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-   -   Impact of wheels? (http://www.bikeforums.net/road-cycling/928409-impact-wheels.html)

RollCNY 01-04-14 08:47 AM

Quote:

Originally Posted by BillyD (Post 16381166)
He's gotta be a commie, what do you think?

Now my face is Red. :D

Herbie53 01-04-14 09:01 AM

Quote:

Originally Posted by WhyFi (Post 16381211)

...but a compilation of Riker sitting down in his unique fashion? Well, it is strangely enthralling, but it still doesn't make sense.


I never noticed that. This thread delivers.

RollCNY 01-04-14 09:12 AM

OK, I have a serious post to make, and it goes to @Smokehouse 's discussion of increased descending speed with new wheels.

My first bike was a Diamondback Insight $300 beaut, and I replaced it with a Specialized Sirrus. I set the Sirrus up as aggressively as possible, and felt it was a vast improvement over the Diamondback, except for the S500 stock wheels. They were flexy, and made me think I had a flat tire on every aggressive hill climb. As I am a big guy, every hill climb is an aggressive hill climb.

So I replaced them with Easton EA50 aero's, and the flat tire feeling greatly decreased. And because that decreased, I would hit hills harder. And because I hit the hill harder, I would carry more speed over the crest. And since I was already going fast on the crest, I could hit 32-35 mph and tuck for the backside descent faster. And because I tucked sooner and felt faster, I would rest my chest on the flat bar and get as deep as possible, and kick my butt to the top tube. And heck, since my nipples were on the bar, I could rest my hands comfortably right next to the stem.

I pretty quickly noticed that my max speed on a frequent 12% descent had improved by 1.5 mph. And it was all because of those wheels.

I bought them to fix flexy flat tire feel, and they did it wonderfully until I cracked the freehub body. But that is a different story.

Looigi 01-04-14 09:15 AM

Quote:

Originally Posted by Sixty Fiver (Post 16381396)
The best place to improve one's bicycle is to improve the wheels and tyres to reduce unsprung weight...

It's all "unsprung" if there's no suspension.

rpenmanparker 01-04-14 09:17 AM

Quote:

Originally Posted by WhyFi (Post 16381703)
DAMN! How could I have forgotten about that source of free energy?!

I know, huh!

lsberrios1 01-04-14 09:21 AM

Quote:

Originally Posted by Looigi (Post 16381781)
It's all "unsprung" if there's no suspension.

The rider is the only sprung weight in that equation. Good observation, i did not have that in mind. Coming from motorcycles and car forums it's all about unsprung weight. However i do believe that the bike itself acts like a spring all the way down to the contact patch. Reason why stiffer bikes (less springy) make for better and quicker power transfer.

WhyFi 01-04-14 09:53 AM

Bull****tery aside for the moment, I have a not-at-all-thought-out theory that a lot of the sensation of increased speed and nimbleness that many associate with lighters wheels (rims/tires particularly) is because of a diminished gyroscopic effect - this could mean less effort when leaning the bike over in a turn or flicking side-to-side (when sprinting, for instance). This may explain the divide between riders that report a much easier 'spin up' effort and those that are dismissive because of calculations that show spin-up power differences (of a static wheel) that would likely be imperceptible to the rider.

gc3 01-04-14 09:59 AM

^^^^ you're alleging this is "all bull-sh*ttery aside"....? ^^^

WhyFi 01-04-14 10:02 AM

Quote:

Originally Posted by gc3 (Post 16381878)
^^^^ you're alleging this is "all bull-sh*ttery aside"....? ^^^

:roflmao2:

StanSeven 01-04-14 10:09 AM

Quote:

Originally Posted by zymphad (Post 16381285)
Do bike shops let you test wheels?

Mine does. Also twice a year Zipp comes by and brings a lot of wheels to test. You call, make an appointment for testing, bring your bike it and they set you up for one or more tests. They sell a lot from those weekends.

rpenmanparker 01-04-14 10:09 AM

Quote:

Originally Posted by WhyFi (Post 16381866)
Bull****tery aside for the moment, I have a not-at-all-thought-out theory that a lot of the sensation of increased speed and nimbleness that many associate with lighters wheels (rims/tires particularly) is because of a diminished gyroscopic effect - this could mean less effort when leaning the bike over in a turn or flicking side-to-side (when sprinting, for instance). This may explain the divide between riders that report a much easier 'spin up' effort and those that are dismissive because of calculations that show spin-up power differences (of a static wheel) that would likely be imperceptible to the rider.

I like that. There has to be something that gives the impression of speed and nimbleness. Small forces affecting handling could be much more significant than a small weight difference affecting acceleration, even rotating weight.

Smokehouse 01-04-14 10:23 AM

Quote:

Originally Posted by WhyFi (Post 16381866)
Bull****tery aside for the moment, I have a not-at-all-thought-out theory that a lot of the sensation of increased speed and nimbleness that many associate with lighters wheels (rims/tires particularly) is because of a diminished gyroscopic effect - this could mean less effort when leaning the bike over in a turn or flicking side-to-side (when sprinting, for instance). This may explain the divide between riders that report a much easier 'spin up' effort and those that are dismissive because of calculations that show spin-up power differences (of a static wheel) that would likely be imperceptible to the rider.

Hmm…

Some things are hard to explain or prove. I shed nearly a pound switching wheels (1950g vs 1500g). They ride considerably different…it's hard to "put on paper" but the difference is immediate.

I swapped back to my stockers for winter riding and the sluggish, more "clunky" feeling was back. I had forgotten how they felt until I put them back on...

pgjackson 01-04-14 11:04 AM

Quote:

Originally Posted by gc3 (Post 16381144)
It's really all about the decals. deep wheels with big flashy logos just seem to go faster. That's a true fact. I know because i read it on the interwebs a couple of years ago.

If you knew what you were talking about you would know that those stickers create unnecessary drag. The fraction of a mm thickness of the stickers create repeated rotational drag and disrupt the natural airflow around the tire. That could mean the difference between winning and losing. I gained about 1.5 mph by simply removing my stickers. This is science. :thumb:

pgjackson 01-04-14 11:10 AM

Quote:

Originally Posted by SHBR (Post 16381392)

When I really think about it, I bet most non-competitive riders have limiting factors that come into play well before the weight of their wheels.

Whoa...hold on. Reason and logic have no place in this conversation. You will get nowhere with your line of thinking here. Everyone knows that more money means greatly increased speed. That is a fact. Every advertisement in Bicycle Magazine tells us this. You better go out and get your super-light inner tubes and aero seat post or else you just won't be able to hang with the peleton.

gc3 01-04-14 11:15 AM

Quote:

Originally Posted by pgjackson (Post 16382028)
If you knew what you were talking about you would know that those stickers create unnecessary drag. The fraction of a mm thickness of the stickers create repeated rotational drag and disrupt the natural airflow around the tire. That could mean the difference between winning and losing. I gained about 1.5 mph by simply removing my stickers. This is science. :thumb:

wait a minute, wait a minute....flashy big logo decals look cool....if I look cool, I'm much more motivated...If I'm more motivated then I try harder, therefore I go faster....now, THAT'S science...

pgjackson 01-04-14 11:16 AM

Quote:

Originally Posted by WhyFi (Post 16381866)
This may explain the divide between riders that report a much easier 'spin up' effort and those that are dismissive because of calculations that show spin-up power differences (of a static wheel) that would likely be imperceptible to the rider.

Or it could all just be someone desperately wanting to feel the improved effects to justify in his mind his tremendous loss of $$$ on high end wheels. I think they call the the Placebo Effect. Just sayin'.

pgjackson 01-04-14 11:17 AM

Quote:

Originally Posted by gc3 (Post 16382064)
wait a minute, wait a minute....flashy big logo decals look cool....if I look cool, I'm much more motivated...If I'm more motivated then I try harder, therefore I go faster....now, THAT'S science...

Crap. Guess I have to buy new stickers.

WhyFi 01-04-14 11:39 AM

Quote:

Originally Posted by pgjackson (Post 16382068)
Or it could all just be someone desperately wanting to feel the improved effects to justify in his mind his tremendous loss of $$$ on high end wheels. I think they call the the Placebo Effect. Just sayin'.

NSS. I would have thought placebo effect being a potential cause for discrepancy was so obvious that it didn't warrant mentioning. Thanks for demonstrating that the bar is lower than expected.

pgjackson 01-04-14 02:59 PM

Quote:

Originally Posted by WhyFi (Post 16382153)
NSS. I would have thought placebo effect being a potential cause for discrepancy was so obvious that it didn't warrant mentioning. Thanks for demonstrating that the bar is lower than expected.

Awesome.

rpenmanparker 01-04-14 03:53 PM

Wait a minute. I thought Placebo was an opera singer. Placebo Domingo. The Placebo effect: you think you're hearing music, but it is just your imagination because he looks like a singer. Does he cycle too? Big guy!

SHBR 01-04-14 09:01 PM

Quote:

Originally Posted by Smokehouse (Post 16381721)
Off topic…but I don't get that one either. Beginning my "journey" at well over 265lbs, I refused to even think of getting a modern road bike until I could drop weight. I began riding a SL2 Roubaix in 2012 at 200lbs. I bought my Tarmac at 170lbs last winter.

I have dousing who is a large fella…6' 3", 250+. He keeps wanting to get on my bike for a test ride and I won't let him, he gets all offended. I don't have the heart to tell him he's WAY too large for my equipment.

I would have been brutally honest with him and would have said something to the effect of, you break it you buy it.
It depends on how close of friendship you have though.
I found being direct often cuts through the B/S and often earns respect even if they might feel offended at first.

Smokehouse 01-04-14 09:16 PM

Quote:

Originally Posted by SHBR (Post 16383475)
I would have been brutally honest with him and would have said something to the effect of, you break it you buy it.
It depends on how close of friendship you have though.
I found being direct often cuts through the B/S and often earns respect even if they might feel offended at first.

typing on an iPad always gives interesting autocorrects...

I apparently typed "dousing" and meant cousin. My XL cousin wants to get on my bike (he has a domane)...and I tell him no...

lsberrios1 01-04-14 09:21 PM

Quote:

Originally Posted by Smokehouse (Post 16383516)
typing on an iPad always gives interesting autocorrects...

I apparently typed "dousing" and meant cousin. My XL cousin wants to get on my bike (he has a domane)...and I tell him no...

A roubaix can easily carry 250#. Now i dont know about the wheels you have but unless they are high end carbon wheels or low spoke alum it should be fine.

Smokehouse 01-05-14 08:13 AM

Quote:

Originally Posted by lsberrios1 (Post 16383531)
A roubaix can easily carry 250#. Now i dont know about the wheels you have but unless they are high end carbon wheels or low spoke alum it should be fine.

I have a Tarmac Sl2…with a CG-R seat post and ROL Race Sl wheels. Now…I'm not completely sure what the rider weight limit is for the Frame or seat post…but ROL lists the weight limit for those wheels at 210lbs, which my cousin is far beyond.

I'm willing to say he wouldn't crush them…but I'd rather not take a chance.

FatBottomedGirl 01-05-14 12:54 PM

This thread has gotten wildly out of hand.
Although I still find some interesting information.
So thanks for that !!


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