ISIS Bearing Woes

[sspielman]

I would be really interested in hearing tales of woe of the short bearing lifespan of ISIS bottom brackets.....and more importantly, any tips or brand recommendations for longer lasting units.

[Dave]

I've had nothing but good luck with my ISIS BBs for over 3 seasons. FWIW, they have the same spindle diameter as a shimano octalink and the same bearing size restrictions.

For the maximum durability, try the latest FSA megaquad.

http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=29&pid=73

[Jeremy]

Both of the platinum series (steel and ti) from FSA are very nice. They use a wide double row bearing on both sides that substantially increases bearing life over a single row set up. That being said, there is an issue with ISIS bb's and durability. Because the difference between ID and OD is smaller on an ISIS bearing than the common square taper design (9mm vs 13mm), the individual balls are much smaller. These bearings have a lower load capacity and they are more prone to damage because of contamination. There are two primary causes of premature bearing failure: contamination and improper adjustment. Most modern bb's are the cartridge type and it is not possible to adjust the bearing preload. However, it is still important that the shell be properly faced (at least on the drive side). Unless the face is square to the threads, the bearings can be improperly loaded. If your frame is faced and you keep your bike clean, you should get very good life from either of the FSA bb's.

Jeremy

[pdxmech13]

what jermey said :cool:

[sspielman]

The BB in question has about 2k miles on it and has never been ridden in the rain. Upon heavy loading of the crank (as in standing to climb or sprinting) the BB will make a "tick" sound. The bearings feel smooth and spin freely without any roughness or sound. The sound has been isolated to the left side of the bb, as it can be replicated on the repair stand. The BB was tightly installed and grease was applied to all contact points during assembly. My inclination is to think that the bearings are fine, and that the sound is coming from the bearing/cup interface or fron the cup/shell interface. I am thinking of re-assembling with loctite applied to these areas...any thoughts?

[dave thompson]

The BB in question has about 2k miles on it and has never been ridden in the rain. Upon heavy loading of the crank (as in standing to climb or sprinting) the BB will make a "tick" sound. The bearings feel smooth and spin freely without any roughness or sound. The sound has been isolated to the left side of the bb, as it can be replicated on the repair stand. The BB was tightly installed and grease was applied to all contact points during assembly. My inclination is to think that the bearings are fine, and that the sound is coming from the bearing/cup interface or fron the cup/shell interface. I am thinking of re-assembling with loctite applied to these areas...any thoughts?
Instead of using Loctite, use teflon (plumber's) tape and liberal grease. Works for me!