Bicycle Mechanics - compact build

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View Full Version : compact build


slisk
05-03-06, 11:57 AM
I'm thinking about a bike build in the near future and have heard a bit about front derailleur issues so here is the deal. 2006 Look 585 w/dura ace (rear wheel is Shimano) so no Campy on this one. The plan is to use FSA Carbon Compact Megaexo & BB and run a 48/34 ring combo instead of the 50. I'm trying to gain low gears and doubt very seriously I will ever run a 48/12 at more than 90 rpm for long. Will using the 48 solve any potential shifting issues with a Dura ace 10 front derailleur. I'd rather use that derailleur instead of an FSA or other.

Slisk:eek:


Landgolier
05-03-06, 12:02 PM
So what's the question here -- you asking if people think this is a good idea, or what?

'nother
05-03-06, 12:07 PM
I'm thinking about a bike build in the near future and have heard a bit about front derailleur issues so here is the deal. 2006 Look 585 w/dura ace (rear wheel is Shimano) so no Campy on this one. The plan is to use FSA Carbon Compact Megaexo & BB and run a 48/34 ring combo instead of the 50. I'm trying to gain low gears and doubt very seriously I will ever run a 48/12 at more than 90 rpm for long. Will using the 48 solve any potential shifting issues with a Dura ace 10 front derailleur. I'd rather use that derailleur instead of an FSA or other.

Slisk:eek:

I doubt that using a 48 large ring would make a lick of difference in shifting performance as compared to a 50. But if that's what you want to do, there's no reason it won't work.

BTW, compacts do not require a special FD, if that is your concern. They do perhaps require that you pay a bit more attention to installing and adjusting them properly, since you're kind of pushing the stated limits a little bit. But plenty of people are running 50/34 with standard FDs; they work fine.


legstwelve
05-04-06, 02:59 AM
A 50/34 50/36 48/34 or 48/36 will all work with a standard Shimano FD *IF* set-up properly. If i was spending that much on a bike though i'd spring an extra $40 for an IRD compact-specific FD.

HillRider
05-04-06, 06:13 AM
Have you considered the new Shimano 700 compact crank? Shimano claims the chainrings work properly with their standard road fd and a special design isn't needed.

slisk
05-04-06, 07:13 AM
Thanks for the help. This is a high end project so the Shimano "no name" compact is not worthy. It is an Ultegra level crank I have heard. I have a nice set of new Ksyriums that are Shimano and may check to see if Mavic makes an adapter that will allow me to convert the freewheel body to Campy (like Zipp makes). I may build a Record bike. Either way, I want to be able to place a nice set of carbon compact cranks on it which Shimano doesn't make.

Slisk

HillRider
05-04-06, 08:57 AM
Thanks for the help. This is a high end project so the Shimano "no name" compact is not worthy. It is an Ultegra level crank I have heard. I have a nice set of new Ksyriums that are Shimano and may check to see if Mavic makes an adapter that will allow me to convert the freewheel body to Campy (like Zipp makes). I may build a Record bike. Either way, I want to be able to place a nice set of carbon compact cranks on it which Shimano doesn't make.

Slisk
Well, excuse me, I didn't realize that a Shimano crank wouldn't meet your style requirements. :rolleyes:

If you are going for Campy, they offer carbon compact cranks at both the Record and Chorus levels as well as specific compact fds. A recent test in the Australian bike magazine "Ride" showed that Campy carbon cranks were stiffer than the FSAs, even with their "old fashion" square taper bottom bracket design.

Another possibility with Campy is that you could get around your gearing problems with out switching big chainrings by using their 13x26 (or 13x29 if you want real low gears) cassette. A 50x13 high gear is actually slightly lower than a 48x12.

slisk
05-04-06, 02:24 PM
Thanks again. I'm starting to think that maybe going with Campy is the ticket. I've sent the hub freewheel question to a bike shop for a clear answer and if I can do the switch, problem is solved.