I bought the FSA titanium platinum set up, I will call them and inquire on there bearing's or any problems theese bottom bracket's may have had, though you know they will say WHAT PROBLEMS .
Giovanni.

< Why buying one of the lightest crank arms when you have to stick with heavy ISIS BBs? >

There are light ISIS BB's like Pazzaz and FRM. And you get the axle stiffeness compared to square taper if that's important to you.

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Ride lightly!

My experience with ISIS BBs is that the lighter they are, the earlier they fail. I've seen so many ISIS BBs with defective bearings, I can't count 'em anymore.

IMHO ISIS is a single design flaw.
The axle diameter was dimensioned too big, leaving too less space for normal-sized bearings, that's why small bearings have to be used which can't withstand the load. Now Race Face is trying to solve it by positioning the bearings on the outside of the BB shell (just like Shimano).

The only ISIS BBs that tend to last longer are the heavier DH ones.
But who wants to ride a 300 g Race Face DH BB?

Stiffness of Power Arms Pro ISIS compared to square taper version:
I expect only a very minimal boost in stiffness by adding an ISIS interface to the Power Arms Pro.
To overstate it little bit: you can't make a wet noodle stiff.

Thats why I want ISIS, axel stiffness. The ISIS axel has a much larger diameter then the square taper, plus the square taper design has a greater tendency to wear and come loss, causing that dreaded squeek from below. As for bearing problems, yeah there are more, because of the large axel the bearings have to be smaller, i.e. not as durable, but through better design ISIS are becoming much more relieable. And they are lite too! American classic has a cromolly spindle BB that weighs 140g and with replaceable bearings, so if you did have problems then it could be easily sovled. The lightest square taper BB I saw was 135g, so why are you saying ISIS weigh alot more? 5g for added stiffness and interface durability are the whey to go!

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MAMA SAID KNOCK YOU OUT! HUH!

giovanni,
You can get TA or Tiso chainrings at around 120g for 53/39.

And why don't bike manufacturers build their bikes with ISIS BBs?
Because they don't want to exchange every second BB within a year.

So Florian are you saying that Power Arms are not stiff at all? Compared to what?

I think it all depends on how well you take care of your bike, how much you weigh and how you ride. I use a DA BB with octalink, know to lots of people to be as bad as ISIS, if not worse. But I have put over 13,000 miles on mine this season and it works perfect. the only problem I ever had was when I was riding in the rain for about a week when water got in the BB. Started making noise, so I took my bike to the shop, they drained the water regreased, and adjusted, and just like new.

What I'm trying to get at is ISIS or DA octalink isn't for everyone. It's something that can't be abused, which is why it's good for small riders and roadies, and it's something that needs attention when it starts to act up, other wise Florian, your absolutly right, and they are not that relieable.

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MAMA SAID KNOCK YOU OUT! HUH!

I quote from Nino:

according to german crank arm comparison test the Storcks are the flexiest about half the stiffness of some ISIS cranks.I have tried several cranks up to now and i find it difficult to detect any real weakness.I rode with RF Turbines in 01,Tune Bigfoot in 02 and also RF just before mounting the Storck on my bike and can`t tell the difference.

I`m no heavyweight at 155 lbs.I also use them together with 143g FRM BBs so that`s for sure a flexier setup but no complaints at all.

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PLAY DARTS! *WARNING* MUST HAVE A SENSE OF HUMOR TO PLAY!!!

I talking about the Power Arms themselves regardless of ISIS or square. Florian your quote I beleive was "to overstate a little you can't make a wet noodle stiff". That implies that the Power Arms are not stiff cranks.

This is MTB but a good read by Nino:

http://forums13.consumerreview.com/crfo ... .ef66750/0

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PLAY DARTS! *WARNING* MUST HAVE A SENSE OF HUMOR TO PLAY!!!

It's all in the eye of the beholder - some call it "relatively stiff" others find it too soft. I know 90 kg riders who find it acceptable stiff, but I know also lighter riders who prefer stiffer cranks.

Anyway - I'm still waiting for a scientific test that shows me that a stiffer crank/BB combination gives a significant advantage in power output compared to the loss of power due to the increased weight of most splined cranks/BBs.

True Florian. I am a little concerned though since I have a new set of Power Arms sitting in my garage. I have used Record cranks and the first version of the FSA carbon cranks (without carbon spider) and I have had no problems with either. I wonder how stiff the Power Arms are in comparison to these?

I would have bought the american classic isis design chro/mo set up because at 140g it would have saved me 37g(1.32oz) alot of weight to me.
But they only make it in english thread not italian , If I hear of a bottom bracket(isis) that is lighter and as STRONG as what I have I will buy it.
Giovanni.

I saw broken bearings on a Race Face ISIS BB of someone who uses his bike only to ride on pavement to his workplace (and only when it's dry).
I know a guy who was tired after the third FSA Platinum Pro had rough bearings within half a year - he now rides Octalink and is very happy with it.

May I quote the signature of somebody in the forum:

This is also one of my principles and that's what I didn't see on most ISIS BBs.