Considering changing the chainrings on my Campagnolo Record crank instead of purchasing a compact crank. It's cheaper. Any disadvantages?

If you can find what you want in the correct BCD....

I only know about Shimano chainrings so your possibilities may vary. If you have a normal Shimano double road crankset on a bike, the spider's bolt hole dimensions are usually 130mm. The problem is that the smallest chainring that you can put on a 130mm crankset is a 39t chainring (I vaguely remember hearing about a 38 but have never seen one). So you would end up with at best a large chainring of your choice such as a 52t and the smallest chainring which would be a 39t which is a far cry from a real compact.

Compact Shimano doubles use 110mm chainring bolt spacing so they can use much smaller inner chainrings and end up being a real compact.

If your Campy spider can handle small chainrings, then you could swap out the small chainring for a smaller one of your choice and that should work provided the front derailleur can handle the larger spread between the teeth counts.

If you have a standard Campy Record crank with 53T/39T chainrings, the bolt circle diameter is 135 mm and 39T is the smallest chainring it will accept. To get compact gearing (normally 50T/34T) you will have to replace the entire crank with one that has a 110 mm BCD. Campy does offer them.

Thanks, that's what I needed to know.

Over the years, Campagnolo "Record" cranks have used a number of bolt-circle diameters: 151mm, 144mm, and now 135mm. If your crank is one of the older (151 or 144mm BCD) versions your small ring cannot be smaller than 44T (151mm BCD) or 41T (144mm BCD); these may not allow the compact gearing you're hoping to get. The 135mm BCD version can take a 39T minimum ring.

The next question involves riding hills, not mountains. Is it feasible then to change the cassette from 11/23 to 12/29 and leave the standard crank 53/39 or change the crank to compact 50/34 or both.

Hi,

Both are feasible, but as I understand it you wouldn't want to
increase the range of the rear if you went for a compact crankset.

rgds, sreten.

52/42 front, 14,16,18,20,22,24,28 rear. 40 to 100 gear inches.

29t rear cog? You more than likely will need at minimum a medium or even better, a long cage rear derailleur. I doubt very much that a short cage road derailleur will handle a 29t rear cog. I have even had issues with the jockey pulley rubbing on my 28t rear cog using a medium cage 105 Shimano rear derailleur.

Edit: after googling a bit, it appears that in reality, short cage=double crankset and long cage=triple cranksets. So you might get lucky with a 29t rear even with the short cage. Might have to extend the b screw out all the way.

I keep a 32t cassette, a chain for it and a long cage derailleur and swap them onto my roadie for long alps trips. I switch back to normal road gearing for the rest of the season. (I am weak, lazy and a bit of a spinner). I always leave the standard chainrings on the front - can't remember what they are, it's a non-compact double though. I rarely hit the very lowest (32t) gear unless really tired and/or steep road. I do notice the larger gaps between gears.

The dinnerplate sized cassette worked out cheaper and easier than finding small chainrings - it does look a bit strange though.

Since it's cheaper changing the cassette from 11/23 to 12/29 and keeping the 53/39 crank rather than changing to a compact crank, would there be any issues with the derailleurs?