What makes a fast bike fast?

[donncha]

After having a day to ride around on the latest & greatest of the bike world, I'm curious for people's input on what makes a fast bike fast.

My normal ride is an '08 Ridley Damocles, SRAM Rival and Aksiums (8.7kg).

Today's ride was a Cannondale SuperSix EVO, 2012 SRAM Red, ZIpp 303 Firecrest carbon clinchers (6.5kg)

It's probably no surprise that I felt a lot faster on the Evo. I'd look down at my Garmin expecting to see a certain speed and invariably I'd actually be going a few km/h faster. Climbing felt great (at 85kg it's always a bit of a slog) and it just felt like the bike wanted to go fast all the time.

So, what's the major factor?

Both are full carbon frames, and while the Evo is super stiff, the Damocles was stiff enough in its day too. I'm also no Marcel Kittel, so I'm certainly not pushing the boundaries of either frame. Would I really be 'wasting' any power on the Damocles?

The Evo package is 2kg lighter, which, although it would help uphill, doesn't make much difference on the flat, so that just leaves the wheels. Could wheels really make that much difference, or am I isolating things too much and it's just a collection of small differences adding up to one big difference?

[Nobody]

If your position on both bikes was identical for aerodynamics (unlikely) then it's likely going to be the wheels and/or tyres/tubes.

It could also be the wind conditions on the day.

[deadrat]

Nothing....bikes don't go anywhere without a rider pushing the pedals. There are many factors that go into why one bike feels faster than another, eg. fitting. Wheels make a difference but it's marginal.

[Cardy George]

Nothing....bikes don't go anywhere without a rider pushing the pedals. There are many factors that go into why one bike feels faster than another, eg. fitting. Wheels make a difference but it's marginal.

Sorry, I disagree. For reasons the LBS Owner doesn't want to discuss, I rode my frame on consecutive days with two wheelsets, Mavic Kysrium SL vs Mavic Cosmic SL, which negated my positon related aerodynamics.

Both days I rode the same route home to get a clear idea of the difference between the two. Both days I rode into a headwind with the Cosmics copping a 5kmh stronger breeze (15-20kmh vs 20-25kmh). Both days I rode at the same time of day.

The results? The Cosmics delivered a 3kmh faster average speed into a stronger headwind.

Not bad for a flimsy Corbon Fibre fairing!

[gururug]

1. Rider strength and efficiency
2. Aerodynamics
3. Weight / Rolling resistance

[notwal]

Adrenalin. When you sit on the seat it squirts a shot of adrenalin into your bum. Its an old trick.

If its not that it may be new bike effect. Shop floor sparkle is mesmerising and renders us vulnerable to the power of suggestion. The sales johnnies are sensitive to this state of vulnerability and make suggestions like "This is a fast bike mate" and we can't help but believe them. We happily embrace this delusion like dying atheists embracing a new found faith. We want it to be true so we try harder when we pedal. We will even persist in the face of overwhelming evidence to the contrary for example when we get dropped for tenth time on the club recovery ride. We tell ourselves things like "Woo I must have really over done it yesterday" and "Those guys must have been into the caffeine again". We hardly ever say "This is a slow bike" unless we bought it with that expectation and we don't often do that do we.

[PawPaw]

Nothing makes me smurk more than an advert for a used or new bike saying it is "fast".
If a bike feels fast, it is because it is lighter, or is set up to make you more aero.
Give me objective information like bike weight and geometry, or go play with yourself. But don't try and sell me scientifically illiterate delusion.

[toolonglegs]

Supersix Evo's are not very aero compared to many out there.
I would think you would notice 2 kilos difference a little bit in bike feel... bit it won't make much difference at all on the flat.
Your position may / probably will be more aggressive on the Cannondale.
I would be surprised if a test bike would be fitted with latex tubes... but maybe they are, slight advantage there.
Wheels will make a difference period...while the 303 may not be a very deep wheel it will be faster over a Ksyrium for example.
I have a 135km race on Sunday with 2000 meters of climbing... my DuraAce 50mm wheels maybe a fair bit heavier than my Kyriums but the choice is very simple for me... aero benefits out weigh the slight climbing advantage I might get over them with the lighter Mavics.

[RonK]

It's the 2 kgs weight difference, purely and simply.


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[donncha]

Thanks for all the replies!

New-bike-itis was partly a factor. Though I was only borrowing it from a mate for the day (so no sales staff were involved), I was aware of the latest reviews of the Evo as super-stiff & light, so there was an element of "let's see what this baby can do" in parts of the ride plus a general curiosity as to whether I'd notice much difference between my bike and a WorldTour quality package.

Evo was more aggressive, w/ a 155mm (slammed) head-tube versus my 195mm (inc. spacers).

Looks like the influence of the wheels is slowly decreasing

Maybe I'll save for a set of C24s as mentioned in the 'road wheels' thread. Stiff, nice hubs & lighter weight, so quicker to spin up and nicer uphill as well, so should add some 'zing'' to my existing setup without breaking the bank.

[rkelsen]

Lighter wheels and tyres make all the difference, IME.

[Daccordi Rider]

I think a lot of things add up but the frame is a great contribution. I upgraded last year and had the same reaction, this new bike just wants to go faster, climbs better, accelerates quicker etc.

The new frame feels to me like it is making better use of my input, more direct from legs to wheel if you know what I mean. And that is the frame builders art, stiff effecient power transfer whilst still providing a ride you can live with day in, day out. I don't have aero wheels but will be keen to try some to see what they feel like.

So it's the sum of the parts that do it.

[BarryTas]

IMO weight and wheels and your perception - ie placebo

[Daccordi Rider]

So you're saying all the time and money spent on refining frames, geometry, layups, aero flourishes, tube size/shape/length etc is wasted and weight is the only defining factor in frame performance?

[sogood]

For the given bikes, I'd say the major differentiator is in the wheel and service. Aksium isn't a premium wheelset and superficially is the obvious performance differentiator, the other major worthwhile aspect is service. A bike a few years old deserves a complete strip and rebuild of all the components. Cleaning, lube and fine tuning will also make a significant difference. For a start, the freehub of the Aksium have probably had it if it has not been serviced/replaced over that period.

[Nobody]

So you're saying all the time and money spent on refining frames, geometry, layups, aero flourishes, tube size/shape/length etc is wasted and weight is the only defining factor in frame performance?

Don't believe the marketing hype. The average ride has a 1% incline on average. Plug that into the calculator below and figure it out If you finish in the same place then obviously you get some of the climb back on the down hills too. With the numbers I plugged in for a 6.5 to 8.5 Kg bike is 0.2Km/h on a constant 1% climb. So for a whole hour considering there are down hills too, there would be less than 200m between the two bikes.

http://bikecalculator.com/veloMetric.html

[mateyboi]

My 2 cents

The fit, Frame, wheels, tyres and BB will make a difference to the ride.

When I changed from a medicore alo frame (english thread) to a high end carbon frame (BB30) I noticed the difference in power transfer/efficiency on the same wheelset. It just felt smoother.

On the road, the high end carbon frame felt more comfortable and absorbs bumps better. The more comfortable you are, the better and faster you ride.
Seriously a better frame just taunts you to go faster.

When i changed my wheels to aero Carbon tubulars it was a whole different ball game. I found myself holding high speeds easier than before.

Weight usually makes it easier on the hills and you would have alot more energy if needed later. Carry an extra 2kg for 100km would have a big impact I'd say.

[sogood]

Subjective perception often don't translate well when tested by scientific methods. The OP needs to know whether the search is for perceptual or factual benefit. Not saying placebo don't work, but it should be an informed consideration.

If the search is for bling, then it does not require justification. The best kind of purchase!

[Daccordi Rider]

So you're saying all the time and money spent on refining frames, geometry, layups, aero flourishes, tube size/shape/length etc is wasted and weight is the only defining factor in frame performance?

Don't believe the marketing hype. The average ride has a 1% incline on average. Plug that into the calculator below and figure it out If you finish in the same place then obviously you get some of the climb back on the down hills too. With the numbers I plugged in for a 6.5 to 8.5 Kg bike is 0.2Km/h on a constant 1% climb. So for a whole hour considering there are down hills too, there would be less than 200m between the two bikes.

http://bikecalculator.com/veloMetric.html

Interesting Nobody, thanks, what I am saying is weight is not the only defining factor to a bike frame and it's performance. In my recent upgrade the frame weight was barely different (100gr), groupset is the same and the wheels are a bit different, now Mavic Krysium Sl's vs Campag Vero's.

I still have the old bike and put the new wheels on it to compare to the old frame and there is certainly a quicker feel to the new frame, more direct response to input be it via pedal or handling. Is it quantifiable? My speedo and times on known routes, climbs etc are better on the new bike so I believe so.

So in summary same groupset, wheels, weight but different frame I measure a difference in my know performances, not scientific I know but for me enough to say upgrading my frame was a good investment for me.

[Abby]

I know for me, tyres make a huge difference. Switching from a set of Vittoria Rubino Pros to either Vittoria Open Corsa's or Michelin Pro Race 3's makes the bike sing on race day.

The other big difference I can make is cleaning my drivetrain...

Cheers,
Abby

[Daccordi Rider]

That's very true, try some Schwarble ZR's. They go , and a clean chain etc is a must for races and optimum performance.

[Nobody]

Interesting Nobody, thanks, what I am saying is weight is not the only defining factor to a bike frame and it's performance.

Sorry. After reading your post again it's obvious that I read it wrong.

[Daccordi Rider]

Interesting Nobody, thanks, what I am saying is weight is not the only defining factor to a bike frame and it's performance.

Sorry. After reading your post again it's obvious that I read it wrong.

S'ok, and that is a genuinely interesting set of figures!

[Nikolai]

Would I really be 'wasting' any power on the Damocles?

On a 6% 5km climb @250 watts output, 2kg lighter package (83kg vs 85kg) will give you 117m advantage at the top of the climb. In other words, nothing to be excited about. The weight game is a window dressing to sell higher priced products.

[ni78ck]

bottom brackets will help too.
i see lots of bike companies shifting from a standard bb to a bb30 or bbright .