Why Are Road Bike Gears Getting Smaller? | SRAM RED eTap AXS Ratios Explained

Why Are Road Bike Gears Getting Smaller? | SRAM RED eTap AXS Ratios Explained


(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.