Compact crankset

dvince said:

I am interested in purchasing one of this two crankset (combined with Dura Ace 10s):
FSA SL-K Compact or Shimano R700 Compact.

Sl-K is lighter (is it?), R700 is cheaper and 100% compatible with Shimano 10s. About stiffness I heard different opinions.

So, what do you suggest? 🙂

Depends. What do you value most? Lightest weight? Most stiff? Best value considering quality and price together? Asthetically what looks better to you? Functionally they are so close it's a wash, in my opinion. Compatablity is spot on. FSA has maybe a slightly better look to it, but that's just my opinion.

I've never ridden the R700s, but I have the SL-Ks on my current bike (ultegra 10 speed). The crank arms flex a little bit, but I am 187 lbs, so I'm heavier than most. They're really light as cranks go, so I'll trade some minor flexing for lighter weight. My only complaint is that the SL-Ks use an ISIS BB, and IMO I'm not a huge fan of ISIS.

Functionally, I would go with the R700 if the SL-K is an ISIS type BB. Just from personal experience, I went from an ISIS type crankset (FSA Carbon Pro Team Issue) to the external BB type crankset (D-A 7800) and immediately noticed the difference. The external BB crankset was much stiffer and every pedal stroke just seems more purposeful and efficient. If you like the SL-K, just go for the EXO BB version. If price is a factor, the R700 works just as well the pricier SL-K, if not as flashy in looks.

Sorry to butt in but I was wondering what is it that makes a crank compact is it just that the chainrings have less teeth than normal. Is there something about the design that compensates for the less teeth?

OneRing said:

Sorry to butt in but I was wondering what is it that makes a crank compact is it just that the chainrings have less teeth than normal. Is there something about the design that compensates for the less teeth?

A compact crank is a crank with chainrings with less teeth (usually the big chainring is a 48-50t as opposed to a 52-53 for a 'normal' big ring) and the smaller ring is also much smaller (34-38t).

Obviously it is smaller... but what exactly do you mean by your question re: design? 😕

OneRing said:

Sorry to butt in but I was wondering what is it that makes a crank compact is it just that the chainrings have less teeth than normal. Is there something about the design that compensates for the less teeth?

What makes a compact crank a compact crank is a smaller bolt circle diameter. Standard cranks can't fit the smaller chainrings (i.e., chainrings smaller than 38 teeth) because the bolt circle diameter won't allow the chainring to go that small. That is the only difference. In fact if you have a compact crank, you can run the typical compact gear combos up front, or if you're so inclined, you can run standard combos up front (53/39, etc.).

Standard Crank has a PCD of 130mm,
Compact Crank PCD, 110mm,
they use them on MTBs. 😄

Go with the new shimano, I've had a few issues with the FSA chainrings shifting worth a damn. In fact I just put shimano's new rings from the r700 on my SLK and now it finally upshifts correctly.

dvince said:

I am interested in purchasing one of this two crankset (combined with Dura Ace 10s):
FSA SL-K Compact or Shimano R700 Compact.

Sl-K is lighter (is it?), R700 is cheaper and 100% compatible with Shimano 10s. About stiffness I heard different opinions.

So, what do you suggest? 🙂

gclark8 said:

Standard Crank has a PCD of 130mm,
Compact Crank PCD, 110mm,
they use them on MTBs. 😄

Unless you use standard Campy in which case the BCD is 135mm. Parts of the world have seen some use of non-Shimano components.

dvince said:

I am interested in purchasing one of this two crankset (combined with Dura Ace 10s):
FSA SL-K Compact or Shimano R700 Compact.

Sl-K is lighter (is it?), R700 is cheaper and 100% compatible with Shimano 10s. About stiffness I heard different opinions.

So, what do you suggest? 🙂

You have a lot of opinions here. All of them very good.
I spent one year with the SLK compact crank. It's a very nice crank. Shifted very well with both my original Ultegra 9spd front derailluer and with my upgraded Dura Ace 10spd derailleur. Maybe I have a really good LBS that had the talent to set it up properly. Both are 100% compatible.

The thing that I feel the compact cranks lacked - speed and power.

If you don't have hugh hills to deal with, stick with the standard Shimano crank. In the long run, you'll be stronger for it.
I really like - and prefer - the Dura Ace 10spd crank. The shifting is EXACT - with the compact, it took longer to engage.

In addition, other forums have mentioned one of the SLK compact crank arms falling out. Have your LBS do the installation - or someone that has a lot of wrench experience. My LBS mentioned to me that the installation can be a bit tricky - especially if you don't have the right tools.
Cheers and good luck

mfoswterwa said:

You have a lot of opinions here. All of them very good.
I spent one year with the SLK compact crank. It's a very nice crank. Shifted very well with both my original Ultegra 9spd front derailluer and with my upgraded Dura Ace 10spd derailleur. Maybe I have a really good LBS that had the talent to set it up properly. Both are 100% compatible.

The thing that I feel the compact cranks lacked - speed and power.

If you don't have hugh hills to deal with, stick with the standard Shimano crank. In the long run, you'll be stronger for it.
I really like - and prefer - the Dura Ace 10spd crank. The shifting is EXACT - with the compact, it took longer to engage.

In addition, other forums have mentioned one of the SLK compact crank arms falling out. Have your LBS do the installation - or someone that has a lot of wrench experience. My LBS mentioned to me that the installation can be a bit tricky - especially if you don't have the right tools.
Cheers and good luck

So far my FSA K-force with MegaExo BB is super smooth! and shifts are like the DA10. In fact, I'm actually shifting in the front like I used to on just the back.

Once in shape, I can do any climb in northern california with a 39/25, but I think I will be much better off with a 34/25 ratio. I've been reading about the benefits of keeping a higher cadence and it's a part of my cycling performance that I really want focus and improve on. I'm a bigger guy (mesomorphic) so your mileage may vary, but for my size a compact crank is essential.

I've had my FSA SLK compact cranks with megaexo BB for 2 months. In that time I kept having an issue with either the BB cups coming loose or the crankarm bolt coming loose in spite of being torque to specs as provided by FSA. Called FSA and they asked me to ship them back. Will let you know what they say when it is returned. Shifting was not a problem with my 9-speed dura ace front derailleur.

Yesterday I got my Shimano R700 🙂
Didn't test it yet on the road (stupid weather) , but the first impression on the indoor trainer is very good. Shifting works perfectly and about stiffness, think is same as Dura Ace.
Weight is 70g more than Dura Ace FC-7800 (770g with BB, Dura Ace is 700g).
I am waiting to test it on some big climb (10+%) and then will report.

I too just got my Shimano FC-R700 today. Formerly I had ridden an FSA Pro Elite. The two cranks are like night and day. The first day I rode my FSA crank it derailed 3 times when shifting from the big to the little chainring. Furthermore, wouldn't shift under power from the little to the big chainring.

Today I rode up the hill I live on with my Shimano. I shifted from the little ring to the big ring while pedalling UPHILL under considerable load! I also rode to a short flat and spun the big ring out then shifted to the little ring doing about 130 RPM --- WALLAH, perfect shifting! At 130 RPM under power my old FSA compact Pro Elite would unquestionably derailed off the smaller ring.

ALL HAIL SHIMANO!!!

dvince said:

. About stiffness I heard different opinions.

crank stiffness article
bikesportmichigan.comcrank.shtmlOpen ↗

Like other here have stated concerns about FSA compacts I have been researching for my 2nd bike purchase. One of bike manufacturer reps that I spoke with said he is going to discontinue using FSA compact cranks and go strictly with Ultegra. The more I read the more I see the same sentiments. I also rode next to a guy that had a FSA compact and he complained the whole ride that he was having a problem shifting and I saw him drop a chain at least once. I suppose he could fine tune his bike, but this has been enough to convince me to go with Ultegra compact even if it does weigh a little more. Plus it seems hard to beat an Ultegra bb.

Luckily the Cannondale six13 Pro2 ultegra version is complete ultegra including the crank. The dura ace version comes with a FSA compact crank. I think I will opt to spend less and hope that the ultegra crank is as good as people say it is. The LBS owner seems to believe this is a better option for me.

Believe me, I have tried AGAIN and AGAIN to fine tune two separate bikes for an FSA compact crank. IT CANNOT BE DONE!!! It's just that simple.

*** Buy the Shimano FC-R700 compact crank ***

MRW

Felt_Rider said:

Like other here have stated concerns about FSA compacts I have been researching for my 2nd bike purchase. One of bike manufacturer reps that I spoke with said he is going to discontinue using FSA compact cranks and go strictly with Ultegra. The more I read the more I see the same sentiments. I also rode next to a guy that had a FSA compact and he complained the whole ride that he was having a problem shifting and I saw him drop a chain at least once. I suppose he could fine tune his bike, but this has been enough to convince me to go with Ultegra compact even if it does weigh a little more. Plus it seems hard to beat an Ultegra bb.

Luckily the Cannondale six13 Pro2 ultegra version is complete ultegra including the crank. The dura ace version comes with a FSA compact crank. I think I will opt to spend less and hope that the ultegra crank is as good as people say it is. The LBS owner seems to believe this is a better option for me.

mikael17128 said:

Believe me, I have tried AGAIN and AGAIN to fine tune two separate bikes for an FSA compact crank. IT CANNOT BE DONE!!! It's just that simple.

*** Buy the Shimano FC-R700 compact crank ***

MRW

I've had the FSA Energy crank for over a year with no problems. I originally used it with my Mirage front derailleur. I had to lower the mech a little bit on the seat tube, retighten the cable, play with the limit screws and it worked perfectly, apart from having to double shift to get from the small to the big ring, but that's to be expected. Back in January I splashed out a whole €30 and got an FSA compact front mech and now it still shifts perfectly and I don't have the double shift anymore.

*** Your results may vary ***

Mine sure did. I have professional mechanics from 2 separate shops try multiple times to work it. Both finally told me there was, quite literally, nothing more they could do. I then bought an FSA front derailer which helped for awhile. FSA are slick marketers: Their derailers are very lightweight which make them quite susceptible to wear. The magic front derailer fix stopped working after about 500 miles or so. I brought it to the shop again and the master mechanic took a look at it, tightened all the screws on it and told me that it was a lightweight P.O.S. and that I should return to a Dura Ace derailer. Soon thereafter I returned to a Dura Ace Fc-7800 53/39 crank and 7800 model front derailer and all my troubles melted away --- Well until the summer, when, to avoid the oppressive heat I have to return to the mountains. My solution: The new and glorious perfect shifting Shimano FC-R700.

I did 112 miles on Sunday with 10,000 feet of climbing. No derailing, no shifting problems of any kind! I just cannot get enough of the Shimano FC-R700!!! I cannot say the same for my FSA (the two cranks don't even deserve to be mentioned in the same sentence).

*** ALL HAIL SHIMANO ***

Tonto said:

I've had the FSA Energy crank for over a year with no problems. I originally used it with my Mirage front derailleur. I had to lower the mech a little bit on the seat tube, retighten the cable, play with the limit screws and it worked perfectly, apart from having to double shift to get from the small to the big ring, but that's to be expected. Back in January I splashed out a whole €30 and got an FSA compact front mech and now it still shifts perfectly and I don't have the double shift anymore.