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


Go Back   > >

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.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-03-02, 10:15 AM   #1
stewartp
put me back on my bike
Thread Starter
 
stewartp's Avatar
 
Join Date: Sep 2001
Location: La Rochefoucauld, Charente, France
Bikes: Airbourne Carpe Diem + own brand fixed gear
Posts: 329
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Scientific Method

"The real purpose of scientific method is to make sure Nature hasn't misled you into thinking you know something you don't actually know" - Robert Persig, Zen and the Art of Motorcycle Maintenance.

I was convinced the bottom bracket on my Airbourne was giving up. This was disappointing because it was a Campag Centaur with only 3000 klimotres on it.

The symptoms was an intermittant tick/rumble when pushing hard on the cranks when climbing a hill. It didn't happen when I stood up on the pedals.
It got worse and worse until it happened on every pedal stroke, and even on the slightest gradient. It didn't do it when the bike was under no load so I couldn't get it to happen on the bike stand.

The sound definitely seemed to come from the bottom bracket.
And because it occurred when pushing hard on the cranks, and not when coasting or cruising on the flat, I was sure it was the BB.

I shelled out for a new botom bracket and tool to remove it. Did the replace and stripped and cleaned up the chainrings while I was at it. The old BB was rusty on the outside and had a slight "notchy" feel. I was convinced I'd cured the problem.

Imagine my dissapointment to find no change.

Further investigation reveals the fault to be with the saddle!! (or perhaps seat post) I can get the same tick without pedalling and just rocking back and forward on the saddle!

When I climb hills in the saddle I must be shifting my position on the saddle slightly, and rocking too, whereas cruising I must use a more balanced "circular" pedalling motion.

doh!

Stew
__________________
The older I get the better I used to be.

Last edited by stewartp; 09-03-02 at 10:18 AM.
stewartp is offline   Reply With Quote
Old 09-03-02, 11:43 AM   #2
a2psyklnut
NCAA - DUAL CHAMPIONS!
 
a2psyklnut's Avatar
 
Join Date: Mar 2000
Location: From Sarasota, FL sitting in front of a computer spewing random thoughts!
Bikes: Intense Uzzi SL, Masi Speciale, Trek 3700 Nashbar Single Speed, Old Cilo Road frame
Posts: 7,964
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Well, it was about time to replace the bb anyways, now you've got the tools, the experience and keep the old bb as a backup!

Money well spent Regardless!

L8R
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming, "WOW, What a Ride!" - unknown
"Your Bike Sucks" - Sky Yaeger
a2psyklnut is offline   Reply With Quote
Old 09-03-02, 03:59 PM   #3
khuon
DEADBEEF
 
khuon's Avatar
 
Join Date: Aug 2002
Location: Catching his breath alongside a road near Seattle, WA USA
Bikes: 1999 K2 OzM, 2001 Aegis Aro Svelte
Posts: 12,242
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally posted by a2psyklnut
about time to replace the bb anyways
At only 3000km?
khuon is offline   Reply With Quote
Old 09-03-02, 04:16 PM   #4
Buddha Knuckle
Infamous Dumpster Diver
 
Buddha Knuckle's Avatar
 
Join Date: Jul 2002
Location: West Philly, PA
Bikes: '89 Nishiki Cascade (set-up as a tourer); '99 Gary Fisher Aquila; late 80's John Howard (by Dave Hesch); '70 Schwinn 3spd
Posts: 191
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Same thing happened to me, only I what I thought was a BB click was actually...a broken frame! You'd think that would be obvious, but that BB is like a mysterious black box. You could convince yourself that dwarves lived inside it if you had never seen the inside of one.

Evil bottom brackets...

BK
Buddha Knuckle is offline   Reply With Quote
Old 09-03-02, 05:09 PM   #5
Maelstrom 
Wood Licker
 
Maelstrom's Avatar
 
Join Date: Apr 2002
Location: Whistler,BC
Bikes: Transition Dirtbag, Kona Roast 2002 and specialized BMX
Posts: 16,885
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Wow I replace a bb every 2000 km. Sometimes sooner depending on how rough I am.
Maelstrom is offline   Reply With Quote
Old 09-03-02, 07:07 PM   #6
Jean Beetham Smith 
Slow Moving Vehicle
 
Jean Beetham Smith's Avatar
 
Join Date: Oct 2000
Location: Norwood, MA
Bikes: Felt F-70, Terry Madeleine, Novara Safari fully customized by me
Posts: 1,068
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Geeee, every 2000 km? Poor "Little Pony" has 3093 miles=4977km, and I haven't heard a peep from her BB. Maybe I better listen harder.
Jean Beetham Smith is offline   Reply With Quote
Old 09-04-02, 06:06 AM   #7
stewartp
put me back on my bike
Thread Starter
 
stewartp's Avatar
 
Join Date: Sep 2001
Location: La Rochefoucauld, Charente, France
Bikes: Airbourne Carpe Diem + own brand fixed gear
Posts: 329
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'd hope and expect to get 10000 out of a good Campag BB. Which is why I was disappointed when I thought it was collapsing after only 3000.
Especially since all my cycling is road and I'm not huge. (ducks as he makes reference to a Rants & raves thread)

Stew
__________________
The older I get the better I used to be.
stewartp is offline   Reply With Quote
Old 09-04-02, 06:26 AM   #8
chewa
The Flying Scot
 
chewa's Avatar
 
Join Date: Aug 2001
Location: North Queensferry Scotland and London (and France)
Bikes: Custom (Colin Laing) 531c fast tourer/audax, 1964 Flying Scot Continental, 1995 Cinelli Supercorsa, Holdsworth Mistral single speed, Dahon Speed 6 (folder), Micmo Sirocco and a few more
Posts: 1,902
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The other week my friend had a weird clicking coming from his bike. It dissapeared if he sat back and came back when he got on the drops.

After two stops to adjust everything in sight we noticed it was the zip pull on his jacket hitting the top tube.
__________________
plus je vois les hommes, plus j'admire les chiens

1985 Sandy Gilchrist-Colin Laing built 531c Audax/fast tourer.
1964 Flying Scot Continental (531)
1995 Cinelli Supercorsa (Columbus SLX)
1980s Holdsworth Mistral fixed (531)
2005 Dahon Speed 6 (folder)
(YES I LIKE STEEL)
2008 Viking Saratoga tandem
2008 Micmo Sirocco Hybrid (aluminium!)
2012 BTwin Rockrider 8.1
chewa is offline   Reply With Quote
Old 09-05-02, 06:56 AM   #9
stewartp
put me back on my bike
Thread Starter
 
stewartp's Avatar
 
Join Date: Sep 2001
Location: La Rochefoucauld, Charente, France
Bikes: Airbourne Carpe Diem + own brand fixed gear
Posts: 329
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
That's EXACTLY what I'm getting at. I hate when that happens.

Squeaky pedal cleats also cause panic attacks.

On my motorcycle I had a helmet with a visor that used to "ping" intermittantly in turbulent air. It sounded just like a metallic tick from the bars/forks/front end.

Also I've often had a terrible fright when roadworkers let rip with their pneumatic drill just as I'm wondering if there's a noise coming from the gearbox!

Stew
__________________
The older I get the better I used to be.
stewartp is offline   Reply With Quote
Old 09-05-02, 12:42 PM   #10
khuon
DEADBEEF
 
khuon's Avatar
 
Join Date: Aug 2002
Location: Catching his breath alongside a road near Seattle, WA USA
Bikes: 1999 K2 OzM, 2001 Aegis Aro Svelte
Posts: 12,242
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally posted by chewa
After two stops to adjust everything in sight we noticed it was the zip pull on his jacket hitting the top tube.
The origin and direction of a sound while on the bike can be so confusing. Once on a ride, I had a ticking noise that I thought was coming from my headset so I loosened the stem bolt and tried retightening it... didn't help... then I thought it was maybe a spoke or my hubs. The spokes were all tensioned properly. The sound only occurred when I hammered out of the saddle. I eventually realised it was coming from the zipper-pull of my jersey.

While on the STP, I was riding behind some guy who I thought was dragging his brakes. The noise was horrible... Then I realised it was occurring even when he wasn't braking. It was coming from his freehub! The thing sounded like it was about to detonate any minute. After a few miles, I decided to pass him because I couldn't take the noise any longer. It was a grinding/grating type of noise on the same level as nails across a chalkboard and it occurred anytime he freewheeled. I noticed that not many people rode around him for very long... poor guy. The bike looked in otherwise good condition.
khuon 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 04:43 PM.