How much faster would I be with better wheels & tires?
05-06-24, 09:11 AM
#76
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So, what I'm gleaning from this discussion is that 1) the answer to the question the OP asked is, "A bit." and 2) the difference in acceleration between the 500g Mavic CXP30 rims that came on my Ritchey and the 425g Velocity Aeroheds I later replaced them with was probably just placebo effect.
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05-06-24, 09:48 AM
#77
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So, what I'm gleaning from this discussion is that 1) the answer to the question the OP asked is, "A bit." and 2) the difference in acceleration between the 500g Mavic CXP30 rims that came on my Ritchey and the 425g Velocity Aeroheds I later replaced them with was probably just placebo effect.
But nice tires and wheels feel nice, so there's that.
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05-06-24, 09:55 AM
#78
Newbie
I've been riding all winter on HardCase Lite R3 tires that came on a Trek I bought last fall with zero flats for 2200+ miles, and I've sure liked the zero flat part as well. I don't ride in the mountains in winter so I figured I'd beat em up on bad roads and see how it went. Didn't care so much about performance off season and they've served their purpose. No, they're not supple and I wouldn't want to ride anything challenging at all on them and I'll lose them going into summer. I had similar tires on a different Trek a few years ago and knew on my first ride down a mountain they had to go straight away. So anyway I have recent experience with similar tires
You're gonna flat more regularly. Period. I usually ride GP5s in winter and don't get many but some
Pretty sure your tires are around twice as heavy as a better performing choice, so you'll immediately lose about a pound from your wheels. It's gonna feel different and better whether or not you're faster, and it'll handle way better when you need it
I replaced my last stock wheels because they weren't stiff enough for me, but I'm going to replace the ones on the new Trek because they're just too heavy and narrow. Unsure about the faster part, but if you go aero they'll definitely look cooler
You're gonna flat more regularly. Period. I usually ride GP5s in winter and don't get many but some
Pretty sure your tires are around twice as heavy as a better performing choice, so you'll immediately lose about a pound from your wheels. It's gonna feel different and better whether or not you're faster, and it'll handle way better when you need it
I replaced my last stock wheels because they weren't stiff enough for me, but I'm going to replace the ones on the new Trek because they're just too heavy and narrow. Unsure about the faster part, but if you go aero they'll definitely look cooler
I just buiilt up a Gary Fisher Rail Super frame w/identical mechanical Shimano 105, but with Ksyrium SL's (1480 grams/pair claimed weight on Mavic's site) and GP5000's. I noticed right away the Fisher was faster than the Felt and today on the same 20 mile ride with the faster profile averaged 19.8 mph. So in my mind it's the greatly reduced rotational mass coupled with the much lower rolling resistance of the GP5000's. I don't ride in the drops on these rides, but on the hoods, while trying to keep myself as small as possible while staying comfortable.
Someone above mentioned they thought a lighter wheel set coupled with a lower rolling resistance tire could give back around 0.5mph and I think this is probably a good ballpark, but it could even be a little more.
05-06-24, 10:20 AM
#79
Newbie
Wide versus Narrow
Not sure if this will help you decide, but it may be worth considering. The weight of you and your bike combine to slightly flatten the tires where the rubber meets the road. This constantly changing shape is called deflection, which is the main cause of rolling resistance. Since it requires energy to overcome deflection, it makes sense to choose tire width, pressure, casing and tread thickness with care. A general rule of thumb is that wide tires have less rolling friction than narrow tires. The reason is that a wide tire has a wider but shorter contact shape, whereas a narrow tire has a slimmer but longer contact shape.
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05-06-24, 10:40 AM
#81
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This constantly changing shape is called deflection, which is the main cause of rolling resistance. Since it requires energy to overcome deflection, it makes sense to choose tire width, pressure, casing and tread thickness with care. A general rule of thumb is that wide tires have less rolling friction than narrow tires. The reason is that a wide tire has a wider but shorter contact shape, whereas a narrow tire has a slimmer but longer contact shape.
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05-06-24, 10:47 AM
#82
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Would it be correct to summarize posts #75 and #77 by RChung as the changes in rotational inertia of the wheels during acceleration and deceleration largely cancel out on most rides because the wheels act as flywheels? This presumably assumes that one is not slamming on the brakes all the time?
05-06-24, 11:11 AM
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Would it be correct to summarize posts #75 and #77 by RChung as the changes in rotational inertia of the wheels during acceleration and deceleration largely cancel out on most rides because the wheels act as flywheels? This presumably assumes that one is not slamming on the brakes all the time?
20+ years ago, I borrowed a friend's Mavic Cosmic Carbone wheels for a couple of crit races. They were heavy and aero. They felt sluggish to accelerate, but once spinning over 30mph, the flywheel effect was vivid. However, carrying more speed into corners than those around me also meant more time on the brakes.
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05-06-24, 11:12 AM
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Would it be correct to summarize posts #75 and #77 by RChung as the changes in rotational inertia of the wheels during acceleration and deceleration largely cancel out on most rides because the wheels act as flywheels? This presumably assumes that one is not slamming on the brakes all the time?
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05-07-24, 06:08 AM
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Real world - over the same repeatable flat bike path ride - over 300+ rides on this path.
Trek ALR5 with the heavy/shallow stock wheels and Armadillo Elite tires vs Roval C38's and GP5000's.
About .5 mph in all conditions at similar power levels. Most of that speed came from switching to GP5000's, the rest from the wheels.
This translates to about 10-15w in savings at the same speed.
Trek ALR5 with the heavy/shallow stock wheels and Armadillo Elite tires vs Roval C38's and GP5000's.
About .5 mph in all conditions at similar power levels. Most of that speed came from switching to GP5000's, the rest from the wheels.
This translates to about 10-15w in savings at the same speed.
Last edited by Jughed; 05-07-24 at 06:14 AM.
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05-07-24, 06:22 PM
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