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Discussion Starter · #1 · (Edited)
i just installed my tuned scandium BB in my roadbike last weekend and it performs great. feels really stiff.

- i started with a 120g scandium BB (68/108mm BSA)
- removing the middle spacer tube brought it down to just 104g . but this leaves you with no option to thighten it. the cups might become loose...maybe Loctite would do the job of hindering it from becoming loose but i preferred a more serious way: i switched out the left side cup with a cup i had that is a little bit longer outwards and allows the use of a counternut. this way i can adjust bearing play and fix it thight. weight is 2g more though: 106g ;(

all together, including the really long bolts you have to use the whole weighs now 134g. that's the weight of a FRM Al BB WITHOUT spacer tube and crank fixing bolts! the FRM Al-crankbolts weigh 21g, the spacer tube another 17g...

best of all: the cups are still long on both sides ( inwards) and i will reduce their lenght. this might save a couple of grams . i guess it will be just about 100g when done;)
 

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how long will it last?

Hi Nino.....

that's a cool weight, nice one, but......how long will it last?

In my experience bad ISIS BB's last 1 week, and good ones 6 months.

I'm giving up on it and going to XTR style outboard bearings now. I hate it when my bike squeaks/grinds!

Anyone want to buy an Extralite ISIS E Bones crankset? Ultra light, 480g i think.
 

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In my experience, the problem many encounter with ISIS is caused by the frame. In a perfectly machined BB shell I managed to get almost a full season out of a FRM ISIS BB, and fellow racers have been using Race Face for the second season. The problem that manufacturers find it too expensive to do proper machining of the BB housing, and you have to DIY. I found all Giants to have almost perfect BB housings, and a Mongoose I encountered had it so much off, that it could not even be remachined!

So Nino's tuning method is ok, just as old FRM BB worked as long as the shell was perfectly aligned. Integrated cranks solve the problem, which ought not exist, if frame-makers were doing a good job - just as italian frame-makers were 20 years ago...

-b
 

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nice job nino, i can fairly imagine how well your BB works - have been doing this to the same BBs i'm selling, and it still holds up well. just keep in mind, that the 2 bearings-versions have NO SEAL on the inward bearing side. i placed one 0.2x21x30 mm (or so, cant remember, but fits perfectly) spacer between the axle and each bearing to keep dirt out
 

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Discussion Starter · #5 ·
they are sealed!

Max said:
nice job nino, i can fairly imagine how well your BB works - have been doing this to the same BBs i'm selling, and it still holds up well. just keep in mind, that the 2 bearings-versions have NO SEAL on the inward bearing side. i placed one 0.2x21x30 mm (or so, cant remember, but fits perfectly) spacer between the axle and each bearing to keep dirt out
mine are sealed on both sides!
i have an older one, where i have that cup from, that has indeed open bearings to the inside. but the ones i have are all sealed on both sides! you can see the seals on the 2nd picture above.
 

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Discussion Starter · #6 ·
another 2g lighter

nino said:
mine are sealed on both sides!
i have an older one, where i have that cup from, that has indeed open bearings to the inside. but the ones i have are all sealed on both sides! you can see the seals on the 2nd picture above.
so, as i said in the 1st post i did the final work on my scandium BB. i jsut took it out and checked if it's still running smooth...everything perfect!

i then shaved both cups to the minimum on the inside. now the BB weighs 104g incl. counternut.sweet;)
 

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macsi said:
In my experience, the problem many encounter with ISIS is caused by the frame. In a perfectly machined BB shell I managed to get almost a full season out of a FRM ISIS BB, and fellow racers have been using Race Face for the second season. The problem that manufacturers find it too expensive to do proper machining of the BB housing, and you have to DIY. I found all Giants to have almost perfect BB housings, and a Mongoose I encountered had it so much off, that it could not even be remachined!

-b
so, what do you mean by a "full season"? at least 10000km ok?

and if the problem is on the frames, why this happens only with ISIS bbs? my xtr m950bb is almost 9 years old, bought it back in 97,and its still smooth, no play, no rough bearings, no need to buy new bearing every two months.... :rolleyes:
 

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Discussion Starter · #8 ·
carlos said:
so, what do you mean by a "full season"? at least 10000km ok?

and if the problem is on the frames, why this happens only with ISIS bbs? my xtr m950bb is almost 9 years old, bought it back in 97,and its still smooth, no play, no rough bearings, no need to buy new bearing every two months.... :rolleyes:
from what people tell ISIS hardly do a full season.
i don't care since i have about 20 spare BBs ;)
 

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Discussion Starter · #11 ·
20 BBs + 3 bikes

carlos said:
i wouldnt be surprised if you have 10 spares scott team issue frames either... freak!
no 10 CR1 spares;(

but about 20 BBs and 3 bikes as a backup isn't bad either;)
 

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