Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

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!

User Tag List

Reply
 
Thread Tools Search this Thread
Old 06-20-12, 02:45 PM   #1
EnzoRWD
enginerd
Thread Starter
 
Join Date: Nov 2005
Location: MKE
Bikes: Cannondale Track, Romic Track, GT Track, 3Rensho, Cinelli Supercorsa, Burley tandem, Cinelli Zydeco, Stevens Ventoux, Bianchi, 29er, Mash SSCX, Dahon
Posts: 520
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
check braking surfaces for wear! yeesh

Had a tire blow off the rim after fixing a routine flat. Saw this:


Upon closer inspection, there were several small dings around the rim. The braking surface was very, very worn. We built this 48H Deep V wheel about 4 years ago. I guess it's a great sign we're riding enough!

I know the black arts so rebuilding to a fresh rim was no big deal.


All done!


With higher loads and higher speeds of tandems, this was a good wake-up call to pay close attention to details.
EnzoRWD is offline   Reply With Quote
Old 06-20-12, 03:45 PM   #2
Tandem Tom
Senior Member
 
Join Date: Dec 2011
Location: NE Ohio
Bikes: 1992 Serotta Colorado II,Co-Motion Speedster, Giant Escape Hybrid, 1977 Schwinn Super Le Tour
Posts: 1,318
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 14 Post(s)
Learning to build a wheel is one of my winter projects! I already asked the LBS guys if they might teach me.
Tandem Tom is offline   Reply With Quote
Old 06-20-12, 04:07 PM   #3
EnzoRWD
enginerd
Thread Starter
 
Join Date: Nov 2005
Location: MKE
Bikes: Cannondale Track, Romic Track, GT Track, 3Rensho, Cinelli Supercorsa, Burley tandem, Cinelli Zydeco, Stevens Ventoux, Bianchi, 29er, Mash SSCX, Dahon
Posts: 520
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
go for it! it's actually pretty straightforward. it's math, not voodoo. take your time, don't be afraid to start over to correct tension errors, and you'll get it. I've had many a wheel that had a hop that could only be fixed by detensioning and starting over. a pain in the butt but in the end the wheel is better for it.

this is all you need:
EnzoRWD is offline   Reply With Quote
Old 06-20-12, 06:21 PM   #4
CaptainHaddock
Senior Member
 
CaptainHaddock's Avatar
 
Join Date: Feb 2012
Location: PDX!
Bikes: Custom Single, factory fixed, Cannondale RT2
Posts: 252
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by EnzoRWD View Post
I know the black arts so rebuilding to a fresh rim was no big deal.
So we're talking sacrificing chickens, rattling bones and burning the black candle? Nice!
CaptainHaddock is offline   Reply With Quote
Old 06-20-12, 06:35 PM   #5
prathmann
Senior Member
 
Join Date: Nov 2008
Location: Bay Area, Calif.
Bikes:
Posts: 6,142
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 113 Post(s)
Quote:
Originally Posted by EnzoRWD View Post
this is all you need:
I've found a spoke wrench and a new rim (with compatible ERD) to be useful as well.
prathmann is offline   Reply With Quote
Old 06-20-12, 09:47 PM   #6
obrentharris 
Senior Member
 
obrentharris's Avatar
 
Join Date: May 2012
Location: San Francisco Bay Area
Bikes: fewer (n-1)
Posts: 1,156
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 27 Post(s)
Many years ago Robert Wright, a wheelbuilder from Santa Cruz, CA, put out a little book called "Building Bicycle Wheels" a very nice, concise how-to book. It still pops up used pretty regularly.
Brent
obrentharris is offline   Reply With Quote
Old 06-20-12, 11:48 PM   #7
Carbonfiberboy 
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Posts: 11,358
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 144 Post(s)
Usually I feel it in the brakes before the rim actually goes. Usually there'll be one spot that's a little thinner and it'll start pooching out and I'll feel it. I'll stop braking on that wheel and creep home. With the higher pressures on tandem tires, though, that margin of safety is uncomfortably small, so I'll replace my rims earlier than I would on my single.
Carbonfiberboy is offline   Reply With Quote
Old 06-21-12, 09:39 AM   #8
tandem rider
Senior Member
 
Join Date: Dec 2005
Location: Indianapolis, IN
Bikes: Co-Motion tandem, Serotta, and Specialized mt. bike
Posts: 348
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
One advantage to disc brakes is the rim is not worn down from braking.
tandem rider is offline   Reply With Quote
Old 06-21-12, 10:05 AM   #9
msvphoto
Senior Member
 
Join Date: Mar 2008
Location: Santa Cruz, CA
Bikes: a lot... mostly vintage, one vintage made of plastic, er carbon
Posts: 88
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by tandem rider View Post
One advantage to disc brakes is the rim is not worn down from braking.
Good point, but I kinda doubt the rim damage in the OP's picture was caused by braking (but perhaps a lack of braking before hitting a giant pothole, or something). I don't have a lot of tandem experience, but I have always been a fairly heavy rider and live in a hilly area. In 40 years of riding I have never worn through rim braking surfaces before other issues (like the picture above) destroyed the wheel.

Great recommendations for both books. Building a good wheel isn't real difficult to do if you pay attention to details. It has been years since I built a wheel, but this thread is encouraging me to do so when I am ready to switch our vintage Santana over from 27" to 700c
msvphoto is offline   Reply With Quote
Old 06-21-12, 10:57 AM   #10
B. Carfree
Senior Member
 
Join Date: Jan 2010
Location: Eugene, Oregon
Bikes:
Posts: 6,302
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Quote:
Originally Posted by msvphoto View Post
Good point, but I kinda doubt the rim damage in the OP's picture was caused by braking (but perhaps a lack of braking before hitting a giant pothole, or something). I don't have a lot of tandem experience, but I have always been a fairly heavy rider and live in a hilly area. In 40 years of riding I have never worn through rim braking surfaces before other issues (like the picture above) destroyed the wheel.

Great recommendations for both books. Building a good wheel isn't real difficult to do if you pay attention to details. It has been years since I built a wheel, but this thread is encouraging me to do so when I am ready to switch our vintage Santana over from 27" to 700c
I had a wheel give me 250,000 miles (on a single), but that was in the Bay Area/Central Valley. It's just different in places where the roads get covered in wet grit (wet by rain, grit by the county roads department). Rim life is pretty short when the brake pads get that sand-paper assist and they do blow out just like the OP shows, usually just after being re-inflated.
B. Carfree is offline   Reply With Quote
Old 06-21-12, 12:00 PM   #11
Carbonfiberboy 
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Posts: 11,358
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 144 Post(s)
Quote:
Originally Posted by msvphoto View Post
Good point, but I kinda doubt the rim damage in the OP's picture was caused by braking (but perhaps a lack of braking before hitting a giant pothole, or something). I don't have a lot of tandem experience, but I have always been a fairly heavy rider and live in a hilly area. In 40 years of riding I have never worn through rim braking surfaces before other issues (like the picture above) destroyed the wheel.

Great recommendations for both books. Building a good wheel isn't real difficult to do if you pay attention to details. It has been years since I built a wheel, but this thread is encouraging me to do so when I am ready to switch our vintage Santana over from 27" to 700c
On my single, I have to replace a rim about every 2 years. On the tandem, we go through about a rim/year. I've never had a wheel fail except by rim wear, or even a spoke break. OTOH, I build most of my own wheels and use and maintain reliable hubs. My rim failures are usually not so abrupt, the "pooch" being more like 6" long.

Yeah, definitely build your own wheels. You do need a Park TM-1 tension meter. It will pay for itself in two wheels. Besides, it's fun and you get more reliable wheels. When I buy my spokes, I spec the hub and rim and the shop sells me the correct length. I know, I could figure it myself, but it's nice to have the vendor spec it. I always use DT 14-15 double butted spokes, for my singles and tandem. Deep V's build up nicely for our tandem.
Carbonfiberboy is offline   Reply With Quote
Old 06-21-12, 04:01 PM   #12
msvphoto
Senior Member
 
Join Date: Mar 2008
Location: Santa Cruz, CA
Bikes: a lot... mostly vintage, one vintage made of plastic, er carbon
Posts: 88
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Wow, never too old to stop learning as they say! Failures like that are what make me really miss riding tubulars (which I wouldn't be using on either my tandem or my commute bike which besides spin class "bikes" account for the vast majority of my riding now). Really good to know. I would have sworn that was from a pothole, but in thinking about it I get it now. Thank you for the clarification! I guess my commute bike is just so overbuilt (super-strong 26" MTB wheels) it hasn't been an issue (this despite a 800 foot daily descent rain or shine).
msvphoto is offline   Reply With Quote
Old 06-21-12, 04:11 PM   #13
Dean V
Senior Member
 
Join Date: Oct 2009
Bikes:
Posts: 1,130
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 20 Post(s)
Does anyone else think that rims used to wear less? When I was riding 20+ years ago I don't recall rims wearing out as fast as they seem to now.
Dean V is offline   Reply With Quote
Old 06-22-12, 04:54 AM   #14
bikeinxs
Senior Member
 
Join Date: May 2008
Location: Ottawa, Canada
Bikes: Ibis Cousin It converted to a drop bar road cruiser, Comotion Speedster, garage full of half bikes
Posts: 73
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dean V View Post
Does anyone else think that rims used to wear less? When I was riding 20+ years ago I don't recall rims wearing out as fast as they seem to now.
I don't know about you, but 20 years ago now only did I weigh less but I thought I was immortal which I expect led to far less use of the brakes
bikeinxs is offline   Reply With Quote
Old 06-22-12, 09:33 AM   #15
msvphoto
Senior Member
 
Join Date: Mar 2008
Location: Santa Cruz, CA
Bikes: a lot... mostly vintage, one vintage made of plastic, er carbon
Posts: 88
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Dean V View Post
Does anyone else think that rims used to wear less? When I was riding 20+ years ago I don't recall rims wearing out as fast as they seem to now.
My bicycle mechanical mindset is obviously lost in the 1970s, but best I can recall rim failures like in the above photo from brake wear were pretty much unheard of "back in the day" unless you hit something hard, like a pothole, with low tire pressure. Then again, we all rode on silk sew-ups back then (and learned how to repair them every which way at Jobst Brandt's Redwood City home while he held court for all us young riders). I am beginning to think this is a clincher thing, which kinda makes sense.

I think this accelerates the plan to ditch our 27" wheels for new 700c wheels once we wear the current set of Gatorskins out. Thanks again for the heads up!
msvphoto is offline   Reply With Quote
Old 06-22-12, 11:11 AM   #16
Carbonfiberboy 
just another gosling
 
Carbonfiberboy's Avatar
 
Join Date: Feb 2007
Location: Everett, WA
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Posts: 11,358
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 144 Post(s)
To keep track of brake track wear, you really need a pin micrometer. I have a physicist friend who owns a machine shop and uses one. IIRC he said 1.5mm is about the failure point on his singles. Tandems should be more conservative.
Carbonfiberboy is offline   Reply With Quote
Old 06-25-12, 06:39 AM   #17
EnzoRWD
enginerd
Thread Starter
 
Join Date: Nov 2005
Location: MKE
Bikes: Cannondale Track, Romic Track, GT Track, 3Rensho, Cinelli Supercorsa, Burley tandem, Cinelli Zydeco, Stevens Ventoux, Bianchi, 29er, Mash SSCX, Dahon
Posts: 520
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Quote:
Originally Posted by Dean V View Post
Does anyone else think that rims used to wear less? When I was riding 20+ years ago I don't recall rims wearing out as fast as they seem to now.
A guru at a shop once told me this is partly due to much more effective modern brakes. Road dual pivots, linear pull mtn brakes with modern pads have more squeeze than sidepulls ever did.
EnzoRWD is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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



All times are GMT -6. The time now is 10:27 AM.