A probably pointless discussion about watts/effort and bikes

[rain dogs]

Originally Posted by mtechnica

I'm sorry but this is absolutely ridiculous. It's posts like this that make me want to just stay out of the main forum here. People post stuff that is just... wow.

You mad bro?

It's ridiculous based on, what?

Jan Heine says lower pressure, wider tires are much faster.

Joe Fred says skinny tires, higher pressure is much faster.

so? Which is it?

[weisan]

The whole reason for all of this???
Will a larger tire bike, with a higher stack and all of those other "gravel" characteristics, ever be as fast a true road bike? As my interest in racing increases,
I find myself wondering how long I can hold my ground on "steel is real" when I see people on gravel carbon wonder bikes running their mouths and doing 22mph, seemingly
with ease. I know there are an absolute ton of variables here, so I just want to have a conversation about what I could be missing, ways to improve speed on the gravel
bike and if ultimately, Im wasting my time with such thoughts. Are large tire bikes just slower? Is Jan at Reneherse full of crap?

- I have started racing last year and have found some early success (2x 1st Place - 30mile gravel, 2nd place in 280mile gravel)

Hello surfer pal, I read your thread/post a while back but did not respond right away because I want to mull over a bit. Please take what I say with a grain of salt coz' it's coming from someone who is not competitive, ride recreationally, just been really passionate about the sport for the last three decades.

First of all, I don't think this is a futile or pointless exercise. As a competitor, you need to ask those questions or at least look into them because your goal is to keep improving, set higher or greater goals, outdo yourself and others.

But I would say this: equipment is an important component of the overall equation but not the be all and end all. In certain situations, it can make a difference but in others, not so much.

You are already winning and getting good placing in the races you have entered.That means, you have "the right stuff". If you don't already have that, then none of these would really matter, seriously. Like one of the posters said, you are merely improving minor placings from 85th to maybe 82th.

That is NOT TO SAY that anyone who invested their money and time on improving their equipment and placings in a race that they entered is engaging in a pointless pursuit. No! Not at all. Everybody has the right to pursue their dreams and goals in any way they see fit, regardless of their standings. The last guy that crosses the line has as much right to be there in the race as the guy who came in first, maybe 2-3 hours ago. Who cares! They have paid the registration fee, went through the trouble of taking care of the logistics in order to show up at the start line. It's their right to participate. That's not my point.

What I am saying to you, specifically, is you did well so far in the races you have entered, primarily because you are better endowed in the wining qualities like speed, endurance, ability to suffer etc and that happened even when you were using "lesser" equipment. I can guarantee you that someone somewhere in those races is riding a bike that is more "superior" than the one you are riding on, whether it's lighter, or more technologically advanced or have better tires, a better fit...whatever. But because they are so far behind you in their "human" component of the equation that none of these "gains" they have made on their bike or equipment is gonna be enough to make up for their lack of and bridge the gap. It's simply not gonna happen.

If you watch some of the professional bike racing, you will see all kinds of weird stuff that even pros do like unzipping their top jersey and let it flop around in the air....just that is enough to negate all the benefits their team engineers have painstakingly tried to replicate on their bikes by putting them through wind tunnel tests and the careful selection of components they put on their bike. Often times, as the race gets closer to the end, in the final kms, it was mano-o-mano, nobody cares what bike you are riding or tires you are using, it's about who can hang in there, who can endure the pain, who can ride at or above the limit for how long, who is willing to take more risks, who has a bigger craving or hunger to win... That's what separates the first and the second and the ones lower in the placings. Not the bike.

Even in gravel racing, especially in the longer distances, you see the top guys using frame bags, hydration packs or whatever they need in order to survive and get to the finish line. Some may take the minimalistic approach and choose to leave off certain things from the bike and you see them pay the price when they encounter a mechanical.

Am I saying that equipment is not important?

Of course not.

For sure, take the time to experiment and try different setups, try to improve in any areas you can. But know this, the biggest payout for your investments is going to come from training and fine-tuning that internal engine of yours, the human element - not the external non-human part. Obviously the former is harder to do, so everyone tends to flock to the latter and just try to "buy" performance thinking that it will make a difference.

[mtechnica]

Originally Posted by rain dogs

You mad bro?

It's ridiculous based on, what?

Jan Heine says lower pressure, wider tires are much faster.

Joe Fred says skinny tires, higher pressure is much faster.

so? Which is it?

It's ridiculous based on physics and reality. I don't care what Jan Heine or Freds are saying TBH. What I can say for certain is that aerodynamics and rolling resistance directly affect speed.

The difference between an aero road wheel with a matched tire (rim and tire width) versus a shallow wheel with say a 2" wide MTB tire is a significant and measurable amount of aerodynamic drag. Say at 20mph, at least 10 watts if not much more.

Same goes for rolling resistance. Between a great road tire and an average gravel tire there is at least a 10w difference at 20mph, if not much more.

This theory plays out plainly IRL. Ride with the same group of roadies then take the gravel bike one day, it is A LOT MORE WORK to keep up.

Now, this applies mostly to paved surface, but on smooth gravel you will find the fastest riders are using the narrowest tire they can get away with.

[ripvanrando]

Originally Posted by rain dogs

You mad bro?

It's ridiculous based on, what?

Jan Heine says lower pressure, wider tires are much faster.

Joe Fred says skinny tires, higher pressure is much faster.

so? Which is it?

Both or neither.

[rain dogs]

Originally Posted by mtechnica

It's ridiculous based on physics and reality. I don't care what Jan Heine or Freds are saying TBH. What I can say for certain is that aerodynamics and rolling resistance directly affect speed.

The difference between an aero road wheel with a matched tire (rim and tire width) versus a shallow wheel with say a 2" wide MTB tire is a significant and measurable amount of aerodynamic drag. Say at 20mph, at least 10 watts if not much more.

Same goes for rolling resistance. Between a great road tire and an average gravel tire there is at least a 10w difference at 20mph, if not much more.

This theory plays out plainly IRL. Ride with the same group of roadies then take the gravel bike one day, it is A LOT MORE WORK to keep up.

Now, this applies mostly to paved surface, but on smooth gravel you will find the fastest riders are using the narrowest tire they can get away with.

Nobody was talking about MTB wheels. Hopefully you haven't "left the main forum yet" I said "Fat or Skinny" "Big or Small" ie. 32 vs 23, 700 vs 650B... same tire, same bike, set up at same wheel weight. It's Miniscule.

If you want to talk about significant differences in speed on a bike vs miniscule differences the order would start with:

1. Body position
2. Clothing (tight fitting vs loose)
3. Body weight (w/kg)
4. Large differences in bicycle weight >2kg
etc. etc.

Agreed?

the difference between a 23mm tire and a 30mm tire is miniscule by comparison, especially when you measure for factors such as hysteresis, advantages of grip while descending etc.

But maybe you're one of the people who believe that 700x20's at 140psi are saving you massive amounts of time vs 700 x 30's while riding totally upright with a 180mm headtube in a flappy jersey. If so, be my guest.

[mtechnica]

Originally Posted by rain dogs

Nobody was talking about MTB wheels. Hopefully you haven't "left the main forum yet" I said "Fat or Skinny" "Big or Small" ie. 32 vs 23, 700 vs 650B... same tire, same bike. Miniscule.

If you want to talk about significant differences in speed on a bike vs miniscule differences the order would start with:

1. Body position
2. Clothing (tight fitting vs loose)
3. Body weight (w/kg)
4. Large differences in bicycle weight >2kg
etc. etc.

Agreed?

the difference between a 23mm tire and a 30mm tire is miniscule by comparison, especially when you measure for factors such as hysteresis, advantages of grip while descending etc.

But maybe you're one of the people who believe that 700x20's at 140psi are saving you massive amounts of time vs 700 x 30's. If so, be my guest.

I'm talking about road tires versus gravel tires. I would consider 32c or less slicks to be road tires, and gravel tires are larger than 35c with some tread or slicks exceeding 40c.

A typical road tire could be 25c and a typical gravel tire could be 42c. There is a large difference in aerodynamics and rolling resistance there. Between sub 32c road tires no, there is a small difference like you said.

[ripvanrando]

Originally Posted by rain dogs

Nobody was talking about MTB wheels. Hopefully you haven't "left the main forum yet" I said "Fat or Skinny" "Big or Small" ie. 32 vs 23, 700 vs 650B... same tire, same bike, set up at same wheel weight. It's Miniscule.

If you want to talk about significant differences in speed on a bike vs miniscule differences the order would start with:

1. Body position
2. Clothing (tight fitting vs loose)
3. Body weight (w/kg)
4. Large differences in bicycle weight >2kg
etc. etc.

Agreed?

the difference between a 23mm tire and a 30mm tire is miniscule by comparison, especially when you measure for factors such as hysteresis, advantages of grip while descending etc.

But maybe you're one of the people who believe that 700x20's at 140psi are saving you massive amounts of time vs 700 x 30's while riding totally upright with a 180mm headtube in a flappy jersey. If so, be my guest.

It depends on speed and the road surface. On normal asphalt roads at higher speeds, the difference is massive. At 30 mph, I have measured a large difference between a 23 mm and 25 mm. Not miniscule at all.

On rough roads at lower speeds and all else being equal (say...same GP 5000 tire and tube type), the wider tire is much faster.

[mtechnica]

Originally Posted by rain dogs

But maybe you're one of the people who believe that 700x20's at 140psi are saving you massive amounts of time vs 700 x 30's while riding totally upright with a 180mm headtube in a flappy jersey. If so, be my guest.

Here are my two main bikes as my basis for comparison, you can judge how fredly my bikes and riding position are:





Bottom line is the gravel bike is 1mph slower on pavement or more.

[rain dogs]

Originally Posted by mtechnica

Between sub 32c road tires no, there is a small difference like you said.

So we agree. Perfect. We can all be friends again and not get so mad at each other.

[mtechnica]

Originally Posted by rain dogs

So we agree. Perfect. We can all be friends again and not get so mad at each other.

But you're entirely missing the point of the thread which was the OP asking about "large tire" bikes - for example his gravel bike with 43c gravelkings. That's not the same thing is comparing 25c to 32c GP5000TL for example (which I have done). 32c are not large or gravel tires.

[rain dogs]

Originally Posted by mtechnica

But you're entirely missing the point of the thread which was the OP asking about "large tire" bikes - for example his gravel bike with 43c gravelkings. That's not the same thing is comparing 25c to 32c GP5000TL for example (which I have done). 32c are not large or gravel tires.

It's the same thing. No point has been missed by me. Re-read his post. I'm really not interested in continuing on nor explaining it more if you don't understand, it's just too much potential to flip back into a stupid argument.

I'm happy to leave it at agreement.

[mtechnica]

Originally Posted by rain dogs

It's the same thing.

facepalm

[Peter P.]

You need MULTIPLE tests on each bike for a valid comparison. One test on each does not establish a trend.

I would ignore the variability of weather factors as it's too difficult to control. Just perform a minimum of three tests on each bike, not necessarily in order, and you'll have more conclusive evidence.

[Andy sti]

This thread is quite funny. Of course bigger tires are slower. Don't care what JH and the like say. Ride your bike and it will be obvious. Just to add to the silliness I thought I show a couple rides.

Today I did an easy ride with a buddy. Was a beautiful day with temps in the 60s. I rode my Ti gravel bike with 35mm G-one speeds that measure about 37mm at 37-40psi. Ride was entirely on paved roads.

Strava said this was a ride I did earlier in the year on July 25. Same route ridden with the same friend. Only this time I was on my Ti road bike with 25mm Corsas that measure 28mm.

Obviously there are a ton of variables but in the vain of this thread I thought I would post the differences.

Both rides were cruise rides and ended up with the same average speed. I did not wear an HR monitor as I often don't on these sorts of rides. I do have a PM on each bike, however. Positions are not significantly different on each bike and all of the time was spent in the hoods or the tops.

Today's ride on the gravel bike with the bigger and heavier tires required 20 more watts to achieve the same average speed.

Today on the gravel bike


July on the road bike

[fa63]

If you look at Bicycle Rolling Resistance's test data, 10W per tire is about the difference between road tires and gravel tires at medium to high pressure for road riding.

I don't have a power meter anymore, but I have been riding Panaracer Gravelking 40c tires on the road for a while now and my typical group rides do feel a little harder than usual. And not just when I am at the front taking pulls, but even when I am hiding in the pack where aerodynamics are not at play as much.

Originally Posted by Andy sti

Today's ride on the gravel bike with the bigger and heavier tires required 20 more watts to achieve the same average speed.