DeRosa pic/chainline help!!!
 

Long time lurker, first time posting. Just picked up a used DeRosa track bike and building a fixie out of it. It's got an Italian BB so getting parts for it locally (Honolulu) is pretty difficult.

http://bikeforums.net/attachment.php...hmentid=190797

I've got PW hubs and cog on it. According to Sheldon Brown, I've got a chainline of 42.8. I've looked at all the LBSs and there's a Campy Chorus 102mm. Guys around town tell me it's too short and I'll need something between 109-111mm. But according to Campy's website, the Chorus BB produces a chainline of 43.5mm, which should be close enough.

Should I just get the Chorus BB and put on whatever crankset I can find for now? Or will the 102mm Chorus BB not be a good fit?

Any thoughts/suggestions/help is appreciated.

i dont think thats a de rosa.

Why not? http://www.trialtir-usa.com/derosa/kron/kron-mp.htm

Pick a crankset first, then choose a bottom bracket.

The seat tube junction looks rather suspicious.

I'm going to steal this thread for a minute since I too have a chainline question. I'm working on a conversion, and I have all the needed gear it on the road, but I'm not sure if the chainline is going to be right. I have the original 117mm Stronglight/Nervar BB and a Shimano 600 Arabesque double crankset (new chainring on the way; will only use one chainring obviously), a Shimano 1/8" freewheel on a 120mm spacing formula hub.

I have looked over Sheldon Brown's stuff on chainline, but I'm still having a hard time getting a grip on it. Any help?

thanks, nevermind. it slipped out of my mind de rosa still existed.

Yeah, they do, and even still have lugged steel models

http://www.trialtir-usa.com/derosa/n...to-red-lar.htm

http://www.trialtir-usa.com/derosa/n...o-blue-lar.htm

http://www.trialtir-usa.com/derosa/n...o-fiat-lar.htm

Wonder if they still have the <3 BB cutouts.

Yes, total fanboy for detail and lugs.

Oh, and OP...yes, Cranks first then Bottom Bracket.

The seat clamp area looks interesting (I've never seen a newer de rosa before); can I get closer pictures of it supadupa?

Yeah, a quick search on "De Rosa track" will show it's not one. De Rosa make 2 track bikes, neither of which look like the above. They have the Scatto Fissa, which is a titanium track bike with much thinner tubing and the Pista, with similar tubing but a much different rear-end. De Rosa are pretty much my bike obsession, and that is't one of them.

I am confused is there really this much trouble with chainline?

Generally, yes.

And Sherblock, that was my first intuition. Reminded me of the Leader Bianchi Pista Concept. But who knows...?

hmm I guess Must just get lucky most of the time because usually I have just ran into what side of the crank should the chainring go on to make the chain straight.

i would get a frame with more common threading

Everything is propriety anyway. No reason to search for another frame because of Italian threading.

And yes, chainline fun starts with double and triple cranks integrated to a single, track chainline. How can I end up with the outside ring perfect?

Can you guys elaborate on why I should get a crankset and then choose a BB? Living on an island doesn't really give me much of a selection of parts and the 102mm Italian thread Campy Chorus is literally the only BB here that will fit my bike. I have more cranksets to choose from here so I'm hoping one of them will fit.

Another option is to just order an Omnium with BB included but I've read they have chainline problems too. Are they adjustable?

Some more pics attached. I was told the frame is a one-off and I've never doubted that it is real. I'll try contacting the US distributor to see if they can get any more info.

http://bikeforums.net/attachment.php...hmentid=190815http://bikeforums.net/attachment.php...hmentid=190814http://bikeforums.net/attachment.php...hmentid=190813http://bikeforums.net/attachment.php...hmentid=190812http://bikeforums.net/attachment.php...hmentid=190811

that bike looks rad

Are you 100% sure if the bottom bracket threading is Italian? Because it could very well be English/ISO even if it's an Italian frame. If it is indeed Italian, Omniums will not fit on your frame because they don't make Italian bottom brackets for the Omniums. On the plus side, Shimano makes several bottom brackets with Italian threaded cups; as well as Miche. Ask to see if your local shop could get you any of those.

Because a set of cranks determinate what sort of bottom bracket you need, if you buy the bottom bracket first, you're kind of painting yourself into a corner if you know what I mean. Bottom brackets have different lengths, tapers, lengths, some are asymmetrical, some aren't. By deciding what kind of crankset you're getting...let say a Sugino RD-2, then you could buy a Shimano bottom bracket with Italian threaded cups.

I doubt your De Rosa is a counterfeit by the looks of the welding of your bottom bracket shell junction. You've got a great frame!

would a Derosa track bike have a drilled rear brake bridge and undrilled fork?

They may not be willing to sell you Omniums with Italian cups, but I think any GXP cup would fit those cranks and they definitely sell Italian GXP. You might have to buy a la carte, but it should work.

If it's Italian threading, then the BB width may also be 70mm, instead of the 68mm width used on English/ISO/BSC. This will require a different spindle / axle as well.

tire selection could be classier. enjoy it.

Hot bike.

Nevermind, didn't see the second set of pictures.

I just eyeball it.
seems to have worked so far