Fascinating phenomenon

actusreus

I have experienced what I think is a fascinating and puzzling phenomenon with two top level bikes. I am very curious what my fellow riders think about it, and whether you can offer an explanation.

I do the same local climb every weekend - about 1.5 miles long, with about 5% average grade, under 7% at the steepest part. I have a Pinarello Dogma F-10 with the Dura Ace Di2 and semi-compact crank, 11-25 cassette. I recently got the new Tarmac SL-6 Ultralight with the SRAM eTap, semi-compact crank, same crank length, 11-26 cassette. I noticed that at the same or similar sustained effort out of the saddle (wattage), my legs give out much sooner on the Tarmac than the Dogma. I simply have to sit back down on the saddle as the lactic acid build-up (or whatever that burning sensation is) kills my legs.

I'm completely confused by this. I read that press fit BBs are supposed to be stiffer than other BBs, so that would suggest that the opposite should be the case. But the Dogma's Italian threaded BB, or maybe just the frame in general, just seems to transfer the energy better than the Tarmac when climbing out of the saddle. The Tarmac is still a fast bike and climbs fast otherwise, but this repeatable experience makes me very puzzled.

Anyone with a similar experience or possible explanation?

mrb123

I suspect it's your wallet weighing you down.

webboo

It will be the extra weight of the tooth on the Tarmacs 26 tooth sprocket.

First.Aspect

So you've thought it through thoroughly, looked at all of the possible explanations, and settled on the type of BB? Is that what the bloke who sold you the Tarmac said?

Money:sense > 1.

---

I can think of two equally likely explanations; (i) your positions are different on the two bikes (ii) the bar tape is wrapped the wrong way on the Tarmac. You decide.

Yes, its lactic acid mate. Same stuff you get in lemons.

shirley_basso

I wouldn't go so far to say it's fascinating.

If you have a power meter which is calibrated the same on both bikes and power is identical in each case then I would put it down to position

benjamess

actusreus wrote:

I have experienced what I think is a fascinating and puzzling phenomenon with two top level bikes. I am very curious what my fellow riders think about it, and whether you can offer an explanation.

I do the same local climb every weekend - about 1.5 miles long, with about 5% average grade, under 7% at the steepest part. I have a Pinarello Dogma F-10 with the Dura Ace Di2 and semi-compact crank, 11-25 cassette. I recently got the new Tarmac SL-6 Ultralight with the SRAM eTap, semi-compact crank, same crank length, 11-26 cassette. I noticed that at the same or similar sustained effort out of the saddle (wattage), my legs give out much sooner on the Tarmac than the Dogma. I simply have to sit back down on the saddle as the lactic acid build-up (or whatever that burning sensation is) kills my legs.

I'm completely confused by this. I read that press fit BBs are supposed to be stiffer than other BBs, so that would suggest that the opposite should be the case. But the Dogma's Italian threaded BB, or maybe just the frame in general, just seems to transfer the energy better than the Tarmac when climbing out of the saddle. The Tarmac is still a fast bike and climbs fast otherwise, but this repeatable experience makes me very puzzled.

Anyone with a similar experience or possible explanation?

try the climb on each bike in the saddle and compare? not too sure why you would be out the saddle on a climb under 7%

imposter2.0

I notice a similar phenomenon when switching between my Bentley and my Lamborghini...

redvision

As others have said, there could be loads of factors affecting your climbing. Wind, tyres, tyre pressure, road surface (are you riding on the exact same line), your weight; to name a few. But the most likely is that your position is different on both bikes.

Or perhaps your tarmac is a fake

veronese68

I read the title and thought I bet it isn't that fascinating, then I told myself I'm too cynical.
Turns out I was right to be cynical. As said above it's almost certainly down to different positions.

kingstongraham

If you would like more replies in a similar vein, let us know how long it takes you.

singleton

Try to set the bikes up identically.
Try the climb on both bikes seated, with the same set of wheels and tyres.
Compare the power and time results.
If the power meters are correctly calibrated then the difference will likely be caused by your position.

actusreus

Damn, you're a judgmental lot. You know nothing about me other than that I have two bikes. You don't know the sacrifices I have made or who I am. I've come here for advice and get sarcastic replies because of what I've worked very hard to get.

Yes, the topic is fascinating. Maybe not as fascinating as roadside litter to you, but it is to me even if for the value of comparing the two bikes for those who are considering them.

Thank you to those who provided meaningful replies. The others can go and stuff themselves, not to use profanity.

imposter2.0

actusreus wrote:

Damn, you're a judgmental lot. You know nothing about me other than that I have two bikes. You don't know the sacrifices I have made or who I am. I've come here for advice and get sarcastic replies because of what I've worked very hard to get.

Nobody cares how hard you've worked and your 'sacrifices' are irrelevant. As someone once said - "it's not about the bike". You haven't even offered up any ride data for comparison and there are simply too many variables for any possible answer to be meaningful, as has already been pointed out.

First.Aspect

actusreus wrote:

Damn, you're a judgmental lot. You know nothing about me other than that I have two bikes. You don't know the sacrifices I have made or who I am. I've come here for advice and get sarcastic replies because of what I've worked very hard to get.

Yes, the topic is fascinating. Maybe not as fascinating as roadside litter to you, but it is to me even if for the value of comparing the two bikes for those who are considering them.

Thank you to those who provided meaningful replies. The others can go and stuff themselves, not to use profanity.

Betty.

kingstongraham

I find it fascinating that you ride the same hill at all out power every weekend. What sample size are we talking about? Could the difference be to do with what other riding you have done that day? If it is only recent, it could be a sampling error in the data.

First.Aspect

KingstonGraham wrote:

I find it fascinating that you ride the same hill at all out power every weekend. What sample size are we talking about? Could the difference be to do with what other riding you have done that day? If it is only recent, it could be a sampling error in the data.

The only way to be sure would be to buy a Colnago C65 with lightweight wheels and a rotor power meter and then conduct tests of all possible sequences and look for a trend. Don't you think?

veronese68

KingstonGraham wrote:

I find it fascinating that you ride the same hill at all out power every weekend. What sample size are we talking about? Could the difference be to do with what other riding you have done that day? If it is only recent, it could be a sampling error in the data.

Or what was eaten before the ride, some days you just feel better than others, what activities done in the days before the ride, a bit of a hangover, or just coincidence that a number of other factors conspired to produce a similar effect.

First.Aspect

Veronese68 wrote:

KingstonGraham wrote:

I find it fascinating that you ride the same hill at all out power every weekend. What sample size are we talking about? Could the difference be to do with what other riding you have done that day? If it is only recent, it could be a sampling error in the data.

Or what was eaten before the ride, some days you just feel better than others, what activities done in the days before the ride, a bit of a hangover, or just coincidence that a number of other factors conspired to produce a similar effect.

It could be confirmation bias.

He needs to ride the hill blindfolded to rule that out.

kingstongraham

Actually, fascinating is a bit strong.

ricky_h-2

Actus reus, like most people on here, you and I don't know each other from Adam but when I read your post, all I could hear in my head is John Robins reading it out on Radio X's humblebrag section. Sorry if that comes as a surprise to you. I am sure some other posters are just poking fun as a result, it's the internet, what else can you expect when you consult strangers ?

veronese68

actusreus wrote:

Maybe not as fascinating as roadside litter to you, but it is to me...

The difference being roadside litter affects others, not just the person on the bike.

Beatmaker

You haven't mentioned the colour of each bike, critical information if we are to offer a serious explanation.

on-yer-bike

Have you tried Weight Weenies? No one would bat an eyelid on there over you stable of bikes and would find the topic very interesting. Maybe the answer is in the cassette diferences and you arent using the same gear ratio on both bikes?

secretsqizz

My name is Maximus Decimus Meridius, commander of the Armies of the North, General of the Felix Legions, loyal servant to the true emperor, Marcus Aurelius.

Minion Actusreus You are sh it on a bike , sell them.

andi1363

I always thought Specialized bikes were overpriced rubbish and this thread confirms it!

cougie

Different bikes will have different positions and profiles. You might be less aero on the tarmac so you're tiring more easily.

actusreus

Ricky h wrote:

Actus reus, like most people on here, you and I don't know each other from Adam but when I read your post, all I could hear in my head is John Robins reading it out on Radio X's humblebrag section. Sorry if that comes as a surprise to you. I am sure some other posters are just poking fun as a result, it's the internet, what else can you expect when you consult strangers ?

Yeah, not sure what I was thinking. I suppose I thought I was asking a question on a forum dedicated to my fellow cyclist, not a group of insecure and envious douchebags. It's really sad and disappointing that so many people come here to post just to poke fun, criticize, and put down others. This is not the first time I've noticed this kind of drivel on here. It drowns those who actually do provide meaningful and helpful advice.

surfercyclist

actusreus wrote:

Ricky h wrote:

Actus reus, like most people on here, you and I don't know each other from Adam but when I read your post, all I could hear in my head is John Robins reading it out on Radio X's humblebrag section. Sorry if that comes as a surprise to you. I am sure some other posters are just poking fun as a result, it's the internet, what else can you expect when you consult strangers ?

Yeah, not sure what I was thinking. I suppose I thought I was asking a question on a forum dedicated to my fellow cyclist, not a group of insecure and envious douchebags. It's really sad and disappointing that so many people come here to post just to poke fun, criticize, and put down others. This is not the first time I've noticed this kind of drivel on here. It drowns those who actually do provide meaningful and helpful advice.

Twas ever thus. It's called the internet, people write stuff they would not dare say to ones face.

pblakeney

The use of "twas" for example.

sloppyschleckonds

PBlakeney wrote:

The use of "twas" for example.

Would you or would you not say it to ones face.

First.Aspect

actusreus wrote:

Ricky h wrote:

Actus reus, like most people on here, you and I don't know each other from Adam but when I read your post, all I could hear in my head is John Robins reading it out on Radio X's humblebrag section. Sorry if that comes as a surprise to you. I am sure some other posters are just poking fun as a result, it's the internet, what else can you expect when you consult strangers ?

Yeah, not sure what I was thinking. I suppose I thought I was asking a question on a forum dedicated to my fellow cyclist, not a group of insecure and envious douchebags. It's really sad and disappointing that so many people come here to post just to poke fun, criticize, and put down others. This is not the first time I've noticed this kind of drivel on here. It drowns those who actually do provide meaningful and helpful advice.

You know nothing about me, not even how many bikes I've got or even what group set any of them have. I've even got a Brabantia bin. You don't know the sacrifices I have made or who I have killed to get here. I've come here to try to give you advice and tried to be funny and all you do is get hostile because you are envious because I got to post on the forum at work. If I work that is. Which you don't know. Or how hard. Which is very, I'll have you know.