- Right, I'm back again
here at the GCN Tech Clinic
to help answer any of you
technical, bike-related
problems, questions or queries.
So let's crack on,
shall we, with this week
and first up is a question
from Aleksey Malyshev,
who says they have worn out
a cog on a Shimano Ultegra
10 speed cassette. It's the
12 tooth. Does it make sense
to replace the cog only, or is it better
to replace the complete cassette?
Now, Aleksey, I can
relate totally to this.
I always actually just wear
out the 11 tooth sprocket
on my own cassettes because
I'm an absolute monster.
No, joking aside, just
go out and try and buy
one of those 12 tooth cassette sprockets.
You can find them from
really good local bike shops
out there because they will be able
to order in that part especially for you.
So just go ahead and do
that. It saves the expense
of buying a remainder of a
whole cassette. So, there we go.
Now, moving on to DSI: "Why
don't the pros have aero
bottles? Seems weird that
the bikes have anything aero,
from the tires and handlebars
to even the garmin mounts,
except the bottles. I know
they are somewhat aero,
but plenty of room for
improvement I would think."
It's a nice question, DSI.
Yes, they could be a lot more aerodynamic.
And in fact, they did used
to be more aerodynamic.
However, the UCI does have rules in place,
which are on screen
right now, that actually
determine the dimensions of
a water bottle on a bike,
as well as also the
position of it, as well.
So its forbidden, for example,
to have them on the back
of the saddle, like we may
well see in triathlon events.
And I agree that, yeah,
you could make a bottle
extremely aerodynamic,
but I think in this case
it's a good idea by the
UCI, because essentially
you could have riders putting
on a crazy aerodynamic
water bottle for a very,
very short time trial
and basically filling in the
main triangle of the frame.
So, yeah, I don't think it's a good idea
for us to actually
eradicate that rule totally.
Okay, next up is a
question from NickolasRad,
who asks: "I have a question
which is bothering me
a lot of the time. Do ceramic bearings
wear slower than regular or not?"
Now, Nickolas, this is a
really, really good question.
We get a lot of questions in
here about ceramic bearings,
and I'm not a bearing expert per se,
but I'm gonna try and help you out here.
So, with regards to wearing
out or lasting longer,
that is quite subjective,
really, because the ceramic balls
are actually made of a harder material
than that of a steel
bearing, but in doing so
means that if you were not
looking after components,
so, say, in a traditional
cup and cone style bearing,
basically the bearings
become a little bit loose,
they can start to pit the bearing races
a lot more than that of a standard bearing
because obviously its a much
harder wearing bit of material.
So you need to take that
into consideration there.
If you could get ceramic races as well,
well, you'd probably get a lot
more life out of them, too,
rather than damaging the
inside of a hub shell
or a headset shell, that kind of thing -
or headset race, rather.
So, I hope that answers your quesiotn.
Hopefully, soon we'll have
some more in-depth answers,
actually, regarding bearings in general,
so make sure that people do
leave their bearing questions
in the comments down below.
Right, let's move on, shall we?
Next up, from jlebrech: they went from
SRAM Doubletap to 105 and find
that the paddles are flappy
till you get to the gear
you're about to change.
"That's normal, right?"
Okay, so between the two systems,
yes there is a difference in
the actual shifting mechanism
and movements, so with Sram's
Doubletap it's very much
as you move the lever, you
can feel some resistance,
whereas with Shimanos,
yeah, they are quite flappy,
like you say, so as you move
- particularly when you move
the inside lever, so that's
to go into a harder gear,
it is very, well, loose in effect,
because there's no resistance there.
Whereas when you're actually
moving the whole brake lever
across to go into an
easier gear, you do feel
a little bit of extra
resistance, but not a lot.
Now, why is there that
movement inside of those
Shimano levers? Well,
there's a lot of ratchets
and mechanisms inside of
them, which, basically,
they're going into position
when you're moving that lever.
So it's nothing to worry
about. It's perfectly normal.
And you're good to go out
and still munch those miles.
Okay, next up is a question
from Vlad Savin, who says:
"Answer please, is it normal
that there is some playing
between the freehub body and the hub?"
Hi, Vlad. I presume you mean
that basically the freehub
body is rocking - not laterally,
so it's not pulling away
from the actual hub shell.
Rather, it's rocking on the axle.
It's quite common, actually,
for quite a lot of freehubs
to have that after a bit
of use. The reason being
there are some bearings
inside of the freehub
and it's likely, in most cases,
that that needs, basically, replacing.
Now, to remove those bearings
isn't always that easy,
especially for a home mechanic,
who may well not have the tools for that.
Instead, it may well be
easier and probably cheaper,
in some cases, to actually
just buy a new freehub body.
But if you are unsure on how to do that,
yeah, just go for the freehub body
rather than trying to remove bearings
and possibly damaging the
freehub body in the process.
Okay, next question is from
Ben, who says they have
a Sram Force 1x22 speed
on their cross bike -
I think that's 1x11, but I
know exactly what you mean -
they have some lovely
older Zipp 303 tubulars
on Alchemy hubs that they'd
love to use on the bike,
however their freehub is
10 speed only, and Alchemy
have confirmed that it can't
be converted to 11 speed.
This is quite a common one,
to be perfectly honest.
Do they have any options
with the cassette?
Is there an 11 speed
cassette that I can use
with this 10 speed freehub?
I've heard people claim
you can remove a cog and
move a spacer to the inside
to make an 11 speed cassette
work with 10 cogs effectively.
Is that possible and, if so, how please?
Okay, now there is a way or
removing a cog and a spacer
and basically doing exactly
what you've just said there,
but that is a video in
itself. Maybe it's something
I'll try and do in the near future.
However, there is definitely
a solution for you,
and that is the Shimano HG800 cassette.
So, the ration is 11 to 34,
and because it's an 11 speed
cassette it will index
perfectly with you Sram setup.
So, you can use that
and you can basically go
cross riding, gravel riding,
whatever, just make sure
that you rear derailleur
can in fact accommodate
that 34 tooth cassette sprocket, though.
But, yeah, that is your best solution -
I think, anyway. Go ahead and fit it.
Next quesiotn is from Omar Tam, who asks:
My front derailleur shifts
fine on a workstand,
but when they cycle,
it won't shift smoothly
from the small cog to the big cog unless
they slow down their cadence considerably.
Brand new - well, chain
is new, less than 1000Km -
and lucribcated. How do they tun it right
so that it will shift fine on the road?
Right, well, it could
well be that when you're
out on the road, you're
actually flexing the frame
a fair bit, so it's not able to do that.
So have a good look at that.
Also, make sure the adjustment
screws are, you know,
they are actually spot
on, because a workstand -
like I say, you've not putting
any flex through the bike,
so make sure that they
are in the correct place.
Also, it sounds daft but have
a look at the chain rings
and make sure they are
fitted in the correct way,
because if the inner ring,
for instance, is fitted
the wrong way around the
gaps are going to be too big
and you may well find, just
out on the road, a combination
of all different things,
you're not able to get onto it.
So, have a look at that. Failing
that, really, I don't know
what it could be, other
than your cable tension,
so obviously make sure the cable tension
is spot on there, too. And that
when you're out on the road
you are moving that gear lever across
just as much as you are when
you're on the workstand.
Next up is a question from MrZs178.
"Hey, Jon! I've got a mysterious
ticking sound coming from
my single speed. It sounds
like it's coming from
around the chain ring or bottom bracket.
It happens when I'm pedaling hard."
I know exactly that problem,
when you're pedaling hard.
"I think it's always, though,
when the right foot is
applying pressure." They've
replaced the bottom bracket,
as well as removing and
greasing their pedals.
Still no luck. Now,
MrZs178, the dreaded tick,
creak or click on a bike is
probably the most annoying thing
after, and this is very important,
someone sat on your wheel
and not giving you a turn into a headwind.
However, let's try and solve
that creak for you, then,
shall we? Now, You've
already said you've replaced
the bottom bracket, and
you've greased the pedals.
Those are the first two
things I would suggest
actually greasing, so
you've already done that.
Have a look at your chain ring bolts.
So, take them out, refit them,
but freshly greased this time
and torqued up to the
correct torque setting,
go out for a little spin,
see if that's solved it.
If not, then you need to check your chain.
So, first of all, have a
look at the chain tension.
Make sure that it hasn't got
any really tight spots in it.
So unless you've got a
very, very expensive,
premium chain ring, they're
not always actually that round,
so when you're riding on a
fixie or a single speed bike,
yeah, you do sometimes get a
length of tight chain where
a chain ring, or even a
sprocket, is not that circular.
It's invisible to the eye but, believe me,
it can plague you. Still got that creak?
Right, have another
close look at that chain
and inspect really, really
carefully all of the side links,
the inner links, the rollers,
the pins, to make sure
that none of them are
cracked or showing signs
of excess wear, or damaged in any way,
because that could also be causing a tick.
Other than that, I really don't know,
other than looking around
the drop-out, perhaps,
because maybe it's got a small crack in it
and that's giving a little
bit of a tick each time
you put down that torque
on that right pedal.
Anyway, let me know how you get on
with those bits of advice.
Next question is from
Zack Von Kannel, who says
they're thinking about buying
a new bike but can't afford
electronic gears at the
moment. If they buy a bike
with Shimano Ultegra,
can they just switch out
the levers and derailleurs with Di2,
or would they have to
purchase the whole Di2 set?
Well, Zack, it's exactly
that. So you're gonna need
your mechs, your levers,
your cables, junction box,
and importantly, a battery,
too. Get a charger, as well.
Now I'm pretty confident,
Zack, that you will not
look back once you go
choosing electronic gears.
I've never, ever regretted
making that decision.
Although once my battery
did run out, and I was stuck
in a big ring on a
particularly savage route
I was riding, and yeah, there
were a few choice words.
But that was because of user
error. I didn't actually
check the battery status
before I went out,
so, yeah, just bear that
in mind. But yeah, go ahead
and there you are, you
just need those components.
Okay, final question this week
is from Evan V, who says -
I sense a little bit of
sarcasm here, by the way -
"What online retailer can I buy
Jon Cannings' Elbow grease from?"
Well, Evan, I'm sorry mate,
but it's not available online.
Well, it is, only here at GCN Tech. Ha ha!
You have to keep on watching. Anyway,
I do hope that you've enjoyed
this week's Tech Clinic.
And remember to submit your
questions for me to answer,
leave them down there in
the comments section below
and I will do my very best to
get round to answering them.
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at
"https://shop.globalcyclingnetwork.com",
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