Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Do carbon belts stretch?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Do carbon belts stretch?

Old 08-16-17, 06:48 AM
  #1  
valeriano
Member
Thread Starter
 
Join Date: Jul 2017
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Do carbon belts stretch?

Hi,

I'm thinking about buying a belt driven bike. But all bikes I've seen, have vertical dropouts. Like that:


With chains, it doesn't matter how cautious you are, they always stretch and either the derailleur keeps the chain tensioned or you have a horizontal dropout to keep it in the proper tension.
I don't know much about carbon belts, so I'm worried if with time it will stretch and loose tension.
Anyone knows about that?

Also, recommendation on belt driven bikes until €1000 are welcome. But since this is going to be a daily use bike, eyelets for mudgards and racks are important. Also disk brakes are welcome.

Last edited by valeriano; 08-16-17 at 06:51 AM.
valeriano is offline  
Old 08-16-17, 08:31 AM
  #2  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,396

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6950 Post(s)
Liked 257 Times in 211 Posts
in a metal chain, "Stretch" is a way of describing accumulated wear of its metal surfaces as a total increase in length.

bikes, in the eurozone? (I am in the US) German Tout Terrain is more than €1000, Especially with VAT included in that total.


Gates carbon drive-train components come to $500 alone, so i doubt you will find anything at your price,

unless its an Asian copy of the belt drive idea.



...

Last edited by fietsbob; 08-16-17 at 08:58 AM.
fietsbob is offline  
Old 08-16-17, 08:36 AM
  #3  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 12,218

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1949 Post(s)
Liked 135 Times in 101 Posts
Drive belts are very sensitive to tension in that too little is a bad thing. But as a well designed belted bike has an ability to adjust the belt's tension so if any "stretch" does happen it's easily corrected for. Have you ridden a belted bike yet? They do feel a bit different IMO. Andy
Andrew R Stewart is online now  
Old 08-16-17, 09:08 AM
  #4  
rydabent
Senior Member
 
Join Date: Apr 2010
Location: Lincoln Ne
Posts: 7,649

Bikes: RANS Stratus TerraTrike Tour II

Mentioned: 21 Post(s)
Tagged: 0 Thread(s)
Quoted: 1420 Post(s)
Liked 75 Times in 47 Posts
Something that might contribute to premature stretch is the fact that too many people run cog belts way too tight. I worked with them on office machines for 47 years, and many made them way too tight.
rydabent is offline  
Old 08-16-17, 09:17 AM
  #5  
valeriano
Member
Thread Starter
 
Join Date: Jul 2017
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by fietsbob View Post
in a metal chain, "Stretch" is a way of describing accumulated wear of its metal surfaces as a total increase in length.

bikes, in the eurozone? (I am in the US) German Tout Terrain is more than €1000, Especially with VAT included in that total.


Gates carbon drive-train components come to $500 alone, so i doubt you will find anything at your price,

unless its an Asian copy of the belt drive idea.



...
The one I'm thinking about right now is this one:
https://www.boc24.de/shop/fahrraeder...cycles-cx-1000

Last edited by valeriano; 08-16-17 at 09:24 AM.
valeriano is offline  
Old 08-16-17, 09:21 AM
  #6  
valeriano
Member
Thread Starter
 
Join Date: Jul 2017
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Andrew R Stewart View Post
Drive belts are very sensitive to tension in that too little is a bad thing. But as a well designed belted bike has an ability to adjust the belt's tension so if any "stretch" does happen it's easily corrected for. Have you ridden a belted bike yet? They do feel a bit different IMO. Andy
No, I have never ridden a belted bike. I'm thinking about it because of the low maintenance. Specially considering the snow, mud and salt I'll have to face during winter.
What difference did you notice?
valeriano is offline  
Old 08-16-17, 09:28 AM
  #7  
woodcraft
Senior Member
 
woodcraft's Avatar
 
Join Date: Apr 2012
Location: Nor Cal
Posts: 4,429
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1123 Post(s)
Likes: 0
Liked 98 Times in 61 Posts
There's probably an eccentric bottom bracket to adjust belt tension.

IME, belts don't stretch- auto fan belts often run for their service life without being tightened.
woodcraft is offline  
Old 08-16-17, 09:29 AM
  #8  
corrado33
Senior Member
 
Join Date: Jun 2013
Location: Bozeman
Posts: 4,096

Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1125 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by valeriano View Post
The one I'm thinking about right now is this one:
https://www.boc24.de/shop/fahrraeder...cycles-cx-1000
That bike has an eccentric bottom bracket to tension the belt correctly therefore horizontal dropouts aren't needed.

Also, horizontal dropouts with disc brakes are... difficult to say the least. The caliper needs to move with the wheel. Therefore it's easier to put a eccentric bb into the bike instead unless you want to take surly's approach and have a way overengineered dropout.
corrado33 is offline  
Old 08-16-17, 09:52 AM
  #9  
velocentrik
Senior Member
 
Join Date: Sep 2015
Location: Front Range, Colorado
Posts: 127
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 71 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by valeriano View Post
Hi,

I'm thinking about buying a belt driven bike. But all bikes I've seen, have vertical dropouts. Like that:


With chains, it doesn't matter how cautious you are, they always stretch and either the derailleur keeps the chain tensioned or you have a horizontal dropout to keep it in the proper tension.
I don't know much about carbon belts, so I'm worried if with time it will stretch and loose tension.
Anyone knows about that?

Also, recommendation on belt driven bikes until €1000 are welcome. But since this is going to be a daily use bike, eyelets for mudgards and racks are important. Also disk brakes are welcome.
We don't live in a dystopia like 1984.

Gates belts are polyurethane. A toxic NOT environmentally friendly concoction of man's modern excess. There is a marketing gimmick to refer to Gates belts as carbon, but they are what they are.

The belts don't stretch. They are very reliable.

However, from an efficiency perspective belt drive is significantly less efficient than chain drive. Nothing is as efficient as chain drive.

Do you want nearly maintenance free but less efficient?
velocentrik is offline  
Old 08-16-17, 10:06 AM
  #10  
gearbasher
Senior Member
 
gearbasher's Avatar
 
Join Date: May 2009
Location: Sitting on my butt in front of a computer
Posts: 842
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 153 Post(s)
Likes: 0
Liked 26 Times in 18 Posts
I worked as a conveyor mechanic for 30 years (now retired..thank God). I never saw any of our "carbon" drive belts stretch. But, I've seen many of them snap. I wouldn't worry though, you won't be trying to drive a 24" belt from a dead stop with 500+ pounds of product on it. As for the ones that weren't marked "carbon", I've seen many of them shear off their teeth.

Last edited by gearbasher; 08-16-17 at 10:10 AM.
gearbasher is offline  
Old 08-16-17, 10:10 AM
  #11  
valeriano
Member
Thread Starter
 
Join Date: Jul 2017
Posts: 41
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by velocentrik View Post
We don't live in a dystopia like 1984.

Gates belts are polyurethane. A toxic NOT environmentally friendly concoction of man's modern excess. There is a marketing gimmick to refer to Gates belts as carbon, but they are what they are.

The belts don't stretch. They are very reliable.

However, from an efficiency perspective belt drive is significantly less efficient than chain drive. Nothing is as efficient as chain drive.

Do you want nearly maintenance free but less efficient?
Efficiency is not my main concern. This is going to be a daily use bike, so I'm not worried about speed.
But low maintenance is very important to me. Bike shops are VERY expensive here and I want to go there as little as possible until I finish buying all the tools needed to be self sufficient.
valeriano is offline  
Old 08-16-17, 10:15 AM
  #12  
TimothyH
- Soli Deo Gloria -
 
Join Date: Aug 2015
Location: Northwest Georgia
Posts: 14,784

Bikes: 2018 Rodriguez Custom Fixed Gear, 2017 Niner RLT 9 RDO, 2015 Bianchi Pista, 2002 Fuji Robaix

Mentioned: 235 Post(s)
Tagged: 0 Thread(s)
Quoted: 6822 Post(s)
Liked 653 Times in 411 Posts
Gates says that their belts use "Advanced no-stretch carbon cord technology."

Not sure how much of that phrase is engineering and how much is marketing.

Gates Carbon Drive? System for Bicycles | Gates Carbon Drive?
TimothyH is offline  
Old 08-16-17, 10:16 AM
  #13  
corrado33
Senior Member
 
Join Date: Jun 2013
Location: Bozeman
Posts: 4,096

Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1125 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by valeriano View Post
Efficiency is not my main concern. This is going to be a daily use bike, so I'm not worried about speed.
But low maintenance is very important to me. Bike shops are VERY expensive here and I want to go there as little as possible until I finish buying all the tools needed to be self sufficient.
If you have 1,000 euros to spend on a bike, you can spend another 100 on tools. You really only need a 4,5,6mm allen, crank remover, pedal wrench, and normal screwdrivers for a modern bike. Since this bike has an eccentric bb, you'll need a pin spanner as well.

Everything else isn't really necessary until you have to do serious maintence to the bike (bearings etc.)
corrado33 is offline  
Old 08-16-17, 10:19 AM
  #14  
corrado33
Senior Member
 
Join Date: Jun 2013
Location: Bozeman
Posts: 4,096

Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1125 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by TimothyH View Post
Gates says that their belts use "Advanced no-stretch carbon cord technology."

Not sure how much of that phrase is engineering and how much is marketing.

Gates Carbon Drive? System for Bicycles | Gates Carbon Drive?
I find this statement particularly interesting.

Note: the CDN system is not approved for use on mountain bikes, mid-drive eBikes or gear boxes, fixed gear bikes, or high mileage trekking/touring bikes.
I wonder why? Not for fixed gear bikes? Really? Not for high mileage bikes? Seems like they know their belts don't last long and can't stand up to lots of force.

With that said, the strongest mountain biker I know rode a single speed belt drive off road up significant hills, so it seems to work fine even in those situations.
corrado33 is offline  
Old 08-16-17, 10:45 AM
  #15  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,396

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6950 Post(s)
Liked 257 Times in 211 Posts
recommendation on belt driven bikes until €1000 are welcome
they would perhaps be used and/ or Stolen . bring more money, or buy on credit.

or be able to repair a cheaper chain drive bike. while you look for a job that pays much better.

then get the higher end bike of your dreams..





....

Last edited by fietsbob; 08-16-17 at 10:49 AM.
fietsbob is offline  
Old 08-16-17, 10:56 AM
  #16  
AnkleWork
Senior Member
 
Join Date: Jan 2013
Location: Llano Estacado
Posts: 3,543

Bikes: old clunker

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 620 Post(s)
Likes: 0
Liked 52 Times in 38 Posts
Originally Posted by TimothyH View Post
Gates says that their belts use "Advanced no-stretch carbon cord technology."

Not sure how much of that phrase is engineering and how much is marketing.

Gates Carbon Drive? System for Bicycles | Gates Carbon Drive?
Translating into engineer-speak:
"Recent low-stretch carbon cord technology."

So not radically different in this case.
AnkleWork is offline  
Old 08-16-17, 11:44 AM
  #17  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,755

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 1259 Post(s)
Likes: 0
Liked 90 Times in 77 Posts
Originally Posted by corrado33 View Post
I wonder why? Not for fixed gear bikes? Really? Not for high mileage bikes? Seems like they know their belts don't last long and can't stand up to lots of force.
I wonder if the fixed gear prohibition is because the belt won't tolerate the torque reversal during braking. As to the other disclaimers, it seems the belt has a lower torque limitations then a chain and, as you noted, long term durability issues.
HillRider is offline  
Old 08-16-17, 11:50 AM
  #18  
corrado33
Senior Member
 
Join Date: Jun 2013
Location: Bozeman
Posts: 4,096

Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1125 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by HillRider View Post
I wonder if the fixed gear prohibition is because the belt won't tolerate the torque reversal during braking. As to the other disclaimers, it seems the belt has a lower torque limitations then a chain and, as you noted, long term durability issues.
That was my thought as well. It seems those belts have a directionality associated with them as one of the warnings is "don't reverse" but in more ambiguous terms. I wonder if the tooth shape isn't symmetrical.
corrado33 is offline  
Old 08-16-17, 11:56 AM
  #19  
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 41,396

Bikes: 8

Mentioned: 188 Post(s)
Tagged: 0 Thread(s)
Quoted: 6950 Post(s)
Liked 257 Times in 211 Posts
IDK where you get your assumptions, Because, they make a threaded cog for fixies

21T Thread-on/Fixie CDX
fietsbob is offline  
Old 08-16-17, 11:58 AM
  #20  
corrado33
Senior Member
 
Join Date: Jun 2013
Location: Bozeman
Posts: 4,096

Bikes: 199? Landshark Roadshark, 198? Mondonico Diamond, 1987 Panasonic DX-5000, 1987 Bianchi Limited, Univega... Chrome..., 1989 Schwinn Woodlands, Motobecane USA Record, Raleigh Tokul 2

Mentioned: 24 Post(s)
Tagged: 0 Thread(s)
Quoted: 1125 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by fietsbob View Post
IDK where you get your assumptions, Because, they make a threaded cog for fixies

21T Thread-on/Fixie CDX
Very interesting. I pulled my info from their "tensioning and handling" page where it clearly states that

Note: the CDN system is not approved for use on mountain bikes, mid-drive eBikes or gear boxes, fixed gear bikes, or high mileage trekking/touring bikes.
I can only assume the "CDN" system is the carbon... drive....something. CDN isn't referred to elsewhere on the page.

Handling & Tension

EDIT: I got it. They have two different lines of products. A "rugged" product designed for fixies and off-road, and a normal product not "designed" for it.

Sounds like marketing hogwash to me.

Last edited by corrado33; 08-16-17 at 12:01 PM.
corrado33 is offline  
Old 08-16-17, 12:04 PM
  #21  
noglider 
aka Tom Reingold
 
noglider's Avatar
 
Join Date: Jan 2009
Location: West Village, New York City
Posts: 37,968

Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1973 Raleigh Twenty, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem

Mentioned: 454 Post(s)
Tagged: 0 Thread(s)
Quoted: 5866 Post(s)
Liked 364 Times in 258 Posts
Originally Posted by HillRider View Post
I wonder if the fixed gear prohibition is because the belt won't tolerate the torque reversal during braking. As to the other disclaimers, it seems the belt has a lower torque limitations then a chain and, as you noted, long term durability issues.
Is reverse torque higher than forward torque? If so, how?
__________________
Tom Reingold, tom@noglider.com
New York City and High Falls, NY
Blogs: The Experienced Cyclist; noglider's ride blog

“When man invented the bicycle he reached the peak of his attainments.” — Elizabeth West, US author

Please email me rather than PM'ing me. Thanks.
noglider is offline  
Old 08-16-17, 12:10 PM
  #22  
andr0id
Senior Member
 
andr0id's Avatar
 
Join Date: Feb 2009
Posts: 2,522
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 1421 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by velocentrik View Post

Gates belts are polyurethane. A toxic NOT environmentally friendly concoction of man's modern excess. There is a marketing gimmick to refer to Gates belts as carbon, but they are what they are.

The belts don't stretch. They are very reliable.
They are belted with carbon fiber cords. Obviously they must use a flexible poly as a belt material rather than rigid epoxy, but it is still a carbon fiber composite material just like the less flexible stuff they make airplanes and bicycle frames out of.
andr0id is offline  
Old 08-16-17, 12:24 PM
  #23  
ksryder
Senior Member
 
Join Date: May 2014
Posts: 2,276

Bikes: yes

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1041 Post(s)
Liked 284 Times in 169 Posts
Took this guy 19,000 miles to break his first belt: Review: Gates Carbon Belt Drive Centertrack - CyclingAbout

Can't remember the brand but I've seen an LBS selling belt-drive single speed and 3-speed commuters for ~$600. So they're out there.
ksryder is offline  
Old 08-16-17, 12:47 PM
  #24  
JDinTulsa
Senior Member
 
JDinTulsa's Avatar
 
Join Date: Jun 2017
Location: Tulsa, OK
Posts: 99

Bikes: Priority Continuum; Schwinn JetStar

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 11 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
CDN belt is for urban/city riding which "offers a lower-cost option for the casual rider."
CDX belt is for "high-mileage touring, competitive racing, or rugged off-roading" and "performs in the harshest conditions."

Bicycle Belt Drive Products Overview | Gates Carbon Drive?

FAQs

My Priority Continuum uses the CDN belt. I've stood on the pedals and pushed hard to get up a few hills, and haven't had any problems. Granted, I've only had it a few months and am just now coming up on 500 miles, but so far no problems or concerns with the belt.
JDinTulsa is offline  
Old 08-16-17, 02:49 PM
  #25  
davidallenxyz
Member
 
Join Date: Apr 2015
Posts: 46
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
IKEA sell a belt drive bike and it is £400 in the UK. I doubt they sell many in the UK market because it is an unconventional design to British eyes (coaster brakes for example). Perhaps an easier sell in Continental Europe.

I think there is merit in the belt drive from an engineering perspective (it's not just marketing), but the fact that market share for belt drive is tiny (I think I have only ever seen one belt-drive bike being ridden) suggests that chain drive is doing a pretty good job.
davidallenxyz is offline  

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.