These are exterior bearing bottom bracket cranks. They look very smart and ride very nicely. The only problem is that the non-drive side crank arm is perfectly vertical (it doesn’t taper in where the bottom bracket bolt is). Ankle bone, meet crank arm. Again. Again. Again.
My pedal stroke is very parallel - no inward turned heels. Perhaps it’s something that I’ll get used to and after a few rides I’ll never think about it again. Still makes me wonder about the forethought that went into the design.
Did you install the flat washers that were included with the cranks to shim the pedals? Without the washers, effective q-factor of pedals is probably 1.5-2.0mm narrower than expected.
My first impressions (installed Monday evening but rode TT bike Tuesday) - I was disappointed that FSA did not include a wrench for tightening the bottom bracket cups but fortunately the shop had an extra Shimano tool. Also, FSA apparently updated the design to include a plastic sleeve between the bearings (spindle inserts into sleeve) but the documentation did not reflect this change so I had to call FSA as I installed the cranks to get the tech talk! Tightened the non-drive side crank bolt to specified torque but cranks do not spin as freely as I expected but this will probably improve after first ride on new cranks Saturday!
I just got the compacts put on my new bike and am happy with them. A little shoe rub on the left side, but according to FSA, the straighter crank is to improve stiffness. A timely article is on PezCycling this morning:
The only problem we’ve had with K-Force cranks is getting enough of them. They are tough to find and everybody wants them. I tried to buy some compacts for myself yesterday- no luck- four distributors.
The problem isn’t one of Q-Factor. It’s the lack of top-end taper on the non-drive side crank arm. I could widen the Q-Factor, but my feet are where they should be. Shouldn’t need to adjust my fit to accommodate a new piece of equipment.
I just got the compacts put on my new bike and am happy with them. A little shoe rub on the left side, but according to FSA, the straighter crank is to improve stiffness. A timely article is on PezCycling this morning:
Sounds to me like marketing BS. I suspect the real reason that there is less ankle clearance is that the outboard BB bearings pushed the center of the crank outwards. I think this is a bad thing, lots of people, including myself, pedal heels in. For this reason alone I would not consider these cranks.
Compact cranks are a good idea, most riders are overgeared, the top gear that comes on most racing and tri bikes is really only necessary for pack road racing or if you regularly ride long, fast, nontechnical downhills. OTOH, the outboard bearing idea seems like a kludge to me, the added stiffness is great for elite sprinters but not really essential for mere mortals. A better solution would be an oversize BB bracket standard, something that is in the works but hasn’t gotten enough traction yet.
I’m trying to remember what my 2004 XT cranks look like on my MTB and I “believe” they too are pretty straight on the outside on the non-drive side, but curved on the inside (i.e. crank to bike side). Would have to check. Could be marketing BS or a forced hand to hold Q constant. Just trying to think what the Big S does. You can kinda see here what I’m talking about here:
Interesting. I just got a pair of SLKs with teh EXO BB and don’t have the problem you are referring to. I don’t think the shape fo the crank arm is different between the two modesl.
While we’re on in it, other than the 100 grams of weight, does anyone know what substantive difference is between the K Force and the SLK?
As I understand one thing the big S does is play fast and loose with the truth. When they went from "normal) to hollowtech to external bearings their literature always said that Q factor remained the same. If you actually measure it it has gotten wider, not to mention that ankle clearance has gotten lessened.
Also, the K-Force is monocoque, and the SL-K is short fiber injection molded. The latter method allows for automation of the otherwise time intensive layup process, and ensures consistant finish (ala campy).
I recently had a pair of SL-K’s and i have to say that they were not the most impressive piece of equipment i’d ever seen. I opted to sell them and stick with my old relaible Record alu. cranks. Although based entirely on subjective things, my I’ve never regreted my decision. Some of the reasons i decided to do the deed and sell them were: Non-Compatibility with my stock of 135mm 10spd rings (not much of a factor for shimano riders!)
No precievable increase in stiffness (at least nothing that my legs could produce!!)
Not super hot over the asethetics, it takes alot to turn my gaze from a nice campy mirror finish
No real weight savings to speak of…this one is debateable…i’ve heard lots of different weights given, but the way i understand it is FSA SL-K(740)+BB(60)=800gms
Record ALu (635) + Record carbon bb (180)=815 I didn’t bother to weigh them myself, got those numbers out of distributers catalogue.
Also, the fragility of the finish scared me…I like to race crits, and i’m terrified of scuffing a carbon crank/pedal body off the ground in a turn (happens to the best of us)
All that said, these opinions were entirely subjective, and one must take into account that i got a decent buck for selling my SL-K’s, so this opinion is VERY biased
speaking of weight, while Shimano may have been fast and loose with their q-factor claims, their weight claims are reasonably accurate. FSA claimed the K-Force MegaExo at 660g, and it came in (on http://weightweenies.starbike.com/listings/components.php?type=cranksets) at 762g. the SLK compacts came in around 800. oddly enough, the non-external BB K-force is on the money (460g). still, they exaggerated claimed for the Carbon Pro series, and their claims for the megaexo series seem to be seriously off the mark.
I ride 9spd Dura Ave and i hit my heels on the crankarm on the non-drive side. That crank would be torture for me. I’ll knock that one of my next bike list.
Does the 10spd Dura ace have a similar shape to the FSA?
