Factors Determining Wheel Set Responsiveness

[cd_davis]

My bikes use several wheel sets which are similar in reactivity when climbing a hill or trying not to miss the break:
Mavic Heliums with Michelin Pros
DA 7800 with Hutchinson Fusion 3 clinchers or tubeless
Mavic Kysriums 1st generation with Fusion 3s
Mike Garcia custom with DT Swiss rims and Speedcific (sp?) hubs with Vittoria tires

These wheel sets are close to each other in weight and respond about the same with a slight edge given to the DA 7800 and Heliums.

Also I have Campy Neutron (not Ultra) which are the outlier of the bunch. ~1520 grams these wheels are fitted with Conti Gran Prixs and when you want to go, you feel like the brakes are on or you are riding through mud. It takes awhile for them to spin up. Besides changing out the tires, which I'll do, what other factors could cause this sluggishness? I'm tired of missing the break or crawling up the hills.
Thanks for your advice.

[mwynne]

How are you defining responsiveness?
Engagement? "Spin-up"? (dunno how that would be defined either) Other?

[ripvanrando]

Hills in Newbury port?

Have you tried replacing the Continentals? That is what i would do. 1520 gr is not all that heavy.

I had a brand spanking new Bon Jon that was slow as molasses despite mounting and remounting many times. I replaced it and th bike was like night and day faster.

Try swapping out the tires.

If the wheel spokes are not tensioned properly, I "think" the wheel could feel sluggish upon acceleration.

[mwynne]

Related, I wonder if anyone out there has tested this. In theory it would be too hard to measure a wheel's acceleration under a given load/power from stationary to X RPMs.... If Fairwheel is listening, could be a fun addition to their component testing suite.

[benb]

Rider power output and freshness on a given day.

Tire choice since it sounds like you have different tires on different wheels.

Tire pressure on a given day.

[ergott]

what other factors could cause this sluggishness? I'm tired of missing the break or crawling up the hills.
Thanks for your advice.

The wheels won't make you catch the break other than to give you a placebo effect. The difference in performance from what you have to the best wheels out there are rather small in comparison to things like fitness, rider position on bike, and simply reading the ride/race better.

You can drop serious weight with carbon tubulars. The will feel quicker to spin up. In reality, the drop in weight is about 200g X the two wheels or a pound for simplifying this discussion. If you want to really feel how easy it is to spin up the heaviest wheel, put your bike on a trainer and put it in the hardest/fastest gear. Now pedal the bike without the resistance unit attached to the rear wheel. See how easy that was?

While I know that lighter, snappier wheels do feel faster, they don't really change the clock much. They feel different when you corner. Also they feel like they spin up faster since you are not attached to the bike with rigid, fixed point. That's because the bike under you will move around more when it's really light. It will respond to input quicker, but ultimately you still have to get the rider moving as well and that's where 80% or more of of your energy goes.

[carpediemracing]

TL;DR Check your tires

The somewhat recent Velonews tire rolling resistance test (http://velonews.competitor.com/where-the-rubber-meets-the-road-what-makes-cycling-tires-fast) sparked my interest. Based on Velonews's findings a fast tire can save as much as 10-20 watts per tire at 25 mph, so 20-40 watts total, reducing total power required from 100 watts to just over 60 watts.

That may not seem like a huge savings or huge wattage overall but if you consider that I've placed 3rd in a Cat 3 race averaging under 160w, if I'm using say 120w for my 66 tpi training tires (that would be a super optimistic number based on a "better" tire being rated as using 59w at 40kph), going to one of the fastest tires would bring me down to 62-64w total.

I'd be saving about 60w (at 40 kph) by going to a nicer clincher tire.

If I typically average 160-200w in a race, and I'm using 100-120w to overcome rolling resistance if I'm using my clinchers, then I'm really using say 60-100w to overcome air resistance. The rest of my power output, say 100-120w, is going towards overcoming rolling resistance. If I can reduce that by 60w, that's huge!

So maybe check your tires against that list, and consider installing one of the faster tires on whatever wheels you want to use.

[oldpotatoe]

The wheels won't make you catch the break other than to give you a placebo effect. The difference in performance from what you have to the best wheels out there are rather small in comparison to things like fitness, rider position on bike, and simply reading the ride/race better.

You can drop serious weight with carbon tubulars. The will feel quicker to spin up. In reality, the drop in weight is about 200g X the two wheels or a pound for simplifying this discussion. If you want to really feel how easy it is to spin up the heaviest wheel, put your bike on a trainer and put it in the hardest/fastest gear. Now pedal the bike without the resistance unit attached to the rear wheel. See how easy that was?

While I know that lighter, snappier wheels do feel faster, they don't really change the clock much. They feel different when you corner. Also they feel like they spin up faster since you are not attached to the bike with rigid, fixed point. That's because the bike under you will move around more when it's really light. It will respond to input quicker, but ultimately you still have to get the rider moving as well and that's where 80% or more of of your energy goes.

What he said....'or more'...

[cd_davis]

Thanks to all for your comments. The sluggishness of the Campy wheels is there regardless of my condition or fitness. As the wheels are true, the spokes properly tensioned, and the gearing the same on all bikes (39/53, 12-25)the only recource is to swap out the tires. Before every ride, I inflate the tires to ~105 psi, so everything else for the most part is consistent.
We'll see how that works.
Safe riding!

[Fatty]

Do some in house tire swaps. If the Helium's feel fastest with the Michelin Pros put those ties on the Campy wheel set and see what the results are.