ThermionicScott 

@Kapusta, I had a similar experience (and reaction) when I borrowed a friend's 50/34 "cross bike" years ago. Felt like I was always in the bottom end of the cassette in the big ring, or at the top end of the cassette in the small ring, shifting across the whole cassette when the time came to shift the front. I guess some of us are more sensitive to that kind of thing than others.

Since you already have the crank, cassette, and whatnot, I think you might as well try the smaller big ring first. You might be pleasantly surprised with how a 46T gives you lower gears in the big ring and let you hang out there for more of the time. You would just need to bolt on the new ring and lower the FD, no need to mess with the chain length.

restlessswind

I had bought a Surly Cross-check a couple years ago as a primary do-it-all bike. I opted for the flat bar configuration. It was setup as a 1x9. That 42 tooth chainwheel didn't do hills at all. I added a triple (26-36-48) crankset, and found a matching shifter (SRAM x5) on clearance for $5.

Oldguyonoldbike

Until recently I had never had a road bike with a triple. About a year ago I switched out an 8-speed drivetrain with a 53/39 crankset for a 10-speed triple (53-42-30, with a 12-25 cassette). My other two bikes have 50/34 (with an 11-25 cassette) and 52/36 (12-27 cassette). Apart from the front derailleur being quite finicky, the triple setup is great. I find that I shift a lot less at the front, I can maintain a better chain line and I have a really low granny gear if I need it.
Of the other two, I have been quite happy with the 52/36, but as I get older (57 now) I find I don't use the smallest cogs very often. The compact offers a good range of gears, but on the rolling terrain that I ride most often it does seem that I have to shift an awful lot with the FD.

fietsbob

Toured Europe & British Isles, ... several long ones.. 13~34t Freewheel 50-40-24t 110-74 triple...

Under the BB cable routing..

More C&V , Over the BB Cable Guide run, a little higher FD clears it , so I went 52,42, 26..






...

Kedosto

I strongly recommend you consider a 46/34 chain ring setup. Of course, it depends on your terrain, fitness and ability.

I was a bit apprehensive about a 50/34 compact double and sure enough I felt like I was never on the right ring. The big was too big, the small too small. I swapped in a 46 and now I live on the big ring. For me it's almost like a 1X. There are times when I wish I could go smaller (say, 30-ish) on the small ring, but that's not an option with my crankset. My 46/34 with a 11/34 cassette covers about 90% of my needs. I made a run down the PCH and absolutely hated not having a granny ring, but everywhere else the 46/34 does the job.

It's probably best to pay a visit to Sheldon's Gear Calculator and take a look at what you're running now vs what it would be like after some changes. My 10sp setup, paired with 700x42's puts me right in the sweet spot on the big ring. If I did more touring I'd go back to a triple setup.


-Kedosto

blakcloud

I had a triple on my Rivendell and decided to go with a compact double. Like others have mentioned it is a terrible combination for the reasons mentioned. When it warms up, the triple is going back on and I for one will be happier.

Kapusta

daoswald

I have a triple on my road bike (30/39/50) and on my hybrid (28/38/48). In the case of the road bike I toyed with the idea of rebuilding the drive train around a compact double, and going from a 10sp cassette to 11sp. By going to a compact double with 34/50 and a rear cassette of 11-32 I would be at about the same low gear, and same high gear as I currently have with my triple 30/39/50 with an 11-28 cassette. But then why? So I can have a shiny 11sp rear cassette? So I can have one fewer chainring in front?

With a triple I can choose; the 30t chainring for really steep climbs, the 39t chainring for moderate climbs to slight downhill, and the 50t chainring for flat to downhill. With a compact double the purposes are less certain, and the front shifting will happen sooner, at lower speeds as I accelerate from a stop in the 34t ring and then top it out and shift to the 50t earlier in the acceleration curve. The compact double will be 1/3rd pound lighter (maybe), and may have slightly smoother shifts, though with a well tuned triple I wouldn't ever say my shifts are clunky. Ultimately I've decided to stick with the triple. Any additional tweaking I do will be in what I ride on for a rear cassette.

fietsbob

46 : 11 or 12 ought to be high enough , . with a 700c wheel ..

Darth Lefty 

kingston 

Spend the money. I ran a compact crank with a 12-25 for a season because I was too cheap to buy a new chainring. Then I spent the hundred bucks on a 46T, and the difference is night and day better. For very hilly rides I have always used a triple.

Phil_gretz

...whether or not I really might find a practical use for a triple. I can only see doing this on a touring bike, where I need a really wide range with small incremental steps within each range.

For a utility bike or commuter, I'd rather use the 46/34 (or 46/38) combination up front with a wide enough cassette/freewheel to get the lowest climbing gear that I think that I'll need.

For a performance oriented bike, I'd never consider a triple. I might go compact 50/34, though. With STI shifting and enough rear cogs, the chainring plus rear shift transitions are simple enough once you've learned them.

I recently put a half-step plus granny triple on a sports touring/touring bike (1978 Grand Jubile), but because of the six-speed rear triangle limit, I consider this really a compact alpine double. (50-46-28T) x (14-28T 6 speed)

For a cross country MTB, there's no need for a triple. I prefer to remove the outer chainring (if supplied) and replace with a bash guard, so 2 x whatever.

cyccommute 

A 46/34 is only slightly better than the 50/34. There's still a huge gap between the two chainrings when you compare them. Look at a traditional 52/42 double set up. In particular look at the gap between the 52 and 42 on the 15 tooth cog. The 52/13 combination has a gear inch of 90.6 and the 42/15 combination has a gear inch of 76.1. That's a gap of 14.5". On the 50/34 crank, the gap is 29". That nearly 30" gap is a huge transition. In terms of speed at 90 rpm, the difference with the 50/34 is 24.3 mph to 16.5 mph. For the 50/42 crank, the difference is 24.3 to 20.4. From an rpm standpoint, you'd have to increase your cadence to over 120 rpm to maintain that 16.5 mph when you shift with the compact double but you'd only need to increase rpm to about 100 rpm to maintain the same speed using a traditional double. Maintaining a cadence of 120 rpm is difficult for any extended time.

You could get similar results if you went to a 10 tooth gap between the gears on a compact double but you either lose range or you lose top speed. A 44/34 would maintain a similar gap as a 52/42 with the same low end but you would sacrifice the highest gear. A 99" gear is high but it does spin out at a fairly low speed.

A 52/42/30 triple, on the other hand, maintains the same tighter ratios as the 52/42 double but it gives you more useable ratios in the middle where you need them. The middle of the range is has a higher gear range but you have the smaller ring for the range you want and/or need. A 50/39/30 triple gives an even better gear range and ratios.

One of my bikes has "crossover" (not to be confused with cross chaining) gearing. It's called a crossover because you shift through the gears to the middle of the cassette and then "cross over" to the other range. I use a 50/45/30 crank with an 11-34 cassette. A shift on the front or rear results in the same gear ratio. It feels a bit like a single speed but it has a higher top range and larger overall range with the 30 tooth inner ring.

Kapusta

Well what works for you does not necessarily work for me. Different rider, different bike, different roads.

Why spend over $100 on a chainring that MIGHT do what I want, when I can get a whole new set of triple rings for that much for a triple that I KNOW will work?

Honestly, I would probably just get a subcompact crank with a 46t ring before I put more money into the compact crank that keeps me limited to a 34t small ring.

kingston 

I was just trying to be helpful by sharing my similar experience with a compact. Get whatever you want.

Kapusta

Did you read the OP?

Kapusta

Sorry for my tone. I had already mentioned that I have my doubts about a 46t ring doing the trick. But it was buried in the long original post.

kingston 

Likewise for my snippy response. I have a lot of bikes so having one with a 46/34 is fine. If I only had one bike, it would have a triple. I will never have another bike with a 50/34, but it was worth a try since it seem to work just fine for most people.

GrantFlower

actually i am not going but in future hopefully