[kinglh]

Wise forum, can people chime in on the shifting performance of the SL-K mid-compacts that specialized has on many of their 2013 rigs?

I'm getting a Tarmac Expert in the next week or so and considering swapping out the SL-K 52-36 mid-compact for a traditional 130mm 53-39 setup, mostly because my past bike's compact set up was troublesome at times. I know many peeps don't mind a little lag, but as a weekend racer those lags could lead to lost opportunities of glory and fame (ha).

Experiences, comments and ridicule welcomed.

 

[blairellis]

I just picked up the same bike. I upgraded from a 105 bike so I'm no expert, but they shift plenty fast for me. I'm sure it's no Ui2 or Di2, but it's pretty quick on the shifts IMO. YMMV.

 

[PJ352]

When it comes to cranksets, I'm a Shimano fan boy. That said, you don't have to change gearing just to rid yourself of sub-par shifting. You can stay with a 50/34 and go with a Shimano compact. Most any from 105 up will likely be an upgrade over the FSA.

FWIW, my Shimano 105 (5600) crankset shifts as well as my Ultegra, which is to say, very well.

 

[Doc_D]

I ran a 50/34 and really disliked it because I felt like I was "between the rings" a lot. I ride/race a 53/39 and it works well for me but I'm a smaller guy and just feel a bit over geared sometimes (especially when I'm doing a century with 10,000 feet of climbing and 20% grade). So I just built up a Tarmac Pro frameset with Dura Ace 9000 with a 52/36 and a 12-28 cassette. I just rode it for the first time tonight and I'm extremely pleased. I don't feel like I'm between the rings like I did on the 50/34. It has plenty of top end and WAY more bottom end than I'm used to. I honestly think I can go an entire season and never have to change out the cassette. It should work perfectly for everything from flat crits, to downhill sprints, to centuries with 10,000 feet of climbing and 20+% grades.

I know a lot of people rag on the mid-compact but with an 11-speed 12-28, it's a complete winner in my book.

 

[ukbloke]

I'm getting a Tarmac Expert in the next week or so and considering swapping out the SL-K 52-36 mid-compact for a traditional 130mm 53-39 setup, mostly because my past bike's compact set up was troublesome at times.

If you don't like the 16T gap, just change that 36 inner ring for a 39. You won't miss the 53.

 

[alr]

Been going through the same process. What I found with the compact was that the 34T was never used - it was 'easier' to stay on the 50t and go across the cassette - but that leads to a problem. Have a look at your chainline when going across the cassette - when you get to the larger cogs the chain is way off straight - this is both inefficient and causes premature wear on the chain / rings / cogs - which in turn exacerbates the power transfer inefficiency. Similarly, an 11t cog is about at the limit of the tightest the chain can go around - don't like approaching limits!

Since going to a standard (53/39) I am changing on the front ring much more and the rear cassette less - so maintaining a much straighter chain run. A humble opinion.

 

[PJ352]

Been going through the same process. What I found with the compact was that the 34T was never used - it was 'easier' to stay on the 50t and go across the cassette - but that leads to a problem. Have a look at your chainline when going across the cassette - when you get to the larger cogs the chain is way off straight - this is both inefficient and causes premature wear on the chain / rings / cogs - which in turn exacerbates the power transfer inefficiency. Similarly, an 11t cog is about at the limit of the tightest the chain can go around - don't like approaching limits!

Since going to a standard (53/39) I am changing on the front ring much more and the rear cassette less - so maintaining a much straighter chain run. A humble opinion.

What you're describing is cross chaining. While I agree that it's less efficient than maintaining a straighter chain line and can cause more wear, IME occasional use isn't detrimental.

That said, I think your fundamental points are valid and points up the disadvantage of running a 'wider' drivetrain, with the requisite gaps you describe.

Most every ring/ cog combo represents a compromise, so the best we can hope for is one that serves us best, given our level of fitness, terrain and style of riding, promoting a relatively high cadence and smooth pedal stroke.

JMO, but I think the mid-compact mentioned above would suite some riders pretty well.

 

[Dunbar]

Since going to a standard (53/39) I am changing on the front ring much more and the rear cassette less - so maintaining a much straighter chain run. A humble opinion.

Well, some of us need the 34 for climbing purposes. Another option I've seen kicked around here is swapping the inner chainring of your compact out for a 38T. It's fairly easy and quite a bit cheaper than buying a whole new crank. Unless you're racing it's doubtful that you need the 52/53T big ring anyways.

 

[kinglh]

What I'm really looking to hear is how shifting is on the SL-k in a 52/38 combo. Should I consider going with another crankset (ultegra?), of course, i'd need a bb adapter for that.

 

[blairellis]

Decided to pull mine off in favor of a Quarq Elsa power meter with the standard 53/39 chain rings. I don't miss the mid-compact yet, but I have yet to do any large mountains. I do like the additional speed the regular crank gives me on the flats/downhills over the mid-compact.