What makes a fast bike fast?

[toolonglegs]

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

cheaper manufacturing costs .
Will make very little difference in average speed... Will allow for stiffer bb area for accelerations / sprints though.

[sogood]

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.

Depending on where the OP lives, 6% climb of 5km length may not be that readily encountered.

[Nobody]

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

Are there any studies to support that BB30 derivatives are better than external? Does the small amount of extra stiffness overcome the extra bearing drag (bigger bearings) for the average cyclist?

[sogood]

Are there any studies to support that BB30 derivatives are better than external? Does the small amount of extra stiffness overcome the extra bearing drag (bigger bearings) for the average cyclist?

It's another selling point for ceramic bearing.

[Nikolai]

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.

Depending on where the OP lives, 6% climb of 5km length may not be that readily encountered.

The figures were only meant to illustrate a point regardless of where OP lives.

[donncha]

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.

Good point. I'm heading over to France/Italy this summer so will schedule a complete clean/rebuild before then and save up for some new lightweight wheels.

Went out for a ride this morning on my normal bike and it felt pretty good too (though still not as sprightly as the Evo) so perhaps I'm just having "good sensations" as they say

[toolonglegs]

Are there any studies to support that BB30 derivatives are better than external? Does the small amount of extra stiffness overcome the extra bearing drag (bigger bearings) for the average cyclist?

It's another selling point for ceramic bearing.

Biggest problem with outboard bearings is people side loading them... even with those little plastic shimano tools you can load them up... want less friction... don't side load the bearings!.
They are bloody minuscule little things after all .

[Nikolai]

so perhaps I'm just having "good sensations" as they say

This could mean a lot of things so be careful what you say and who you're saying it to

[sogood]

Went out for a ride this morning on my normal bike and it felt pretty good too (though still not as sprightly as the Evo) so perhaps I'm just having "good sensations" as they say

I always have improved "sensation" after I have cleaned and re-lubed the chain.

[Nobody]

Biggest problem with outboard bearings is people side loading them... even with those little plastic shimano tools you can load them up... want less friction... don't side load the bearings!.

+1

The Hope mechanic's explanation is good from 8:45 to 9:55 on the below video.

[zero]

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!

The speed differential you are claiming for the two setups is > 5km/hr given the wind speeds claimed, which I find hard to credit for any semi trained rider.

5km/hr is the average difference in speed between my drop bar teschner with paired spoke 20/24 semi aero 23cs and my 15kg full suspension flat bar MTB (bends in the middle for extra power loss!) with an average of 1.75in tire width and 32 spoke box section rims - and has been repeatedly tested at heffron and centennial park (circular courses on calm days). Knobbies only make the MTB another 1km/hr slower.

[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!

The speed differential you are claiming for the two setups is > 5km/hr given the wind speeds claimed, which I find hard to credit for any semi trained rider.

5km/hr is the average difference in speed between my drop bar teschner with paired spoke 20/24 semi aero 23cs and my 15kg full suspension flat bar MTB (bends in the middle for extra power loss!) with an average of 1.75in tire width and 32 spoke box section rims - and has been repeatedly tested at heffron and centennial park (circular courses on calm days). Knobbies only make the MTB another 1km/hr slower.

Really? Are we going to be that particular about the details?

I'll make my statement again then, without the 'incorrect' details.

Same bike, same rider, same position, same drivetrain, same route, different wheels = higher average speed despite a stronger headwind

[jules21]

for example when we get dropped for tenth time on the club recovery ride.

lol, i know what you mean

no wait i've been told what that would feel like..

[Ken Ho]

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.

Dude, if I'm riding by myself, 117 m is nothing, but in any kind of competition, formal or informal, 117m is a very long nose Repeat a few times over a few hills, and it really is a big difference.

[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.

Dude, if I'm riding by myself, 117 m is nothing, but in any kind of competition, formal or informal, 117m is a very long nose Repeat a few times over a few hills, and it really is a big difference.

Yes, I'm aware of that. The 117m figure shouldn't be taken literally though. Just because the laws of physics suggest a 2kg heavier package will (perhaps) give you 117m disadvantage on a 5km 6% climb, doesn't mean that you're going to be behind by 117m every time there's a climb like that. Psychology, among other factors, is completely ignored for example. The underlining point being, a 2kg difference, an astronomical figure for many a rider, is not such a big deal even when climbing, never mind circling around in a 60min crit. Sure, if you're racing for a pay cheque or taking your racing seriously, the package (bike + rider) should be as light as possible without being stupid (on both fronts). Other than that, the sock's height is the much more burning issue at the moment rather than bike weight.

[sogood]

... if you're racing for a pay cheque or taking your racing seriously, the package (bike + rider) should be as light as possible without being stupid (on both fronts).

Until cross wind hits or needing to go downhill.

[ValleyForge]

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).

Love my 2010 Damocles - now having ~ 15000k on it. Probably one of the best all-round frames according to the tests.

FWIW, I ride it with some DT Swiss Tricon RR-1450 clincher aluminium wheels (1370g). I also have a different frame I've set up for climbing with low-profile full carbon wheels - Campy Hyperon Ultra 2 tubulars (1231g). I have 2 very regular routes. As they are, the Damocles is about a minute slower up Mt Coot-tha, and about a minute slower over out 40k river loop. Both have essentially the same running gear. Swap the wheels and the time differences disappear.

It's the wheels!

[Cardy George]

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).

Love my 2010 Damocles - now having ~ 15000k on it. Probably one of the best all-round frames according to the tests.

FWIW, I ride it with some DT Swiss Tricon RR-1450 clincher aluminium wheels (1370g). I also have a different frame I've set up for climbing with low-profile full carbon wheels - Campy Hyperon Ultra 2 tubulars (1231g). I have 2 very regular routes. As they are, the Damocles is about a minute slower up Mt Coot-tha, and about a minute slower over out 40k river loop. Both have essentially the same running gear. Swap the wheels and the time differences disappear.

It's the wheels!

Hallelujah!!!

Sorry, I'll pull my head in now.....

[Nikolai]

... if you're racing for a pay cheque or taking your racing seriously, the package (bike + rider) should be as light as possible without being stupid (on both fronts).

Until cross wind hits or needing to go downhill.

Couple of bricks in jersey pockets worked for me in the past.

[sogood]

It's the wheels!

Yep, it's those Campy Record level hubs!

[sogood]

Couple of bricks in jersey pockets worked for me in the past.

Great idea! Must remember to load up those bricks in my jersey pocket before the climb so that I can anchor them on my bike upon cresting.

[ValleyForge]

Couple of bricks in jersey pockets worked for me in the past.

Great idea! Must remember to load up those bricks in my jersey pocket before the climb so that I can anchor them on my bike upon cresting.

Maybe some aerodynamic love handles would be lighter....

[mikesbytes]

Back on topic. Last year I did the NSW Masters ITT champs on a road bike with clip-ons, then I borrowed a TT bike and some head 3 spoke wheels, took them down to Victoria for the Australian Masters ITT champs. Carefully comparing the data with the other NSW riders I concluded that I was 3/4 kph faster on the ITT / tri spoke than my road bike with clip-ons.

[Nikolai]

Back on topic. Last year I did the NSW Masters ITT champs on a road bike with clip-ons, then I borrowed a TT bike and some head 3 spoke wheels, took them down to Victoria for the Australian Masters ITT champs. Carefully comparing the data with the other NSW riders I concluded that I was 3/4 kph faster on the ITT / tri spoke than my road bike with clip-ons.

A TT bike alone will trump a road bike with clip on bars every time simply because of a better aero position you can achieve on a TT bike (assuming the set up is correct). I'm not sure about 3-4 km/h difference though. You could be comparing apples with oranges, e.g different weather/road conditions, different form/fitness level , different distance (perhaps) etc.

[sogood]

... assuming the set up is correct...

I often wondered how people know their set up is correct? All without objective wind tunnel testing. Every one have developed the eyes of an aerodynamic engineer?