Will Your MTB Tyres Burst On A Plane? | Ask GMBN Tech


– Welcome to Ask GMBN Tech. This is our weekly Q&A show. You get to ask questions
related to technical stuff with mountain bikes and
hopefully we give you those answers that you need. So if you wanna get involved,
email us on the email address on the bottom of the screen there. Make sure you use that
hashtag #AskGMBNTech or alternatively just get involved in the conversation below in the comments. (metallic percussive sound) A spoke related question from Moejoe33: Andrew correct me if that sounds weird if you’re saying that. I’m gonna say it myself. Doddy, correct me if I’m
wrong but aren’t straight-pull spokes harder to tighten
once they’re assembled to wheel with tire installed? Doesn’t some of them spin when tightening? I haven’t seen straight
pull hubs with grooves or small notches to prevent this. It would be better if they
were on spokes as well. It’ll catch/bite on both
parts to prevent spinning. Okay Moejoe33 yeah um you’re
kind of along the right line. So straight pull spokes
there are actually two types. There’s bladed and then there’s round. Now if you’ve got bladed
spokes, you might think that they’re only for
road bikes but they are in fact for mountain bikes
as well because they can add strength at no additional weight. They’re stronger fore and aft and they offer a bit of flex side to side. Now if you’ve got bladed
spokes there is a tool like this one from Park designed specially to hold,
obviously it’s different sizes here, different options
for different style spokes. Hold the spoke still, adjust
the nipple, nothing moves. Job done. However if you’ve got a round spoke then you’re not gonna be able
to use a tool like that. So in an ideal world when
the wheel is put together there’ll be some sort of assembly compound which is essentially
grease with particles in it to increase friction
and traction, I guess. At the head of the spoke
there that would be used of course and then cleaned off so you can’t get any
near any braking surfaces but if yours hasn’t got
that then you need to look at the other end, so
where the nipple screws onto the thread on the
end of the spoke itself. Get some penetrating oil
or some 3-in-1 or even a decent chain oil and let
it drip its way in there work its way in, and
you’ll find that you should hopefully be able to do this
because there’s way less torque at this end than
there is already on the end of the spoke that’s in the
part of the hub itself. You’ll find that they’re
generally quite wedged in there and if you can make it easier for yourself on the threaded end, you
should be able to adjust it. But obviously that doesn’t always happen and sometimes you’re
gonna get a spinney spoke. So I had to look this up because
I’ve not actually had this problem that hasn’t been on
a bladed spoke in the past. And you can actually get a tool this is it on screen now. It’s quite a specialist tool it looks a bit like a
cable tensioning tool from Park Tools, something
like this in fact. It looks a little bit like this,
it has this section on here in which case it would
hold the spoke itself. Of course you couldn’t use this, it’s not designed for that purpose. But it’s quite a specific
tool to get and I’m not sure it’s actually the best thing. In my eyes I would probably
just get a pair of pliers on it and hold it but of
course I wasn’t too sure about that because I haven’t done it. So I actually buzzed
Calvin from Park Tools and this is what Calvin said. He goes yeah, it’s a tough one. Just grab the thing. If it’s stainless steel,
straight up use pliers and hold them tight, you will not mar the spoke. Again I think he’s emphasizing
the point that if you let it slip, then the spoke
can twist and get scarred on the inside there. He said the special made
tools do the same job and in theory offer better leverage. Painted spokes will get marred
if you grab gently and turn. Make sure you grab tightly
even on painted spokes. So it goes to show you can
use pliers but of course you gotta make sure that
the spoke cannot turn and then you should be okay. If that’s your problem then
hopefully that’s the solution. Good luck. (bike wheel spinning) Next question is from Nixobis. Hi Doddy, can you tell
me if having a spare tube in my backpack for my
tubeless makes any sense? I’ve often heard that we
have to have one in case of a big tear or if we smash
the valve, etc but my tire is full of bramble thorns,
my tube will die instantly in inflating if I have to use one. Well really you should
always be carrying one as a spare part when you’re
going on longer rides. You could end up using it, your
friend could end up using it or you might bump into fellow
mountain biker that needs one. Given how much they cost
and how much they weigh, it’s worth carrying one anyway. But if your tires have
got loads of bramble and thorns and stuff stuck in them, then really you should be addressing this before you go riding because
sooner or later your tubeless they’re gonna work into bigger
holes and might be a hole that your tubeless solution
is not gonna seal properly. So it creates a problem in the long run. So what we always recommend
doing here at GMBN Tech is when you wash your bike or even when you just return home from a bike, give it a bit of a once over, run it around with an Allen key, make sure everything obvious is tight, your controls, all the safety
related things on there. Check your chain is clean and lubed, make sure you haven’t
got any frayed cables that are gonna get worse. And give your tires an inspect. Make sure there’s no
slashes in them and any sort of brambles and thorns
and stuff that are in them take them out, get them out,
erase the problem before it becomes one because it will
become a bit of a nightmare. But also just on that point, there’s other things you
can do with inner tubes. So let’s just say you or
your friend’s unlucky enough to break an arm, you
can do a make due sling using an inner tube. It’s a pretty versatile thing. And if your friend, for
example, breaks a chain you can use an inner tube
as a make due tow rope to get him along or her
along a section of trail without having to walk. Perhaps if you get down to fire
roads you can cover greater ground to get back to
civilization in order to fix that problem, you can use it as a tow rope. Now of course you can use
it in other repairs as well like lashing things together. I know like if your saddle
snapped off the rails you can lash it on with a inner tube,
tie it in a knot, job done. So yeah I think it’s
always worth carrying one and I definitely think you
should go back to your tires and get all those thorns out. Make it easier for
yourself in the long run. (bike wheel spinning) Okay, next up is from Paul Burn. Hi Doddy, do you reduce
air pressure in your shocks and tubeless tires when
traveling by plane? I’m off to Rotorua at Christmas
and have heard mixed views. Cheers and hopefully see you guys in Oz and New Zealand someday soon. Generally I do but not by
much and it’s more a fact of quitting the parts,
I’ve got quite big bikes and it tends to be to get
them in the bags themselves. Our latest bags actually are
big enough, I don’t need to do it anymore but typically
with a 29-er like that Nukeproof Mega in the XL is massive and when I took it out to
Whistler last year I had to deflate the forks in order
to get the whole front end in the actual bike bag. And then tires, same thing. 29 inch wheels and my older bike bag didn’t cater for 29 inch
wheels so I had to deflate them slightly in order to put them in but I’d never deflate too
much because that makes it a bit of a chore if they come unseated and the tubeless sealant goes everywhere. Generally, I wouldn’t. And actually, you don’t
really need to despite what the airlines will tell you. I’m not really sure why
they tell you to do it but the plane is pressurized. Like the storage area, the
cargo area is pressurized. There’s no need to actually do this. But I did have a look online about this because I did wanna know a little bit more despite what the airlines say. And just talking about
pressure and atmospheres. So planes fly at a
highest of 12 kilometers that’s about 7 and a half miles and at sea level air pressure is 14.7 PSI. And at lowest with elevation
I think at ten thousand feet it’s about 10 PSI. So if I understand in theory
your tire pressure can raise by atmospheric pressure difference. So let’s say it was at 50 PSI
at ground zero sort of thing when you’re up top there it
can increase by ten thousand feet by 10 PSI so that
would be outside the plane of course in an unpressurized environment. So you’re talking a nominal amount. At most it’s gonna be
14.7 PSI is the maximum. Which if my rubbish science is correct, that’s nothing critical,
nothing to worry about. And yeah, I definitely
hope to make it over to your side of the pond at some point especially New Zealand actually. Australia, I’ve been pretty close before, and I definitely want to visit there, it’s definitely on my places to visit but I really want to come to
Rotorua for when Crankworx is on I wanna see that gong show, see it. I’ve seen Crankworx in Europe, I’ve seen Crankworx in Whistler, I wanna see how it’s done in New Zealand. And if I fly over then I
definitely won’t be lettin my shock and fork and tires down, I’ll leave them as they are thank you. So uh, there you go! Actually if anyone
actually genuinely knows or are good with mathematics and
stuff about what does happen in pressurized environments
with tire pressure, shock pressures, I would love to know. I’ve tried to have a bit a look at this and it makes no sense to me. I think my rudimental
version kinda makes sense so if anyone does know, let
us know in the comments. Really interested to know. Be kind. (bike wheel spinning) Next question’s from Blake Ashdown. #AskGMBNTech I’ve got two questions hopefully you’ll know this lot but my bottom bracket’s creaking. I’ve removed it, cleaned it,
re-greased it, and replaced it. It’s worked for about one ride and now it’s back to creaking. Should I just start working on it or keep going until it stops? And second question, what does Boost do? Example, Boost Wheels. Firstly let’s think of the bottom bracket. So of course with this sort of thing it’s definitely the age old
thing of having to do the process of elimination to
work out exactly what it is. But suggesting by saying
that you’ve taken your bottom bracket out and put it back in, in that process it has
been temporarily cured. So that tells me that it’s probably not the bottom bracket
itself that was creaking. I suspect it’s something
else like the crank or some other part that you tightened or adjusted in putting it back on. Now you haven’t said exactly what sort of bottom bracket it is. If it was a press fit
bottom bracket there’s a good chance those cups could be creaking in the frame in which
case you’ll wanna use a press fit retaining compound. That with the shim and
everything is cleaned and there’s nothing damaged,
that will cure the problem. At least until the bottom bracket is dead. If you’ve got a bottom bracket for example with a tapered axle on there
then it’s probably the crank that is at fault because
the soft aluminum crank against the steel axle, if
it’s really loose it can stretch and you’ll never
tighten properly and of course any metal to metal movement
you’re gonna get translates into creaking at some
point so that could be it. But also, check your pedals,
check your chainring bolts, check the chainring
direct down to the crank if it’s direct mount,
check every single part. And then of course there can
be other parts of the bike that creak under torque
that you can confuse with the bottom bracket. I mean it does sound like you
do know your way around a bike so not trying to patronize
you but there’s a lot of parts on a bike that can creak
and you would never realize. It can even be saddle
rails that you don’t notice if you stood up but you
notice when you sat down. And you might not be
thinking about that because you concentrate so hard
on one part of the bike. It could be your seat collar. It could be the freehub
body on your rear hub. And it can even be, and
I’ve had this before, a rear derailleur where it’s
been the tiniest bit loose on the hanger bolt into
the frame and that creaks but it only creaks under a certain amount of crank tension and torque. And it’s confused the hell
out of me in the past. So just make sure you’ve
checked everything because there definitely
will be a cure for it. And of course the final one is
if your actual bottom bracket is knackered and somehow
is just massed by grease or something you put it in. It might just be your bottom
bracket that’s knackered. So good luck with that one. It’s a horrible thing to
have to work around and try. In a kinda weird way I
actually really like trying to find those creaks
’cause it bugs the hell out of me and I really wanna stop them. As for your question about
Boost, Boost essentially is a slightly wider platform. So upfront, hubs used to be
100 millimeters, Boost is 110. And that basically compensates, gives you a bit more clearance. But it doesn’t really do too much upfront. It’s out back it makes the big difference. So conventional rear hubs
were 135 millimeters or 142. Boost is 148 so although
it’s only a nominal amount at the back of the bike,
it enables the cranks to be very slightly further apart. You get that better chain
on, you get more clearance around the bottom bracket. Arguably your frame could
be stiffer because it’s got a wider stance there and of
course wheel manufacturers can build stronger wheels
because they can put the flanges on the wheels further apart
which means the spokes have a better bracing angle
so it’s more of a pyramid. So there’s lots of benefits to have Boost but don’t worry if your
bike hasn’t got Boost, it’s not gonna suddenly not ride well. There’s nothing wrong
with non-Boost stuff, it’s just Boost is a
logical progression to have on any bikes you have moving
forward down the line. (bike wheel spinning) And last question this
week’s from Phillip Au GMBNTech, the problem that
I have that wasn’t addressed in the video, the video by the way is “Looking after your riding kit”, is how to dry out the hydration packs
properly post-washing. There always seems to be a
bit of water left behind. There’s a couple of ways you can do this. Personally, I roll mine out
and then when I put it in the fridge it kinda doesn’t really
matter if there’s a few drops in there but of course having
it completely dry is the best way for no bacteria to
grow in the first place. So have a look on screen,
this is a specific dryer. It’s basically like a coat
hanger for your hydration pack. You put it inside, it
springs out, opens it all out and you can hang it upside
down and it enables all of the water to evaporate
and then of course you wanna make sure it’s
treated with either some sort of sterilizing fluid like
a Milton baby bottle cleaner or bang it in a fridge or
freezer to make sure any of that is killed or stays nice and cold. (bike wheel spinning) So there we go. There’s another Ask
GMBNTech session in the bag. Hopefully I’ve answered
some of your questions. If you’ve got any questions,
let us know in those comments below and if you’re an expert
on altitude and air pressure I’d definitely love to know your response to the earlier question as well. For a couple more great
tech related videos, click down here on repairing
a tubeless tire puncture and click down here on
everything you need to know about selecting and replacing
a chain and cassette. As always, don’t forget to
click on GMBNTech to subscribe and of course if you love
mountain bikes and tech give us a thumbs up.