Tandem Cycling A bicycle built for two. Want to find out more about this wonderful world of tandems? Check out this forum to talk with other tandem enthusiasts. Captains and stokers welcome!

Beadless tubeless rims

Old 04-08-14, 11:04 AM
  #1  
waynesulak
Senior Member
Thread Starter
 
waynesulak's Avatar
 
Join Date: Jan 2008
Location: Ft Worth, TX
Posts: 1,969

Bikes: Custom 650B tandem by Bob Brown, 650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Beadless tubeless rims

Given the discussion of tubless blowouts in this thread:

http://www.bikeforums.net/tandem-cyc...ubeless-3.html

I noticed that Enve now makes tubeless rims with a bead or "beadless. Below is a graphic from their web site showing the design.



I don't understand how using a rim without a bead will help keep a tubeless tire on the rim. I can see advantages in manufacturing. Note the text in the graphic states that this design helps avoid unpredictable air loss.
Attached Images
File Type: jpg
M5029C_inframe.jpg (50.2 KB, 55 views)
waynesulak is offline  
Old 04-08-14, 11:49 AM
  #2  
merlinextraligh
pan y agua
 
merlinextraligh's Avatar
 
Join Date: Aug 2005
Location: Jacksonville
Posts: 30,331

Bikes: Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er; Calfee Dragonfly Tandem

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 870 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Originally Posted by waynesulak View Post
Given the discussion of tubless blowouts in this thread:

http://www.bikeforums.net/tandem-cyc...ubeless-3.html

I noticed that Enve now makes tubeless rims with a bead or "beadless. Below is a graphic from their web site showing the design.



I don't understand how using a rim without a bead will help keep a tubeless tire on the rim. I can see advantages in manufacturing. Note the text in the graphic states that this design helps avoid unpredictable air loss.
First, it appears that this is for mountain bike wheels, which run at much lower air pressure. The issue with running low pressures on tubeless tires, as I understand it, is more keeping the tires from "burping", than it is keeping the tire from blowing off the rim.

From the diagram, you can see how beadless could make a better air seal between the tire and the rim, by avoiding gaps at the hook bead.

Also realize that automotive tires are beadless, and they stay on ok.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
merlinextraligh is offline  
Old 04-08-14, 01:26 PM
  #3  
Team Fab
Senior Member
 
Team Fab's Avatar
 
Join Date: Jan 2012
Location: Vancouver BC
Posts: 376

Bikes: Comotion Supremo, Trek T1000, Comotion Supremo Triple

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by merlinextraligh View Post
First, it appears that this is for mountain bike wheels, which run at much lower air pressure. The issue with running low pressures on tubeless tires, as I understand it, is more keeping the tires from "burping", than it is keeping the tire from blowing off the rim.

From the diagram, you can see how beadless could make a better air seal between the tire and the rim, by avoiding gaps at the hook bead.

Also realize that automotive tires are beadless, and they stay on ok.
I think car tires do have a bead, just not as pronounced.

I don't get the Enve design either. Unless a tire was designed for it specifically, don't all bike tires have some sort of bead?(Tubulars excepted).
Team Fab is offline  
Old 04-08-14, 01:49 PM
  #4  
merlinextraligh
pan y agua
 
merlinextraligh's Avatar
 
Join Date: Aug 2005
Location: Jacksonville
Posts: 30,331

Bikes: Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er; Calfee Dragonfly Tandem

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 870 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Originally Posted by Team Fab View Post
I think car tires do have a bead, just not as pronounced.

I don't get the Enve design either. Unless a tire was designed for it specifically, don't all bike tires have some sort of bead?(Tubulars excepted).
Ok, it probably would have been more correct to say that automobile wheels don't have hook beads.

Old clincher wheels did not have hook beads. Clincher rims only started having hook beads with the move to high pressure clinchers. That's why clincher tires used to have maximum inflation pressures like 75psi.

http://www.sheldonbrown.com/harris/tires/630.html
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.

Last edited by merlinextraligh; 04-08-14 at 02:02 PM.
merlinextraligh is offline  
Old 04-08-14, 04:27 PM
  #5  
waynesulak
Senior Member
Thread Starter
 
waynesulak's Avatar
 
Join Date: Jan 2008
Location: Ft Worth, TX
Posts: 1,969

Bikes: Custom 650B tandem by Bob Brown, 650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by merlinextraligh View Post
First, it appears that this is for mountain bike wheels, which run at much lower air pressure. The issue with running low pressures on tubeless tires, as I understand it, is more keeping the tires from "burping", than it is keeping the tire from blowing off the rim.

From the diagram, you can see how beadless could make a better air seal between the tire and the rim, by avoiding gaps at the hook bead.

Also realize that automotive tires are beadless, and they stay on ok.
I understand your point about lower pressure. Stiffer mountain bike tires also might hold their shape and help prevent bow offs.

I think the second point would apply only if the tire and rim were not compatible. I use tubed tires on "tubeless compatible" Velocity A23 rims and my tires kelvar bead fits very tightly in the section below the hooked bead. I can deflate the tire completely and both beads remain firmly in place. To remove the tire I have to use my thumbs pushing sideways in on the sidewalls to get the bead to come out. This seems to offer a much stronger seal than the graphic indicates for a hooked bead. One nice feature of this set up is that the tires line up perfectly when inflated. There are no adjustments needed to center the tire on the rim. These are lightweight road tires designed to be used with tubes so maybe stiff tubeless mountain bike tires would seal less well?
waynesulak is offline  
Old 04-09-14, 06:16 AM
  #6  
merlinextraligh
pan y agua
 
merlinextraligh's Avatar
 
Join Date: Aug 2005
Location: Jacksonville
Posts: 30,331

Bikes: Wilier Zero 7; Merlin Extralight; Co-Motion Robusta; Schwinn Paramount; Motobecane Phantom Cross; Cervelo P2; Motebecane Ti Fly 29er; Calfee Dragonfly Tandem

Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 870 Post(s)
Likes: 0
Liked 2 Times in 1 Post
Enve's not the only one; Specialized also has a beadless MTB rim. Their stated reason for doing it may be a little more candid: ease of manufacturing carbon rims, without the bead. They also point out that automobile tires, motorocycle tires, don't have hook beads and bicycle tires from the 60's didn't have them.

Up Close with Specialized's Beadless Clincher

Looking at the history of clincher rims, I think this is still going to be an MTB thing, and likely won't spread to road tires. Road bike rims were straight sided, no hook bead, until we went to higher pressure clinchers. So the higher pressure in road bike tires may still require hook beads, particularly for a safety margin.
__________________
You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.
merlinextraligh is offline  
Old 04-09-14, 08:00 AM
  #7  
mibike
Senior Member
 
Join Date: Nov 2006
Posts: 190
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Ibis also has hookless bead MTB rims. "The design is intended to be lighter".

Ibis hopes to redefine 'wide' with new mountain bike wheelsets - VeloNews.com
mibike is offline  
Old 04-09-14, 08:09 AM
  #8  
Werkin
Senior Member
 
Join Date: Oct 2010
Location: Texas
Posts: 458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I have wide hookless carbon rims, and run supple high volume/low pressure road tires with and without tubes. The tires are designed for tubes and hooked rims, yet they seal securely when installed tubeless on these rims. While hookless construction does create a stronger rim edge, it isn't the entire story of improved tubeless security. Derby rims have a bead lock that discourages the tire from unseating if deflated, it also cradles the tire bead for improved seal. Greater force is required to move a tire bead over Derby's bead lock than to unseat a tire bead from a rim hook. Carbon rims are formed in a machined mold resulting in accurate & consistent dimensions, extruded alloy rims have a wide range of tolerances.

Werkin is offline  
Old 04-09-14, 09:38 AM
  #9  
waynesulak
Senior Member
Thread Starter
 
waynesulak's Avatar
 
Join Date: Jan 2008
Location: Ft Worth, TX
Posts: 1,969

Bikes: Custom 650B tandem by Bob Brown, 650B tandem converted from Santana Arriva, Santana Noventa, Boulder Bicycle 700C, Gunnar Sport

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Werkin View Post
I have wide hookless carbon rims, and run supple high volume/low pressure road tires with and without tubes. The tires are designed for tubes and hooked rims, yet they seal securely when installed tubeless on these rims. While hookless construction does create a stronger rim edge, it isn't the entire story of improved tubeless security. Derby rims have a bead lock that discourages the tire from unseating if deflated, it also cradles the tire bead for improved seal. Greater force is required to move a tire bead over Derby's bead lock than to unseat a tire bead from a rim hook. Carbon rims are formed in a machined mold resulting in accurate & consistent dimensions, extruded alloy rims have a wide range of tolerances.

Very interesting

What tires and width, Hetre 42mm ?
Pressure that you run them?
Sealant used?
Team weight?
waynesulak is offline  
Old 04-09-14, 09:48 AM
  #10  
Werkin
Senior Member
 
Join Date: Oct 2010
Location: Texas
Posts: 458
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Hetre 42mm nominal (47-48mm mounted), Pari-Moto 38mm nominal (43mm mounted)
33 R, 30 F
Orange Seal
Single rider only, 213 - 217 bike & rider.
Werkin is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kbarch
Road Cycling
13
06-08-16 11:45 AM
Andy_K
Cyclocross and Gravelbiking (Recreational)
0
02-11-13 04:48 PM
martins
Road Cycling
2
02-23-06 05:58 PM

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

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.