Seattle Forrest

Awesome!! Congratulations! I bet it took hard work.

JBerman

Thanks for the info. So as someone like yourself who has raced, and it seems that weight on wheels really matters, what threshold of wheel weight is more important than other functions such as aero, etc... I've read that aero wheels that are heavier are still faster. Is this not accounting for climbing, etc? My wheels are almost 1700g. Does than mean 1500g wheels are inherently faster? Or could the quality of my wheels still make them faster than a spec of weight?

JBerman

Thank you and absolutely! Especially when I love to eat haha. Portioning was a game changer for me as well as cutting out a bunch of crap but yea it took a lot of consistency and resisting temptation lol.

therhodeo

Except that its not.

Seattle Forrest

Here's a complicated and detailed answer. It's focusing on frames and not wheels, but it outlines the type of logic you need to answer the question.

https://new.cervelo.com/en-us/engine...weight-vs-aero

Abe_Froman

Incidentally....anyone have recommendations for common, older roadbikes to purchase used? Thinking about picking one up for the summer.

Seattle Forrest

@abe

The one that fits you. Seriously. Look at Craigslist or whatever source you're comfortable with, and choose among what's available. There are plenty of great road bikes from all manufacturers.

JBerman

That is pretty fantastic info. I'll paste for others:

"So what is more important, saving 0.26 per cent in weight or 1.5 per cent in drag?

The answer depends on where you ride. On the flats, where aerodynamics can be up to 90 per cent of your resistance, saving 1.5 per cent in drag is the answer. But if you are one of those rare riders who only ride up crazy climbs like the Mortirolo (and take the gondola down), take the 0.26 per cent weight savings."

wphamilton

I checked the bike calculator, and it gave .04 mph slower (not .2 mph) when I added 5 pounds. In other words, no measurable difference on the flats.

In theory and in fact, five pounds makes no difference in steady speed. Even accounting for the tiny surges in each pedal stroke, momentum is conserved. Energy is conserved. Those variations will not slow you down either, except for the higher drag from the very tiny speed differences (hundredths of a mph).

It will make it easier to follow a wheel a few inches away, but won't make it easier to go a certain flat speed.

Abe_Froman

Option C: Use the money on better tires Probably notice a bigger difference.

Abe_Froman

The 0.2mph was for a 5% grade. I also rounded a bit to keep things simple.

BigPoser

Amen to that!

wphamilton

Up a steep grade is simple, it becomes close to speed decrease % == total weight increase %. Lower grades that we can take faster, it becomes a smaller fraction of that.

I just want to be clear: on the flats, no difference. For riding solo, reasonable differences in weight makes no difference in one's speed on level ground.

JBerman

I like that logic, since I just bought some new GP4000sII's even though I didn't really "need" them haha

Seattle Forrest

What if you already have the best tires?

The usual advice is to take a dump before you go up a big hill, but what if you already did that and you have three more hills to go? And how much time to you lose crapping in the bushes every time the road goes up?

Seattle Forrest

First time I used GP4Ks, I had been using really crappy tires, and the difference was really big. Not like a new bike, but too big not to notice. Especially obvious when turning.

redfooj

If you think that a rider of average fitness is 90% of performance and the bike is 10%.... A 20# bike to a 15# bike improves overall ride minimally.

Between my 6.8kg bike (modern, compact) and 8.5kg bike (classic, steel) sharing same or similar wheels, by and large my performance on a ride or a climb or a specific segment comes down to how I'm feeling that day and my fitness from the leading prior month...

Bike don't make a piss of.difference

CliffordK

It would seem like that should be true from basic physics. But, in practice, it isn't entirely true.

I pull a trailer quite a bit, and I can definitely feel the difference between pulling an empty trailer, and a 100, 200, or 300+ pound trailer on both flats and hills. And, a small portion of that is due to changes in aerodynamics. The heavier the weight, the more resistance throughout the system. Tires, bearings, etc.

I can also feel the difference between no backpack and say a 30 pound backpack.

So... what about bikes?

I can definitely feel the difference between my 50 pound bike and my 18 pound bike.

As one gets down closer in weights. I can feel a difference in how a 25 pound bike and a 18 pound bike handles. But, it is hard t say how much of a performance difference that makes.

I have been playing with Strava for a while. Not completely topped out yet.
CF PRs:

• My harder hill climbs.
• My 10 to 11 mile segments (could also be training?)

Steel PRs:

• Some of my short, flat segments < 1 mile have been hard to beat. These would be dominated by short term power (and perhaps some wind )

On a hill, if you can cut your weight by 10%, that is huge, and would equate to about 1 MPH in 10, or 2 MPH at 20

JBerman

I've always wanted them! I planned on getting them on my last bike, but needed tires in a pinch and got Bontrager AW3's last minute as that is what the LBS carried. My bike currently has Schwalbe Lugano's (HS384, bottom of the line) which are prob fine but they do have some wear and tear as they came on the used bike.

ravenmore

I'd also like to point out that being a weight weenie is often a completely different hobby than regular cycling. There are people who's sole goal is to see how light they can make their bike.

Also weight does make a big difference on wheels. I can really feel it there.

Abe_Froman

Well, with a trailer, you actually have serious aerodynamics changes. However....


Weight makes a difference on the flats as well. Doesn't matter for a train on steel rails...but on a bike, increased weight means the tire deflects more, increasing rolling resistance. It's a smaller penalty than the pounds make on a steep hill, but it is still there.

Abe_Froman

Hah, that's the other thing I'm contemplating...buying a set of GP4000s and throwing those on my tourer/commuter and ripping the fenders off for the season.

JBerman

Perhaps you are referring to the amount you can minimize? Weight loss will almost always result in "some" loss of muscle tissue.

FlashBazbo

I divide my road training miles almost evenly between my 15 lb. road bike and my 19 lb. gravel bike. Since I live in a very hilly area, I can definitely tell the difference. Over time, on the same roads, I average around .8 mph faster on the lighter bike.

But the practical answer to the question can be answered by carrying a 5 lb. dumbbell plate on your next ride. Can you tell the difference? (I will bet that you can.)

For my weight (170+), I'm a pretty good climber. I have several Strava KOM's on area climbs. But when my 135 lb. friend rides with me, all illusions of being a good climber melt away. I'm dozens of watts stronger than he is -- but it's hard to overcome a 35 to 40 pound difference. When you go vertical, weight really matters.

Abe_Froman

0.8 mph for 4 lbs seems like a lot, even on hills (even with no downhills....). I'd bet anything there is a pretty significant difference in tires and riding position between the 2 bikes as well.