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Message started by Bud_Bent on May 10th, 2010, 7:28pm

Title: The Great Wider Tire Rando Experiment
Post by Bud_Bent on May 10th, 2010, 7:28pm

With boulderseal taking over so many of our Texas roads, I decided to try some wider tires for my randonneuring. Wider tires can improve handling and the ride on rough roads a lot. But, I spend so much randonneuring time trying to ride with riders who are faster than me that I didn't want to give up much speed with new tires.

I'm always surprised at how many people dispense tire width advice without even thinking about what kind of bike the target of the advice is riding. When it comes to tire width, all bikes are not created equal. Bikes that put the rider's profile completely above the tires are much more aerodynamically affected by wider tires than bikes that use small front tires and/or put the rider behind the front tire. A wider front tire may not slow down a low racer much, but it can certainly slow down a high racer. And even on my Stratus XP, which has a fairing and has me partially behind the front tire, I could see a very noticeable difference in speed when I ran wider tires. Of course, how much difference tire width makes is the subject of unending debate, and a very individual thing that depends on the rider and the roads ridden. You can do coast down comparisons, but rides are much more than just coasting down hills, so that doesn't really tell you much.

One of the things that finally jogged me into trying wider tires was the thinking held by some that aero wheels, especially wide aero wheels, can help with the aerodynamics of a wider tire, keeping you from losing much speed with them. I already had a set of aero wheels, which I rebuilt for this experiment. I documented rebuilding them in this thread (http://rbentonline.org/YaBB.pl?num=1261883571). Most riders don't use their expensive, delicate, low spoke aero wheels for randonneuring, but mine don't fit that description. They're old mtb wheels which have 32 spokes, so should be pretty strong, and even after rebuilding them, I don't have cubic dollars invested in them.

There are people who will tell you that aero wheels actually do better in the wind than regular wheels, but don't believe that for a minute. In a 50 mph crosswind, you'll like regular wheels much better than aero ones. With a 40 mph wind, aero wheels still aren't much fun. But with 30 mph or less winds, mine handle well. Since I rarely face winds harder than 30 mph on rides, that small problem isn't a deal breaker for me, so I decided to give these wheels a long run as my randonneuring wheels.

I had always run 559x25 Conti GP's on these wheels. These are fast tires. On my HED wheels, I didn't notice much difference in speed from my old 650c wheels and 23 tires, other than slightly better speed on fast descents. And even a tire that's only 2 mm wider than the 23's makes a difference in ride on rough roads. The GP 25's never handled any better than my 23's, though. I expect that's because a Conti GP just doesn't handle quite as well as a Michelin Pro Race, which is what I ran when I ran 23's.

But the experiment wouldn't be complete until I tried 28 mm tires on the HED wheels. I installed new Conti GP 28's last week, and Saturday's Peachy Keene was my first ride with them. I own this route and ride it often, so I figured it would be a good route for comparisons. The 559x28 GP's do look a bit silly on aero wheels, but I don't worry too much about making a fashion statement these days, anyway.

How much tire pressure to run is a debate, by itself. The GP 28's have a max of 116. I wanted to make sure to run enough pressure that I couldn't blame being slower on tire pressure, so Saturday, I inflated the rear to 108 and the front to 100 pounds. Peachy Keene has some rough county roads, but almost no boulderseal. Tire pressure experimentation will be necessary, and I'll likely end up running lower pressures than that on routes which are mostly boulderseal.

Before I get into the comparisons, let me remind once more that everyone is different. How valid my comparisons would be for anyone else is questionable. Also, I'm only an average speed rider. Since aerodynamics becomes a much bigger factor with speed, my findings especially wouldn't apply to a really fast rider. And Peachy Keene isn't the fastest of 200k routes. It is lots of very small county roads, with blind curves and stop signs, and lots of turns. My personal best time on this route is a 9:30, which I did two months ago. For comparison, My personal best time on any 200k is an 8:06 on Rio Vista Rumble. My best time on a 200k since losing half a lung to a surgeon is an 8:40, also on Rio Vista Rumble. It's plainly a faster route than Peachy Keene. Anyway, the bottom line is that if you're capable of a 7 hour 200k, my ramblings here certainly don't apply to you.

I rode with Steve and Peggy Saturday. One of the first things to do was compare coast downs with them. They are both light, strong riders who can drop me like a bad habit whenever they want. But, with my aerodynamic bike setup (I have a lot of seat recline, and with my long arms, have the handlebar low, out in front of my upper shins, much lower than where my knees are at their highest point), and gravity assist (I weigh 186 right now), on downhills, I out-coast almost everyone I ride with. With the 28's on Saturday, I still out-coasted Steve and Peggy. In the 20 to 25 mph range, my coasting advantage seemed pretty much the same as usual. At above 25 mph, I still out-coasted them, but not as much as usual. Not too much of a penalty, I figured, since I don't spend too many miles above 25 mph on these long rides.

A comparison between Saturday's ride and my ride on Peachy Keene two months ago seems like a natural. Conditions were very similar. On both rides, things started with a tailwind, but quickly changed. Two months ago, it was a hard southeast wind that showed up after a couple of hours. Saturday, it was a straight east wind. Temperatures were almost the same for both rides. I would normally expect to be a bit stronger for a May ride than a March one, but I hadn't ridden 200k or more in a month, because of the shingles I've had for the last three weeks. My strength for the two rides is probably very similar. My effort for both rides was, too. On both rides, I rode a brisk (for me) pace.

I did the March ride mostly by myself. As often happens when I do that, my stops were very short. Saturday, chatting non-stop with Steve and Peggy, my stops were a bit longer. Here are the stats:

                 Overall time      On the bike time      heart rate average
March 14th            9:30                  8:33                  139
May 8th            9:52                  8:21                  142

On March 14th, I spent less than an hour off the bike, pretty good for me for a 200k. The bottom line is that I put out a slightly harder effort Saturday, and had a slightly better time. I'm thinking that, just as it felt, the speed of these 28's is really close to that of the 25's, and to that of the 650C x 23's before them. And the ride of the 28's is pretty unbelieveable, comparison-wise. I quickly got very confident on the roughest parts of the road, and handling was easily the best I've ever seen on the Corsa.

I bought these 559x28 Conti GP's knowing that if I didn't like them for randonneuring on the Corsa, they'd work well as commuting tires on the Stratus XP. As well as they performed on Saturday, there's going to be a lot more randonneuring miles on them before I try anything else.





Title: Re: The Great Wider Tire Rando Experiment
Post by aikigreg on May 10th, 2010, 8:48pm

It'll be an even more interesting comparison when next you ride a boulderseal laden route.  I've always ridden 23mm, and now running 25mm and don't see any real differences except more comfort.  And on the lowracer which has a 28mm front, I was keeping up with no problems with the A paceline at 25-30mph for s steady 5 miles.  

I suspect that it takes minutes off your century time on a highracer going up to 28mm, but how many, and do you care, which is the real bottom line.  Randos aren't races, and part of the whole point of bents is to be comfortable anyway.  That's one reason why the Xstream is now my brevet bike.  Sure I'm slower but a lot more comfortable.

I actually am still currently of the opinion that my aero wheels are better in the wind.  So far they've also been more stable, but maybe that has aprtyle to do with the dimpling of the zipps.  I'm not sure how they'd fare in the Wizard-of-oz like winds we've had lately, though.  But it almost seems like the twisted spokes catch more wind than the rounded spokes of the zipps.  All purely IME of course.

Title: Re: The Great Wider Tire Rando Experiment
Post by FlyingLaZBoy on May 12th, 2010, 7:39am

Good writeup, Bud, thanks!

Personally, always having been in the >200 pounds ("Clydesdale") division, I've typically run 1.25" on the rear and 1" on the front, with a few occasions of putting a 1" tire on the rear of the XS proto for speedier occasions -- but have never really used 23mms.  Granted, the cushy seat of the Stratus was always good insulation from chipseal, but one tends to feel chipseal more in the feet and hands from the front wheel, anyway.

I've recently put 1.1" (28mm) Duranos  at 110 psi on the Xstream26, and they seem to be working nicely for me -- they "feel" faster overall, at least in the high-acceleration situations of the Popsicle ride.

Also, Sam Eason (Season, another 'Clyde') was on the Sunday Roll a week or so ago, and said to me that he had changed from 23s to 28s on his Corsa a while back, and the ride smoothness was MUCH improved, with minimal loss of speed.

Generally, I'm with you, Bud - I think 28s are an excellent idea for Rando riding, overall....

Title: Re: The Great Wider Tire Rando Experiment
Post by Kwijybow on May 12th, 2010, 8:14am

Thanks for the write up Bud!  I'm a firm believer in tires as wide as possible.  At the speeds I normally run aerodynamics doesn't seem to make that much difference,  Weight, and #1 in my book, construction, seem to be the big factors.  I find if a casing is flexible it makes a huge difference as compared to a lined tire or stiff one.  One reason I've never liked gatorskins, as compared to the GP's from continental.  Just about the fastest smoothest tires I've ever owned are the Grand Bois Cypress 32mm 650b tires I got from Jan a couple of years ago.  Unfortunately not going on a bent anytime soon.  

Glad to hear the Durano's are working out Paul, I may try them next.  I'm pretty much sick of the cheap performance Metro K's on my commuter wheelset.  They are indestructable, cheap, and barely show a lick of wear after 2500 miles, but they are SLOW, and ride like they are lined with mortar.

Take Care,
Nelson.

Title: Re: The Great Wider Tire Rando Experiment
Post by FlyingLaZBoy on May 12th, 2010, 1:57pm

See pages 16-17 of this:

http://www.schwalbe.co.uk/shopdata/files/TechInfo2-GB.pdf

Title: Re: The Great Wider Tire Rando Experiment
Post by aikigreg on May 12th, 2010, 2:56pm

That's very interesting reading, Paul.  So in effect scwalbe is saying that unless you're operating above a certain speed, a wider tire is a faster tire, up to a point anyway.  So what Bud is seeing certainly bears out.  Wide rando tires, narrow race tires.

Title: Re: The Great Wider Tire Rando Experiment
Post by Bud_Bent on May 12th, 2010, 7:20pm


aikigreg wrote:
That's very interesting reading, Paul.  So in effect scwalbe is saying that unless you're operating above a certain speed, a wider tire is a faster tire, up to a point anyway.  So what Bud is seeing certainly bears out.  Wide rando tires, narrow race tires.


Yes, on a less than perfect road, a wider tire rolls better, with comparable air pressure. It's the aerodynamics that make one slower at faster speeds, or against a wind. That's why I wanted to see if, with an aero wheel to help lessen the loss in aerodynamics, a wider tire could match the performance of a narrower one. I suspect that on all but the roughest of roads, the narrow tire will be faster for a truly fast rider like JS. But, for someone like me, who isn't really fast enough to take advantage of all that aerodynamic gain, the advantage of wider tires is a bit easier to realize.

Of course, I'm talking about high racers. I'm still amazed at how many people don't seem to realize that tire aerodynamics makes a bigger difference on a high racer than on a bike with a small front tire. When I revived the BROL high racer wide tire thread to post a link to this thread, an entire new crop of posters showed up, testifying how wider tires were faster for them. Then, when you get to the part that says what bike they're riding, it's a Tour Easy. Why they even felt compelled to post in that thread is beyond me.

And, of course, if you average 10 mph on the bike, you'll see an advantage with wide tires, no matter what style of bike you ride.

Title: Re: The Great Wider Tire Rando Experiment
Post by mleuck on May 16th, 2010, 11:16pm

Good writeup Bud!

I can only go by my own experiences, both Barons initially came with Vredestein S-Lick 26/20 1.35" and while those tires were available I ran with them mainly because they seemed to wear well and the ride was decent. After the S-Licks were discontinued I ran with Vredestein Perfect Morii then Primo Conti's for a while and finally Schwalbe Kojak 1.35's because the larger Primo wouldn't fit on the back of the Silver Baron (they worked fine on the Yellow Baron, go figure), ran them all at 100psi

Last year I figured since everyone else ran Stelvio's I'd give them a try partly because I needed a narrower back tire to fit under the Optima Tailbox. The ride was quite a bit rougher and didn't appear to be any faster than the Kojaks. Later when the tailbox rubbed through the Stelvio I switched to a Durano 1.1" front and rear which were just as rough and after two days had a pinch flat at White Rock.

I'm sticking with Kojaks, heck of a lot smoother in the rough and just as fast if not faster than the Stelvio/Durano high pressure tires. I imagine my experiences are different than most here since I'm exclusively a low racer guy

Title: Re: The Great Wider Tire Rando Experiment
Post by aikigreg on May 17th, 2010, 10:17am

Do they make kojaks for the rear as well?

Title: Re: The Great Wider Tire Rando Experiment
Post by Bud_Bent on May 17th, 2010, 11:18am


mleuck wrote:
I'm sticking with Kojaks, heck of a lot smoother in the rough and just as fast if not faster than the Stelvio/Durano high pressure tires. I imagine my experiences are different than most here since I'm exclusively a low racer guy


Yeah, you've been a good reminder to us all along that wider tires are the better choice for low racers. I did like the Stelvio 28mm tire I had on the front of the Roadster, but it was a 451 tire, not a 406.

It's not quite as cut and dried for a high racer, plus the argument can be made that a 559 or 571 front tire doesn't need to be as wide as a 406 front tire to ride well. At any rate, I've been impressed with my new wider tires, so far.

Title: Re: The Great Wider Tire Rando Experiment
Post by evblazer on May 17th, 2010, 3:23pm


aikigreg wrote:
Do they make kojaks for the rear as well?

I've had kojaks on the giro 26 and both the hurricanes at home. I'm pretty certain MarkL is running them front and back.
Wide range of sizes.
Folding bead
32-349      16 x 1 1/4
32-369      17 x 1 1/4
32-355      18 x 1.25
35-406      20 x 1.35
40-507      24 x 1.50
35-559      26 x 1.35
50-559      26 x 2.00
35-622      700 x 35C

Wire Bead
32-349      16 X 1 1/4
35-406      20 x 1.35
35-559      26 x 1.35
50-559      26 x 2.00
35-622      700 x 35C

http://www.schwalbetires.com/kojak
And I did really like them on the Giro 26.. Oy those stelvios I briefly tried were really harsh on bad roads.

Title: Re: The Great Wider Tire Rando Experiment
Post by aikigreg on May 17th, 2010, 4:01pm

wow those suckers are thick!  Dunno if one will fit on the Vk2, but might be worth a shot once the current tires on the vk2 are needing replacement.  

Mark, how easy are the kojacks to install on the 406?

Title: Re: The Great Wider Tire Rando Experiment
Post by evblazer on May 17th, 2010, 5:06pm

I use the folding beads so the wire ones could be tougher. On all mine both 559 and 406s they just slide on without any tools unless it's wet out and freezing cold then I'll cheat and use a kwik stik (?) mount tool thingy.

Some of the comments on the schwalbe board mention that for a 1.35" tire it is on the small side.

Title: Re: The Great Wider Tire Rando Experiment
Post by FlyingLaZBoy on May 19th, 2010, 2:33pm

Yes, the 26 x 1.35" Kojak is 1.25" actual...

Title: Re: The Great Wider Tire Rando Experiment
Post by mleuck on May 19th, 2010, 9:13pm


aikigreg wrote:
Do they make kojaks for the rear as well?


Yea, currently running a 26" and got in a 700 for the new bike

Title: Re: The Great Wider Tire Rando Experiment
Post by mleuck on May 19th, 2010, 9:15pm


aikigreg wrote:
wow those suckers are thick!  Dunno if one will fit on the Vk2, but might be worth a shot once the current tires on the vk2 are needing replacement.  

Mark, how easy are the kojacks to install on the 406?


I never have a problem installing them on either front or rear Aerospokes, put them on without tools

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