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Verdict: 
It's not light but aerodynamic efficiency makes this bike fast over all but the steepest of climbs
Weight: 
9,790g
Merida Reacto 300 road bike
7 10

The Merida Reacto 300 takes features from Merida's Reacto aero road bike and incorporates them into an aluminium frame, making the bike a whole lot faster than its hefty weight might lead you to expect.

Our Reacto 300, a size large, weighed 9.79kg (21.5lb). As £1,000 road bikes go, that's pretty heavy. That means it's slow, right? Well, no, hold your horses. You'd be mad to write off this bike on the basis of its weight.

Everyone likes a lightweight bike. It feels good when you chuck it around, it accelerates fast, and you can boast about it to your mates. But in the overall scheme of things, light weight really ain't all it's cracked up to be.

Of course, in an ideal world you'd have a bike that was both lightweight and aerodynamically efficient. But if you had to choose between them, aero trumps lightweight. It really does. A lighter bike will accelerate faster and it'll be quicker up steep climbs but, all other things being equal, the rest of the time you'll be quicker on an aero bike.

The Reacto 300 has been getting me around my regular routes very quickly over the past few weeks. I've got a 20-mile route that I do at lunchtimes, with just 300m of climbing, and the Reacto 300 has helped me fly around there lately. I'm lucky enough to ride a lot of very expensive bikes but this £999 model has got me around this particular route quicker than a lot of them.

That's not a scientific test, of course – not even close – and the conditions and variations in my level of fitness obviously play a big part. So why do I mention it? Well, a lot of people seem to think that a bike that's, say, 25% heavier than another is going to be much slower. That's not necessarily the case. Put your power into the Reacto 300 and it's very quick. It gobbles up the miles, especially over flat and rolling terrain. This thing can shift.

The 6066 alloy frame is stiff too, particularly at the front end where the oversized head tube with a 1 1/2in lower bearing holds everything securely in place. The full-carbon aero fork keeps the steering tight and precise so you feel you can slam the bike around the bends.

When it comes to the climbs, the Reacto 300 surprised me with its ability. Okay, when you hit the very steep stuff it can't stay with superlight rivals. The weight can become a burden in those situations and you do feel like you're working harder than you should be. But that's fairly rare. I'm only talking about those climbs where you have to get out of the saddle and jump on the pedals. For more gradual climbs, that weight isn't much of an issue.

More non-scientific data alert. I have an eight percent hill around here that takes me six minutes to climb. I ride it in the saddle for hill repeats, five times up. I did it on the Reacto 300 this week and there was no real difference from normal in my times (I do it on a variety of bikes, whatever I'm reviewing at the time). Again, that proves absolutely nothing, but alarm bells would sound if I was heading up there 20 seconds slower than usual, and that wasn't the case.

That's an end to my worthless anecdotes, promise.

The Reacto 300 doesn't accelerate with quite the same spring in its step as a lighter bike. It's more of an estate car than a sports car when it comes to picking up speed, and you do notice that coming out of tight turns, for example. Plus, if someone decides to jump off the front of the group, your response is delayed just a touch as you build up your speed. Acceleration isn't lethargic but it is fairly pedestrian.

The other low point in the Reacto 300's performance is the braking, or more specifically, braking at the rear.

One of the Reacto's aerodynamic features (I'll explain the others later) is the positioning of the rear brake beneath the chainstays, behind the bottom bracket. That makes a lot of sense from an aero point of view but the cable goes all over the place between the Shimano Tiagra lever and the TRP brake: under the bar tape, looping out the front, into the down tube and out again, then around the bottom bracket. The result is a brake that feels, not to put too fine a point on it, wooden.

You can still brake using just one finger but it's hard work. It's more of a yank than a squeeze and even then the feel is, yeah, wooden. If this was my bike I'd be shortening the cable as much as possible to try to get a more direct connection.

Merida's own dual-pivot front brake, on the other hand, is absolutely fine. Chances are that you use the front brake the vast majority of the time anyway, but having an equally effective rear brake would be very welcome.

The Reacto 300 isn't as comfortable as the Merida Reacto Evo Team that I took for a First Ride last year. That bike had the benefit of Merida's S-Flex seatpost: an aero-shaped carbon-fibre post with a notch cut out of it close to the top. That notch allows the post to flex a little to help smooth out bumps and vibration.

The Reacto 300's seatpost is carbon-fibre but it doesn't have that notch. Like many aero posts, it doesn't flex much and you get quite a firm ride. It's not harsh – this isn't an uncomfortable bike – but it is firm. As ever, the saddle is a matter of taste but I found Merida's Race 1 to be pretty comfy with a narrow-ish nose and a reasonable amount of flex in the shell.

Aero features

The aluminium Reacto 300 borrows many aero features from Merida's carbon Reacto frames. Most importantly, the aluminium Reacto's down tube and the seat tube have exactly the same cross sections as those of its carbon counterpart. These are based on the NACA (National Advisory Committee for Aeronautics) 0028 airfoil, truncated at the rear. In other words, the tailing edge of the tube profile has been chopped off square in such a way as to keep the airflow stable without causing turbulence, according to Merida.

The seat tube is cutaway around the leading edge of the rear wheel in tried and tested time trial/aero road bike fashion, and the seat post that fits in there is shaped for aerodynamics too. It's held in place by a wedge system, the bolt sitting within the top tube profile so that it can't disturb the airflow.

I've mentioned that the rear brake is positioned below the chainstays, behind the bottom bracket, to improve the aerodynamics. That allows Merida to do away with a brake bridge between the seatstays.

The front brake, though, sits in the conventional position at the front of the fork. Merida reckons that there's not much aero benefit in moving the brake behind the fork legs, so they don't bother. The positioning is the same on carbon Reactos.

The seatstays are very slim and they join the seat tube low to reduce the frontal area, but they don't kink out as widely as they do on the carbon Reacto, sitting closer to the rear wheel. There are big differences in the head tube shaping too, so this isn't simply a carbon Reacto made from aluminium, although it is a fairly close approximation.

Merida haven't tested the aluminium Reacto in the wind tunnel but they reckon it won't be too far away from the carbon model in terms of its aero performance.

Components

The Reacto 300 is equipped with Shimano Tiagra shifters and mechs that work exactly as they should. The next generation Tiagra groupset that Shimano announced in March comes with gear cabling that goes underneath your handlebar tape, but ours loops out into the fresh air. The shifters have gear indicator windows that are absent from new Tiagra models. I never actually look at them, but you might find them useful.

Merida spec an FSA Omega chainset with 52-tooth and 36-tooth chainrings. I'm a fan of that combination. Matched up to the 12-28 cassette, it gives you the big gears you want for slicing along the flat along with small options for getting up the climbs. Win-win.

The wheels aren't anything to get too excited about but they've stayed true throughout testing and no water has got inside the sealed bearing hubs. Merida's Aero 30 rims are, as the name suggests, 30mm deep. Something a little deeper – 40-50mm – would be more in keeping with the Reacto's aero character. That would be a good upgrade if you were to buy this bike.

The aluminium bar and stem might not be particularly lightweight but they do keep everything feeling solid when you're sprinting out of the saddle. I really liked the straight section on the handlebar drop just behind the levers and found myself using it a lot when plugging away on the flat.

Summing up

The Reacto 300 is no lightweight but don't let that put you off. This bike has aerodynamic efficiency on its side and it really is quick. Okay, it's a bit of a lump on the steepest of climbs, but it doesn't hang about over flat and rolling terrain. Write it off at your peril,

Verdict

It's not light but aerodynamic efficiency makes this bike fast over all but the steepest of climbs

road.cc test report

Make and model: Merida Reacto 300

Size tested: 57

About the bike

State the frame and fork material and method of construction. List the components used to build up the bike.

FRAME REACTO LITE, 6066 Triple butted and Hydroformed aluminium frame with smooth welding, and internal cable routing. Tapered head tube and integrated seat clamp

FORK Reacto Carbon Race

REAR DERAILLEUR Shimano Tiagra

FRONT DERAILLEUR Shimano Tiagra

SHIFTERS Shimano Tiagra Dual control

BRAKES Merida Road Comp / TRP

CHAINSET FSA Omega 52-36 MegaExo

CHAIN KMC Z10-10s

HUBS Road seal Bearing

RIM Merida AERO 30

FREEWHEEL Shimano CS-4600-10 12-28

TYRES Maxxis Dolemites 23 fold

STEM Merida pro OS -5

HANDLEBAR Merida Anatomic road OS

HEADSET Big Conoid semi neck pro

SEAT POST Reacto Aero carbon Comp

SADDLE Merida Race 1

Tell us what the bike is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about the bike?

Merida says, "Brand new for 2015, an aluminium Reacto, bringing the aero bike to the masses with a Cycle To Work friendly price point. No excuses for being late to work!"

It's an aero road bike, so performance-focused.

Frame and fork

Overall rating for frame and fork
 
7/10

Tell us about the materials used in the frame and fork?

The frame is 6066 aluminium, triple butted and hydroformed, with double pass welds.

Merida says, "All Reacto bikes have a full carbon fork, that is steerer and blades, saving weight, reducing road vibration and due to its tapered steerer improving steering precision. Example weight 438g with an uncut steerer."

Tell us about the geometry of the frame and fork?

Our 56cm bike has a 575mm top tube, 560mm seat tube, and 180mm top tube.

The stack is 570mm and the reach is 400mm.

How was the bike in terms of height and reach? How did it compare to other bikes of the same stated size?

The reach is longer than most other 56cm bikes out there.

Riding the bike

Rate the bike for efficiency of power transfer:
 
8/10
Rate the bike for acceleration:
 
6/10
Rate the bike for sprinting:
 
7/10
Rate the bike for high speed stability:
 
7/10
Rate the bike for cruising speed stability:
 
7/10
Rate the bike for low speed stability:
 
7/10
Rate the bike for flat cornering:
 
8/10
Rate the bike for cornering on descents:
 
8/10
Rate the bike for climbing:
 
6/10

The drivetrain

Rate the drivetrain for performance:
 
7/10
Rate the drivetrain for durability:
 
7/10
Rate the drivetrain for weight:
 
7/10
Rate the drivetrain for value:
 
7/10

Wheels and tyres

Rate the wheels and tyres for performance:
 
7/10
Rate the wheels and tyres for durability:
 
7/10
Rate the wheels and tyres for weight:
 
7/10
Rate the wheels and tyres for comfort:
 
7/10
Rate the wheels and tyres for value:
 
7/10

Controls

Rate the controls for performance:
 
8/10
Rate the controls for durability:
 
8/10
Rate the controls for weight:
 
8/10
Rate the controls for comfort:
 
8/10
Rate the controls for value:
 
8/10

Your summary

Did you enjoy riding the bike? Yes, much more than I expected.

Would you consider buying the bike? I'd consider it. Aerodynamics beats light weight!

Would you recommend the bike to a friend? Yes.

Rate the bike overall for performance:
 
7/10
Rate the bike overall for value:
 
7/10

Anything further to say about the bike in conclusion?

Aerodynamics beats light weight. That's why this bike is worthy of serious consideration.

Overall rating: 7/10

About the tester

Age: 43  Height: 190cm  Weight: 75kg

I usually ride:   My best bike is:

I've been riding for: Over 20 years  I ride: Most days  I would class myself as: Expert

I regularly do the following types of riding: commuting, club rides, sportives, general fitness riding,

 

Mat has worked for loads of bike magazines over the past 20 years, and been editor of 220 Triathlon and Cycling Plus. He's been road.cc technical editor for seven years, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a past winner of the Cycling Media Award for Specialist Online Writer.

28 comments

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Must be Mad [610 posts] 2 years ago
0 likes

I wonder where the 'break even' point is in terms of climbing/gradient for the aero vs light weight calculation.

Impressive looking frameset for an ally build. A couple of welds aside, it really does look like the carbon frame. However - rear break under the bottom bracket? Might make sense for a out and out racing bike - but for a bike designed for general riding on the road, its a bit mad. This alone would be a deal breaker for me.

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crikey [1251 posts] 2 years ago
0 likes

The 'lightweight' calculation always concentrates on the weight of the bicycle, and people obsess over minute amounts of weight while spending large sums of money.

In the real world, where most bicycles are ridden, the important weight is that of bicycle and pump, and gels, and phone, and waterproof, and shoes, and socks, and helmet, and glasses, and wallet, and keys and most importantly of all, the big lump of meat sat in the saddle.

The difference between a 'light' bike and a 'heavy' bike might be the difference between 6 kg and 8 kg, but really it's the difference between 95 kg and 97 kg...

People aren't going faster because their bicycle is lighter...

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Must be Mad [610 posts] 2 years ago
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I know I'm going to get flak for this... but then I changed bikes, and shed some 3kgs from the overall weight - the difference was very apparent (and strava agreed). I could accelerate up hills where before I would flounder.

OK, on fresh legs, the difference in climbing speed might be minimal, but when the legs have a few miles in them, the weight saving really pays off.

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crikey [1251 posts] 2 years ago
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No flak, but I bet a whole shiny sixpence that if you put two big water bottles of 750mls on your new bike, you'll still be faster on it.

Physics applies everywhere, all the time and really doesn't care if you are on a bicycle.

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Must be Mad [610 posts] 2 years ago
0 likes
Quote:

No flak, but I bet a whole shiny sixpence that if you put two big water bottles of 750mls on your new bike, you'll still be faster on it.

that is meaningless as - if the ride requires two water bottles, then I will have two water bottles, no matter which bike I'm on. So the bottles are effectively a constant.

If you are suggesting 'New bike + two water bottles' vs old bike with no bottles - again, not really a relevant test. I draw your attention to my observation 'when the legs have a few miles in them, the weight saving really pays off' - so in this instance, I would have drained one of the bottles anyway....

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crikey [1251 posts] 2 years ago
0 likes

Keep believing that minimal weight saving makes you significantly faster. A whole bicycle industry depends on people believing exactly that.

Physics, however, is a less gullible mistress.

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Must be Mad [610 posts] 2 years ago
0 likes

Well, the proof of the pudding, as they say, is in the 'not' eating  3
Also, stop watches don't lie either.
(and my suggestion that saving weight from the bike make you go faster up a hill for the same power input.... kind of is backed up by Physics)

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TheDoctor [220 posts] 2 years ago
0 likes
crikey wrote:

Physics, however, is a less gullible mistress.

true physics tells us less weight will accellerate quicker and with less effort, decelerate quicker and require less effort to climb hills.

So whats your point  39

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crikey [1251 posts] 2 years ago
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The point is that the difference between a light bike and a heavy bike is almost always overstated, and the importance of having a light bike in order to perform is largely mental.
Look at the change in weight as a whole rather than as a change in bicycle weight; the effects, in the real world are small.

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Vegita8 [49 posts] 2 years ago
0 likes

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

It is obvious that it is not the bike what needs improving first.
Of course, it is easier to spend some money rather than work hard to achieve better results.

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Leviathan [2558 posts] 2 years ago
0 likes
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

It is obvious that it is not the bike what needs improving first.
Of course, it is easier to spend some money rather than work hard to achieve better results.

Believe or not it is possible to do both. So people, please don't decry someone who bought a shiny new bike assuming they are a lazy sod with too much money.

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enrique [2383 posts] 2 years ago
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Vegita8 wrote:

You are 6-9 times heavier then your bike... you will never benefit from any aero improvements as... you never ride fast enough...

crikey wrote:

... the difference between a light bike and a heavy bike is almost always overstated... the effects, in the real world are small.

These posts are pretty nice. They made me think about the realities of going for 'lightness' and 'aerodynamics' and seeing them for what they might actually mean in the 'real world'. Thanks!  1

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Vegita8 [49 posts] 2 years ago
0 likes
bikeboy76 wrote:
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

It is obvious that it is not the bike what needs improving first.
Of course, it is easier to spend some money rather than work hard to achieve better results.

Believe or not it is possible to do both. So people, please don't decry someone who bought a shiny new bike assuming they are a lazy sod with too much money.

Don't get me wrong, I have two shiny new bikes myself but the only reason I bought them is because I love the look of them.  16

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crikey [1251 posts] 2 years ago
1 like

As I get older and fatter I keep buying lighter bikes and riding them slower...  2

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joules1975 [454 posts] 2 years ago
0 likes
Must be Mad wrote:

I know I'm going to get flak for this... but then I changed bikes, and shed some 3kgs from the overall weight - the difference was very apparent (and strava agreed). I could accelerate up hills where before I would flounder.

OK, on fresh legs, the difference in climbing speed might be minimal, but when the legs have a few miles in them, the weight saving really pays off.

Yes, but, is the difference all down to the less weight?

- Was the position better and more efficient?
- where the tyres the same or did the better bike have better tyres that roll better?
- are the frame and components stiffer laterally and therefore putting the power through to the rear wheel more efficiently?
- where has the weight been saved? If a fair bit is the wheels, they you might have a bit of a point, but you could have fitted those wheels to your old bike and had a least some of the same effect.

I'm afraid I'm with the other 'enlightened' folks here - overall bike weight, although important, is not as big a deal as many think - it's where the weight is on the bike, and then after that it's a whole load of other factors that make the difference between a fast bike and a really fast bike.

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davecochrane [142 posts] 2 years ago
0 likes

Well said. I train my arse off, so when someone drops a snide remark at the sight of my new Speed Concept 7.5, I'm more than happy to thrash them on it.

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alotronic [510 posts] 2 years ago
1 like

Age. You're all forgetting age.

It is a truth incontrovertible that for the same bike and training that, once you hit 35, you slow down.

Therefore the key to good performance is to get younger.

In order of effect: Get younger, train properly, get a bike that fits you and is suitable for the type of riding you do, get a lighter version of same.

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olic [72 posts] 2 years ago
0 likes
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Avatar
olic [72 posts] 2 years ago
0 likes
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Avatar
Vegita8 [49 posts] 2 years ago
0 likes
olic wrote:
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Uhm, that is strange.
I have studied physics for 4 years but never been told about that.
Is there any proof on that please?

Avatar
dave atkinson [6299 posts] 2 years ago
1 like
olic wrote:
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

not really sure what you mean here. air resistance increases with the square of velocity, so the faster you go the more of an issue it is. simply put, if you need 50W of your output to overcome air resistance at 20km/h, at 40km/h you'll be using 200W.

to say you'll never benefit from aero improvements is palpably and demonstrably untrue, though.

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Must be Mad [610 posts] 2 years ago
0 likes
Quote:

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Although this does depend on how the aero dynamics have been designed - but in general, and if you assume zero wind, then the faster you go, the more air you move through (for a given time period) - and therefore the is more potential for more power to be saved at higher speeds.

However this also has to be balanced against the power put in by the rider - and it is possible that a rider with limited power output may find a bigger % benefit from improved aero-dynamics than a rider able to put out much more power.

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Paul__M [33 posts] 2 years ago
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The counter intuitve idea is based on the fact that the slower rider is out for longer on the course benefitting from the aero reduction.
http://www.cervelo.com/en/engineering/thinking-and-processes/slow-vs-fas...

Interesting stuff on aero v weight here
http://flocycling.blogspot.co.uk/2014/03/flo-cycling-aero-vs-weight-foll...

I'm not convinced the Physics is as simple as suggested rew bike & rider weight. This is because the bike is 'unsprung' weight but the rider is (partially) sprung weight. This should affecct rolling resistance over real world surfaces (and comfort). Never seen an attemot to measure however, but then I haven't seen proof of the converse.

Avatar
olic [72 posts] 2 years ago
0 likes
Vegita8 wrote:
olic wrote:
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Uhm, that is strange.
I have studied physics for 4 years but never been told about that.
Is there any proof on that please?

The physics is pretty basic. Aero savings are about reducing the drag coefficient of a rider, which is independent of the speed the rider is travelling at. There's no end of posts online repeating this and going through the maths, I'm always puzzled why this still comes up!
http://alex-cycle.blogspot.co.uk/2013/06/aero-for-slower-riders.html?m=1

Avatar
dave atkinson [6299 posts] 2 years ago
0 likes
olic wrote:

The physics is pretty basic. Aero savings are about reducing the drag coefficient of a rider, which is independent of the speed the rider is travelling at. There's no end of posts online repeating this and going through the maths, I'm always puzzled why this still comes up!
http://alex-cycle.blogspot.co.uk/2013/06/aero-for-slower-riders.html?m=1

it still comes up because there's more to think about than just what would happen to the numbers in a wind tunnel, although your basic premise – that in absolute terms and perfect conditions, slower riders will save more time over a set distance – is certainly correct.

aero savings on a bike are more about reducing the amount of work a rider is doing; that's related to drag coefficient but it's determined by speed as well. which is why manufacturers will generally state them as a certain number of watts at a certain speed. the faster you ride, the greater proportion of your overall resistance is due to your aerodynamic drag, and less is mechanical stuff: friction, rolling resistance, drivetrain inefficiency, etc, so the more important it is to be slippery. which is why a fiat 500 doesn't look like Bloodhound SSC, and vice versa: look at any vehicle, and aerodynamics is a bigger consideration the faster you go.

as the post you linked to shows, how the saving changes depends on how you measure the improvement. the *percentage* of time saved increases with speed/power. and the further up the speed/power curve you go, the more meaningful those gaps are in terms of *relative* performance, because the rider ability curve flattens out. it's not as simple as just saying 'slow people save more time in absolute terms', although that's technically correct, at least in lab conditions.

we're not riding in lab conditions though. in a real riding situation, where you're experiencing wind from many different angles and going up and down hills, you'll spend more time at yaw angles where aero improvements are beneficial if you're travelling faster across the terrain and cancelling out the wind and inclines.

I still fit tri bars to my audax bike though  3

Avatar
Vegita8 [49 posts] 2 years ago
0 likes
olic wrote:
Vegita8 wrote:
olic wrote:
Vegita8 wrote:

You are 6-9 times heavier then your bike.
Also, your bike adds only 20% to the overall drag (not to mention that you will never benefit from any aero improvements as quite simply you never ride fast enough).

The first part is correct, but the whole 'you will never benefit from aero improvements as you never ride fast enough' is absolute nonsense. In terms of time to cover a set distance, you benefit *more* from aero improvements at a slower speed than at a faster one.

Uhm, that is strange.
I have studied physics for 4 years but never been told about that.
Is there any proof on that please?

The physics is pretty basic. Aero savings are about reducing the drag coefficient of a rider, which is independent of the speed the rider is travelling at. There's no end of posts online repeating this and going through the maths, I'm always puzzled why this still comes up!
http://alex-cycle.blogspot.co.uk/2013/06/aero-for-slower-riders.html?m=1

Sorry, I can't see the math there. I see a post in a blog with some misinterpreted data.

Obviously I am not in the position to do a complete research on the subject but it worth mentioning the following:

F=1/2*ρ*v2*C*A where:

F is the drag force,
ρ is the density of the fluid
v is the speed of the object relative to the fluid and it is squared (could not do it here).
A is the cross sectional area, and
C is the drag coefficient – a dimensionless number.

As you can see all these parameters are linear except the speed which is squared. That is why it is not just important but the most important parameter in the equation.

What also worth mentioning is that A is the cross sectional area where your bike will count only as 0.2*A (average) as you are the other 0.8*A.

Based on the above I must assume that there is hardly a big difference between road bikes nowadays in terms of aerodynamics or mechanics (same group set) especially on the level of an average user.
I can imagine that the top level may benefit marginally but for an everyday Joe like me there is no reason to spend big other than to feel great about the look of my bike.

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philtregear [121 posts] 2 years ago
0 likes

totally agree with the last post. new light bikes are great fun and a motivator to get riding. However, I eventually went for function over form for my 40 mile round commute along shite roads come rain or shine. a steel framed juggernaut with bulletproof wheels and tyres, hub gears, brakes and dynamo, mud and chain guards. Serious riders will eventually settle on a bike suitable to their needs and not be enticed into forever buying something lighter, more beautiful etc.
I love riding my carbon bike with mavic wheels and campag gear, but, I have to admit, it is a bit of a pose compared to my true ability!!

Avatar
philtregear [121 posts] 2 years ago
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PS the other advantage of riding a heavy bike is that you can always blame your poor performance on the bike!!