Fifty Plus (50+) - Feeling the weight of new tires, maybe.

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alexdrozd
06-07-12, 10:24 AM
I just changed the Continental GP4000 700 x 25 tires on my Giant FCR1 for Continental Gatorskin 700 x 28 tires for a "better" ride. Am I crazy or should the 145 gram difference (215 vs 360) per tire be that noticable? I have not ridden very far yet but they seem slower to me. Not sure if my mind is playing games on me or not. I didn't expect to feel any difference.

What are your thoughts?


NOS88
06-07-12, 10:28 AM
The weight may be noticable, especially during accelerations. Two other things to consider. First you went to a wider tire. Second I believe the Gatorskins are a stiffer feeling tire thant the GP4000. All of this might contribute to a sense of being slower.

OldsCOOL
06-07-12, 10:35 AM
I could easily feel the difference (on 2 occasions this season) when changing over from Bontrager B's 25mm to Michelin Krylion 700x23s. Both bikes are very responsive. And in reverse manner, when I changed from a racing Vredestein 23 with folding bead and put on new Bontrager B's in 25....that first ride I knew it was a bad choice.

Yes, you can feel it.


BikeWNC
06-07-12, 10:37 AM
I would find the weight difference very noticeable. You've added about 2/3 of a pound of rotating weight to the bike. Also, the wider tires can feel a little vague compared to 25s which might feel slower, whether it actually is or not.

Barrettscv
06-07-12, 10:37 AM
The weight may be noticable, especially during accelerations. Two other things to consider. First you went to a wider tire. Second I believe the Gatorskins are a stiffer feeling tire thant the GP4000. All of this might contribute to a sense of being slower.

+1

When I switched from 700x28 Gatorskins to 700x24 Grand Prix, I noticed easier rolling and a smoother ride. Not much, but noticeable.

Alex, What air pressures have you tried? Sometimes less is better when using 700x28 Gatorskins.

curdog
06-07-12, 10:39 AM
I don't think the speed difference is significant, but in my opinion the Gatorskins have a much hasher ride.

Hairy Hands
06-07-12, 10:56 AM
Lots of testing has been done that seems to indicate that a rider cannot actually tell a rolling resistance difference. Its seems that the harder the tire is pumped up the higher frequency vibrations the rider feels which transfers into the rider thinking he is faster. Wider tires usually require lower pressure and thus lower frequency vibrations making the rider think he is slower when he is not. The weight difference will definitely effect acceleration, but should help when maintaining a steady speed on the flats. Also, there is much to be said about the flexibility/suppleness of a tires sidewall which will also affect the riders perception of speed.

GFish
06-07-12, 12:39 PM
Lots of testing has been done that seems to indicate that a rider cannot actually tell a rolling resistance difference. Its seems that the harder the tire is pumped up the higher frequency vibrations the rider feels which transfers into the rider thinking he is faster. Wider tires usually require lower pressure and thus lower frequency vibrations making the rider think he is slower when he is not. The weight difference will definitely effect acceleration, but should help when maintaining a steady speed on the flats. Also, there is much to be said about the flexibility/suppleness of a tires sidewall which will also affect the riders perception of speed.

Then this is my problem, the mind is playing tricks on me. :eek:

Last summer, had Continental Ultra Sports 700x25 at 330g on the bike. For the winter, switched over to Continental Gatorskins 700x28.

From I've read, people recommended lower air pressure with 28's. I started at 90psi front, and 95psi rear. The bike felt slow, like pushing into a constant headwind. My perceived effort also felt harder while trying to maintain speed and cadence that I normally rode at.

My son suggested increasing air pressure, which I did. Increased the front to 105psi, and rear to 115psi. That worked, the bike performed and felt normal again.

I'm riding a steel frame, so I never felt like hand vibration was an issue. I just noticed how much slower the bike was with lower tire pressure. The difference to me, was very noticeable. With low tire pressure, I kept stopping to see if the brakes wear rubbing or something else caught between the frame and wheel.

My suggestion is, to try different air pressures to see if this helps.

Hendo252
06-07-12, 01:34 PM
I hadn't ridden in years... when I got back on the bike earlier this year.

The existing tires were Specialized 23mm that I was inflating to ~120PSI. My weight had ballooned to over 230 lb and the ride was atrocious.

Old steel-framed Trek FWIW. But between my weight and the hard tires it was very uncomfortable.

I faced reality and retired the 23mm and moved to 28mm Gatorskins. Still using high pressure -- 110 PSI F&R.

Still pretty harsh ride.

Then I read an article linked from BF that provided guidance for inflation based on tire size and total weight (bike + rider + cargo). That pointed me to ~80 PSI front, ~95 PSI.

MUCH better ride. My weight has been steadily dropping and I'm sure that helps too, but I think proper pressure is the biggest factor.

Here's the link:
http://www.bikequarterly.com/images/TireDrop.pdf

-Tom in SoCal

CraigB
06-07-12, 01:40 PM
I swapped out wheelsets a couple of weeks ago and I swear I feel a difference. How much is attributable to wheels and how much to tires (and, for that matter, how much to imagination) I can't say, but the new setup (Neuvation M28X Aeros with Vittoria Rubino 23s) feels quicker and smoother than the old (OEM Shimano RS10 with Schwalbe Lugano 25s).

Shimagnolo
06-07-12, 01:46 PM
I just changed the Continental GP4000 700 x 25 tires on my Giant FCR1 for Continental Gatorskin 700 x 28 tires for a "better" ride. Am I crazy or should the 145 gram difference (215 vs 360) per tire be that noticable? I have not ridden very far yet but they seem slower to me. Not sure if my mind is playing games on me or not. I didn't expect to feel any difference.

What are your thoughts?

I have GP4000 700 x 25 on an 18 pound bike, and Gatorskin 700 x 28 on a 20 pound bike.
I like the latter so much better than the former, that I will probably eventually have the Gator 28's on both bikes.

David Bierbaum
06-07-12, 02:34 PM
700x38 Maxxis Overdrive tires for me, at 50lb pressure. Comfort before all, for me! :)

Wildwood
06-07-12, 03:53 PM
I don't think the speed difference is significant, but in my opinion the Gatorskins have a much hasher ride.

+1
Gatorskins suck as far as a smooth ride. Great commuter tire.
Go tubular - less weight, smoother ride, period.

fietsbob
06-07-12, 04:09 PM
Put in thorn resistant tubes, in my bike friday's wheels. front one I did not notice,
rear one I did, but after a while , pumped up hard, I stopped noticing.

Ran TR tubes in my 622-40 wheels on my touring rig,
they let me know when the PSI needed to be topped off..
rolling resistance increased..

But I rode from South- west Eire , to NE Scotland on a 6 month trip
[Lots of dawdling, Pub Jams to sit in on , etc. ], with out a Flat.

Timtruro
06-07-12, 04:24 PM
Not sure that the added weight is the issue, but the wider tires mean more rubber on the road, thus more friction, then add lower tire pressure you are going to go slower.

Mobile 155
06-07-12, 04:37 PM
I don't notice much difference between 23s and 25s but I haven't tried them using the same tire. Gatorskin, 4000, Seca, Pro slick or whatever. But once I get to 28 I notice. In my case a the weight of the 28 would be close to 400 grams more. The one time I tried 28s I found them slower to get going, slower to close when a gap developes and slower up hill. But yes smoother. I also found it was harder to get to max speed with the 28s. But that was because I was trying to keep pace with several roadies.

alexdrozd
06-08-12, 09:51 AM
Thanks for all the replies. I have learned a lot in the responses.

Hermes
06-08-12, 10:24 AM
There are several factors that determine tire performance. A wider tire typically, has more aero drag. Wider tires may offer lower rolling resistance that narrower tires but this has a lot to do with road conditions. If a tire is skipping on the road surface, frictional forces go up. Once a wheel is rolling at constant speed, weight is negligible for the purposes of how much power is required to keep it going. So the physics are clear but knowing how a tire is performing in the moment is difficult to determine.

I like narrower tires that match the width of the rim (better aero performance) and lower tire pressure for lower rolling resistance but enough to prevent pinch flats. If the road surface is rough, then a wider tire will work better with less rolling resistance.

Having said all that, cyclists are very sensitive to feel. Just as better golfers can feel the difference in clubs. So if it feels better and faster damn the physics and ride what feels good.

Retro Grouch
06-08-12, 10:41 AM
Having said all that, cyclists are very sensitive to feel. Just as better golfers can feel the difference in clubs. So if it feels better and faster damn the physics and ride what feels good.

I think so too.

A heavier tire might not make very much difference once you get it up to speed, but every ride starts at 0 MPH. Even if it has zero effect on a 30 mile ride, your first impression, what you feel as you initially accelerate up to 15 MPH or so, is likely to stick with you.

GFish
06-08-12, 12:07 PM
Once a wheel is rolling at constant speed, weight is negligible for the purposes of how much power is required to keep it going.
Isn't that the key, that "constant speed' is elusive. With all the variables encountered in road cycling, people are constantly adjusting their power output. Essentially, starting and re-starting.

Over the course of a 50 mile ride in changing terrain, I wonder how much difference lighter weight wheels and tires would help reduce energy expenditure. There must be something to it, otherwise why would people buy expensive wheels and tires.

Shimagnolo
06-08-12, 01:02 PM
There must be something to it, otherwise why would people buy expensive wheels and tires.

Why do audiophiles pay exorbitant prices for Monster cables?
Don't assume there is a cost/benefit analysis behind something just because some people do it.

jppe
06-08-12, 01:13 PM
I just changed the Continental GP4000 700 x 25 tires on my Giant FCR1 for Continental Gatorskin 700 x 28 tires for a "better" ride. Am I crazy or should the 145 gram difference (215 vs 360) per tire be that noticable? I have not ridden very far yet but they seem slower to me. Not sure if my mind is playing games on me or not. I didn't expect to feel any difference.

What are your thoughts?

They would be slower on accelerations, going up hills etc. That is a lot of weight difference for each tire....If you don't mind a heaver tire you might check our Vredesteins in a 25. They have a little wider footprint but should have a smoother ride at much less weight than the 28's. You can generally get them pretty cheaply as well with a little shopping.

Racer Ex
06-08-12, 01:58 PM
Gatorskins roll like carp.

They are also as tough as carp.

If you want to improve the ride quality and have a few extra bucks, go with latex tubes. And you can run a bit lower pressure with the 28's.

Hermes
06-08-12, 02:03 PM
Isn't that the key, that "constant speed' is elusive. With all the variables encountered in road cycling, people are constantly adjusting their power output. Essentially, starting and re-starting.

Over the course of a 50 mile ride in changing terrain, I wonder how much difference lighter weight wheels and tires would help reduce energy expenditure. There must be something to it, otherwise why would people buy expensive wheels and tires.

IMO, this is a tricky area. For example, I purchased a front disc for racing at the indoor velodrome. Front discs are faster than a trispoke or pentaspoke but also heavier. When I tried the wheel for the first time, the thing in noticed was that I maintained speed easier. The theory is more rotating inertia and better aerodynamics. One can argue that the indoor track is an ideal condition and on the road a heavier wheel is worse. I think it depends on the road and wind conditions.

Cyclists buy lighter wheels to improve climbing performance and trade off having a heavier wheel for better aerodynamic performance. Aerodynamic carbon wheels are more expensive. Typically, the break point for club riders is 5% grade. That is a heavier more aero wheel will outperform a traditional but lighter wheel on grades below 5% and one gets the aero benefit all the time. Above 5%, weight is more important. For pros the break point is 8%. They climb faster.

Racer Ex
06-08-12, 02:21 PM
IMO, this is a tricky area. For example, I purchased a front disc for racing at the indoor velodrome. Front discs are faster than a trispoke or pentaspoke but also heavier.

Here's where it get fun.

A spoked front wheel (or a tri spoke) will sometimes return a better CdA number than a front disc. Yet the disc will return a better w/kmh number because it has a much less rotational drag.

Unless you put a Gatorskin on there. Then it'll roll like carp.

stapfam
06-08-12, 11:53 PM
I run Michelin PR2/3's in 23 on all my bikes. I have one set of winter/foul weather wheels with Lithions in 23 fitted and they are fractionally heavier but so are the wheels. I do notice the difference with the Lithions but that is probably down to the Quality of rubber and wheel.

But I changed over to the PR2's many years ago from the original of Kenda's in 26 size. They were heavy and did not grip and there was a difference. My son-in-Law needed new tyres and I gave the Kenda's to him as they had plenty of life left in them. Within a week he had returned them as it took him a good few minutes and some extra energy to do his 10 mile commute.

ThatBritBloke
06-09-12, 05:05 AM
This (http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/)is an interesting article:

http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/

255066

http://www.wheelenergy.com/

qcpmsame
06-09-12, 08:09 AM
BritBloke,
Thanks for the links, they have some good data and info in them. Food for thought, I had read an article about the wider tire and its benefits. A bit more research for me but I'll probably go the wider rim route next wheel set. Appreciate the time and efforts.

Bill

Shimagnolo
06-09-12, 08:20 AM
This (http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/)is an interesting article:

http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/

255066

http://www.wheelenergy.com/

They have been mentioned here before, but still no one has seen their actual test results.

GeoKrpan
06-09-12, 09:25 AM
Thanks for that link.


This (http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/)is an interesting article:

http://www.bikeradar.com/gear/article/bicycle-tires-puncturing-the-myths-29245/

255066

http://www.wheelenergy.com/

GeoKrpan
06-09-12, 09:37 AM
The advantage of fatter tires, if they are not over inflated, is ride quality.
They absorb the vibrations so your body does not have to.
Over the length of a ride those vibes will wear you out more than the extra energy required to get fatter tires rolling.

Hermes
06-09-12, 09:41 AM
Nothing beats your own testing. It is very possible to test and measure variables that affect bicycle performance using a power meter and a stop watch. If one cannot measure it, it may be too small to make a difference. There are also coast down tests that can be useful. And there is qualitative logic that relies on basis physics. IMO, the "normal" / "regular" cyclist has a lot of tools to work with that can be coupled with work published by wheel energy.