I am looking for a new crankset and have narrowed it down to Shimano's new Ultegra SL and FSA's SL-K. Any info or opinions that would help make this decision easier would be appreciated.
Ultegra SL vs. FSA SL-K
- Thread starter LewisBricktop
- Start date
Personally, I have never ridden the FSA cranks. Many people on my team do though and most actually don't think they're as stiff as the Shimano cranks. Take it for what it's worth
I have tried the FSA carbon cracks and personally I reckon they suck. They flexed every time I put in a sprint or stood up and put the hammer down on a climb. Stick to the Ultegra Cranks, they cost less, weight the same and are far stiffer which means more power into the system and not being wasted.LewisBricktop said:
Its not easy to make carbon fiber stiff in all directions and still maintain lightness that you want from carbon. This is the reason why most carbon cranks are just as heavy as alloy ones, and quite often have a alloy core, or light and flexable.pistole said:
during the TDF Shimano had a play with carbon cranks but decided that the cost involved did not match the benifits and the riders perfered the alloy version.
Next time you see pictures of the CSC guys have a look at what they actually ride in the race. Most of them do not use the FSA carbon cranks, but the Alloy Dura Ace ones.
You apply a load, it bends. You're doing it too! Whether it is noticeable or actually makes a difference to efficiency is another matter.pistole said:
Get Campagnolo UT!
But if you must choose between the two you indicated in your original post, go for the Shimano. FSA just does not seem to be able to get their quality right... lots of stories of problems on their bottom brackets and nothing particularly positive about their cranks.
N.B., this is all hearsay from other riders/the web. I would not ride FSA however, FWIW.
But if you must choose between the two you indicated in your original post, go for the Shimano. FSA just does not seem to be able to get their quality right... lots of stories of problems on their bottom brackets and nothing particularly positive about their cranks.
N.B., this is all hearsay from other riders/the web. I would not ride FSA however, FWIW.
Had loads of trouble with the FSA SLK, but I did get decent support from them and several replacement parts (chainrings, crank arm bolt to replace the non harded one that broke). I would never buy FSA again. I only keep it because I put shimano chainrings on it, which finally got the shifting where I wanted it, and it's now functional with no problems.
thanks for the responses. i had no idea that fsa would have such negative feedback. as for the DA, not quite ready for that investment. if only textbooks were free.
the ultegra cranks are even stiffer if you go by the review that Ride magazine did a while back. The only real difference between ultegra and dura ace is weight, they both work just as well as each other and are just as reliable. The only difference is the lower weight and that dura ace clusters wear out a bit quicker. funnly enough the chains last longer then ultegra ones.LewisBricktop said:
to be fair some of the negative feedback has come from people who've heard if from someone else.LewisBricktop said:
i read all the **** reviews and decided i've give them a shot anyway (partially due to getting a decent price on a set of k-force). part of my decision was when i looked about a lot of the guys i race with, many of them have k-force and slk's. i asked quite a few whether they'd had any issues with the non-drive side getting loose. none reported any issues.
assembled them to spec including the special loctite. used a little teflon tape on both the crank bolt and the end cap. i've raced them for a month and a bit now, and as it's on my race bike it's also the same bike i usually do hill repeats on, where i'd imagine you are probably loading your drive line up more than anything except sprinting.
do date (knock on wood). i haven't experienced any issues at all. i sprint like a climber, so any comments i could make regarding stiffness would be irrelevant anyway ;-p i'll also note apparently this year the new k-force and slk's use a taper on the spindle which would probably resolve the issue people have reported.
--brett
A few engineering types have posted to this forum with the news that 10spd/Hollowtech II 105 is the stiffest crankset they've ever measured and certainly stiffer than Ultegra. I think, however, that crankset stiffness, given the current crop of cranksets available, is irrelevant to efficiency.jcjordan said:
Did an informal test a while back on my FSA Team Carbon vs. an old (~1992) Ultegra crank. Put the bike in a big gear, front wheel against the garage wall, clipped in and stood on a pedal. The Team Carbon seemed to have some torsional flex compared to the Ultegra which felt rock solid.artemidorus said:
Perhaps others with both FSA and other cranksets have done similar "tests"....would be interesting to hear from them. Note, have never noticed "flex" on the road and doubt it would represent any real loss of power.
Considering the Team Carbon is built from an aluminum core with a CF overwrap, it wouldn't surprise me that a hollow cast (or forged?) piece could be stiffer.
Certainly wouldn't give the FSA negative feedback though. I selected Team Carbon triple for my frame build in late 03, and have had no problems with arms or chainrings in the 15K miles since the bike was built.
And tires and wheels and fork... 
There's a lot of things twisting and flexing in that experiment. A bit tough to figure out what the cranks are doing. And crank flex really doesn't rob you of much efficiency at all (I've calculated and posted the info once or twice before). It's more of a "feel" issue than a performance issue.
John Swanson
www.bikephysics.com
There's a lot of things twisting and flexing in that experiment. A bit tough to figure out what the cranks are doing. And crank flex really doesn't rob you of much efficiency at all (I've calculated and posted the info once or twice before). It's more of a "feel" issue than a performance issue.John Swanson
www.bikephysics.com
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