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BB install on road bike
#1
Hi,
I'm building my first bike from scratch, a road bike for my wife. I have a Ridley Asteria frame (68mm BB shell) and an FSA K-Force Light crankset. I cleaned out the BB housing, greased it up and threaded the BB cups without issue. My problem is with the crank axle. If I just have the drive side BB cup in, the axle pushes all the way through like it should. If I put the non drive side cup in, the axle stops about 5-8mm short of pushing through. If I take it out and try to put it through from the wrong side it fits through the non drive side cup no problems but still stops short of pushing through the other side.

Any ideas? I'm hoping its just an alignment thing and I've considered taping the drive side crank with a mallet to get it through but I don't want to cause any damage. I thought it should be snug but push through by hand since the axle will push through either cup with ease.

I was under the impression that road bikes don't require spacers? Even still the gap is much to large for a few millimeters of spacers
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#2
(04-24-2013, 03:21 AM)Benen Wrote:  Hi,
I'm building my first bike from scratch, a road bike for my wife. I have a Ridley Asteria frame (68mm BB shell) and an FSA K-Force Light crankset. I cleaned out the BB housing, greased it up and threaded the BB cups without issue. My problem is with the crank axle. If I just have the drive side BB cup in, the axle pushes all the way through like it should. If I put the non drive side cup in, the axle stops about 5-8mm short of pushing through. If I take it out and try to put it through from the wrong side it fits through the non drive side cup no problems but still stops short of pushing through the other side.

Any ideas? I'm hoping its just an alignment thing and I've considered taping the drive side crank with a mallet to get it through but I don't want to cause any damage. I thought it should be snug but push through by hand since the axle will push through either cup with ease.

I was under the impression that road bikes don't require spacers? Even still the gap is much to large for a few millimeters of spacers


Is your road bike frame a new frame and never been built together?

You probably need to get the bottom bracket and head tube faced and chased. Facing means getting your edges (face) on your bottom bracket parallel to the other side. Chasing means getting your threads cleaned up and reworked.

you can get a LBS to do the work or buy the tools..
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#3
Ah really? Boo! Makes sense. Thanks for your help. I guess I assumed that sort of thing would be done already!
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#4
Even with some new bikes if you disassemble them and check that it has not been done. Mean, eh?
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#5
Ah I've just had a good look. When the external cups are both screwed in, the drive side sits flush with the frame but the non drive side is at a slight angle to the frame. I'm assuming the thread that the BB screws into inside the frame is just pressed in? This is fixable yes?
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#6
(04-24-2013, 06:38 AM)Benen Wrote:  Ah I've just had a good look. When the external cups are both screwed in, the drive side sits flush with the frame but the non drive side is at a slight angle to the frame. I'm assuming the thread that the BB screws into inside the frame is just pressed in? This is fixable yes?

Ugh... doesn't facing and chasing allows things to align up correctly? (rhetorical question) I still think you need to get the Bottom Bracket faced and maybe chased...

By the fact that you mentioned that the non drive side cup is at a slight angle to the frame .. says you need it faced for sure and or chased.
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#7
This is all new to me. I've placed around with my pre-built bikes previously but have never installed a crankset on a new bike. I'd never heard of facing and chasing until today.
I rang a bike shop and am taking it there on the weekend.

Thanks again for your help

Benen
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#8
(04-24-2013, 07:05 AM)Benen Wrote:  This is all new to me. I've placed around with my pre-built bikes previously but have never installed a crankset on a new bike. I'd never heard of facing and chasing until today.
I rang a bike shop and am taking it there on the weekend.

Thanks again for your help

Benen

Yeah no worries...... oh btw.. did you get your fork and headset installed yet?
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#9
No not yet. I needed a new headset. The one from the crashed bike was 1 1/8" - 1 1/2" I needed straight 1 1/8 and a starnut as the new bike had an alloy steerer. Cheers for asking :-)
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