- 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!