Weight Weenies – Crank Sets. I’m trying to decide on a compact crank set for my Trek. Right now I have a 39/53 ring and Brad and others have really been telling me that a 34/50 is more practical.
But, which one to get? Weight Weenies is a good source to at least find out what is the lightest. Here is the scoop:
FSA “Carbon Pro Elite”:http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=21&pid=51 Compact comes inat 512.5g to 522g for a 172.5mm 34/50 without the crank fixing bolkt. The other big attraction is that it is about “$290”:http://froogle.google.com/froogle?q=fsa+compact+carbon+elite+pro+crankset according to froogle.com.
This thing uses an ISIS bottom bracket, so my Record bottom bracket would have to be replaced as well. The choices are according to “bottom bracket”:http://weightweenies.starbike.com/listings/components.php?type=bottombrackets&sortby=manufacturer listings you can get the American Classic ISIS Road at 141gram with about 22grams more for the self extracting bolts but there is a “durability”:http://www.roadbikereview.com/drivetrain/bottom-brackets/American%20Classic/PRD_326174_2479crx.aspx problem. If you want sonething that will last forever but be incredibly expensive, the Phil Wood “Premium Titanium”:http://www.philwood.com/Price%20List/TitaniumCrankBottomBracketSets.pdf ISIS at 145g but it does need new Phil Wood “cups”:http://www.philwood.com/Price%20List/BottomBracketCups&Tools.pdf as well and is incredibly expensive at $150 plus $40 for the cups. That gives you a systme that is 522g+140g or 662g without 20 grams for alloy bolts and 11grams for each cup (not clear in the count below if the cups and bolts are included by the way).
If you don’t want this exotica, then FSA makes the “PLATINUM PRO TI – MEGAQUAD”:http://www.google.com/search?q=FSA+PLATINUM+PRO+TI+-+MEGAQUAD (what a name!) for about $90 hours and it is 189 grams with an additional 19g for the fixing bolt.
The Campagnolo Chorus CT Carbon is 565 grams so about one ounce heavier without the crank fixing bolts as well, although it means I don’t have to replace bottom brackets. Right now, this is $540 from Coloradocyclist.com and about $500 from Lickbike.com. This combined with the 190g Campagnolo Record bottom bracket that I already have gives me a weight of 755g.
FSA “SL-K Compact Megaexo”:http://www.fullspeedahead.com/fly.aspx?layout=product&taxid=21&pid=202. This isn’t in weight weenies, but it like the CArbon Pro Elite, but integrates a Megaexo (FSA’s proprietary bottom bracket). These are apparently cheaper and have a 40% great bearing life than ISIS at least according to the FSA “FAQ”:http://www.fullspeedahead.com/fly.aspx?layout=tech&cid=79. The drawback is that installation is different and you have to be very sure that your bike’s bottom bracket is correctly faced (e.g., totally parallel). According to “Bike Tires Direct”:http://www.biketiresdirect.com/productdetail.asp?p=FSSLK this whole setup weighs 785 grams and costs $340 so is roughly the same as the ones above. Maybe a little heavier.
For both a Chorus front derailleur is needed at $82 to match the curvature difference or according to FSA, you can also just lower the front derailleur about 10mm and it should work fine.