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PostPosted: Sun Feb 22, 2009 9:41 am 
Old School Grand Master
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Mmmm....nearly finished the Kish, but for the BB.
I have fitted my FSA Ti BB...68shell 116spindle. But its too short.
When fitted I have 1.0mm/1.5mm gap between the chainring and frame :?
I had thought to space on the drive side with a 1.0mm spacer....that would give me approx. 2.5mm gap on the drive side....and about 3.0mm gap between non-drive crank arm and frame.
Is that enough do you think :?:
Cranks are WI Enos BTW.
Want to get out riding...but don't want to damage the frame either :x
Cheers
Carl


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PostPosted: Sun Feb 22, 2009 10:51 am 
retrobike rider
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What is the distance from the centre of your bottom bracket shells width or middle of the seat tube to the inner side of the middle ring (flat part, not ramps).
If that's hard measure to the teeth tops and it'll be ~1mm more.

See what your chainline is first, if it's less than 47.5mm (using this measurement on triples) you need a longer bottom bracket anyway, else you can shift it up to 50mm, though using spacers will put the left crank arm out of symmetry.

any pictures.


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PostPosted: Sun Feb 22, 2009 11:00 am 
retrobike rider
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ok a bit of searching, ENO are single speed modern stuff (probably explains the forum section we're in )
:lol:

so err, longer bottom bracket or spacer the rings out EDIT cannot spacer the ring /EDIT

from White industries site...

Bottom bracket: The ENO crank is designed with an extremely low Q factor: 160mm ENO; 142mm for VBC. With a 68mm BB shell we recommend a 113mm square tapered bottom bracket, however, some frames have wider chainstays and need a longer BB. By simply taking a few measurements on your frame you can determine a suitable BB spindle length for your frame. First measure from the center of the BB shell back along the chainstay 180mm. At that point, measure across the stays. Your measurement should be from the outside of the stay to the opposing outside stay. If the measurement is 135mm or less, use a 113mm BB. If your measurement is higher than 135mm, then add the difference to the base 113mm to determine you BB length. For instance, if the chainstay measurement is 140mm then the BB length would be 118mm.

What do you get as your length.

Though if you're happy to space the bottom bracket out, it seems fine to me, my FC-M900 runs very close to my frame and that's an old steel one, but if you take the measurement above as a guide to how far it should be away.


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PostPosted: Sun Feb 22, 2009 11:12 am 
Old School Grand Master
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Thanks FC.....the chainline is flexable as I am using spacers at the rear, rather than screw on freewheel.
I'm really after peoples thoughts on how much gap is acceptable regarding flex......how long is a piece of string Q I guess as all frames are diff.
If I bought a new BB, I guess it would be a 118mm, but thats only going to give me an extra 1mm....same as a spacer. Then it would go to 122mm...but that would be too much :?
Cheers
Carl


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PostPosted: Sun Feb 22, 2009 11:52 pm 
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Normally I'd say a couple of mm should be fine, but titanium bottom brackets can be quite flexible. In particular, I once used an FSA Ti unit that flexed enough to allow the tips of the cranks to graze the chainstays with about 3mm of resting clearance. If in doubt, I'd look for more clearance, or use a steel BB.


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PostPosted: Sun Feb 22, 2009 11:59 pm 
Old School Grand Master
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one-eyed_jim wrote:
Normally I'd say a couple of mm should be fine, but titanium bottom brackets can be quite flexible. In particular, I once used an FSA Ti unit that flexed enough to allow the tips of the cranks to graze the chainstays with about 3mm of resting clearance. If in doubt, I'd look for more clearance, or use a steel BB.


Thanks Jim..that is what I am going to do...122 UN54 until I can find/afford something else.

Cheers, Carl


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