I'm using an Ofmega bottom bracket with Campy Victory cranks. The crank arms fit on nice and tight and feel solid. But the driveside crank seems a little further out than what I'm use to. I had to adjust the front derailleur out a bit, but it feels and shifts smooth. Should I be concerned of any issues?

Ofmega BB spindles had a proprietary taper, different than ISO or JIS. If the FD is working well and the wider Q factor doesn't bother you, I don't see the problem, though. Is the chain reaching the largest cogs on the freewheel ok? That would be my chainline concern.

It's hitting all the gears with no problem. I didn't even adjust the limit screws on the r/d after the swap over to the new frame.

Why would you need to adjust the limit screws? If it's the same set of wheels and the dropout is the same thickness (like both were Campy), that wouldn't change.

Re: if the crankset is outboard a bit from the rear, then you might have enhanced wear on the chain, freewheel or crankset. If it works and you like it, I see no reason to change.

Read Sheldon Brown on chainlines. Chainline on Bicycles with Derailers It is nice to have a perfect chainline but many bikes (probably millions) do not, usually through time, replacement of bottom brackets and cranks, square taper cranks sitting further inboard after many removals and installations and in some cases the installation of the bottom bracket. Some folks like chainlines further in to have better chain angles in low gears. Some ot bring their pedals closer together for a lower "Q-factor". Etc., etc.

Now if you want to pass through the hallowed gates into the heaven of perfect bikes, your bike will have to have the 43.5 mm +/- 0.3 mm chainline offset from centerline. That way, when you install one of those hallowed wheels, the angels can sight up that middle cog to exactly between your chainrings. (Of course, with two chainrings and an odd number of cogs, or and odd number of chainrings and an even number of cogs, a straight chain never happens. But if we don't want to jeopardize our place in bicycle heaven, we keep our mouth shut.)

Sight up the middle cog to the chainrings. If they line up to within a half cog, the bike will do just fine. If it's off by that little, ignore it until you have reason to mess with the crank/BB or wheel anyway. More than that and you might want to take action or maybe just bear in mind that some of you big crossover gears will be hard on the chain, cog and more work for the rear derailleur.

(This is a lot like wheel alignment in cars. Yeah, you want all 4 wheels parallel and parallel to the car frame, but look at how many cars out there happily crap down the road sideways.)

Ben

Well, obviously it's going to make any large-large cross-chain issues more pronounced. If you don't use the cogs on that end of the freewheel very often in combination with the large c/r then maybe it's fine.

I would take an aft view of the chainline in the gear combinations you are most likely to be in for sustained riding. If you see a lot of bad angles, using a shorter spindle is probably in order. If not, no real worries.

This might be the cheap bastard in me talking, but has anyone flipped the spindle around and used the shorter end? Would it help or is it a stupid idea and I should just get a new b/b and shut up?

What, that I'm a cheap bastard?

I know, I was joking. I sit at work for 24 hours thinking of stupid things. This one popped into my head and I can't go home to try it.

Yep, done that. Less about being cheap, than lacking patience. But i haven't changed it. I don't log too many miles on that bike, but it's never bothered me.

I never felt the pea under the mattress either.

Best regards, Eric

I have flipped the spindle for fg conversions. Depending on how short your short end is, you might have inner ring/stay interference. If you measure the present ring-to-stay clearance so you know how much room you have to play with, you will probably save some time downstream.

Changed over my old Schwinn to 8 speed , with a different crankset and had to flip the spindle to get it to work right . Works swell !

due route made a very good point about optimal chainline having everything to do with your shifting sequence preferences, i.e. which gearing combinations that you would want to put emphasis on being smoothest.

I nearly center my freewheels with my large chainring whenever I tinker with chainline, since I only ever use the largest few cogs with the small chainring. I thus can use the entire spread of the freewheel with the big chainring without any critical extreme of chainline causing noise, friction or other problems.

Since I also employ cheapskate methods, I keep a variety of lengths of bottom bracket cartiridges on hand for test-fits, many of these being discards with rough bearings. I can thus determine what if any bottom bracket parts that I might have to actually go out and buy if I don't have the exact length part I need.

I've fitted Ofmega spindles with both ISO and JIS-taper cranks, so as I recall Chas often saying, "if it fits it works" or thereabouts.

I have at least one crankset where the best chainline is achieved with the shorter end of the spindle on the drive side. That was a triple conversion, using a double spindle, to boot! (Yes, inner ring clearance to the chainstay is not an issue. )

It can be, as the inward limit of chainline is usually ether the chainring/chainstay clearance or the front derailer's reluctance to pull in both far enough and with enough force as the spring relaxes. Other times it might be chainring bolts that first threaten contact the chainstay.
Oh wait, I see a wink-smiley...

Flipped spindles are somewhat a kluged fix when it leaves the left pedal unnecessarily far out to the left, but a few millimeters isn't noticeable and can be somewhat balanced out using lateral cleat or toe-clip adjustments.

One more possible fix is to reverse the spindle and add a fixed-cup spacer, which can produce or approach a symmetrical bb.

I've got this going on at least one bike right now. I think the spacer my LBS gave me is actually a spacer intended for stacking a shorter cassette on a longer hub. Does that sound right, same size?