Notices
Long Distance Competition/Ultracycling, Randonneuring and Endurance Cycling Do you enjoy centuries, double centuries, brevets, randonnees, and 24-hour time trials? Share ride reports, and exchange training, equipment, and nutrition information specific to long distance cycling. This isn't for tours, this is for endurance events cycling

Help me with my tire selection for 300k-400ks...

Old 04-09-21, 09:52 AM
  #26  
GhostRider62
Member
 
Join Date: Apr 2021
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Liked 15 Times in 6 Posts
I have done a ton of tire testing in a variety of ways. Really fast tires on real (good) roads might have as low as 0.0042 Crr and pretty good tires might roll at 0.0055 but lousy tires can be as high as 0.01!! If someone is interested in a decent Crr estimate on real roads, temperature stability is critical. RChung method at two speeds lets you get a pretty darned good estimate of Crr. The best I ever measured was 0.004 with GP5000 and latex tubes on good roads, Supersonics with latex also in that range. The rolling resistance figures from drums are generally helpful to order tires but they way, way underestimate real road conditions. My favorite very quick and dirty test is to rolldown a shallow hill from a marked position on a perfectly calm day. I only hit a peak speed of 9-10 mph. Then, I roll on a flat until friction pulls me to a complete halt. I have a control set of wheels. I compare against that control on that day. My testing like that was always aligned qualitatively in rank position to Tom Anhalt's testing. It helps if you think you have a new tire that is bad and sadly, that happens.

The effect on average speed going from 0.0042 to 0.0055 is much more apparent on a very aerodynamic bike like a laidback recumbent. It can be 1 mph. I had found that it was only 1 km/h on my upright. (I am neglecting aerodynamic effects in my statement). Riding at modest speeds like a long distance brevet? Comfort, durability (puncture resistance), and Crr in the order are how I think about it. At higher speeds of say a recumbent or velomobile, other factors come into play. For instance, how does the tire fail? If the casing ruptures spectacularly, you are potentially facing a very serious crash if it happens on the rear of a tadpole trike (velomobile) or the front tire on a recumbent, Aerodynamics are also more important.

The best to decent tires might only cost 10 watts at modest speeds, about the cost of a poorly maintained chain. But 10 cents here and 10 cents there, it eventually adds up to dollars or more poignantly, more sleep in a long brevet.

Personally, I will never again ride a brevet with gravel due to risks on gravel and if the choice was a slightly longer route, I would put fast tires on and just suck it up.

A velomobile rider had some pretty decent tests of the G One Speed, it rolled pretty well but there were better. I have found Schwalbe tires and ultralight tubes to be slower than expected....a bit less average than Compass tires but I do not trust the casings and such a failure on a bent could be death because the speeds are very high on one. The Compass tires are comfortable for sure and they roll pretty well. Me? I only ride Conti.

Last edited by GhostRider62; 04-09-21 at 10:02 AM.
GhostRider62 is offline  
Old 04-09-21, 07:15 PM
  #27  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 21,289
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 1,127 Times in 820 Posts
Originally Posted by GhostRider62 View Post
Personally, I will never again ride a brevet with gravel due to risks on gravel and if the choice was a slightly longer route, I would put fast tires on and just suck it up..
So I guess I will not be able to interest you in my gravel 200K?
Everyone has finished it so far, although we did have a crash on the first scouting ride.
unterhausen is offline  
Old 04-10-21, 11:39 AM
  #28  
GhostRider62
Member
 
Join Date: Apr 2021
Posts: 37
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 15 Post(s)
Liked 15 Times in 6 Posts
Originally Posted by unterhausen View Post
So I guess I will not be able to interest you in my gravel 200K?
Everyone has finished it so far, although we did have a crash on the first scouting ride.
Very difficult on 25mm tires on recumbent that is not only laid back but the CG also down low making balance doubly more challenging. There is gravel and there is gravel. Towpath along the Delaware is tame. Some Forest Service roads? I would want to be in a lifted off road motor vehicle although you will see cyclists on them. A recumbent that has wider tires, a more upright seat angle, and a higher overall position would be more suitable and doable for a younger buck. I went into a "gravel" section on a brevet and immediately flatted both tires and went down and I have to admit, this was the only brevet that I ever quit. I was not really hurt that bad, I was sick and tired of riding a recumbent and always being in pain. I am not proud, I gave up. I like dirt roads on uprights but I just am not skilled or it could be a vestibular thing, loose gravel gets me. The gravel was largish chunks of granite usually reserved for the first layer of a highway. There is no way to unweight or maneuver like on an upright. I like the DC crowd handles gravel or at least as I remember. They give you two options with the road option the longer one and maybe more climbing. Thanks for the invite, it is more than I can handle and I understand it is a bit hilly, too.
GhostRider62 is offline  
Old 04-10-21, 12:24 PM
  #29  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 21,289
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 1,127 Times in 820 Posts
The 200k in question has been finished at least twice on a recumbent, although that bike has reasonable size tires, 50mm or so. Granted, the crash on the scouting ride was also the recumbent.
I tried to get it up to 9000 feet of climbing, but couldn't do it without making it longer. Not a towpath
unterhausen is offline  
Old 04-10-21, 12:37 PM
  #30  
bikemig 
Senior Member
 
bikemig's Avatar
 
Join Date: Apr 2012
Location: Middle Earth (aka IA)
Posts: 18,239

Bikes: A bunch of old bikes and a few new ones

Mentioned: 156 Post(s)
Tagged: 0 Thread(s)
Quoted: 5007 Post(s)
Liked 1,513 Times in 997 Posts
The Iowa randonneurs do rides near you as well if you're looking for other routes/rides.

I'm getting a late start this year but I need to start logging some miles as well.
bikemig is offline  
Old 04-11-21, 06:51 PM
  #31  
GrainBrain
Senior Member
Thread Starter
 
GrainBrain's Avatar
 
Join Date: Aug 2017
Location: Central Io-way
Posts: 1,874

Bikes: LeMond Zurich, Giant Talon 29er

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 996 Post(s)
Liked 286 Times in 215 Posts
Yes riding with the Iowa rando club will would be nice. I have yet to commit, I'm tight for time so I've kicked around buying a trainer to stay in shape. Doing a whole series seems like it would be tough, like a 1200.

I've been using my treadmill alot, and constantly talking about weight lifting. My longest rides have been 150 miles, I can do a century at 7 hours, and for back to back days. Just thinking of 200 miles seems tough with these tires. Not that they're bad, they're nice. I just wonder if I'll see a speed increase going to 32s. The gravel I'd have to use would be very rideable, but I would ride it slower then my 40s. Thing is I'd only have 25ish miles of gravel total, with each segment no longer then 8 miles and they're a few hours apart. I'm afraid I'd miss the volume of the 40, but they don't just cruise along and saving weight off the wheelset seems tempting.

​​​​​
GrainBrain is offline  
Old 04-13-21, 04:41 AM
  #32  
Richard Cranium
Senior Member
 
Richard Cranium's Avatar
 
Join Date: Jun 2002
Location: Rural Missouri - mostly central and southeastern
Posts: 2,967

Bikes: 2003 LeMond -various other junk bikes

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 55 Post(s)
Likes: 0
Liked 18 Times in 17 Posts
I've read some tire threads on here and I understand I can get 100 different answers so I'm really curious to hear your comparisons. Like have you ridden multiple sizes of the gravel king and what differences have you felt? Should I consider 32mm? Thanks again!
I always thought tire-size selection, much like all sorts of sporting equipment - should be based on the size of the athlete. Typically, bigger riders need bigger tires.
Of course, tires do not perform their function without being influenced by the size and type of rim they are mated with.
And of course, modern technology forces a rider to consider a range of tube sizes and or no tube at all tire-configurations.

And last but not least - each rider has their own innate comfort/compliance/performance expectations of a wheel setup for a given bicycle ride or event. All the elements listed above are a compromise of these "ride characteristics."
And the priorities or importance of the these compromises are only to be considered in the context of a "300k to 400k" scenario - as the OP to distinctly notes in the subject of the thread.

OK - now that everything is cleared up and decided - go ride.

.
Richard Cranium is offline  
Old 04-14-21, 08:32 AM
  #33  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 21,289
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 1,127 Times in 820 Posts
It has been a long time since I rode in Iowa, but I doubt the roads have gotten better since I did. I doubt you will pick up much speed by going to 32 over 40mm tires. And you certainly will lose speed on the gravel. I have ridden gravel on 32mm tires and it's not great. I don't see the weight being that much of a difference even if you sprint to every town limit sign.
unterhausen is offline  
Old 04-14-21, 01:05 PM
  #34  
Tourist in MSN
Senior Member
 
Join Date: Aug 2010
Location: Madison, WI
Posts: 8,039

Bikes: 1961 Ideor, 1994 Bridgestone MB-6, 2006 Airnimal Joey, 2009 Thorn Sherpa, 2013 Thorn Nomad MkII, 2015 VO Pass Hunter, 2017 Lynskey Backroad, 2017 Raleigh Gran Prix, Perfekt 3 Speed -age unknown, 1980s Bianchi Mixte on a trainer. Others are now gone.

Mentioned: 35 Post(s)
Tagged: 0 Thread(s)
Quoted: 2193 Post(s)
Likes: 0
Liked 469 Times in 385 Posts
There is gravel and there is gravel.

Last summer I frequently rode on three Wisconsin rail trails, one of them had a good firm base, 32mm road tires were fine. I used 37mm tires on the other two that were pretty firm but occasional soft spots.

Two years ago, one of the trails that I used 37mm tires on last year, two years ago I was using 57mm mountain bike tires because they had repaired a number of washouts with beach sand, you would be riding along at 12 to 15 mph and with narrower tires you could suddenly hit a soft spot and dig in and lose the ability to steer. Some of my friends crashed with narrower tires.

I have toured on gravel roads that were as solid as asphalt, but I have also toured on gravel 4X4 roads that was so rough that if you saw something smaller than a tennis ball in the road you did not bother trying to miss it. I have also toured on gravel roads that had washboard that was so rough I could not go over 8 or 9 km/hr.

There is a huge range of gravel.
Tourist in MSN is offline  
Old 04-18-21, 07:14 AM
  #35  
Steamer
Zircon Encrusted Tweezers
 
Steamer's Avatar
 
Join Date: Nov 2008
Location: high ground
Posts: 1,199
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 192 Post(s)
Liked 54 Times in 38 Posts
Originally Posted by unterhausen View Post
The 200k in question has been finished at least twice on a recumbent, although that bike has reasonable size tires, 50mm or so. Granted, the crash on the scouting ride was also the recumbent.
I tried to get it up to 9000 feet of climbing, but couldn't do it without making it longer. Not a towpath
I finished it 3 times officially for RUSA credit and one time informally (the last time we scouted it and when we were still questioning the feasibility of you and I riding it within the time limit). The earlier scouting ride crash was bad judgment on my part. Crossing the crown of a recently re-graded dirt and gravel road at relatively high speed without sitting up was stupid. You live and learn. I used 42mm tires because that was the fattest that would fit in the fork. Something fatter would be better.
Steamer is offline  
Old 04-18-21, 12:36 PM
  #36  
GrainBrain
Senior Member
Thread Starter
 
GrainBrain's Avatar
 
Join Date: Aug 2017
Location: Central Io-way
Posts: 1,874

Bikes: LeMond Zurich, Giant Talon 29er

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 996 Post(s)
Liked 286 Times in 215 Posts
Yeah that soft crown has nearly put me down sideways a few times as well. I'm really loving these 40mm Maxxis tires, I'm starting to see that the middle tread of maybe 32mm is all that touches the road when going straight. Of course on gravel the contact pad is probably larger.

For the gravel segments I'll be on I could ride them at an acceptable pace probably. Though it would not be pleasant if it's freshly graded. Would probably scout those sections the day before.

As I gain back the spring form I've been putting in times close to what I did with the LeMond and 25mm tires. I feel far less beaten up! The LeMond excelled on the smooth rail trails but oh those frost cracks on the roads were brutal after 120 miles.

Nutrition wise I've gotten close to putting together a decent food intake of rotating 200 cal servings of rice/cream cheese cakes, hammer nutrition bars, white bread with soft cheese or butter/jam/PB. Mixing in 100 calories of HEED with my water. Been trying to get used to taking small bites and chewing well.

I'm getting excited about the nicer weather, soon I'll have a chance to get a good 4am start and aim for a 14 hour ride and see where I end up. After I manage to get at least 150 miles in then I'll really know if I want to go with some Rene Herse or not. Previous century attempts I ate too much too quickly around 60 miles and it put me off a bit the last 20 miles.
GrainBrain is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright İ 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.