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 02-24-07, 08:58 AM   #1
sam83
On Two Wheels
Thread Starter
 
sam83's Avatar
 
Join Date: Mar 2005
Location: Middle Tennessee
Bikes: Moots Vamoots, Bianchi Volpe, 2 Salsa Casserolls (fixed & Triple), 2011 Salsa Chili Con Crosso, 1983 Schwinn Supersport, Schwinn Mesa MTB
Posts: 511
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Bottom Bracket Smooth, but...

I've got a Truvativ Giga Pipe Ti bottom braket that turns very smoothly, but with a noticable resistance when compared to my old Ultegra 9-spd bottom brackets. It's been that way for over 2000 miles and turns the same installed or not.

So, I bought a Truvativ Giga Pipe team SL and it feels similar; smooth, but with resistance. Like it's in thick grease.

Did a crank conversion on a friend's bike and have a left over FSA Platinum bottom bracket. It has noticably less resistance, but maybe not as easily as the Ultegra.

Are these Truvativ bottom brackets steeling what little power I have?!

What's a good choice for an ISIS BB for road use?
sam83 is offline   Reply With Quote
Old 02-24-07, 11:17 AM   #2
MudPie
Senior Member
 
MudPie's Avatar
 
Join Date: May 2004
Location: Southern California
Bikes:
Posts: 1,874
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Dang good question. I too would like some suggestions. I installed a Truvativ Gigapipe about nine months back and as I spin the spindle with my fingers, it's smooth, but stiff. I've learned to live with it and consider it a "training feature". When it's off the bike it spins easier, but once mounted, it stiffens. The original bottom bracket was always easy to spin. I've installed it the recommended installtion torque, too. I'm hoping my bottom bracket shell is not distorting it.

I looked up bottom brackets on http://www.mtbr.com/reviews/bottom_bracket/ and it seems most of the more common ISIS BBs (Race Face, Truvativ, FSA) had extremely poor ratings and common talk of bearing failure measured in months. As a corollary to the original post:

1. Why do ISIS BBs have such poor quality (or is it just a few disgruntled riders complaining the loudest?)
2, BBs are relatively simple - spindle, cartrdige bearings, seals, and cups - what can go wrong?
MudPie is offline   Reply With Quote
Old 02-24-07, 12:26 PM   #3
Nessism
Senior Member
 
Nessism's Avatar
 
Join Date: Jun 2004
Location: Torrance, CA
Bikes: Homebuilt steel
Posts: 2,332
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
No worry about a little seal drag in the bottom bracket. As I recall, Velonews quantified the power loss to be all of 1 Watt from this. My farts generate more power than that so I don't waste time thinking it.
__________________
Becareful buying/selling bike parts on-line. I learned the hard way. :(

Good/Bad Trader Listing
Nessism is offline   Reply With Quote
Old 02-24-07, 12:33 PM   #4
TO11MTM
Senior Member
 
Join Date: Mar 2006
Bikes:
Posts: 387
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by MudPie
Dang good question. I too would like some suggestions. I installed a Truvativ Gigapipe about nine months back and as I spin the spindle with my fingers, it's smooth, but stiff. I've learned to live with it and consider it a "training feature". When it's off the bike it spins easier, but once mounted, it stiffens. The original bottom bracket was always easy to spin. I've installed it the recommended installtion torque, too. I'm hoping my bottom bracket shell is not distorting it.

I looked up bottom brackets on http://www.mtbr.com/reviews/bottom_bracket/ and it seems most of the more common ISIS BBs (Race Face, Truvativ, FSA) had extremely poor ratings and common talk of bearing failure measured in months. As a corollary to the original post:

1. Why do ISIS BBs have such poor quality (or is it just a few disgruntled riders complaining the loudest?)
2, BBs are relatively simple - spindle, cartrdige bearings, seals, and cups - what can go wrong?
There's a few factors working against an ISIS BB; the primary of these is the size of the Euro/English BB Shell compared to the size of the spindle; especially compared to that of a square taper. The Larger ISIS Spindle size means you have to use smaller balls in the bearings, and that typically leads to shorter lifespan (Oddly enough Shimano's Octalink stuff holds up quite nicely even though in theory it has the same drawback... I wonder why.)
TO11MTM 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 04:12 PM.