- Now, I'm back and a big thanks to Si for looking after
the GCN Tech Clinic last week.
And also I'm glad he didn't faint over the question
I sneakily added in at the end there
when he had to answer a question asking to explain
the difference between a cyclocross bike and a gravel bike.
- Oh my word, this is like opening Pandora's box.
How can Jon have left this question to last.
It's going to take an hour and a half at least
to even get started on this.
(sighs) Okay.
- Let's move on and see what questions
we can tackle this week.
First up, a question from Tarcis who wants to know
about chains and are they directional or not.
How to recognise them, brands and the rules.
Thanks and he loves the show.
Well, this one is actually fairly complex in that
there's no easy way to identify if your chain
has a direction or not.
Ultimately when you're installing it,
actually read the instructions.
I know people haven't done it in the past
and they've actually fitted a chain on backward.
Yet it can happen surprisingly.
As for compatibility, well, 11-speed,
we're kind of all laughing and happy.
Because Campagnolo, Sram and Shimano their chains
are all interchangeable with one another's cassettes.
To a pretty good degree actually, I've tried it out
and they work alright.
And also you've got KMC chains and they work fine there.
It's when we go to 10-speed that things get a little bit
more complicated and a little bit more difficult.
So, Shimano and Sram, they're OK,
they work with one another.
If you try using one of theirs on Campagnolo.
And Campagnpolo's chains on Shimano and Sram's cassettes
then you don't get optimal shifting.
So it's not really advised.
So basically if you use Campagnolo,
stick with the Campagnolo chain or use a KMC or Wipperman.
Some of those chains, other chains, actually,
are universal so they work across
all different brands of groups there.
So that's really what to stick with.
And then Shimano and Sram you can just interchange them
and they're fine.
So there you are, that's for your 10-speed.
Next one is from Betty Fischer.
Betty wants to know, can you put disc brakes on a bike
that has rim brakes?
They always ride to school in rainy conditions
and discs would be fantastic.
Unless you've got the Wilier Cento 10 NDR,
I think it's called.
You cannot, because that bike does allow you to actually
run either direct rim brakes or disc brakes.
I've not seen any other frames like that that allow it.
I have seen, however, some brackets or fittings
that allow you to retrofit a disc brake
onto a non-disc specific frame.
I wouldn't recommend using that though.
It's a bit of a bodge hack.
To be honest a bit of a recipe for disaster.
You want decent braking, don't risk messing everything up
by putting those one, it's just really not worth it.
OK, next up, question from Dave Pratt who asks
When sealant dries out, what happens to it?
If I add more, will it be less effective?
Will I eventually fill up the tyre?
It's a great question actually.
I was also looking at some sealant yesterday.
Ultimately, it does yes.
And I found out the hard way
because one season I actually punctured a lot
when I was racing and I decided to fill my tubular tyres.
Obviously not totally filled but put some sealant in them
to try to prevent any punctures mid race.
So after I finished racing and about a year later
I got the race wheels back down out of the shed
and I tried to put some air in them.
However, the sealant had moved around and clogged the valve.
So yeah, basically it does clog it up.
Some of the sealants they on mountain bike tyres
or cyclocross tubeless tyres or standard road tubeless tyres
they actually coat the inside of tyre with latex
when it dries up.
Sometimes though it can basically come in little clumps
and you can pick those out of the tyre as well.
What I would be keen to find out though,
is if you were to put it into an inner tube
and rest it at the bottom away from the valve
after say a year or so, would it actually go solid
and if you tried to pump it up would no air pass through it?
And you'd have a little bit of bad riding.
You know, the feel.
I don't know, I'm going to give that a go.
Alright now Chuck Clark wants to know,
If they switch to the increasingly popular option
of a single chain ring on their road bike
can they replace the rear derailieur and 11-speed cogset
for a 14-speed Rohloff hub?
Oh Chuck, the Rohloff hub.
Now for those of you who don't know what that is,
basically gears are internal to the hub shell.
So you can get rid of all the sprockets on the rear
and just have a single sprocket drive the rear wheel.
Inside of that hub there's 14 gears and gear spread ratios
are actually really really wide.
So it's a great, almost maintenance free solution.
However, if you do have to maintain it,
I've seen the inside of a Rohloff hub
and it's not something to tackle unless you really know
what you're doing.
But it's certainly an option for you, Chuck.
One thing to bear in mind,
is actually the controls of gear shifting.
So have a little look around and see what's available
as obviously you can't just connect it up to
a standard ergo power, STI or double tap lever.
So make sure you're happy with those gear shifter
options available.
And finally,
what I can only class is a can of worms basically
because this question always lights up the comments.
Jeffrey wants to know,
Why is handlebar tape always wrapped up from the bar end
to the top and secured by ugly tape?
In Jeffrey's opinion.
Well, you could actually finish the tape with some superglue
doing away with the ugly tape that you call it.
So the electrical tape or PVC tape
that we normally finish bars with.
Or instead of wrapping a lot around there
actually just have a very thin amount of tape
to finish off with.
The reason why, personally, myself and every single
pro mechanic I've ever asked, starts at the bottom
and finishes at the top.
Is that when you move your hands towards
the brake hoods you're not flaring up any tape.
And basically it looks ugly, it looks bad.
However, there is one rider in the Pro Peloton
that I know that actually prefers to have his handlebar tape
start at the top, finish at the bottom.
And that's (mumbles).
So just personal preference but there's no pro mechanic
out there that does this as a matter of course.
We asked all of them at the Dubai Tour
and all of them just looked at us like,
like we were crazy really for even asking the question.
So there we are.
Now remember as well to leave your questions for
the GCN Tech Clinic on all forms of social media
using the hashtag askgcntech.
And remember as well to give this video a like
and share it with your friend if you enjoyed it.
Or just share it with them anyway.
And for a great video on the power metres
of the 2018 Peloton, click just down here.