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


Go Back   > >

Commuting Bicycle commuting is easier than you think, before you know it, you'll be hooked. Learn the tips, hints, equipment, safety requirements for safely riding your bike to work.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 08-16-13, 07:37 AM   #1
genel
Senior Member
Thread Starter
 
genel's Avatar
 
Join Date: Dec 2004
Location: Antioch, IL
Bikes: Giant Defy Advanced I, Montague folding bike, and Cannondale Road Warrior 500
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Seat Post failure

Shortly after I started home (13m) the saddle mount on the seat post failed. It is a single boltstyle and the bolt failed. It fell in the grass along the bike path and was lost forever. I searched for about 15min. Unfortunately it took the top half the clamp with it. So the spare bolt I carry was useless.

Riding the full 13m while standing was quite a workout.

LBS had a spare clamp that fit so all is well. I thought I was covered by carrying a spare bolt, but Murphy never sleeps.
__________________
"Why is there a hill after every meal, but not a meal after every hill?"
--Overheard on Grabaawr
genel is offline   Reply With Quote
Old 08-16-13, 08:10 AM   #2
Bjforrestal
Senior Member
 
Join Date: Jul 2013
Location: South St. Paul, MN
Bikes: Trek 520, Peugeot PX-10
Posts: 260
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Seat Post failure

I am trying to visualize how it is possible to loose the bolt, nut and collar...how loose was the bolt? Figured the loose clamp would've had your seat post slipping like crazy. Need more details....I mean I've lost a kickstand on a motorcycle, but this seems bizzare
Bjforrestal is offline   Reply With Quote
Old 08-16-13, 08:39 AM   #3
Dwayne
Rocketship Underpants
 
Dwayne's Avatar
 
Join Date: Sep 2005
Location: Atlanta, GA
Bikes: '94 RS Bikes Stampede (commuter), Scattante XRL Team road bike (formerly '05 Cannondale R5000), '05 Cannondale Prophet 1000
Posts: 328
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Bjforrestal View Post
I am trying to visualize how it is possible to loose the bolt, nut and collar...how loose was the bolt? Figured the loose clamp would've had your seat post slipping like crazy. Need more details....I mean I've lost a kickstand on a motorcycle, but this seems bizzare
Bolt wasn't loose, it broke, at least that's the way I understand it. Wouldn't be as tragic on a two-bolt seatpost, but on a one-bolt, yup, there goes the whole kit and kaboodle.
Dwayne is offline   Reply With Quote
Old 08-16-13, 01:54 PM   #4
Bjforrestal
Senior Member
 
Join Date: Jul 2013
Location: South St. Paul, MN
Bikes: Trek 520, Peugeot PX-10
Posts: 260
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Seat Post failure

Crazy. Better than a wheel I suppose.
Bjforrestal is offline   Reply With Quote
Old 08-16-13, 03:37 PM   #5
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Bikes: Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
Posts: 18,052
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Quote:
Originally Posted by genel View Post
Shortly after I started home (13m) the saddle mount on the seat post failed. It is a single boltstyle and the bolt failed. It fell in the grass along the bike path and was lost forever. I searched for about 15min. Unfortunately it took the top half the clamp with it. So the spare bolt I carry was useless.

Riding the full 13m while standing was quite a workout.

LBS had a spare clamp that fit so all is well. I thought I was covered by carrying a spare bolt, but Murphy never sleeps.
Pish! What's 13 miles? If Cindy Whitehead can ride 50 miles race and win, what are you complaining about?
__________________
Stuart Black
New! Pokin' around the Poconos A cold ride around Lake Erie
New! Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline   Reply With Quote
Old 08-16-13, 04:25 PM   #6
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Bikes: '15 Kinesis Racelight 4S, '76 Motebecane Gran Jubilée
Posts: 7,882
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 213 Post(s)
A seatpost clamp bolt broke? That's gotta be one of the rarest failures of all possible failures, right up there with brake lever mounting bolt failure and top cap bolt failure. I wouldn't ride that bike until you get it exorcized; stem might break.
chaadster is offline   Reply With Quote
Old 08-16-13, 04:38 PM   #7
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 20,393
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 643 Post(s)
so what better an excuse to buy a new seatpost can you get.

Lapade and a bunch of other cheap posts are often specified just to keep the price point down ..

how about a Cane Creek Thudbuster .. I have a LT on my BiFri, thinking of a ST for my Koga WTR, it has a sus post now

thats fine , but zero setback the other has setback .. seat tube is a bit steep.
fietsbob is offline   Reply With Quote
Old 08-16-13, 09:36 PM   #8
Bjforrestal
Senior Member
 
Join Date: Jul 2013
Location: South St. Paul, MN
Bikes: Trek 520, Peugeot PX-10
Posts: 260
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Seat Post failure

Ok even if the bolt busted how does the clamp fall off? All of my bikes I have to remove the seat post and remove it from the top. Still confused, and baffled. It's going to keep me up tonight.
Bjforrestal is offline   Reply With Quote
Old 08-17-13, 07:55 AM   #9
cyccommute 
Mad bike riding scientist
 
cyccommute's Avatar
 
Join Date: Nov 2004
Location: Denver, CO
Bikes: Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
Posts: 18,052
Mentioned: 8 Post(s)
Tagged: 0 Thread(s)
Quoted: 222 Post(s)
Quote:
Originally Posted by Bjforrestal View Post
Ok even if the bolt busted how does the clamp fall off? All of my bikes I have to remove the seat post and remove it from the top. Still confused, and baffled. It's going to keep me up tonight.
The bolt keeps the whole clamp assembly in place, especially for a single bolt clamp. Remove the bolt and everything falls to pieces. I'm not sure what kind of clamp you are using, however. All of the single bolt clamps I've used are tightened from under the saddle and the bolt goes into a threaded "nut" on top of the clamp. The "nut" sits in a recess that keeps it from turning. I've had a couple of PITA dual bolt systems that used a bolt under the saddle for leveling but those are pretty rare.
__________________
Stuart Black
New! Pokin' around the Poconos A cold ride around Lake Erie
New! Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Days of Wineless Roads. Bed and Breakfasting along the KATY
Twisting Down the Alley. Misadventures in tornado alley.
An Good Ol' Fashion Appalachian Butt Whoopin'.
cyccommute is offline   Reply With Quote
Old 08-17-13, 08:05 AM   #10
Bjforrestal
Senior Member
 
Join Date: Jul 2013
Location: South St. Paul, MN
Bikes: Trek 520, Peugeot PX-10
Posts: 260
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cyccommute View Post
Quote:
Originally Posted by Bjforrestal View Post
Ok even if the bolt busted how does the clamp fall off? All of my bikes I have to remove the seat post and remove it from the top. Still confused, and baffled. It's going to keep me up tonight.
The bolt keeps the whole clamp assembly in place, especially for a single bolt clamp. Remove the bolt and everything falls to pieces. I'm not sure what kind of clamp you are using, however. All of the single bolt clamps I've used are tightened from under the saddle and the bolt goes into a threaded "nut" on top of the clamp. The "nut" sits in a recess that keeps it from turning. I've had a couple of PITA dual bolt systems that used a bolt under the saddle for leveling but those are pretty rare.
I was thinking of the seat post collar, this makes much more sense thank god I thought I was loosing my mind!
Bjforrestal is offline   Reply With Quote
Old 08-17-13, 09:27 AM   #11
rebel1916
Senior Member
 
rebel1916's Avatar
 
Join Date: Aug 2011
Bikes:
Posts: 2,992
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Great opportunity to go carbon. Lighter, stronger, more comfortable.
rebel1916 is offline   Reply With Quote
Old 08-19-13, 08:38 AM   #12
genel
Senior Member
Thread Starter
 
genel's Avatar
 
Join Date: Dec 2004
Location: Antioch, IL
Bikes: Giant Defy Advanced I, Montague folding bike, and Cannondale Road Warrior 500
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
To answer a few of the questions. The seat post is a suspension post that came with the Cannondale. The bolt goes up through the mount on the post through the clamp. It is(was) quite tight as any loosening allows the saddle to shift positions. The bolt fails at the bottom of the upper clamp. This is the third time I've had one fail. First time I was only a mile or so from a hardware store, Second time I had a spare with me. This time, as I said, the upper clamp and the broken bolt section, fell in the grass along the bike path, and disappeared, so my spare bolt was useless. My best guess is about 8000 miles between failures, so not something I worry all that much about. Probably should be a hardened aircraft grade bolt but they're not easily available at the local Ace.
__________________
"Why is there a hill after every meal, but not a meal after every hill?"
--Overheard on Grabaawr
genel is offline   Reply With Quote
Old 08-19-13, 09:19 AM   #13
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 20,393
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 643 Post(s)
''//,, I have a Cane Creek Thudbuster seat post, now.. an excellent suspension seat post.

It's not a telescopic seatpost.. and so will not have the saddle wiggling radially around the posts axis.

CC offers several rider weight appropriate Elastomers .. to fine tune them.

http://www.canecreek.com/products/seatposts

Last edited by fietsbob; 08-19-13 at 09:29 AM.
fietsbob is offline   Reply With Quote
Old 08-19-13, 09:26 AM   #14
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 20,393
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 643 Post(s)
Quote:
Probably should be a hardened aircraft grade bolt but they're not easily available at the local Ace.
or the auto parts store , [try] bolts marked 8.8, are stronger than the generic mild steel in hardware store bolts.

FAA certified bolts will be really pricy.
fietsbob is offline   Reply With Quote
Old 08-19-13, 02:39 PM   #15
genel
Senior Member
Thread Starter
 
genel's Avatar
 
Join Date: Dec 2004
Location: Antioch, IL
Bikes: Giant Defy Advanced I, Montague folding bike, and Cannondale Road Warrior 500
Posts: 326
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by fietsbob View Post
or the auto parts store , [try] bolts marked 8.8, are stronger than the generic mild steel in hardware store bolts.

FAA certified bolts will be really pricy.
Oddly enough I never thought of the Auto Parts Store, I'm on it!
__________________
"Why is there a hill after every meal, but not a meal after every hill?"
--Overheard on Grabaawr
genel is offline   Reply With Quote
Old 08-19-13, 05:17 PM   #16
modernjess
ride for a change
 
modernjess's Avatar
 
Join Date: Nov 2006
Location: Minneapolis, MN
Bikes: Surly Cross-check & Moonlander, Pivot Mach 429, Ted Wojcik Sof-Trac, Ridley Orion. Santa Cruz Stigmata
Posts: 2,225
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Buy a thomson post and be done with it . Just my $.02.
modernjess is offline   Reply With Quote
Old 08-20-13, 03:59 AM   #17
billyymc
Senior Member
 
Join Date: Nov 2010
Bikes:
Posts: 944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Quote:
Originally Posted by chaadster View Post
A seatpost clamp bolt broke? That's gotta be one of the rarest failures of all possible failures, right up there with brake lever mounting bolt failure and top cap bolt failure.
I've had it happen. It's quite a surprise when you're cruising along and - SNAP - the seat goes out from under you.
billyymc is offline   Reply With Quote
Old 08-20-13, 05:22 AM   #18
Germany_chris
Senior Member
 
Germany_chris's Avatar
 
Join Date: Jan 2010
Location: Southern Germany
Bikes:
Posts: 705
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by modernjess View Post
Buy a thomson post and be done with it . Just my $.02.
Hes should definitely spend $100 on a new seat post over $1.50 to fix his current one.
Germany_chris is offline   Reply With Quote
Old 08-20-13, 06:23 AM   #19
chaadster
Thread Killer
 
Join Date: Aug 2008
Location: Ann Arbor, MI
Bikes: '15 Kinesis Racelight 4S, '76 Motebecane Gran Jubilée
Posts: 7,882
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 213 Post(s)
Quote:
Originally Posted by billyymc View Post
I've had it happen. It's quite a surprise when you're cruising along and - SNAP - the seat goes out from under you.
Wow, really? Okay, it's not that I don't believe it, but I just want to make sure that something else isn't going on.

I mean, I've been a strong, aggressive, 200lb rider since the mid-80s, back in the days when MTB specific stuff was kinda rare, and we'd even run road gear on the trail to get lighter stuff, or even drill out clamps and stuff to shave grams. Bombing trails from the Apennines to the Rockies to Moab, not only have I never broken a seat clamp bolt, I don't recall seeing anyone break one. I've also ridden the road all that time too, and never seen that, either. Pedal spindles snap, seat rails break, handlebars crack, frames break, fork dropouts fail...I've seen just about everything break except seat clamp bolts and stems.

So forgive me for being very surprised to hear the OP has had two seat clamp bolt failures. I just wonder if it could be due to a stripped nut, overtorqued bolt, or wrong bolt threading or spec. I just cannot imagine how a seatclamp bolt head could shear off...
chaadster is offline   Reply With Quote
Old 08-20-13, 09:33 AM   #20
billyymc
Senior Member
 
Join Date: Nov 2010
Bikes:
Posts: 944
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 33 Post(s)
Quote:
Originally Posted by chaadster View Post
Wow, really? Okay, it's not that I don't believe it, but I just want to make sure that something else isn't going on.
Yes really. I can't really tell you why it broke - don't think it was overtorqued or damaged in any way. It was on a 2007 Specialized Tricross Comp (2007). I bought it used with almost no miles at all on it, and I had been riding it for a year or so when it occurred. I inspected the bolt - didnt seem to be any real problems with it. Fortunately I was only a mile from a LBS and had it fixed up within just a few minutes.

Replaced it with a larger diameter bolt (that still fit the clamp/post). It's a single bolt clamp. The owner at the LBS - in the business for at leaset 30 years - didn't express any surprise at the broken bolt. Have about 8k miles on the bike since then, no issues with the new seat bolt (yet!).
billyymc is offline   Reply With Quote
Old 08-20-13, 09:46 AM   #21
PatrickGSR94
Senior Member
 
PatrickGSR94's Avatar
 
Join Date: Apr 2012
Location: Memphis TN area
Bikes: 2011 Felt Z85 (road/commuter), 2006 Marin Pine Mountain (utility), 1995 KHS Alite 1000 (gravel grinder)
Posts: 6,179
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Quote:
Originally Posted by cyccommute View Post
Pish! What's 13 miles? If Cindy Whitehead can ride 50 miles race and win, what are you complaining about?
Rob Greenfield just completed his Off The Grid bike ride across America journey, and I heard on a recent episode of the Outspoken Cyclist podcast that he rode across an entire state standing up, with no saddle. 300+ miles.

http://www.greenfieldadventures.org/...ss-america/cp4
PatrickGSR94 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 09:50 PM.