast, while avoiding riders having to expose every bump and lump on their body in the search for speed?
A little history lesson
Before we get into the testing, let's have a little history lesson.
Back in the early days of mountain biking, Lycra was all the rage, and skin-tight clothing was de rigueur, regardless of which strand of mountain biking you chose to compete in.
By the late 90s, though, the more rebellious streak in downhill mountain bikers saw many riding in ‘cooler’ baggy kit. This separated them from cross-country racers, for whom Lycra did, and does, reign supreme.
Full Lycra skinsuits didn’t disappear entirely, though. For example, national bodies’ kits at World Championship races were often of the old-school, with riders slipping them on instead of their regular baggy attire, for their do-or-die run.
However, in 2008, when Chris Porter’s Mojo Orange team turned up to the Fort William World Cup wearing black PVC-coated Lycra, heads were turned.
Porter’s strive for speed, via his own testing on the hills of South Wales, suggested to him at least that his riders would be faster in their unique-looking kit.
Later that season, Tracy Moseley beat Rachel Atherton by 4 seconds in Canberra, wearing a skinsuit. Atherton wasn’t impressed, writing ‘Skinsuits Suck’ on her arms for the podium.
Tracey, for the record, acknowledged that her kit wasn’t cool, but it was an advantage on the track that she was willing to take some stick for.
Soon after, the UCI banned the Lycra skinsuit, dictating that riders had to wear baggy kit, and helmets had to have peaks.
Why? Well, the UCI wanted to preserve the ‘image’ of the sport, and baggies definitely looked better. It also felt baggy kit offered increased rider protection, and wanted to prevent a technological arms race when it came to clothing.
Changing times
Over the next decade and a half, baggies ruled the roost, but there was definitely more and more customisation of kit going on.
It was not uncommon for teams to have their needles and threads out, cinching in kit to keep flapping to a minimum at the arms and chest, while tucking jerseys in has become ubiquitous. After all, flapping fabric slows things down.
Reflecting trends, in 2023 the UCI updated the rules, stating that jerseys and pants should be designed for DH and BMX racing, and that one-piece skinsuits or kit designed for road cycling still weren’t allowed.
However, the ban on Lycra or elastane materials was removed.
In 2024, Fox almost broke the internet when riders pitched up at the opening round of the World Cup in Fort William wearing its new Speed Suit.
It was an ingenious bending of the rules that riled up competitors in non-Fox kit.
Riders still wore two items of outer clothing – a jersey and pants – to stick to the rules, but nowhere had the UCI stipulated that trousers couldn’t have a tight-fitting vest stitched to the waist.
The go-fast kit made famous by Jackson Goldstone and Tahnee Seagrave has a ‘baggy’ jersey under a tight vest top, to ensure wind slipped over the body as smoothly as possible. Genius.
Time to go testing
To find out whether baggy kit really is slower, and whether a full skinsuit is faster, we needed three sets of kit, a fire road, a DH track and someone competent at riding both.
Fortunately, MBUK’s Rob Weaver stepped up.
Not only does he have World Cup racing experience (and thus can cope with rolling down a fire road), but he also has kit for every situation.
He has his old team kit, with chunky shorts and a jersey that almost swamps him, kit that modern-day racers pull on every week, and… an original Team MBUK skinsuit. What a sight to behold!
BikePark Wales was our location, and they kindly shut off their black-rated 50 Shades Of Black track. We hunted down a fire road for the roll-down tests.
Our tests were simple, designed to measure which kit was the fastest.
First up, we had a 400m-long section of descending fire road. After hitting ‘Record’ on his action camera, Rob would lift his feet off the ground and let gravity do its job, while stood on the bike in the attack position.
At the steepest part, his speed would be measured with a radar speed gun, while at the end of the day, his time from setting off to crossing the finish line would be calculated via the camera’s footage.
Two runs per kit would give us a basic average speed.
Then it was on to the race track. While there were more variables here, the goal was to see whether over a longer distance, with jumps, drops, corners and ruts, the different clothing might make a noticeable difference.
Using a Garmin Edge MTB with its Timing Gates setting would give us an accurate time.
Roll deep
The idea of doing a roll-down test was to minimise the number of variables. With no technical ground to cover, a consistent position over the bike and the same distance each time, the differences in time should, in theory, be almost all down to the kit Rob was wearing.
Rolling past, there wasn’t much to discern between the three styles of kit, although both the speed gun and times at the end of the day showed some differences.
Most noticeable to Rob, though, was the flapping material of the baggy kit, moving around over his arms and torso.
More practically, the lack of pockets on the kit from the 2000s meant he had to leave his phone at the top.
With seven full runs (one sighting, six timed), and nearly a dozen half runs to get the photos, it was the Canyon Sender DH bike’s sticky tyres and supple suspension, on the climbs, that made its presence felt the most.
Ruts galore
We then moved over to 50 Shades.
We used the Timing Gates function on the Garmin Edge MTB. This mode makes the GPS receiver even more sensitive to its position on the globe, and so it was ideal for setting up our timed section.
A sighting lap was completed, to make sure Rob knew the lines and to get the Timing Gates set up. It was then a case of rolling in from the start mound and hurtling down the track as consistently as Rob could manage.
To help keep Rob in peak performance, I was there with a rather punchy Amflow eMTB and a suitably long stick, enabling him to tow Rob back up the hill.
A word of caution
Before we reveal the results, we should explain that you need to take our numbers with a huge fistful of salt.
While the roll-down test was as standardised as we could make it, with the time constraints we had, we were only able to complete two runs per outfit.
More runs would have given us more accurate results, and sadly, we weren’t able to block every breath of wind from the hillside.
There was also a small margin of error in the speed gun to account for.
When it came to the DH runs, our control over the variables clearly diminished. Rob had also spent the day riding uphill on a downhill bike, which isn’t exactly ideal race-run prep, so he was getting progressively more tired. On the flipside, each run added to his knowledge of the course.
Putting some numbers down
Across the roll-down runs, there was an increase in speed and a decrease in time, as we moved from baggy kit through to the Lycra, and Rob’s times down the hill were moderately consistent in each kit.
On average, the skinsuit was 1.1 seconds faster than the baggy kit, over a 41-42 second, 400m course.
That’s roughly 1.5% faster, all thanks to some kit that doesn’t flap in the wind.
It was also 2kph faster at the fastest part of the roll-down test, giving a speed of 45.5kph versus 43.5kph in the baggy kit.
Understandably, the modern kit sat somewhere between the two.
It was 0.75 seconds slower than the skinsuit, but 1.35 seconds faster than the baggy kit. At the speed gun, it was 0.5kph slower than the skinsuit, but 1.5kph faster than the baggy kit.
When it came to the timed runs down 50 Shades of Black, the time differences were reflected.
The baggy kit was the slowest – three seconds slower than the modern kit and four seconds slower than the skinsuit.
Rob’s take: how it felt on the track
"Riding in the three different kits was interesting. The one that really stuck out was the old, baggy kit. The shorts felt heavy and the top massive, and constantly flapping, even at slower speeds.
"Both the modern kit and skinsuit felt quite similar. They’re more tightly fitted, have a decent amount of stretch and feel really easy to move around, never getting in the way or snagging on the saddle. The modern kit was more breathable compared to the skinsuit, which really surprised me.
"At the end of the day, maybe this just shows we’ve come full circle and, despite the UCI ban, brands and riders have found a decent workaround. We’re in a good place, though. One thing is for sure, I don’t want to take my peak off again any time soon."
What can we conclude?
While our results should be afforded a little grace, the results definitely back up the hypothesis that the Lycra skinsuit is the fastest clothing possible.
The excess material of the baggy kit, flapping in the wind, adds resistance and reduces speed.
However, with tailored kit, and items such as Fox’s Speed Suit, it feels as though the clothing of 2025 is nigh-on as fast as that worn in the 90s.
Would the likes of Bruni, Höll, Goldstone and Seagrave sniff at a 1.5% increase in speed, for free? Likely not – over a 3-minute course, that’s a difference of 2.7 seconds. It's a hefty margin on all but the gnarliest of tracks, and one that would definitely have a significant impact on podium placings.
However, the decision of the UCI to mandate against Lycra kit no doubt helped propel the DH scene into the modern world.
While the ultimate test of speed is marginally limited by the rules imposed, there’s little doubt in our eyes that the sport is in an incredible place. High speeds, modesty intact.
Thanks to Auto-Trail
We would like to thank Auto-Trail for sponsoring this feature, and keeping us in coffee and biscuits while we tested the skinsuits.
Auto-Trail’s Expedition 68 XL is a camper van made for the mountain biking family. Its interior offers a comfortable living space, with a pop-top bedroom, large main bed, shower, toilet and kitchen to make sure you’re well-rested, fed and clean. Under the bed, there’s a large garage area with two pull-out bike shelves, onto which four bikes can be mounted.
You can find out more at www.auto-trail.co.uk
