Road Cycling - Bottom bracket compatibility.

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View Full Version : Bottom bracket compatibility.


Patriot
08-24-04, 12:22 PM
I have an old Centurion Ironman from 1989, and it has a full Suntour GPX component group. The problem I am having is that when I go up a steep hill and really put serious power stroke torque on the crank, it flexes so much that the front derailer rubs the chain from side to side on each stroke. The frame appears to be fine, no crakcs or damage that I can see.

So, the only thing I can think of is that the bottom bracket is just old and it flexes too much for me, and I would like to get one that is much stronger than the original. It is the square peg design.

Will brackets made by Shimano fit? Are they all pretty much standard size? Or, do I need to try and find one made specifically by Suntour. Hardly anybody carries anything made by Suntour anymore, as they are pretty much a thing of the past.

Any recommendations?

Patriot


sydney
08-24-04, 01:19 PM
I have an old Centurion Ironman from 1989, and it has a full Suntour GPX component group. The problem I am having is that when I go up a steep hill and really put serious power stroke torque on the crank, it flexes so much that the front derailer rubs the chain from side to side on each stroke. The frame appears to be fine, no crakcs or damage that I can see.

So, the only thing I can think of is that the bottom bracket is just old and it flexes too much for me, and I would like to get one that is much stronger than the original. It is the square peg design.

Will brackets made by Shimano fit? Are they all pretty much standard size? Or, do I need to try and find one made specifically by Suntour. Hardly anybody carries anything made by Suntour anymore, as they are pretty much a thing of the past.

Any recommendations?

Patriot I seriously doubt you are flexing the spindle.The cranks or frame maybe.The only really stiffer spindle is one that would be significantly shorter or an an octalink or isis type, which would also require a new crank.

Patriot
08-24-04, 03:07 PM
Maybe the cranks then. I don't really know. All I know is that I wish it didn't flex so much, but it doesn't seem to be hurting anything. It's just annoying.

Patriot