Author Topic: 26" v. 700...again  (Read 1695 times)

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Offline TwoWheeledExplorer

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26" v. 700...again
« on: June 28, 2011, 09:07:35 pm »
Very simple question: Is it actually harder to pedal a bike with 26" (Conti T&Cs) than 700s, or is it just me? I have been riding my Safari for the past week and it just seems like a whole lot more work than the Volpe. (w/Schwalbe Marathon HRs) ??? I know I am not back in shape yet, due to my TBI recovery that took 9 weeks out of my ride schedule, but... Both sets of tires are inflated to optimal pressure, riding both on long stretches of new "road candy" asphalt.

Or am I just getting wimpy?  ::)

Ride safe,
Hans
The Two-Wheeled Explorer: Ride the River
www.twowheeledexplorer.org
"Every person has a river to ride...you are to Ride the River."--Pr. Larry Christenson

Offline driftlessregion

Re: 26" v. 700...again
« Reply #1 on: June 28, 2011, 11:03:34 pm »
Hard to compare since there is about 4# difference in the weight of the two bikes isn't there?

Nine weeks recovery for a TBI; not bad. Keep riding; there is no doubt it will do you good and get you well!
Best wishes.

Offline DaveB

Re: 26" v. 700...again
« Reply #2 on: June 29, 2011, 08:13:43 am »
26xwhat and 700xwhat?  If the tires are about the same width, the same weight and inflated to about the same pressure, the rolling resistance should be similar.  If the 26" tires are wider, heavier and at lower pressure, they will have more resistance.  Also, are the wheels and rims similar in width and weight?  They could effect your perceived effort too.

Offline ChromolyWally

Re: 26" v. 700...again
« Reply #3 on: June 29, 2011, 02:47:12 pm »
Very simple question: Is it actually harder to pedal a bike with 26" (Conti T&Cs) than 700s, or is it just me? I have been riding my Safari for the past week and it just seems like a whole lot more work than the Volpe. (w/Schwalbe Marathon HRs) ??? I know I am not back in shape yet, due to my TBI recovery that took 9 weeks out of my ride schedule, but... Both sets of tires are inflated to optimal pressure, riding both on long stretches of new "road candy" asphalt.

Or am I just getting wimpy?  ::)

Ride safe,
Hans

Actually it's not a simple question at all.  It's not just the tires that are different, it's the entire bike.   Even when you're just comparing different tires, it's not so straightforward.  According to Wheel Energy, for example, a wider tire does not necessarily have more rolling resistance than a narrower one.  In many cases, just the opposite is true.

"...the key to reducing rolling resistance is minimizing the energy lost to casing deformation..."

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

Offline TwoWheeledExplorer

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Re: 26" v. 700...again
« Reply #4 on: June 29, 2011, 03:07:20 pm »
Well, my physical therapist may have hit the nail on the head: It's not about the bike (or the tires). It is a combination of physical symptoms from the ongoing TBI recovery coupled with a bout with Lyme Disease, for which I am still on medication. (It has not been a great spring for me.) She said that even though I feel better, it is going to take a while to recover my stamina and endurance.

Duh!  ::) I've been a Wilderness EMT for 30+ years. I should have thought about that part. And yes, for the moment, I am wimpy.  ;) This too shall pass.

Thanks,
Hans
The Two-Wheeled Explorer: Ride the River
www.twowheeledexplorer.org
"Every person has a river to ride...you are to Ride the River."--Pr. Larry Christenson

Offline whittierider

Re: 26" v. 700...again
« Reply #5 on: June 29, 2011, 04:37:06 pm »
ChromolyWally, that link should do a lot to dispell myths.  I think it does a better job of explaining than http://www.rouesartisanales.com/article-1503651.html does, although that's a good one too.  The only problem I see in the bikeradar.com article is what many of the commenters wrote, about the fact that 25% more rolling resistance and 25% slower are two very different things and the latter term was misapplied.

Quote
"...the key to reducing rolling resistance is minimizing the energy lost to casing deformation..."

What was not pointed out is that a narrower tire's casing has to deform at a sharper angle at the edge of the contact patch, which is why the narrower one has more rolling resistance (ie, consumes more energy) compared to a wider one if both are at their max pressure or the same percentage of it, all other factors being equal.  Unfortunately the best-performing tires are not made in widths above about 25mm.  It would be nice if the same construction and quality were carried into tires of at least 28mm, especially for tandems where wanting a bigger tire doesn't mean you'll be going off road.  The article did allude to the fact that a thinner tube reduces rolling resistance because there's less rubber to deform.  I've been using Performance's ultra-thin 49-gram LunarLite tubes for this reason (not particularly to reduce weight).  I don't get any additional flats, they're just as easy to patch, and spares take less room in your bag.  (Just keep it in a ziploc-type snack bag with plenty of talc.)

There are several web pages comparing the rolling resistance of various tires, but they don't get updated as often as they should.  One I like but I wish they tested a lot more tires is this one.  Continental definitely did a lot of things right in that GP4000 which took the gold.  Besides being a hot performer in rolling resistance, it is the best tire I've ever had for puncture resistance and life as well.  It has a combination of strengths that was previously impossible.  Who would have thought I could get more than 4,000 miles on the rear with one of the greatest racing tire and still pull a box staple out of it and not have to fix a flat because it did not penetrate the vectran breaker layer!

Offline TCS

Re: 26" v. 700...again
« Reply #6 on: July 05, 2011, 10:22:40 am »
Try replacing your Conti T&Cs with tires like the Schwalbe Kojak folding, Avocet FasGrip City Carbon 12, Specialized FatBoy or Continental SportContact, all in the 32/35mm width.  All have finer carcass construction, much lighter weights and smoother treads than your present Conti Town+Country tires.  And mate them with some quality, light tubes like the Maxxis Flyweight.
"My name is Pither.  I am at present on a cycling tour of the North Cornwall area taking in Bude and..."

Offline TwoWheeledExplorer

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Re: 26" v. 700...again
« Reply #7 on: July 08, 2011, 11:00:58 am »
It was me all along. Finished the course of antibiotics for the Lyme disease and was feeling stronger with each day. Did a rec. ride on the Safari today (Volpe is in the shop in prep for next week's trip.) and did my fastest average of the season. And I wasn't even pushing it...until I passed the garbage truck and had to stay ahead of him for a quarter-mile!  :o

Thanks for you advice!
Hans
The Two-Wheeled Explorer: Ride the River
www.twowheeledexplorer.org
"Every person has a river to ride...you are to Ride the River."--Pr. Larry Christenson

Offline rcrampton

Re: 26" v. 700...again
« Reply #8 on: July 10, 2011, 02:22:47 am »
Kind of obvious, but I've got a safari and I have noticed a big difference in rolling resistance depending on the tire I use.

I also tend to sit up more with the trekking bars than drop bars so my wind resistance is higher which can be a big effect too.

The difference between my Safari with high pressure tires and a 700c road bike is in the noise for me, I'm not that consistent of a rider to really say.

I love my Safari though, perfect bike - it rides well on the road and when the pavement ends I keep going!