- Welcome to Ask GMBN
Tech, this is our 31st show
where we get to answer your
mountain bike tech-related questions.
Any questions you've got,
add them in the comments below this video,
or fire them in to the email address
at the bottom of the screen, right there.
Don't forget to use the
hashtag #AskGMBNTech
so we can find your questions.
Right, so first up, Ask GMBN Tech,
I've got problems on all of my pedals.
They're always creaking. I
put grease on the threads
but it doesn't work. I've bought so many
pedals with creaking problems. Any tips?
Well, my instant thought
is it's not the pedal.
If it happens on all of your pedals,
then it might be something else
in your bike or in your shoe.
So, our firstly, do you
use clipless pedals?
Uh, do you clip into your pedals?
If so, then it could be a loose cleat.
It could be a protruding cleat bolt
that makes the cleat creak on the pedal.
That's worth checking.
And of course, your cranks.
And then everything that
goes along with that.
So, what you think might be the pedals,
it could be any part of that
part of the transmission,
'cause it's all load-bearing,
all the torque goes through there.
So, check your actual crank bolts
onto the bottom bracket spindles,
so normally an eight millimeter.
Sometimes it's on the right and
sometimes it's on the left,
depending what brands you have.
Check your BB cups are in correctly.
Check that it's not
the BB itself creaking.
If you wanna know about
that, we're gonna put a link
in the description below this video
for how press fit bottom brackets
can sometimes creak and how
to stop it if it is that.
And check your chainring bolts as well.
They're always a likely contender.
Even if they're a fraction loose
or they have some sort of grime
in and amongst the threads,
they'll creak, so you're
gonna have to check
all of these things and hopefully,
you'll find the answer to it.
Good luck!
Alright, nice quick one
here, Ask GMBN Tech,
Is it okay to use zip ties to set the sag
on your suspension fork? Yes.
But in all seriousness, you can use them,
but don't leave them
on the stanchion tubes,
and that's the upper tube of your bike.
And the reason for that is because
they're made of quite a tough material
that can actually scuff
or scratch the surface.
So, if you're gonna do this,
try this little method,
and it's also good 'cause
it'll save you a few quid.
Normally, you would put
the cable tie in this way,
do it up tight and then
probably snip the end off.
Set your sag, maybe
monitor it over the ride,
and then you've got to
worry about cutting the cable tie off.
Now, of course, the stanchion tubes
on any suspension fork
could very easily scratch,
so you've gotta be careful
in the way you cut it off.
So, a better idea is to
actually reverse the zip tie,
and you put it on backwards,
tighten it up so it won't
lock in the same way.
You can find a way of
tucking this in somewhere.
Check your sag, and then afterwards,
you can just pull it off
again and you can reuse that.
So, a much better solution for
just wasting the cable tie,
and you're not gonna scuff your tube,
'cause you can take it off.
Okay, next up is wheel-related,
in particular building wheels.
Hi Doddy, I've got to
build some new wheels
and I was wondering what the difference is
between the lacings patterns
two-cross, three-cross,
four-cross, especially
in terms of stiffness.
I've always used used three-cross
but was thinking maybe
two, 'cause the spokes
are a bit shorter and could stretch less.
Thanks in advance.
Okay, so there's various different ways
a wheel can be built. The
four common ones are radial,
two, three, and four cross patterns.
Radial is obviously the spoke goes
straight from the flange and out,
and fans like straight out to the rim.
Then you get two-cross,
where the spoke will
cross over twice, and then
three and four-cross options.
Four-cross are the strongest
and they form a bit more
of a structure because the
spokes overlap each other
a lot more. But they do
involve longer spokes,
so it therefore is gonna
be slightly heavier.
And it's also a bit harder
to build, so a three-cross
is your optimum. It's
easy to build, the spokes
are a bit shorter, they're
very strong, very reliable,
and it's probably the most common form
of bicycle wheel,
especially if you're getting
a set of custom hubs, let's say Hopes
or Chris Kings, laced up on some I dunno
Maverick rims or ENVE rims or whatever.
You can do two-cross
as well. It's less seen
on mountain bike wheels,
except for purpose-built
wheels. We'll get there in a second.
Now, one of the downsides
with traditionally spoked
wheels, four-cross,
three-cross, et cetera,
is that on extreme dish
wheels, so you're seeing
wheels now changing shape,
because you're getting
stuff like 157 and 148
spacings on the back.
On extreme dishing
traditional spoked wheels
which would use a J-bend spoke,
and combine that with
the fact it's gonna bend
to get through the flange, then it bends
as it crosses over the others, it creates
more problems in the
wheel because the spokes
can actually become
stressed, and that does
lead to breakages in the long term.
So if the back of it you
see brands like Maverick
developing wheels using
multiple patterns like
radial and the two-cross for example.
So they're trying to get like-
Keep the weight down to a minimum,
keep the stiffness up.
'Cause you think the wheel
itself actually has to do quite a lot.
It's gotta cope with
all the twisting forces
from day-to-day riding, you know,
pushing your bike into
burn. Don't forget the hubs
from (mumbles) part of the structure
of the bike. Then they've gotta cope
with the acceleration and the braking,
which go in different ways on the hubs.
There's a hell of a lot it has to do
so it's really important
you pick the right option
for you. Two-cross, obviously the spokes
are gonna be shorter again,
and because they don't
overlap as much they're not
gonna be quite as strong
in a wheel set. So they might be ideal
for something like
cross-country, but if you like
to throw your bike around a bit,
probably three-cross is
gonna be better for you.
Ah, this is a cool one.
This is from Wade Cox.
Doddy, I'd love to see
a video on how to make
a cheap tire insert like
Cushcore, Vittoria Air Liner,
et cetera. I really want one but they're
very expensive. I'm thinking
some kinda hack video.
Actually, Neil was on
about this the other day
because he's racing the
Enduro World Series Finals
at Finale Ligure. Hopefully
I'm going out with him
to sorta do a bit of
spannering work on his bike.
And we've been talking about how we should
set his wheels up. We're
obviously gonna set up
tubeless, and we're looking
at a lot of fail-safe
options just like Cushcore. And of course
there's a lot on the
market, so I think we're
gonna be calling in quite a lot of them
so we can do our own
research and see what works
but also I think it's a great
idea for us to have a go
at making a few ourselves.
I know that Tom,
who works on our social
media, he's got some friends
that are developing their own system,
so I'm gonna speak to them and see how
they've gone about it,
and I reckon we can make
a really good video.
Okay, this is a good one.
So, I'm having a creaking
noise from my headset
or fork when rotating the
bars doing a track stand
or going over the bumps. So I put on a new
crown race and a complete set of bearings,
no change. I swapped the
fork onto a different bike,
swapped the tire, thru axle,
the noise was still there.
The steerer's got some
minor wear, but no play
is felt in the headset.
Have you got any idea
where the noise is
coming from on the fork?
Thanks for the help. Just the first one,
just to be clear, so
you say you put the fork
on another bike, does that
mean you tested the fork
out on another bike, or you put another...
You it took off and put
another fork on your bike
to see if it still creaked?
If you're talking about
the fork that was on your bike originally
creaking and then you
put it on another bike
and it creaked, then clearly
it is the fork itself.
If not it'll be your
frame, so if it's the frame
it could be headset cups
in the frame, in which case
knock them out of the
frame, give them a clean,
make sure the frame hasn't
(mumbles) or it's got any
cracks in it. Clean it
and reinstall those,
reinstall your fork,
hopefully that's the solution.
It could be a crack in the frame.
Hate to bring the bad news to you.
When you're washing your
bike I always advise people
to sort of go over it
with a fine tooth comb
and just check all the
sort of stress areas
all around the headtube
being one of those areas.
But in your case what I think
if I've read this right,
the fork creaks when you
put it on another bike
totally, and you've
changed the headset cup,
you've changed the
bearings, so you've done
all the other stuff.
So to me it sounds like
it could be steerer tube
creaking within the crown.
Now although this is not common at all,
I've had this on a couple
of forks in the past.
It's just unlucky if it
happens. It'll be something
that happened in the factory
when it's push-fitted
to start with and it's just worked its way
a tiny bit loose. Now I don't know
if you've got rock shocks or forks
or whatever your fork is, you haven't
actually said here, but
get the serial number
on there, then go to
your bike shop and see
if there's any sort of recall information.
'Cause it does happen time to time,
and they might be able
to advise you on it.
But I reckon that is what it is because
there's not many other
things on a suspension fork
that creaks like you said about
the checking the thru axle
and that? Literally like that is about it.
So fingers crossed for you,
that is what your problem is
and you can sort it, and
hopefully it's not a crack
in the frame. Street Hawkerz wants to know
is it suitable to use the
fuel from his dad's chainsaw,
which he's already done by the way,
to clean his chain
with. Is it a bad thing?
Okay, Street Hawkerz,
yeah, you can use fuel
or kerosene, assuming that
is what you've been using
and not the two-stroke
oil from the chainsaw.
Two-stroke oil, I can't
imagine that's any good,
and it's only gonna gunk up your chain.
The fuel itself, yeah, you can use that
to clean the chain with. It's not gonna be
as effective as L and L degreaser
or a specific chain cleaner,
but you can definitely do it.
I don't need to be the person to tell you
that vapor is extremely flammable,
and really it's not the ideal thing
to be using a chain with-
cleaning a chain with.
So preferably not, but yeah, you can.
And you've obviously proven that.
If you do continue to
use it, just make sure
your chain is fully
clean and dry afterwards,
maybe clean it with some water.
Give it a wipe-down, 'cause you don't want
any of that residue on
there when you put the oil
back onto your chain
links. The whole point is
that when you put the chain oil on
it needs to penetrate into the rollers
and the pins of the chain
to do its job properly.
And if you've got any sort of solvent,
any fuel, anything on
there, it's gonna help that
not do its job. So just
make sure it's fully clean.
Next up is from Beto AG.
Doddy, great show. I'm
itching to pull the trigger
on a 2018 Canyon CF Lux 7.0. (whistles)
Nice bike, dude. Love the build,
except maybe the grip shifts.
Any thoughts on those?
Also can I get a discount
if I tell them you sent me?
And what would you upgrade on the bike,
besides the drop post?
You can try the discount.
I'm pretty sure it doesn't work
'cause I've been trying
it myself for ages,
but as far as upgrades on the bike go,
I would personally have a
look at your particular one,
there. Does look really nice.
I'd swap out the rear tire,
don't get all the icon
too well, it's too much of a
low-profile XE tire for me.
I'd use that front tire,
the Ardent, on the rear,
and I'd get something a
little bit more aggressive
on the front, but that's
just me, you know?
That doesn't apply to everyone out there.
I'd probably fit some wider
bars, just looking at it,
as well. They're quite narrow on there,
and although I know it's an XE trail bike,
I still like a wide bar.
It's about what fits me
and what feels nice,
not about how aggressive
a bike necessarily has
to be or be perceived.
As far as the grip shift goes, actually,
I quite like them. They're a bit odd,
and grip shift used to be terrible,
if you can imagine what
the name used to be
back in the day, or how they referred to
wasn't grip shift, put it that way.
But grip shift these days
is genuinely really good.
Seen it on a lot of the XE well-cut bikes,
it's super light because it's basically
just some sliding parts with
a spring system in there.
It works exceptionally well.
I urge you to try it,
and see how you get on.
A lot of people don't like it,
does depend on how you position
your hands on the grips.
I tend to run my hands
right to the outside
of the set of grips anyway.
I run my brake levers
really far inboard. And
I would just move in
to change gears sort of thing?
But if you're one of the riders that likes
to butt the hand up
against like the flange
of a grip, then you might not work it,
'cause as you go over rough terrain
you could accidentally change gear.
But definitely give it a
try. And they look so neat
on the handlebar with
no extra sort of parts
hanging down with extra cabling.
Super clean and tidy, definitely try them.
Hi Doddy, can you please
explain how a derailleur clutch
works? And how it works,
because mine doesn't seem to do
anything when it's turned on and off.
Yeah, I can. It's fairly simple.
It's essentially a friction damper
on the pivot of that lower cage.
In fact, actually, there's a
bike just beyond the camera-
I'm just gonna go and
get it and I'll show you.
Okay, so I haven't got
one of my bikes here
to show you, 'cause my
bikes both got SRAM on
at the moment, but this bike
has a Shimano rear derailleur.
So as you can see here, it's got a clutch
that is in the 'on' position,
and down is in 'off'
position. And what this affects
is in this part of the derailleur here
is basically a friction...
You know, it dampens
basically that pivot point.
So when you put the
clutch on it makes that
substantially harder to basically pivot.
Now I'm just gonna show
you that inside of this
so you can get your
head around this a bit,
it's quite simple. It's
the same sort of system
on all of them on the market, although
they might look very slightly different
from the outside. This is obviously
quite a high-end one,
this is a Shimano Saint
downhill derailleur. All the Shimano ones
will have a lever. Some
will be gray in color,
some will be black, and then
some of the high-end ones
like this will be gold. So bear with me,
I'm just gonna take these bolts out.
So there you go, the
protective cover is off,
and as you can see, you
see the pivot point there.
This is with the clutch
off so you can see it
actually moving on the
derailleur itself there
as I move the cage forwards.
Now note that it's basically
wrapped all the way
around the outside there,
and it's literally-
As I apply the lever it closes that,
so adding that additional
friction onto it.
So it makes it substantially stiffer.
But you can actually tune
out on this particular
derailleur by tightening
this up a little bit more.
Can't do that on all
derailleurs, but it sounds like
your one just isn't engaging properly.
So you might wanna have
a look and make sure
it looks like that. Makes
sure there's no problems
going on. They're fairly simple, though.
That's how they work.
And just to finish this show this week
is some really cool special news
that we've got a guest
coming in to join us
in a couple of weeks
time and his name Calvin.
To you or I, he is Mr. Parktools.
He is the guy with the great mustache
that you see in all the
ParkTools tutorials.
This guy knows everything
about bike tools.
And we're gonna be doing
a special Ask GMBN Tech
with Calvin of course. So
get all your questions in
specifically for Calvin, use the hashtag,
the one on the screen,
#AskCalvin, and make sure
you get them in. Put them in the comments,
send them in to the address
at the beginning of the show.
Anything mountain bike tool-related,
he is gonna know the answer,
so get those questions
coming in. And for a couple more videos
firstly click down here if you wanna see
our XTR Geek Edition,
where I take a look at
the whole transmission,
the whole group set
including the brakes, and
that wonderful new rear hub,
and click up here for something
a little bit different.
I get to try my first
e-bike mission basically.
So it's not really tech in the same way,
but I'm riding a very tech-heavy bike,
a specialized Kenevo, and
that's out with Steve Jones
from EMBN, so check that
one out. It's a very cool,
very different video.
And show a bit of support
for our EMBN brothers over there.
As always, click on the
round globe to subscribe
to GMBN Tech, we love having you around,
and make sure you tell any of your mates
that might need some help
fixing their own bikes
about us. And of course
if you like fixing bikes,
and you like Calvin from
ParkTools, give us a thumbs up!
