I have a compact 50/34 and an 11/26 on my tri-bike. I never run the 34/26 and very rarely use the 34/23, except on steep inclines. Does it make sense to run a 50/36? Is it as simple as just swapping out the 34 chainring with a 36? It seems like a cheaper option than replacing the rear cassette.
I run a 50/36 with (I think) a 12-26 and like it.
never had a 34; seems like it would be a bit small for the hills where i live.
I feel that 50/36 also provides more overlap between big chainring and small chainring gears and depending on where you live and your watts/kg, and your largest rear cog, 34 may not be that useful. I never use the 34x25 on my bike locally, but I have the 34 on there for when I head out of town and have to do long hillclimbs
It may be a bit cheaper than a new cassette, but you would probably be better served with an 11-23. You’ll get the 16T cog, and avoid the 15-17T jump, but that all depends upon how wide a range of cadence you’re comfortable with.
I had a 50/34 on my previous tri bike and my main complaint was that I was always back and forth between the chainrings - seemed like the sweet spot was in between the two ring sizes. A 36 small ring might be better for that - allow you to spend more time in the small ring, but the difference in gear inches between a 34:26 and 36:26 is pretty small (2.6 vs 2.7 according to http://www.sheldonbrown.com/gears/)
I would just wait until your rear cassette wears out and then replace it with one that matches your riding style a little better (maybe a 12/25 if you don’t find yourself in the 50:11 much either - a tighter gear cluster just feels better)
You can just swap the 34t ring for a 36t if you want. Some brands mate their chainrings (shimano for sure, less sure about others) - so you may consider trying to find out if you there is a 36 that mates with your 50 (shimano used to use A and B - for example, there was a 53A that mated with the 39A and a 53B that mated with the 42B - not sure if they still do or if it really makes that much difference in shifting)
have fun
Andy
Hi, I rarely post on this board, but this is something I like to advocate.
I am a lightweight (135 -140) cat 1 road racer. I run a 36x50 all year while racing.
A 50x11 is a harder gear than 53x12.
The 14 tooth gap is standard (standard road bikes have 39x53 which is a 14 tooth difference).
36x50 is a 14 tooth gap. This is standard because it has the least overlap and allows the front derailer to function best.
You could buy a 36, put it on with an 11-23 rear cassette and have wider gears than you would with a 39x53 and 11-25.
wider gears being your low end is lower (36x23 is like a 25.5 on a 39) and your high end is higher 50x11 is harder than 53x12 (its like a 53x11.5).
And do you really need a 53x11? thought this was slow twitch?