How To Find The Perfect Tyre Pressure | High Vs Low Pressure

How To Find The Perfect Tyre Pressure | High Vs Low Pressure


– Finding the right tire
pressure is a bit of a dark art, you don’t really know you’ve got it wrong till it goes wrong. It really does affect
your grip, feel and speed. So I’m going to try some
different pressures today, until I try and find the
perfect numbers that suit me. We’re here in Finale Ligure,
riding the Rollercoaster, one of the most famous trails here. Also one of the most well used trails. It is lovely and up and down, but it gets loads of people riding down it, so there’s lots of
braking bumps, the stones. All sorts things that will
really affect my tires. (relaxed music) (logo whooshes) Now let’s start by saying this video is going to be very specific to me. Obviously, I hope this will help you find your correct tire pressures, as well. There’s so many different factors that go in to find those numbers that they really can’t be
swapped between riders. Rider weight. Heavier riders and bikes
will need tougher tires or higher pressures. Rider skill. It doesn’t mean that faster riders will have to run higher pressures, although sometimes they will. They might be really
fast and really smooth, which means they don’t really
push their tires to the edge. Slower riders can potentially
run lower pressures for maximum grip, but riders
that make more mistakes could end up hitting rocks or roots. And that means if their
run to lower pressure they can risk ripping the
tire or puncturing the tube. Tubes or tubeless? Sometimes you can get away with running lower pressures in tubeless tires, ’cause there’s no tube in there to pinch or get a snakebite, we used to call ’em. But I think above a certain threshold, let’s say 28 psi on the
front, 30 in the back, pretty high pressures, I don’t think you’ll get away
with running two psi less because your own tubeless. ‘Cause you’re running your
tires that hard for a reason. It’s probably ’cause you’re
really pushing into ’em. Type of rider that maybe rolls a tire and could potentially burp them. Type of riding. Could be cross country,
marathon, trail riding, enduro, downhill, bike packing. So many different options here. And it’s not we go into performance, here, where you might choose a tire pressure. For example if you’re going out
on an epic bike packing trip into the wilds of Canada, and you think, “Well, I’ll run low pressures,” you could end up ripping a tire and that gets you into trouble. You’re running out of
spares, things like that. But definitely, performance
does come into it. When we’re talking about racing, cross country riders really have to weigh up the grip versus rolling resistance. Actually, as do downhill racers. So there’s definitely a
lot of experimentation with those pro riders when it
comes down to tire pressures. Trail conditions, be it
rocky, smooth, wet, dry, clay or sand, there’s so many
different variables here. You could find the perfect
pressure of one trail and then it gets dark,
there’s moisture on the track or it rains, or you go
right different a trail, that sometimes you have
to find happy medium that works in the area that you ride. Type of tire. A super skinny, super lightweight tire could be run at normal pressures, even under a bigger rider, if
you’re riding smooth trails. However, if you go to rocky trails, that tire probably won’t be up to the job. So that’s when you have to think about how many ply a tire is. So downhill tires, two ply. So basically two sets of
rubber, makes it super tough. Talk about TPI, threads per inch. I’ve done a video where I’ve visited the Continental tire factory, where I tell you a lot more about that. But basically, I find easiest way of working out how tough a tire is is by looking at the weight of it. If you’re looking at a tire
that weighs 1,300 grams that’s a big robust downhill tire. Potentially down to less than half that, maybe 600 grams for a
Continental Cross King, cross country tire. Tire width. So the volume of a tire really makes a difference to how it rides. So, big 2.4 versus a 2.2. Definitely more compliance
in those bigger tires, depending on the pressure. Rim width. Big trend here is for
getting wider rims now. It does affect the shape of the tire. So it could be a bit
egg-shaped with a narrow rim, which means it might
roll around a bit more. Wider rim makes a more stable tire. So there are hundreds, maybe not hundreds, but lots and lots of variables that will affect the
perfect tire pressure. Have I missed any? Heat, atmospheric pressure. Tire inserts, lots of people run them now. (screen beeps)
Right, onto the tests. The tires I’ve got on my Nukeproof Mega. Upfront, I’ve got my
Continental der Baron. 27.5, this bike. 2.4 upfront, quite a big tire. On the back I’ve got
the Trail King in a 2.3. So this is my faster rolling setup that I would use on enduro bikes. The rear tire, it’s pretty quick. Don’t mind pedaling that around. However, if I’d of known
I was doing this test, on this track, in these conditions, I’d probably of put the
Baron on the back, as well. ‘Cause they do offer just a bit
more sort of, chunk to them. I’m less like to puncture it, I think. Just with more rubber,
bit of a heavier tire, bit more protected. And I’m going to to start
with my normal tire pressures. So 28 on the rear, 26 up front. Which has come down a couple of psi from when I used to race, just because now I’m not
quite as fast as I used to be. I’m not pushing the task quite as hard. And I’m probably less
likely it smash into rocks (upbeat music) Run one done, using the
tire pressures that I know. And to honest I’ve spent
years riding and years racing and these are the pressures
I’ve come to from experience. And, like I say, I’ve
dropped a couple of psi since I properly raced. Now I’m running 28, 26.1. Because I can get into those details, I’m actually running
these Quarq TyreWhizzes, so super clever little things
to help out this video. They send my tire pressures
digitally to my phone. I can even set the parameter
of where I want it, plus or minus two psi, and it flashes green to
tell me I’m in that zone. Even sends it to my Garmin. So like I say, I got 26.1 in the front, 28.1 in the rear. So for the sake of this
test I’m going to now reduce my tire pressures
by 25%, which is a lot, down 19 on the front and 21 on the rear. But I have seen pro bike
checks with other enduro riders and know that they do run
them that low sometimes. So I’ve always wandered
if I’m a bit conservative with my tire pressures and I’ve erred on the
side of caution too much. ‘Cause normally I feel like
I’d rather run too hard, just sacrifice a little bit of grip, for having them be reliable and know that I can make a
mistake and slam into rock, and hopefully get away with it. But it’s time to see if
I can find some more grip and get more feel with
lower tire pressures. (intense music) Tell you what, already, I’m not feeling those little
rocky bumps quite as much. Definitely getting some sort
of dampening from the tires. Feels a bit smoother. Oh, does feel quite low
on the back, actually. Whoa, big compressions in those corners. Where they’re berms and
they’re bowled out, as well. So that is where you’ve really put a lot
of pressure on the tires, ’cause you’re squashing them
in and pulling them around. I can feel them, sort
of, rolling a little bit. Not enough to burp, but feel
a bit of movement down there. Right, I’ve rode the top,
probably, quarter of the trailer, and it just feels too soft to me. Like, any small mistake
feels like I am going to just rip my back tire, especially. So although it feels good,
feels less rough on the trail. Just feel like it’s too risky
for me, it’s not worth it. So I’d rather run more
pressure in the back and just lose a bit of grip. I think it’s going to be
hardly anything on this trail, in these conditions, it’ll
be like nothing, grip wise. So for sake of security and not getting stranded on this hillside, got the pump, I’m going to
put some more pressure in. (intense music) ‘Kay, so I’ve gone up to what
I think is bit of compromise. So I’m running 23 on the
front, 26 on the back. See how that feels. And it doesn’t feel like
I’ve lost any grip for it, but, whoa, who knows. Whoa. Oi. Stuff like that, where I can gap a bit. And I’ve only been this
trail couple times, so I don’t really know
what’s on the backside. I feel just more confident. ‘Cause if I jump and
there is a rock there, least I’ve got the harder tires that I know can deal with it. This is it. (groans) Mean, that’s so lose and dry. Feels different to my
front, back tire there. I’ve a Baron on the front. It digs into that dust, the
rear one doesn’t, as much. And it’s the rear one I’m tryna use to slow down quite a lot. Higher pressures mean a
smaller contact point, less grip and can feel harsh, but they’re more resistant
to punctures from impact. Lower pressures mean a
larger contact point, more grip, more compliance,
but more tire squirm and more likely to get impact punctures. So I think the conclusion for me is I’m going to lower them a little bit and go down to a 27 and a 25. So one psi lower than I normally am. Maybe it’s a bit of age, I don’t need them quite
as hard as it used to, but that feels about right for me. And I’d rather lose a little bit of grip and have a reliable tire that hopefully will get to the bottom of
the track in one piece. If you want to see a video, the tour of the Continental
factory, see how tires are made. That was super interesting one. Over there for that one. Another video on tire pressure over there. Jack, have we got time for another run? – Oh yes.
– Needs tests again. Right. Subscribe, give us thumbs up.