(techno music)
- The launch of SRAM new RED eTAP AXS Group set
with its smaller chain rings,
seems to be continuing the trend
of road bike gears getting easier,
and you may be wondering, why?
- I wonder why road bike gears are getting smaller?
- Well, in this video we are gonna explain,
and also show you why in this case,
smaller chain rings don't actually mean smaller gears.
Then finally, we'll be working with SRAM
to talk you through their thinking behind it.
- [Narrator] Just to recap, what SRAM has done
is reduce the sizes of the chain rings upfront.
Instead of 53/39 we have, 50/37.
Instead of 52/36 we have, 48/35.
And lastly offering smaller gear
ratios to 50/34, we have 46/33.
- Three things have happened to spark this
trend in shrinking chain rings.
Firstly the roads that professional
cyclists race on have changed.
Secondly the roads that normal
cyclists ride on have changed, and then lastly,
improvements in technology have
actually allowed it to happen.
- Now our journey begins in the mists of time.
1999 to be exact, a year
of Britney Spears, and Lance Armstrong.
- Not together?
- Who knows?
Anyway, back to 1999 and the fearsome Angliru,
was something of a pivotal moment in bicycle gears.
It was the first time that brutal super steep
monster climb had featured in a grand tour.
- On a reconnaissance mission, Pedro Delgado said that
nothing like this had ever been seen before.
Pro cyclists were forced to adapt their
gearing heavily just to get up.
Even Jan Ullrich, one of the biggest grinders of all time
unusually opted for a smaller ring.
- Anyway, the pros moaned, but it was a
huge hit from the perspective of the fans,
and so the race organisers of the world tour in Dejiro
sought out to include even more brutal climbs like,
The Zoncolan, and the Alto de los Muchachos.
Pro riders regularly had to fit even smaller gears
so manufacturers followed suit.
- Meanwhile, Lance Armstrong, was suddenly becoming famous
for peddling with a really fast cadence,
whilst dominating seven Tours de France,
and at the time, many people were
attributing to success to that.
We now know of course, that's not entirely true.
But there was a positive knock on effect for the rest of us.
Which is that while peddling a
fast cadence is not efficient.
Peddling at your optimal cadence,
and having the gears to allow
you to do that, suddenly became cool.
Hardened roadies, started to use easier gears.
- A few years later a shift in where we ride also began
as for pro race organisers, the rest of us also started
wanting to explore the world more,
and conquer brutally steep climbs.
Take for example, Oman, where we are riding now.
It hasn't traditionally been thought of
as a road cycling destination.
And that's partly because many of the beautiful climbs here
are just so brutally steep in places.
However, modern road bike gearing is so versatile,
that it's making places like this more accessible.
Whereas in the past, you would have required a touring bike,
or even a mountain bike to get up
these ridiculous 20% gradients.
- And lastly, technology, as technology is improved
bikes have become more versatile.
You didn't have many gear options with a six speed cassette
riding up a super steep climb like the Angliru
or Jebel Shams in Oman where we are today,
Simply wouldn't have been possible in the 70s or 80s
with the technology available.
- No but as chains, and gears, and wheels improved,
so to, did extra sprockets now start appearing at the back
and with each new sprocket so the gear ratio began to spread
- So pro cycling started racing up super steep climbs.
They now had the technology to do it.
Riders like Lance Armstrong made spinning smaller gears cool
and normal riders like us increasingly started
riding up harder and harder climbs,
sometimes not even on tarmac.
- Nope, which brings us up to 2019.
We now have twelve sprockets at the back,
and even smaller chain rings up front but,
this is not about easier gears.
Perhaps the biggest shift here. Thanks, is that SRAM say
that they designed this group set around gear ratios
rather than just gently evolving what has gone before.
- Right okay, strap yourselves in now.
Grab yourself a double espresso because
Si is gonna go full on uber tech nerd on us all.
- SRAM have reduced the size of their chain rings,
that much we already know. But, it's important to know
that in isolation, chain set size
doesn't actually tell us anything.
And that is because gears work as a pair.
So at that point we need to talk
about SRAMs new 12-speed cassette, which has a ten tooth.
Now traditionally road bike cassettes
have only ever really gone down to an 11/2 sprocket.
So actually, although the chain rings are smaller,
the top gear is larger, and that's because
that one tooth difference at the back,
has a greater effect on your gear ratio than
adding four extra teeth to your big chain ring.
For example, if you were to use 50/10,
that has a gear ratio of 5:1 meaning that for every
turn of your cranks, your back wheel will spin five times.
If however, you're using a traditional racers top gear
of 53/11, that's got a ratio of 4.82:1 meaning that
for every turn of the cranks, you would travel an extra
37 centimetres when using 50/10.
Now that might not sound like very much,
but if you're spinning at 100 rpm,
that's 37 metres per minute. 2.2 kmph faster.
- The effect of that ten tooth, is so pronounced,
that even on this bike where I've got a 48/10,
I've got virtually the same gear ratio
as the racers choice of 53/11.
Now, in practical terms, that means I'm currently
doing 60 kmph, and peddling at just 100 rpm.
Of course you don't get something
for nothing with gear ratios,
if you wanna go faster, you are going to
need to put more power output.
But, it does go to show that if you've got the legs,
or in this case the descent,
you do have the gears to allow you to pedal.
- At the other end of the spectrum,
my 35/28 gear, is allowing me to inch my way up
this killer section about 20% on Jebel Shams.
- With some nerdery, and practical demonstrations,
we can see that smaller gears doesn't
necessarily mean smaller ratios,
and by redesigning the three hub body,
it's allowed SRAM to fit this
super small ten tooth sprocket at the back.
But also make the most of twelve gears by minimising
the jumps between the individual sprockets.
But that doesn't explain SRAM's thinking behind it.
- No. So apparently it's not just about
high top gears and lower bottom gears.
By moving the range of the gears to the cassette,
it's allowed them to reduce the gap
between the chain ring sizes up front,
which they say improves front shifting.
So instead of a sixteen tooth gap
on a traditional compact chain set.
Across all three of the new chain ring size options
you've got just a thirteen tooth gap.
Which SRAM say, allow them to tweak
the design of the front de railer,
and also, that smaller gap means the chain
doesn't have to climb as far anyway so both things
they say improve that front shifting.
- By having most of the range at the back and
pairing it with a smaller chain ring.
Either 3, 4 or 5 tooth smaller,
it means that riders can use the
front de railer less anyway.
Because although you have the small ten tooth sprocket
giving a higher top gear, when you pair the smaller chain
rings with the rest of the cassette,
it means you actually have easier gears in the big ring.
- Why does that matter though,
particularly if you've got super smooth shifting?
And it's a good question, I think for most of us,
we tend to try and avoid using the front derailleur
as much as possible, it always feels
quite a significant event, disrupting your cadence,
potentially losing a bit of momentum.
And so, being able to do that less
would be something of an advantage.
Particularly, in a situation like this one
where I'm riding along a flat road
and getting towards a little ramp,
and instead of having to shift, I can simply leave it in the
big chain ring and avoid that potential
loss of momentum at the bottom.
- SRAM will have to convince us cyclists of two things.
Firstly, the minority of people that
still believe that big chain rings are cooler.
- Yeah, there is a certain amount of
snobbery in certain cycling circles.
Even gear snobbery would you believe?
To ride a traditional 53/39 chain set
with a close ratio 11:23 cassette,
is viewed by some as a badge of honour showing just how
strong and powerful you are that
you are able to turn those gears.
- Yeah and on the flip side, if you ride smaller gears
such as a compact chain set, there can be the perception
that that's because you're a weaker cyclist,
or perhaps less experienced.
On the internet I believe they're called noobs.
- Well we strongly disagree with this.
Your gears show where you ride, not how strong you are.
And as you've heard already, the best climbers in the world
choose to ride smaller gears for the most fearsome climbs.
And yes, whilst Eddy Merckx did
once tell me that he didn't need a compact,
I don't think Eddy Merckx ever went up the Angliru.
- And the other thing, which one or two people pointed out
at the launch of the new group set,
is the perception that smaller cogs are less efficient
than bigger ones and this is because on a smaller cog,
the chain actually has to go through a tighter angle
which is thought to perhaps increase drive train friction.
- Yeah, theoretically, a ten could cost you a fraction of
a what to an eleven tooth sprocket.
But if you are genuinely interested in drive train
efficiency, then you'll also understand that given how much
SRAM redesigned the chain and the cassette, and the chain
rings to actually make any meaningful comparison between new
and old, the whole system would need to be tested.
- Absolutely, and if you want to find out more,
about SRAMs gear options, and the new group set,
then you can click down here.
Because Si, has done an excellent video explaining it all.
- Thanks mate.