How much slower can crappy tires slow you down compared to nice tires? Let's so over 20 miles. 1mph, 0.5 mph, more, less?
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Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
No hard data to hand, but I have seen tests before where the slower tyres required >10W extra per tyre to roll at typical riding speeds when compared to quicker tyres.
20W at cruising speeds is significant.
20W at cruising speeds is significant.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
Somewhere in-between a lot and a bunch.
Re: How much can crappy tires slow you down? [Zenmaster28]
[ In reply to ]
Zenmaster28 wrote:
Somewhere in-between a lot and a bunch.Good to know. I always thought the answer was "plenty".
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I run Vittoria Rubino's with standard butyl tires for training and Conti GP Attack/Force with latex tubes for races. It is a world of difference. I cannot give you a definite number in terms of speed but just holding the tires in your hand you can feel how rigid and tough the Rubino's are whereas the Conti's are much more pliable and much easier to mount. Probably also doesn't help the Rubino's having a metal wire running through it and the Conti's are folding tires. Ride quality is very different, much smoother and that alone makes me "feel" faster, and therefore worth it to me ;) (how much of this is attributed to latex vs the nicer tires, I cannot say). I run them at the same tire pressure and on the same wheels so that is a constant.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
Here's a table of Crr's from 2010: http://www.biketechreview.com/...ire_testing_rev9.pdf
The best in that table was 0.00220
The worst in the main table was 0.00448.
Rolling resistance force is <your mass in kg> * Crr * 9.81
Rolling resistance power loss is <your speed in m/s> * <your mass in kg> * Crr * 9.81
So for a 85kg bike+rider @ 25mph:
The best tire would take 20.3W to keep rolling.
The worst tire would take 41.5W.
A 20W loss is pretty substantial.
"How would it affect you over 20 miles?"
We can figure this out by looking at how much energy your tires waste over 20 miles, which is actually completely constant and not affected by your speed.
Work = Force * Distance
Force = <your mass in kg> * Crr * 9.81 = 1.83N or 3.73N
Work needed = <force> * <distance = 20 miles> = 58.8kJ or 120.0kJ
So the amount of time added would completely depend on your actual power output. The worse tire would require 61 extra kJ of work to be done to keep those tires turning. At 300W, that'd add 3m 20s to your ride. Which seems high, so feel free to find an error in my calculations.
That table, though, seems confined to plausible race tires. I imagine gatorskins or cheapo no-name tires could be even worse.
STAC Zero Trainer - Zero noise, zero tire contact, zero moving parts. Suffer in Silence starting fall 2016
The best in that table was 0.00220
The worst in the main table was 0.00448.
Rolling resistance force is <your mass in kg> * Crr * 9.81
Rolling resistance power loss is <your speed in m/s> * <your mass in kg> * Crr * 9.81
So for a 85kg bike+rider @ 25mph:
The best tire would take 20.3W to keep rolling.
The worst tire would take 41.5W.
A 20W loss is pretty substantial.
"How would it affect you over 20 miles?"
We can figure this out by looking at how much energy your tires waste over 20 miles, which is actually completely constant and not affected by your speed.
Work = Force * Distance
Force = <your mass in kg> * Crr * 9.81 = 1.83N or 3.73N
Work needed = <force> * <distance = 20 miles> = 58.8kJ or 120.0kJ
So the amount of time added would completely depend on your actual power output. The worse tire would require 61 extra kJ of work to be done to keep those tires turning. At 300W, that'd add 3m 20s to your ride. Which seems high, so feel free to find an error in my calculations.
That table, though, seems confined to plausible race tires. I imagine gatorskins or cheapo no-name tires could be even worse.
STAC Zero Trainer - Zero noise, zero tire contact, zero moving parts. Suffer in Silence starting fall 2016
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I can't tell you from first hand experience from when I started training for my first Tri I bought a used older road bike a few years ago that was steel framed, downtube shifters, quill stem and some crappy tires. Already knew the tires were worn out but they finally called it quits after a few rides. I then bought brand new GP 4 Seasons in a 25mm (same sized tire as what was already on there). The next ride the difference in feel and speed was night and day with my average pace increasing by about 0.75mph for the ride (similar route but a mile longer than the previous ride).
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
The rule of thumb is 50g aero drag = 5w = 0.5sec/km. 20miles = ~32km. It's not inconceivable to see a 20w delta between slow tires and butyl tubes and fast tires with latex tubes so ~64seconds over 20miles.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
TRIDAVID2 wrote:
How much slower can crappy tires slow you down compared to nice tires? Let's so over 20 miles. 1mph, 0.5 mph, more, less?Run the wheels that came with your bike until they're worn out. Spend the money and get a nice set of tires, GP4000S or similar
By the time you wear out your stock tires, you'll have an idea of how long it takes you to do a handful of various distance loops around your area. See if that time doesn't stay slightly to noticeably lower when you switch to good tires.
If you want to see something even further, start using latex tubes when you switch to the good tires.
No, this isn't perfect but over two/three dozen rides you'll get an idea no matter what the temp and weather differences are.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I understand there were no finishers at Kona until tires really stepped up their game.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I think the Crr chart is a load of nothing, but if you select the right class of tire for your application, then that is most important thing. Ride with what feels good and reputation/feedback from users.
A fresh road race tire will feel fast and be fast, no question. Track tires are thin suckers, TT are a tad thicker, then road race are more built up. Training tires are heavier and the compounds & construct tend to be less supple. I rarely ride cheapo training tires too harsh.
Up the protective layers the tire starts to slow down just a bit.
Aero rider-induced drag is the wall you are going to hit and the difference in Crr between two quality race tires is really minuscule. During my rolling tests between 3 high-end tire combos was no difference and between a stock road bike there wasn't that much difference either.
Bottom line I am deciding based on what gives the best feeling ride & cornering, no other aspect. Veleoflex isn't mentioned much on here but considering their noticeable use in the pro ranks ...not sure why.
Training Tweets: https://twitter.com/Jagersport_com
FM Sports: http://fluidmotionsports.com
A fresh road race tire will feel fast and be fast, no question. Track tires are thin suckers, TT are a tad thicker, then road race are more built up. Training tires are heavier and the compounds & construct tend to be less supple. I rarely ride cheapo training tires too harsh.
Up the protective layers the tire starts to slow down just a bit.
Aero rider-induced drag is the wall you are going to hit and the difference in Crr between two quality race tires is really minuscule. During my rolling tests between 3 high-end tire combos was no difference and between a stock road bike there wasn't that much difference either.
Bottom line I am deciding based on what gives the best feeling ride & cornering, no other aspect. Veleoflex isn't mentioned much on here but considering their noticeable use in the pro ranks ...not sure why.
Training Tweets: https://twitter.com/Jagersport_com
FM Sports: http://fluidmotionsports.com
Re: How much can crappy tires slow you down? [AHare]
[ In reply to ]
AHare wrote:
Here's a table of Crr's from 2010: http://www.biketechreview.com/...ire_testing_rev9.pdf The best in that table was 0.00220
The worst in the main table was 0.00448.
Rolling resistance force is <your mass in kg> * Crr * 9.81
Rolling resistance power loss is <your speed in m/s> * <your mass in kg> * Crr * 9.81
So for a 85kg bike+rider @ 25mph:
The best tire would take 20.3W to keep rolling.
The worst tire would take 41.5W.
A 20W loss is pretty substantial.
"How would it affect you over 20 miles?"
We can figure this out by looking at how much energy your tires waste over 20 miles, which is actually completely constant and not affected by your speed.
Work = Force * Distance
Force = <your mass in kg> * Crr * 9.81 = 1.83N or 3.73N
Work needed = <force> * <distance = 20 miles> = 58.8kJ or 120.0kJ
So the amount of time added would completely depend on your actual power output. The worse tire would require 61 extra kJ of work to be done to keep those tires turning. At 300W, that'd add 3m 20s to your ride. Which seems high, so feel free to find an error in my calculations.
That table, though, seems confined to plausible race tires. I imagine gatorskins or cheapo no-name tires could be even worse.
Guess if my tires aren't on this list, I'm pretty much F'ed? That's OK, I catch you aero-geeks on the run anyway.
Re: How much can crappy tires slow you down? [Danielg]
[ In reply to ]
I don't get why latex vs. Butyl makes so much a difference. Care to explain? I'm genuinely unsure and want to know.
Re: How much can crappy tires slow you down? [littlefoot]
[ In reply to ]
littlefoot wrote:
I don't get why latex vs. Butyl makes so much a difference. Care to explain? I'm genuinely unsure and want to know.Read this to understand what affects rolling resistance: http://www.slowtwitch.com/...ling_events_226.html
Then, this for tube specific info: http://www.slowtwitch.com/...in_a_tube__1034.html
http://bikeblather.blogspot.com/
Re: How much can crappy tires slow you down? [Tom A.]
[ In reply to ]
I'm very doubtful on this since I haven't found any but do you know of any data for Maxxis (campione and forza) tubulars? I don't have a choice on the tire that I ride but maybe I can put it into terms that the team will understand.
Re: How much can crappy tires slow you down? [Ohio_Roadie]
[ In reply to ]
Swapped from vittoria zaffiro pro to schwalbe one, it felt like a new bike. Faster and more comfortable, and I got my first KOM...
Re: How much can crappy tires slow you down? [Ohio_Roadie]
[ In reply to ]
Ohio_Roadie wrote:
I'm very doubtful on this since I haven't found any but do you know of any data for Maxxis (campione and forza) tubulars? I don't have a choice on the tire that I ride but maybe I can put it into terms that the team will understand.Easiest thing to do to figure this out is to ride them on rollers back-to-back at the same speed and observe power. The rollers act as "Crr amplifiers" and with, for example, 4.5" diameter rollers, the "on road" power difference for a pair will be ~1/3 of what you observe on the rollers (assuming rollers front and rear - no fork stand).
http://bikeblather.blogspot.com/
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I no longer have the data but I remember the original Armadillo tires required an extra 30-40W at typical flat terrain speeds. Newer and/or lighter Armadillo variants were a bit faster but couldn't reliably stop goatheads.
Re: How much can crappy tires slow you down? [Sausagetail]
[ In reply to ]
Sausagetail wrote:
I no longer have the data but I remember the original Armadillo tires required an extra 30-40W at typical flat terrain speeds. Newer and/or lighter Armadillo variants were a bit faster but couldn't reliably stop goatheads.Cool, glad it was not all in my head.
.
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Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
For a while I was using the bontrager version of gator skins and then went to pro3s on my training wheels. It was close to a 1 mph difference.
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
I don't run with power yet but I just did a similar test. I will put as much information that I have here. The past 3 Sunday's I have ridden the same route. 15 miles with elevation gain 535 feet, elevation loss 554 feet. 100 psi. Garmin 920xt.
First ride was stock aluminum wheels (Specialized DT Axis 2.0) with stock tires (Specialized Turbo Elite)
0630am, 65°, average mph 19.7, max mph 30.6
5 miles 20.0 mph, 15:02 min.
5 miles 20.4, 14:43
5 miles 19.0, 15:48
Second ride was Reynolds Aero wheels 72mm with same stock tires;
0630am, 55°, average mph 20.1, max mph 32.3
5 miles 19.0 mph, 15:47 min.
5 miles 21.0, 14:17
5 miles 20.5, 14:38
Third ride was Reynolds Aero wheels 72mm with Continental GP4000 ii;
0630am, 65°, average mph 21.2, max mph 35
5 miles 21.1 mph, 14:12 min.
5 miles 21.2, 14:08
5 miles 21.5, 13:58
On the second ride I did go out a little easy on the first 5 miles because I have never ridden deep wheels and I had already blew out a tube (pinched and scared the shit out of me).
Edited to add times to 5 mile intervals.
http://www.sfuelsgolonger.com
First ride was stock aluminum wheels (Specialized DT Axis 2.0) with stock tires (Specialized Turbo Elite)
0630am, 65°, average mph 19.7, max mph 30.6
5 miles 20.0 mph, 15:02 min.
5 miles 20.4, 14:43
5 miles 19.0, 15:48
Second ride was Reynolds Aero wheels 72mm with same stock tires;
0630am, 55°, average mph 20.1, max mph 32.3
5 miles 19.0 mph, 15:47 min.
5 miles 21.0, 14:17
5 miles 20.5, 14:38
Third ride was Reynolds Aero wheels 72mm with Continental GP4000 ii;
0630am, 65°, average mph 21.2, max mph 35
5 miles 21.1 mph, 14:12 min.
5 miles 21.2, 14:08
5 miles 21.5, 13:58
On the second ride I did go out a little easy on the first 5 miles because I have never ridden deep wheels and I had already blew out a tube (pinched and scared the shit out of me).
Edited to add times to 5 mile intervals.
http://www.sfuelsgolonger.com
Last edited by:
hickorynotch: May 10, 15 10:34
Re: How much can crappy tires slow you down? [superdea]
[ In reply to ]
agreed that those zaffiro's are beasts. they make gatorskins feel like velvet. good trainer tire though.
Re: How much can crappy tires slow you down? [triordie1994]
[ In reply to ]
well i guess the jury's out. just ordered new Continental Grand Prix and my Gatorskins will be banished to the trainer
Re: How much can crappy tires slow you down? [TRIDAVID2]
[ In reply to ]
TRIDAVID2 wrote:
How much slower can crappy tires slow you down compared to nice tires? Let's so over 20 miles. 1mph, 0.5 mph, more, less?depends on how long it takes you to fix a flat. that's a very personal thing, and quite a big variable.
but no tire is as crappy as a tire that flats too easily.
This is true, but I ran Vittoria Evo Corsa's with latex tubes for years and never had a flat in racing.
You cant get a much thinner tire with zero flat protection than that.
Only reason I changed was they suck pretty bad in the wet and by the time they wore out to the point that they may indeed flat, GP4000's was found to be faster up front anyway.
You cant get a much thinner tire with zero flat protection than that.
Only reason I changed was they suck pretty bad in the wet and by the time they wore out to the point that they may indeed flat, GP4000's was found to be faster up front anyway.