﻿Welcome to the GCN Tech Clinic where
we aim to answer your bike and bike
tech-related questions and issues.
If you'd like to get your questions
into as you can do using the hashtag
ASKGCNTECH in the comment section
down below or on other
forms of social media
as well, and we'll try and answer
as many of them as we can.
First up we're not further ado,
this week we have a question from Kevin
Timmons who says "Ollie, since you're
the experts on marginal aero gains,
does sunscreen/sunblock
make you more aero?"
Well, Kevin, if I could offer
you only one tip for the future,
sunscreen would be it.
The long-term benefits of sunscreen
have been proved by scientists,
whereas the rest of my advice
has no basis more reliable
than my own meandering experience.
I will dispense that advice now.
There you go.
The next question is from
Darren Clare who says,
"Can you recommend a degreaser
or hack or do I need to purchase
a specific kind of degreaser?"
Yes, I would say any organic
solvent will pretty much work.
I'd avoid really potent solvents
because they could potentially damage
your frame, but you should be
okay with petrol and white spirit,
acetone is pretty polar might
rip your frame, I wouldn't use that.
My favorites organic solvent,
dichloromethane,
I'd quite like to try that,
but it's another one for GCN
Tech after dark so
we don't need to go into that.
However,
if you are washing stuff down the drain
I would say purchase specific
products because there are products
available now that are
more environmentally friendly
and are designed to be
washed down the drain.
A lot of organic solvents should
be disposed of in dust really
in solvent waste, so I would
say try and avoid using those.
If you can get your hands on proper
bio degreaser or something do it.
Next one is for a Mads Buus Olsen
who says "Hi, GCN, love your show.
I was wondering if it's possible
to throw a Dura Ace rotor
on a Shimano 105 disc brake caliper.
What do you have to be aware of?"
That should be absolutely fine as
long as the rotor diameter is the same
so that, the dark what?
Is that a 140 or 160,
that's a 160 on mine.
You need to make sure
it's also the same diameter.
Something to be aware of though
is that Shimano when they knew,
they obviously we're down,
but when they're new, they're 1.8
millimeters thick.
That's the rotor thickness, whereas
SRAM start out at 1.85 millimeters
or even 1.9 millimeters in some
of the smaller of like 140s.
In an emergency,
if you were getting, I don't know
a neutral service weõll or something
and you needed to put in a ceram
disc rotor into a Shimano thing,
it could potentially work, but it might
rub because the rotor
is that bit thicker
whereas the other way around it'll work.
The braking is not as
optimal because the interface
for the pad and the rotor is
not as good but it does work.
I've done that. There you go.
Cam packs narrower as well that's
usually at 1.8 mil thick when they new.
Next question is from Random Asian
who says,
"Hi Ollie should I get ceramic bearings
and ceramic jockey
wheels is it really worth it?"
Well, Random Asian,
if you can afford it and you want to do
it and you want to bling
your bike out go for it.
Why not, but if it was me, I see
ceramic bearings as
the cherry on top of the Schwarz
of Al-bakr shorter Black Forest gateau.
In that respect, I'd say, ask yourself
or I'd ask myself,
have you done everything else.
Have you got latex inner tubes, have you
got aero wheels power meter,
have you optimized your position
on the bike and become
as aero as possible
and clothing and things like that,
because they're all things
that offer greater performance
more bang for your buck, so I'd probably
do those things
first but it's up to you.
That's one of the great
things about freedom of will.
Now,
the next question is from Luke Jackson
"I was supposed to be
doing the Fred Whitton
for the first time this year but it's
been canceled. I live in the Lakes.
That's at Lake District in the UK,
national park, beautiful place.
He knows how hard it will be but can
I give him any advice on completing it?
I love that event, man.
I've done it a few times
and I love the Lake District.
It's one of my favorite places
and in fact, it's going to be
one of the first places I go to
when the lock-down ends because
it's such a beautiful part of the UK.
I'd say, if you live in the Lake
District, you have no excuse.
Sorry but I'ds they practice
on the 30% hills as much as you can.
Get used to riding
there's really steep climbs
and build the strength
required for that.
Also, fit a 32 cassette but you probably
knew those things already.
For anyone else that doesn't know,
that's the best advice.
Next question is from Lukas Svendsen.
“Hello guys, love your knowledge.
As a student and always on a budget,
will it be smarter for me to
buy a bike with Shimano 105
instead of Ultegra
because of the savings when
certain parts start to wear
out and need replacing?”
Yes, I think you're right like,
when you look at the cost of, say,
a Shimano 105 chain over an Ultegra one,
it's like twice the price.
Like, the cassette,
it's like twice the price.
Is it twice the performance?
I'd say no. The Ultegra one,
and that is slightly lighter.
The Ultegra chain, it's been
shown to be slightly lower friction.
It's slightly faster, maybe like
a watt or something but very little.
Yes, twice the price but it's
not twice the watt saved.
If you're on a budget,
I would definitely say get 105.
When I was a student
and I was on a budget,
I bought a Cannondale SuperSix
and I'd save up for ages to get it,
with 105 on it, and it was amazing.
It did everything I needed
it to do and yes, I think
if I were to make that choice again,
I would buy 105
at that point in my life again.
Also, 105 is so good, like we've done,
I don't know if you've seen
it but I did a video with Psy,
where we did a blind test
where we were trying to guess
if we were using Dura-Ace
mechanical or 105 and genuinely,
can't tell the difference.
11 speed 105 is so good these days that
the shifting is absolutely,
is brilliant, so I'll go for it.
Save your money and you can
always put the money saved
towards something else like aero wheels,
which will probably give
you a more bang for your buck
in terms of performance
than the difference
from the step up from 105 to Ultegra.
Yes, I would think along those lines.
Plus, you can always potentially upgrade
your 105 shifters in bits and pieces
further down the line if you
get a bit more money or whatever.
Yes, go with that.
105 is a mint, probably.
Anush LTI. Yes, Anush.
“Could I use a pinch
of salt in water while
training indoors instead
of using salt tablets?”
Yes, you can or you could also
do it when you're training outdoors
if it's a hot day.
It doesn't really matter.
If you're feeling particularly
middle-class, may I recommend
Maldon sea salt flakes?
It's quite a nice salt that.
Yes, also bear in mind that if you're
making food, a lot of food does have
salt in it as well, so you are actually
getting quite a bit of sodium from.
If you have rice cakes
there's quite a bit of salt
in the cheese that you would
put in the standard recipes.
You're getting salt there.
Even if you're having
energy bars, a lot of them do contain
salts and gels and things but yes,
it's a cost-effective thing, bit
of salt in your water bowl, go for it.
Next question is from Jabin Lim,
who says, “Hey there.
I recently changed my
KMC X11 SL DLC chain,
and the chain keeps skipping
on the smallest sprocket.
Is it possible that my
smallest sprocket has worn out
or is it just that the chain needs
to stretch a bit more? Thank you.”
Oh, well, it's not down to chain
stretch. You don't want your chain
to stretch,
and someone pointed this out correctly.
We often talk about chain
stretch and chain wear.
It's not technically
the chain stretching.
It is the wear within the chain links.
It could be that your cassette
is slightly worn,
so if you've just replaced your
chain and your previous
chain worn out a lot, it's
like worn out, the cassette as well,
at which point, you do then need to
change your cassette and your
chain at the same time usually.
You can usually get away
with the chain rings though.
They should be okay but it could also
be down to the set up if you reenact.
I'd pay attention to this.
Whether it being the smallest
ring at the back, it could be that your
lower limit screw needs adjusting.
If you turn the lower
limit screw or move
the derailleur inboard and outboard
and you need to get that perfectly
in line with the smallest cogs.
Check your lower limit is set properly.
We've got videos that can
show you how to do that as well
or if it's not the limit, the limit's
fine, it could just be the indexing
needs to be just tweaked and sorted out.
While that wasn't a problem
with your old chain running,
now you've fitted a new one,
it just needs to be tweaked slightly.
It could just be that.
Let us know how you get on and if
you have any issues with that
just drop us another comment
in the comment section.
Next question is from Marcus
Antonio Emia who asks,
"Hey, is it possible
or okay to ride fixed gear
or track bikes in a busy
or traffic street?" I would say no.
[chuckles] Don't do it.
I don't know what the rules are
in every country in the world
but I do know what we have in the UK
and that is under the Highway Code.
Your bike has to have brakes.
If your bike doesn't have brakes,
technically it should be
fitted with lights at night as
well and reflectors during the day.
The issue you've got is
if you are in an accident
which is probably
the likelihood of that is
going to be increased by not having
brakes especially when you want to
run on a busy street, then
you become liable in the eyes of the law
and culpable for causing
the accident because your
bike wasn't properly fitted with brakes.
I would say, don't do it.
Some people think they're cool
and it's a hipster thing to do and ride
fixies in the street but unless
it's got a brake on it don't do it,
I would be what I'd advise.
The next question is
from JPLSenpai who says,
"Hey guys,
quick question regarding cleats.
I recently noticed that one of mine
is way more worn out that the other
possibly because that's the one
I disengage with when I come to a stop.
If this is the case what's better,
swap it with the other side shoe
[scoffs] or swap them over,
or just buy new
cleats and replace
both at the same time?"
I would just buy a new pair and just
replace both at the same time.
It's important you do
this and it's something
that I've fallen foul of in the past,
years ago.
A lot of people don't realize
how much their cleats have worn.
Once your cleat has worn lots,
what you'll find is that the shoe
will move a lot more within
the pedal and it'll be a lot looser.
What this can cause then is bad
knee alignment and then
that can cause knee issues
and aggravation further down
the line as you're peddling along.
Yes, always replace your cleats
because they do become loose.
Anyway,
just replace both at the same time.
The last question this week is
from Zachary Starkey who says,
"I'm riding on tubeless tires
for the first time." Nice one.
"From the look of your other videos
there are a lot of great benefits.
However, I'm wondering,
is it okay to put tubes
in them if there's
a puncture and it won't seal?
Any downsides to running
tubes inside of tubeless tires?"
Well, the downside is that you don't
get the benefits of the tubeless system.
You don't have that puncture
protection of the sealant.
You don't the lower weight
of sealant compared to a new tube
and you don't have
the lower rolling resistance
of a sealant compared to running
tubes which adds a bit more
friction although some people say
that's more down to the construction
of the tire than the inclusion
of the inner tube,
but that's another story altogether.
The other downside is
that trying to get the tire off,
trying to get a tubeless tire
off requires a bit more effort
than getting a normal
clincher off and that's
usually because the bead is stiffer.
This is because it needs to
create an airtight
seal against the wheel
so it usually has
a stiffer construction.
That can be a bit more
difficult but if you really
need to put in a tube then
that's what you do. It can be done.
I've done it in the past but very
rarely does it happen because
tubeless is if you use a good
sealant that seals most punctures.
Then, if you get a puncture that
won't seal you can out a tire plug
in there as well and that usually
gets it to seal most of the time.
Very rarely do you get to
the point where you've to
put an inner tube but in my experience,
it can happen.
There, now you know
but I would say tubeless is great.
Keep up to it.
Well, I hope you've enjoyed this
edition of the GCN Tech Clinic.
As ever, if you want a sports channel,
GCN shop.globalcyclingnetwork,
and grab yourself a mug
and give this video a like
if you enjoyed my Baz Luhrmann reference
right at the start of the video.
I'd like to say I got that right
in one take but that would be a lie.
[laughs]
All right. See you next time.
AskGCNTech,
that's how you get your questions in.
Ciao.
