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 10-18-06, 07:16 AM   #1
pel
Senior Member
Thread Starter
 
Join Date: Oct 2004
Location: Perth WA
Bikes:
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Anybody run a rear crankshaft bearing after 6000km??

Got a 2006 Cannondale Mountain Tandem in April 2006 for European tour.
Rear crankshaft bearing failed completely after 6000km.
Is this to be expected/normal??
Thanks
pel is offline   Reply With Quote
Old 10-18-06, 07:42 AM   #2
mrfish
Senior Member
 
Join Date: Dec 2005
Location: London, UK
Bikes: Trek T200 plus enough others to fill a large shed
Posts: 562
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
On a single bike, low quality b/bs ridden as winter trainers without mudguards can easily fail at about this mileage. Failure is normally due to lack of lubrication (being washed out as the bike is washed / spray from the road) rather than stresses per se. Thus you should view the current sealed b/bs as a disposable wear items.

Whether the economics are in favour of buying cheap or expensive depends how many $ you assign to changing the worn one. For example (in GBP):
I normally need to replace the 10 bottom of the range campag b/b in my training bike every 2 years. Cost per year 5 plus 1 change.
Record b/b in my race bike lasted 6 years. Theoretically you could replace the bearings, but I just bought a new one.
Cost per year 8.5 plus 1/6 change
My Royce bottom bracket cost 2.5x the Record one, but is now 12 years old, has had bearings changed once and is still sweet as a nut. It will probably last for ever. Disadvantage is that it won't be very light compared with b/bs and cranks available in 2020.
Cost per year 10 so far plus 1/12 change

The other cause of early failure on b/bs is having a poorly faced frame - have a look when you take out the failed b/b. Surfaces that the b/b screws into need to be smooth, bare metal all at 90 degrees. If it's not get your local shop to run their facing tool over it.
mrfish is offline   Reply With Quote
Old 10-18-06, 08:57 AM   #3
ElRey
Senior Member
 
Join Date: Aug 2005
Location: New Jersey
Bikes: Colnago C40 HP, Aegis Trident, Cannondale tandem
Posts: 491
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
yep. normal.
ElRey is offline   Reply With Quote
Old 10-18-06, 02:57 PM   #4
stapfam
Time for a change.
 
stapfam's Avatar
 
Join Date: Jan 2004
Location: 6 miles inland from the coast of Sussex, in the South East of England
Bikes: Dale MT2000. Bianchi FS920 Kona Explosif. Giant TCR C. Boreas Ignis. Pinarello Fp Uno.
Posts: 19,915
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by pel
Got a 2006 Cannondale Mountain Tandem in April 2006 for European tour.
Rear crankshaft bearing failed completely after 6000km.
Is this to be expected/normal??
Thanks
Had about the same milage when mine went. When it went- I wanted to fit a better quality Shimano BB in but due to the length- I couldn't. The quality as fitted was LX and in 118mm length, if I remember correctly. I could not get a 118 in XT so had to get the LX. By chance- I had an XT in 115 in my box for the Solo, and tried fitting it. It would fit. So I now have a 118 LX in the spares box and I am still running 118 on the front and the XT 115 on the rear. By adjusting the concentric off-centre, I still have the Crossover sprockets in line and the pilot has not realised that he is offset a fraction on his cranks. When I get round to it, I will fit an XT 115 on the front- some when.
__________________
How long was I in the army? Five foot seven.


Spike Milligan
stapfam is offline   Reply With Quote
Old 10-18-06, 10:23 PM   #5
zonatandem
Senior Member
 
zonatandem's Avatar
 
Join Date: Dec 2003
Location: Tucson, AZ
Bikes: Custom Zona c/f tandem + Scott Plasma single
Posts: 10,908
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Better quality sealed BB costs more to start but will be more cost efficient in the long run.
Had a Phil Wood BB get a bit loose after 30,000 miles. Phil replaced it, for free.
The other Phil lasted us 64,000 miles and still ran smoother than Campy when we sold that tandem.
Put 57,000 miles on 2 Syncross BB on another tandem, still working fine when we sold that tandem too.
Anybody can make something cheaper, but quality lasts . . .
zonatandem is offline   Reply With Quote
Old 10-21-06, 07:35 PM   #6
pel
Senior Member
Thread Starter
 
Join Date: Oct 2004
Location: Perth WA
Bikes:
Posts: 177
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks for your comments Mrfish, ElRey, Stapfam, Zonatandem.
Must admit I was disappointed at the Truvativ bearing failure at 6000km.

Will be following up on the one year warranty.
Regards
pel is offline   Reply With Quote
Old 10-25-06, 05:46 AM   #7
dubbelop
Senior Member
 
Join Date: Aug 2005
Location: Netherlands
Bikes: Santos Dual Travel touring tandem, MSC Zion MTB-tandem, Santos SCC03 MTB, Santos STR01 trekking bike, Cannondale F500 MTB, Kalkhoff E-bike, Centurion Cross 4000 cyclocross bike (converted to road bike)
Posts: 124
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by pel
Thanks for your comments Mrfish, ElRey, Stapfam, Zonatandem.
Must admit I was disappointed at the Truvativ bearing failure at 6000km.

Will be following up on the one year warranty.
Regards
FWIW: in the cycling community, the ISIS system is also known as the CRISIS system

I do the maintenance for a set of spinning bikes; we managed to destroy the Truvativ ISIS bottom bracket on the instructor bike (used in eighteen 45-min. spin classes a week) after just over a year. I replaced it with a 4-bearing 'Downhill' model by Truvativ, hoping this will hold up longer. The simple Shimano square-axle models last over three years and then sometimes the axle ends break off, the bearings never seize.

The ISIS problems are caused by the big axle. This is nice for stiffness but since the bottom brackets shells are still the same size, the bearings had to become smaller to accomodate the axle. Nowadays you get all kinds of BBs with 'outboard' bearings; not only with ISIS BBs, but also on Shimano's Octalink models. That's a workaround which turned out to be necessary to overcome the problems with the smaller bearings.
dubbelop 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 05:30 AM.