gbel
new member
Reged: 12/24/03
Posts: 9
Loc: California
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I have had trouble with my Campy Record 39-53 crank. The chain won't stay on when I am in my 53/12. The front derailleur is adjusted correctly but the chain tracks off the large chain ring. I have been told this is due to the wearing of the square tapered spindle designed crank. After 2.5 years, I need to replace the crankset. I have decided to go with the FSA Carbon Pro Compact crankset and Pro TI BB.
Has anyone else experienced this problem? I would also welcome input on the crankset choice and change to a compact gearing. I do quite a lot of climbing in the Sierra Nevadas, and I welcome the extra gearing but I don't want to lose velocity in pace lines over flat terrain. I have been riding a Tetra Pro with a Campy Record 12-25 cassette.
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Insightdriver
captain
Reged: 03/07/04
Posts: 472
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I can't say anything of value. I only have a bit over 200 miles on my FSA Carbon Pro compact crank. I can say it's way stiff like it should be and I have no problem with the shifting, but I'm using 12-27 2005 Ultegra on my Tetra Pro.
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skuke
captain
Reged: 12/22/03
Posts: 323
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Quote:
gbel wrote:
I have had trouble with my Campy Record 39-53 crank. The chain won't stay on when I am in my 53/12. The front derailleur is adjusted correctly but the chain tracks off the large chain ring. I have been told this is due to the wearing of the square tapered spindle designed crank. After 2.5 years, I need to replace the crankset. I have decided to go with the FSA Carbon Pro Compact crankset and Pro TI BB.
Has anyone else experienced this problem? I would also welcome input on the crankset choice and change to a compact gearing. I do quite a lot of climbing in the Sierra Nevadas, and I welcome the extra gearing but I don't want to lose velocity in pace lines over flat terrain. I have been riding a Tetra Pro with a Campy Record 12-25 cassette.
Is the chain ring(s) running out (wobbling around) when there is no load on the pedals?? While you're pedaling with heavy load??
Spindle tapers don't "wear out" unless your installing and removing your crank arms eighteen gazillion times. The Aluminum crank would wear long before the steel spindle would wear. I'm not sure what your exact problem is, but I am sure it's not taper wear. Incorrect taper perhaps, but not wear.
Possiblities might be worn chain ring, but you'd have to put a lot of miles on it in the last 2.5 years. Wrong chain. Something else broken/cracked that is causing flex and thus derailing. Incorrect chain line.
Replacing with all new parts will probably fix the problem, but is a rather expensive way to diagnose. If you want all new toys on your bike, that's fine. Just understand that if, for example, the problem was chain line and you set up your new stuff wrong, it may still derail.
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Skuke
95 Carbonframes Tetra Pro
92 Bridgestone MB-1
90 Moser 51.151
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Limace
journeyman
Reged: 03/09/05
Posts: 54
Loc: Oregon
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No idea on the chain slip problem with your existing crank but am familiar with the FSA compact set up you are looking at. I have exactly the same combination and have put several thousand miles on it during the past fourteen months or so. Absolutely no problems.
Regarding cog selection. I did change from a 12-27 to an 11-25 this Spring and am loving it. The 27 was just too high. I could climb anything, but a raisin (oops, elderly person) with a walker could drop me half-way up. Slllloooooow. The 25 is just fine for the toughest climbs and most of the time the 23 will handle it.
I went down to an 11 because of the paceline. There were times I just couldn't seem to hang in with the single step range being 12-16, particularly on anything "challenging" downhill. 11-15 works much better.
Not the cheapest alternataive though, I had to take two Ultegra 10 speeds and combine them to get the progression I wanted.
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skuke
captain
Reged: 12/22/03
Posts: 323
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Quote:
gbel wrote:
The front derailleur is adjusted correctly but the chain tracks off the large chain ring.
This is very unlikely, but can you bolt the chainring onto the crank spider backwards?? That is to say, the side that normally faces inward is now facing outward?
If so, the shifting guide/lift pins would be on the wrong side and could be causing the chain to lift and ride off the large chainring. But like I said, since the mounting bolts are usually counterbored and only (usually) fits on one way, this scenario is highly unlikely. ...just something to look into.
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Skuke
95 Carbonframes Tetra Pro
92 Bridgestone MB-1
90 Moser 51.151
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gbel
new member
Reged: 12/24/03
Posts: 9
Loc: California
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Skuke,
Thanks for your thoughts and responses. The chainrings are not warped or on backwards. The crank has been removed and replaced twice by a pro mechanic. I was able to view the crank on the spindle and observed the crank's position as being too far inward. A trusted mechanic looked at it and informed me that even though that type of wear does come from removing and replacing the crank several times, it can also be caused by the exertion of power. The mechanic says he sees the problem somewhat often and feels it is a design flaw in the campy groupsets. The reason I have changed to FSA is to avoid a repetitive problem.
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bike_boy
new member
Reged: 03/09/05
Posts: 10
Loc: East Texas
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I am not a big fan of the square taper design, but it is difficult to beleive that it is roasted after only 2.5 yrs. and only being removed a few times. If so, it would appear that you 'da man. It is also a wonder why you are not considering the FSA w/ Shimano-esque exterior mounted bearings. It seems that you would benefit greatly from such a design.
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gbel
new member
Reged: 12/24/03
Posts: 9
Loc: California
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I checked on the design you are referring to, the SL-K MegaExo. My lbs says it isn't availble for 2 months and the Pro crank's ISIS spline will be more durable than the campy square taper. What advantage to you see with the outboard bearing design?
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Limace
journeyman
Reged: 03/09/05
Posts: 54
Loc: Oregon
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Talk to a different lbs. The MegaExos are on the street. I've got a set at home waiting to be installed.
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BikerDoug
friend
Reged: 12/29/03
Posts: 88
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I've had one installed for a couple of months. You can read my short review in this forum a little further down the list.
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bike_boy
new member
Reged: 03/09/05
Posts: 10
Loc: East Texas
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I take it that you did not see the Velo News article where they tested the new-at-the-time DuraAce cranks w/ virtually everything else on the market. The carbon spline cranks did have less deflection than their aluminum counterparts, but the DuraAce cranks were in an entirely different category.
Even if you need to wait for your cranks, face it, you own a Calfee and waiting is something that you are probably accustomed to. And, IMO, it would be worth the wait.
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flythebike
captain
Reged: 08/26/04
Posts: 272
Loc: N. Virginia, USA
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I think that the stiffness of cranks is highly overrated. Most of us are not strong enough to lose energy from flexing any crank that Velonews tested (yes I saw the test). Yes I'm saying that for an average Joe, all those cranks are good enough. So pick one you like, shush up, and ride your bike.
The Mega Exo cranks are out. Get 'em on eBay or wherever if that is what you want.
I run Campy Chorus Carbon and Phil Wood Ti. Eat your heart out, they feel like very firm, cold butter.
i think the outboard bearings offer an incremental improvement, as FSA has said. It is not a breakthrough. Use what you have until it is worn out. If indeed it is worn out replace it with your heart's desire. Not worth replacing your perfectly good stuff that you will eventually wear out, until it is really worn out, as it may be in this case. Instead, build up a fixed gear, ok? I've put almost 150 miles on mine since Monday, and I'm getting strong like ox.
Edited by flythebike (04/22/05 05:21 PM)
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