That’s why I was wondering if I could put a cassette with a 32 on the back, would give me nearly the same bailout gear ratio.
I use 34/28 occasionally, I very rarely use 50/11 and actually pedal hard.
I finally got round to swapping in the replacement chainrings and cassette on my Stealth. So now have 50/39 to 11-28 instead of 55/44 to 12-25.
I was a bit surprised to find the new 50T ring was thinner than the 55T I took off and the chainring bolts were about 0.5 mm too long to tighten down - there’s always something, isn’t there? I cut some washers out of an old Tupperware box (chalk one up for the “keep old junk in case it’s useful one day”) and squeezed them between the ring and the spider. Seems totally snug. I did wonder if it would throw the chainring spacing out but it seems to change up and down alright. Then I swapped the cassette. Absolute bastard getting the old one off. Now, I swear I got a 12-28 but it was 11-28 when I went to put it on. Not sure if that was me or a bad description from the person selling. Anyway, it came with 11T lockring and my freehub body is compatible so all good.
Shiny (for now)!
On the road, the lower gears are good. I was getting on okay with 42-25 but the extra gears do make climbing easier. I’ve only spun out the top end once when I was feeling brave enough to actually pedal. Sits with decent chain line on big ring for fast and flat. Only niggle is a jump somewhere in the middle of the cassette that’s just a bit bigger than I’d like for perfection. Might be the 13 to 15. Maybe a 12-27 cassette would be even better if one comes up on eBay. Good advice, everyone from earlier. Many thanks.
2 Likes
I’ve done the IM Wales course 5 times now (3 x LCW) on a TT bike with 52/36 and 11/28. I’m the world’s worst climber (for reference 
)Pretty happy with that.
Years and years ago, Campag did a limited run of 52/36 for the Daytona group, I had one and it was also brilliant (until it came time to replace the rings and found out they’s stopped making it 
)
That sounds horrible for any kind of meaningful incline!
Interesting decision to see that you went 50/39? Not heard of anyone considering that combo before, especially on a 5 bolt spider. Didn’t even know you could get 130bcd 50t chainrings, but just looked and they are available (obviously, if you got one!).
What was the motivation of dropping the big ring so much to normal road compact, and yet leaving the little ring still relatively large and a normal standard chainring size? I’ve always found my friends and I looking at wanting a slightly larger big ring, and smaller little ring, but then running into issues with the jump/capacity. For me, that’s where default semi-compact (52-36) slots in just about perfectly, not being such a powerful rider.
Not much in the way of meaningful inclines round me (Hampshire - if it’s steep, it’s short) but, yes, 42 was too big for racing on. Previous owner either had massive thighs or only did flat courses.
The crankset is 130 mm BCD so 39T is as small as will fit (actually can get 38T, I think, but they’re not very common). Combination of being tightfisted and fear of BB standards meant I really only wanted to change rings. Only a couple of runs out so far but it’s okay and quite nice being able to just stay in small ring on some local rolling, twisty lanes.
You might be right about 52T being better than 50T but I don’t think I’m going to run out of gears at the top end (unless I get a lot braver going downhill) so I think I’m going to benefit slightly from being able to stay in the big ring on gentle rises / grim headwinds. If you look up the thread, there were votes for both 50T and 52T and I have small, puny legs.
If I’m ever doing something properly long and hilly I might look at swapping the crankset completely to semi-compact. All a bit of an experiment so far.
Ooh, my neck of the woods. Where are you Matt? (Winchester for me)
Romsey
More hills if you go past Winchester 
ah right. That’s Setonia country isn’t it?
52/34…
Works perfect.
I’ve recently gone through this. Long story short I ended up with 52/36 on the front and 12-25 on the back. I wanted the 12-25 because that’s the only cassette in Shimano’s current range that includes an 18 cog. All the other 11- cassettes skip the 18. Looking on a Cadence to speed chart, that 18 cog was where I wanted to be for an average speed.
I also bought an 11-28 and can make up a 12-28 using the 2 sets, still keeping the 18…
1 Like
I’ve got a new 55-42 chainset on order
Currently using 52-36 usually with 12-25 cassette, which is my favorite cassette. I find that even on flat courses, I would like a bigger gear than 52 - 12 hence the bigger chainset. On Hilly courses, I do have an 11-30 or a 12-28 cassette that I can use (I prefer the 12-28)
I can grind up hill at low cadence pretty efficietly, so using a smaller cassette is an option for me
52/12 @ 90rpm is 49.07kph, you missed your calling!
Couple of points. On a flat TT I am averaging 45kph, with small descents, or with a tail wind, I am up to 55kph+. Secondly the chainline is not perfect with the 52 - 12, it all runs fractionally smoother a couple of cogs lower. Finally the smallest cog also looses some efficiency, so running on a bigger rear sprocket has some benefits.
Yeah, aligning the chain ring makes sense but needing 55 instead of 52 because you were pushing over 49kph didn’t.
1 Like
You are right. Chainring and cassette size is far more than just spinning out. On my road bike, I can still descend at 70kph with a 50-12 combination, however, I am riding slower on the flat, so 50-14 works well
Yeah, a lot of focus has been put on that in the last couple of years. Do you run oversize jockey wheels?
I may be ridiculed for this, but yes I am on TT bike