(whooshing sounds)
- Welcome to this week's Tech Clinic,
where we answer all of your questions
about bike tech and kit.
Now if you're wondering where Jon is,
don't worry, he's not died,
he's actually at the Vuelta,
looking for all the latest and hottest new tech
out in Spain,
but he should be back soon and in the mean time
you've got me.
So, if you haven't already,
make sure you subscribe and also
click the little bell icon as it'll give you
a notification every time we upload a video.
And that might even include an answer
to one of your questions.
So without further ado, let's dive in
with a question from Gordon MacDonald.
Gordon writes, "Thanks Jon,"
presumably he means Ollie, um,
"loves the show, it's no miss viewing."
Now his question is that he has a new
Canyon Endurace CF SLX Disc 8.0, great choice,
and it's fitted with Shimano Ultegra 8000.
Now he has just one problem,
which is that the 16 tooth or 14 tooth sprocket
at the back is clicking with every wheel rotation.
Even when he's pedaling.
Now he's tried adjusting the barrel adjuster
at the rear on the derailleur,
but it just throws the gears out,
and he's cleaned it and he's looked for any dirt in there
or any other bits, and there's nothing.
And the ticking just persists.
And he says, "It's beyond annoying."
It is, I agree, whenever there's a clicking
on my bike I find it really annoying.
In this case, I would say
what you wanna do is eliminate
every single possible cause.
Now, based on what you've said,
the first thing that I would look at
would be, if it was my bike, would be
the possibility that your mech hanger is slightly bent.
And you might think,
"Well, I've been really careful with my bike."
"I've not knocked it,"
but, in my experience, you know I'm,
really careful with bikes as well,
but I have bent the odd hanger
and it can just be the slightest of knock that bends it.
Now, it might not be a bent mech hanger.
In which case, I would also suggest you check
that the derailleur is fully set up properly.
So check the high and low limit screws
and the B limit screw as well,
and check that they're all in the correct positions.
And if you're not sure how to do this,
then we've got some really good videos on it.
So we'll post a link in the description below
and you can check that out.
Hope this helps.
The next is from Angelo Gallo, who has asked,
"Would using a heat gun to remove tubular glue"
"on carbon rims be okay?"
"Secondly," he asks "I've heard that there"
"are some tub glues that are easier to remove"
"and manage that others."
"For example, I've read that Conti black tub glue"
"is easier to remove than other brands."
"As an aside, I'm replacing damaged Continental tires"
"with a new one on the Zipp 303."
"Starting to regret going with tubs."
Well, you've got some bangin' wheels there.
So, quite envious of those.
With your first question, the heat gun,
wouldn't recommend it, at all.
I think, as you suspect by asking the question
in the first place,
using a heat gun, such as what you'd use on wallpaper,
it could potentially seriously damage your rim.
The other thing to bear in mind is how the tub glue works.
So the tub glue contains a solvent
and when that cures and sets,
the solvent evaporates and leaves the adhesive behind.
So, melting it really isn't the best way.
Unfortunately, removing tub glue is a pain
and the simple way, well the easiest way
that I've found to do it and the rest of us,
is by using good old Jon Canning's patented elbow grease
and also some solvents, such as
rubbing alcohol, petrol, or white spirit,
that sort of thing.
If you're worried about the solvent
damaging your carbon rim,
which is a sensible thing to be worried about,
then perhaps just get a bit on a cloth
and try it on a smaller area first
and see how it responds.
But generally speaking,
most rims should be okay with white spirit,
but maybe just check first.
Next questions is from Simon Morrissey,
and he writes, "Hi Jon."
(sighing heavily)
It's alright, I'll forgive you Simon.
"I need to buy a new outer chain ring."
"I'm currently on a 50/34
"but would like to replace it"
"with a 53 outer and keep the 34 inner."
"Is there any problem with doing this?"
Well, you might be able to budge it,
but I really wouldn't recommend it.
And that's because, if you had a 53/34 combo
the drop off between the big chain ring
and the small chain ring is massive.
It's like shifting your chain off the edge of a cliff.
And therefore, you face a much greater chance
of dropping your chain when you shift
on the front rings,
which you don't want to happen.
Also, big standard chain sets often have
a different BCD spacing to a compact chain set.
So the BCD is the bolt spacing diameter
of where the chain ring bolts go on the chain set.
Now typically, a standard chain set has a 130
or a 120 BCD
and a compact chain set typically has a 110 BCD.
Meaning, that the two aren't compatible.
Now, this is actually one of the great things
about the new Shimano Ultegra Endurace
because they actually have the same BCD
throughout the entire range.
So they have a universal crank set,
and so that means you can change the chain rings,
be it, 34/50, you know, compact
or 53/39 or 52/36.
All those different rings fit on the same crank set,
which is really cool.
So, some good innovation on the new Shimano stuff.
The next question si from Ambor Gislason.
Now, I hope I've pronounced your name eh,
slightly correct.
(laughing)
Sorry about that.
Your question is, "Can I upgrade a 68 millimeter"
"BSA threaded square tape bottom bracket"
"to a HollowTech two on my 2010 Trek 1.5?"
"Is this worth it?"
"What are the benefits?"
Well, I would say yes.
If your bottom bracket needs replacing
and your bearings probably are quite worn
if it's an eight year old bike,
then a HollowTech would be a fine choice
of bottom bracket to go with.
You'd simply take out your square taper bottom bracket,
clean the bottom bracket area thoroughly,
and then just simply screw in the new
HollowTech bottom bracket.
It's a great option because there's a lot of chain sets
that are gonna be compatible.
Lot of newer chain sets, as well,
are gonna be compatible with that HollowTech.
So, yeah, great great option.
Next question is from Vincent Bon,
who asks, "How come if I corner fast"
"my discs rub against my brakes?"
Well Vincent, this is something I've actually
experienced myself on a number of different bikes
and wheel combinations
and there's a few things that, that can cause it.
So, if your brakes, calipers, and discs, and everything
are set up absolutely perfectly
and you're still getting some rub,
it can be caused by torsional flex in the fork.
Now, there's not really much you can do about that.
You're just too powerful for your bike.
But, the other thing could be
just a slight misalignment in either
the brake, the rotor, or the caliper.
Or if there's a slight little bend in your rotor blade.
Now,
this only has to be slight,
because the tolerances and the spacing in between
the calipers and the rotor is really really small
on road bike disc brakes.
So, yeah.
You might want to check that everything.
Only a small amount of movement can cause
the discs to rub.
The next question is from Cam Held.
Who asks, well he says,
"Last week while descending the steel bolt"
"on my seat clamp sheared in half"
"and resulted in a high speed crash."
"Is this something that is well known to happen"
"and to give out on bikes?"
"While I'm not the smallest guy"
"and my bike is four years old"
"with regular use and maintenance,"
"I would expect a bolt to last more than four years"
"or expect to be told to replace it regularly"
"as part of maintenance."
"Is this just a fluke accident"
"or am I out of the loop and should I be replacing"
"my bolts more regularly?"
Whoa, I mean, sorry to hear about your accident,
and, you know, really hope you're okay.
I mean, bolts really should be lasting,
to, oh, indefinitely.
Certainly longer than four years.
However, there are a few things that you should consider.
The first thing is, did you torque it correctly?
Now, a lot of people, you know, lot of home mechanics,
they sim-, like seat post bolts especially,
they'll just tighten them with a regular Allen key
or Hex Wrench, if you're watching in America,
and, and this is a common way
to damage areas of your bike,
such as your seat post,
or your seat post collar,
or your steerer tube,
and it can also over stress bolts as well.
So, that is a way that you can then cause them to fail.
The other thing that can affect
the lifespan of a steel component, like a bolt,
would be if you rode in salty or corrosive conditions,
such as, you know, wintry wet roads,
because they can become rusted and corroded over time.
And the other thing is, yes, flukes can happen,
you know, the quality control is in place
in manufacturing things,
but occasionally things, you know,
dodgy components can go through the net.
Though this is something that is very, very rare.
Compassion Six has asked,
"Is there a disadvantage to using"
"a derailleur hanger extender?"
"Any downsides?"
"I prefer to spin versus grind"
"and I have a 53/39 up front."
"Thanks."
Not really.
A tiny, tiny little bit heavier.
You're adding a little bit more weight.
You have a slightly heavier chain,
'cause it's probably gonna be a couple of links longer.
And there's a tiny little bit of arrow drag
if you're really payin' attention,
'cause the derailleur's a bit longer,
but no, not really.
I prefer to run a 53/39 as well,
and I will routinely fit a 32 tooth cassette
because I also prefer to spin.
And with the new 11 speed cassettes
that a lot of people have these days,
the range is so great on them that
an 11 to 32 is a great thing to ride.
You don't feel like you've, there's bit steps
in between the gears, so.
If you want a bigger range at the back,
absolutely go for it.
You might also want to consider
a long cage rear derailleur.
In which case, you wouldn't have to fit the extender.
Next up we have Simone Pernice.
Now Simone asks.
Well, he says, "Hi Jon, great videos, thanks."
Well, anyway, I'll forgive you.
"I have a problem with my Shimano hydraulic brakes."
"They work fine until I brake hard for some time"
"and then they begin rubbing for a while,"
"then the rubbing disappears."
"I centered the discs between the pads"
"to avoid the rubbing,"
"and although there is very little clearance,"
"the discs are almost true."
"The problem looks to be on both brakes."
"Thanks for your answer."
Well,
I think I know what the problem is here.
So, when you break really hard
the fluids, the hydraulic fluid in your brakes heats up.
Now if there is air that's got into your brake lines,
which can happen over time,
then that air expands as the oil heats up.
Now, what this causes is for the pads to come out
and then just stick a little bit
and then when the air cools down
the pads can then retract.
'Cause as air heats up, air expands.
Now, the solution here is to bleed your brakes
and remove those air bubbles.
We have videos on this and some really good ones.
So we'll post links to those in the description
and you can check them out
as this should help your problem.
But yeah, I'd say the best thing to do
is to bleed your brakes.
The other thing to factor in is
that you say your discs are almost true.
Now, bear in mind, that any slight bending
in your discs is gonna make any, sort of,
rubbing issue worse as well.
So that can compound it.
And then the other one thing to point out
is that if your discs are
a little bit old, if you've worn out your discs,
if your brake calipers are a little bit old,
then sometimes the pistons can start to stick slightly.
So, I don't think it will be that.
I think it will be air bubbles in your brake lines,
but yeah, should be something
that you can fix, quite easily.
Thanks for watching and I hope you've found
this Tech Clinic useful.
As ever, if you have any questions about tech, kit,
upgrades, maintenance, or any problems at all,
then let us know in the comments section below
and we'll potentially answer it in a future
Tech Clinic video, so.
The one question I'm sure you're all wanting
to know the answer to though is,
where can I get one of these awesome
Spanish themed tee shirts?
Well, that's easy.
You just head over to the GCN shop,
but they're only available for a limited time only, so.
You wanna head over there sharpish.
Right, I'm going now, see ya, bye.