Review: Shimano Compact Chain Ring

I'm a spinner when I ride my bike. I spin on the flats, I spin in the hills. Grinding is just not my game. The challenge this presents is that I'm constantly shifting from my small chainring to the big ring, and back. This type of shifting is just not as smooth as flicking the chain up or down the cassette in back. Front shifting is rougher, mucks up your pacing and can lead to a dropped chain. Mind you, it's not that I have any particular problem with the front derailleur, I'd just like to ignore it once in a while.

"Get a compact crankset", says The Boss, "I have one and love it. I can finally use all ten of those gears in back". The Boss' advice is usually sound so I've been poking around bike shops looking at compact cranksets and discussing the advantages/disadvantages of going compact. Going compact refers to moving from the usual 39/53 tooth rings up front to something like 34/50. Compact has been de rigeur since Tyler Hamilton (Doper!) used them and finished well in the 2004 Tour de France.

I've only heard about two negatives. One is that going compact requires you to swap out the whole crankset since the smaller rings have a different hole pattern than their bigger brothers. Buying a good quality compact crankset runs in the range of $300.00 to $500.00. And the other negative is that some riders complain of running out of gearing on long, fast descents. Furthermore, I like Dura Ace stuff and they don't make a Dura Ace compact crankset. They did introduce a compact set this year in the Ultegra class (see HERE), but nothing Dura Ace as of yet.

I was convinced that the "running out of gears" issue wasn't going to be a problem. The hills here in Wisconsin can be steep, but they're short and usually have a stop sign or 90 degree turn at the bottom anyway. So the chances of a long, fast run-out are minimal. That left the issue of cost. $400.00 or so seemed just too expensive. Especially since my cranksets are still in good shape and are not in need of replacement. And what if I didn't like the new, expensive set? Elvis Kennedy does these equipment reviews because he cares. Not because some manufacturer sends Elvis free stuff in exchange for a positive review. If an expensive compact crankset doesn't meet expectations, the cash is gone. (Editor's note: If you'd like to send Elvis some free stuff in exchange for a positive review - please feel free!)

The Boss offered to let me ride his bike but I've discovered that to really test bike stuff you need to ride 200 miles or more to get a good feel for something. 500 miles is better. What to do?

Enter Shimano's new 50 tooth chain ring (see HERE). The hole pattern is compatible with my current Shimano set up (130mm spacing) and it's of Dura Ace lineage. For whatever reason there has not been a lot of press or advertising coverage of this little beauty. Which is surprising given all of the attention paid to compact cranksets as of late.

The new 50 tooth on top of the 53 tooth for size comparison

It lists for $119.99 but you can get it for a bit less at places like THIS. Note: as nice as it sounds to get into compact by buying a $120.00 ring instead of a $400.00 crankset, it stills befuddles Elvis that a small, stamped piece of aluminum runs this high. With the crankset you get a nice bottom bracket and carbon crankarms to go along with the rings. Surely the two rings of a crankset don't represent half the manufacturing costs of a compete crankset.

Some cycling buddies of mine discuss 'chain inches' when talking about chain rings and cassettes. I've never taken the time to figure out that rather complicated formula ( chainring / freewheel x 27 = chain inches). If I'm in the small ring up front and the fifth cog from the left in back I consider myself in fifth gear (out of twenty). But as a service to my dear readers you are hereby provided with a handy, dandy chart of chain inches for a rather wide range of chain ring and cog combinations. Pay close attention to the differences between the 53 tooth ring and the 50 tooth.

Handy, dandy chart

For you mathematically minded, here are a couple of formulas you can play with;

chainring / freewheel x 27 = chain inches
chain inches x PI (3.14) = distance per pedal revolution
chain inches x PI (3.14) x RPM x 60 / 63,360 = speed

My typical gear usage is as follows (I have an 11-23 cassette); climbing: 2-4, cruising 5-9, time trials or group ride speed: 13-17. By viewing the chart you can see that with a typical 39/53 set up I'm using both chain rings, but with a 50 tooth ring I can do everything but steep climbing on the 50 tooth ring. As I said earlier, there's nothing wrong with using both rings up front but the advantages of not having to front ring shift as often are smoother riding and reducing the chances of dropping a chain.

When I built up my bikes I paid special attention to the distance from the bottom of the front derailleur and the top of the big chain ring. According to Shimano this distance must fall within a certain range for proper shifting. As I mounted the 50 tooth ring I figured that I would also have to play with the front derailleur height. Since I was just planning on trying out the ring I really didn't want to mess around with anything else in fear that I would never get everything back to where it was. As it turns out, I made no adjustments to anything and the drivetrain works splendidly with either the 50 tooth or the 53 tooth ring mounted. Your mileage may vary but give it a go without mucking around with adjusting stuff.



Mounting was easy, of course. Remove the five hex bolts, take off the ring, put on the new one, make sure that the little peg on the ring is aligned with the crank arm, replace the bolts, tighten the bolts. Done. Truth be told, nothing is ever quite that easy. The small ring has to be removed from the crank in order to get the big ring off and the small ring must be aligned a certain way too. Look closely on your small ring and you'll see a little arrow kind of like this "<". Just make sure that the little arrow is aligned with the crank arm (just like the little peg is on the big ring) and you'll be fine. Since the little ring is now loose you might as well take if off and give it a good cleaning. If you feel that you need a more complicated set of instructions you can go HERE to download Shimano's service documentation and exploded views for the Dura Ace crankset.

The 50 tooth ring itself is of Dura Ace quality. It's light in weight, strong and has that Dura Ace high quality finish. It's built to the same exacting standards as the 53 tooth ring so there is no reason to feel that you've lost anything in terms of quality. It's simplicity is brilliant and Shimano's decision to offer this stand alone ring instead of forcing Dura Ace fans to buy a whole new crankset is refreshing in these days of corporate greed.

In action the ring behaves just like it should, namely; you don't have to think about it. There's nothing to adjust and it won't break. The only question is whether the gearing will work for you.

Although this particular chainring is designated Dura Ace, you don't have to have a Dura Ace crank to use it. Any Shimano or other brand crank will suffice as long as the bolt pattern is 130mm. It will work wonderfully on an Ultegra set-up.

In my testing I was surprised by how different the gearing felt. Look at the chart above and take the 53-20 combo for example. In gear inches it's 71.6. The closest on the 50 ring is a 50-19 which gives you 71.1 gear inches. This may sound funny but that 0.5 difference in gear inches 'feels' different to me. Oftentimes I feel like I'm in-between gears. This is surely a result of too much riding and a good reminder of just how in-tune a person can become with a machine. Is that a good thing?

Riding with the 50 tooth ring is a refreshing change of pace and as soon as I adjust to the slightly different gearing I'll be happy. Infrequent use of the front derailleur means I have less to think about and it means that I be a smoother rider. And if other riders who are unaware that Shimano makes a 50 tooth ring think that I'm a stud by climbing in my big ring, all the better!

With a (relatively) inexpensive way of going compact all while keeping the option of going back to a standard set-up with a simple swap of chainrings, I couldn't be happier. The Shimano 50 tooth chainring is highly recommended.

Elvis Kennedy's Rating:

Overall: 9.3
Ride: 10.0
Fit/Finish: 10.0
Value: 8.0

Hey Shimano, if you didn't charge $120.00 for a piece of aluminum (or, al-u-min-e-um to you Brits out there) you would have received a perfect 10.