For reasons of parts-bin build , I have only three chainrings to play with. 49, 46, and 34. I'll be using an 8-speed rear wheel that I recently got for cheap.

I'm wondering if there's any real benefit to including the 46 ring when I'm going with a larger cassette. Wouldn't I be just as well off with only the 49 and 34? Especially since I'm in San Diego and deal with constant hills, rather than flatland that's conducive to finding the perfect cadence.

Thoughts? Thanks.

Probably Palomar mountain, but that's more due to fitness. I'm stopping at 8speed because all of my chains are 8-speed.
Thanks for the advice, I think I'll go that route.

Typically half-step gearing has two chainrings with a 3, 4 or 5 tooth difference. The cassette would also need to have a 2 or 3 tooth difference in the progression.

You could do an 11-13-15-17-20-23-26-30 cassette with a 49 & 46 chainring combination, it's not ideal, but that would work. I'm not sure you would like it in a hilly area.

I think what you are really inquiring about is chainring selection, not half-step gearing.

In that case, a 49 & 34 chainring set is a good choice.

​​​​​​No, I am interested in half step because I could set up my bike as half-step plus the 34t chainring. It's just I've never tried half-step and am unsure of its benefits both in a hilly area and on a bike with an 8speed cassette. Plus I've always thought cranks set up with half-step plus granny simply look cool...but based on the advice given and my own research into previous forum threads it just isn't the right set up for the bike.

Did you just get back from the future, Doc?

I built up a custom half-step and a granny on this PX10, it's designed for hilly rides like L'Eroica. The Stronglight crankset has a 46, 42 and 30. The freewheel is a 13-30 six speed Suntour. It has a useful range and can climb any hill. However, going up and down the range in sequence is not rapid, but more leisurely.

I have half step on 3 bikes, 2 with 10 speed cassettes and on e with 9. My Fuji is a half step with 49x46 and a 11-36 10 speed cassette. My Centurion Pro-Tour is half step and granny with 49x46x30 also with a 11-36 10 speed cassette. My Zunow is half step 49x46 with a 12-36 9 speed cassette.
I am finding that the spread of the cassette is typically good enough for the mostly flat riding here where I live in Cambodia.
I am thinking of changing the Fuji to a compact crank setup with 48x34 front and 10 speed rear 11-36 using a flat bar and ultegra 10 speed flat bar shifter for the cassette and a DT shifter for the front.
Nine speed cassettes 12-36 have the best spacing for the half step it give 18 separately usable gears with no overlap. A 9 speed cassette inherently has the same gear % spacing as a 6 speed freewheel and half step chainring setup but with higher and lower ratios added.

My first reaction was that half step gearing is useful for 5 or 6 speed freewheels, where the gaps between shifts are quite large. Shifting the chainring gets you the gear in between.

But it works quite nice with 8 speed.
Here's your 34, 46 and 49 with a wide range 12-30 cassette.

For example, at 90 rpm, it's 16.4, 17.5, 18.2, 19.4, 20.5 mph.
You probably wouldn't shift the front to do the half step very often, but getting that "just right" cadence with a front shift would be nice at times.
I like 1 mph difference shifts when I'm working hard. For more typical riding, the 2 mph shifts on either the 46 or 49 would be good.



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If you get new chainrings, lower gearing would be nice.

I really like my gravel / all-day-ride gearing.
It's 30-39-52 and 11-speed 12-25 or 12-29.
I rarely use the 52 unless it's at least slightly downhill, but it's nice to have it for those times. The 39 is good from around 10 mph all the way to 20-22 mph.
The approximately 1:1 low gear is great on paved roads up to 12%, and usable on even steeper grades, 18-20%.
I would like an even lower ring for long, steep climbs, a 28 or 26, but my crankset won't fit anything smaller than 30.

In theory, you could make a pretty sweet half-step setup (ab)using 1x11 parts, if you wanted to.

sun race makes a wide range cassette. obviously the last two or three cogs might be a huge jump, but you'll definitely have enough range. i'd suggest splurging and getting a 9 speed chain + cassette. you can still use the rings you have (on the right crankset), and you'll get a smaller jump between cogs.

Ha, that's great!
39/42 front
11-50 11-speed rear !!

Or the new Sram:
10-50 in 12-speed...


Sheldon Brown would approve.

The problem with doubles and triples are 'theoretical' ratios because you really don't ride cross chained. So if you examine a 3 x 8, you really don't have 24 speeds.

Rather should base your needs and focus on your 'effective' ratios.

I'm convinced with a 1 x 11 on my MTB, aided by a clutched derailleur. A key ingredient is the clutched derailleur. Lighter in weight, works flawless, fast, zero chain drop and haven't noticed any chain slap. But the real ~numbers~ is in having ALL effective ratios.

We're already seeing this adopted to gravel / adventure whatever bikes so I would think some roadies will take to the 1 by system. I'm exploring adapting to a vintage bike, a wide ratio 1 BY and using a clutched derailleur.

Also, the made in Spain company Rotor, just introduced a 1 x 13 drive system using hydraulic actuated derailleur. No cables, no battery / electronic. Cool stuff.

I'm not sure about the world embracing 1x11, or 12. Personally, I don't recommend 1x11 (or 1x12) setups even for gravel. Most friends who started with this combination either need to change the chainring size several times a year (depending on the events planned) or have gone back to doubles. It's difficult to improve on a 46 & 33 combination with a 11-36 cassette on gravel (yes, I mean 33, they are available for a 110 BCD crank).

But if a 1x12 with drop bars is the combination you seek, ​​​​​​and you want want the the latest eTap technology: see...

https://launch.sram.com/en/axs/the-mullet-bike

(Sram) "recommend(s) combining a pair of AXS drop bar levers with an Eagle AXS rear derailleur, Eagle chain, 10-50t Eagle cassette, and your choice of either an Eagle or road AXS 1x crankset to build the raddest drop bar bike on the block".

^That Sram setup is pretty wild! Terrific how the competition is heating up.

Here's Rotor
https://rotorbike.com/1x13-the-only-one/

I have always liked half-step. As pointed out above, 49-46 is a classic chainring combo, mainly because it works so well with a 2-tooth progression in back.

I currently run the Bianchi with a 1.5-step 50-42 / 14-16-18-20-23-26, but I can swap in a 47 for the 42 for flat work. If I wanted a higher top end and a lower bottom gear, an 8-speed cassette would still make sense with the 50-47 (or a 49-46): 12-14-16-18-20-23-26-30, or add a 34 or 36 with a 9-speed.

Another half-step I really liked was one I put on the Peugeot PKN-10: 48-45-34 / 13-15-17-19-21-24. Again, start with 12T for a higher top gear and end at 28 or in the 30s for a lower bottom gear, and once again half-step (this time with granny) still makes sense with 8 or 9 cogs in back.




The only problem I have experienced is that many of the newer spiders are too thick for a 3-tooth drop between the two outer chainrings. Unable to do 53-50-39 on a Campag. Veloce, I ended up doing half-step-plus-overdrive, with 50-42-39 / 13-15-17-19... , which is not as satisfactory, but interesting, anyway.

You've all given me a lot to think about, I appreciate the theorizing! After reading, and finding a 28t ring in the bottom of the bin, I think a 28/42/46 mated to an 11-32 8speed cassette would work pretty well.

Thermionic, what gearing app is that?

Found it, Dirk Feeken's!

Bicycle Gear Calculator

Thanks for the assist, [MENTION=332373]bwilli88[/MENTION]! Yes, Dirk Feeken's calculator has changed looks a couple times as he's updated it over the years. Apart from wishing for a few more (obsolete) cassette and tire options in the menus, it's my favorite gear-tweaking tool.

Even if you find that the half-step pattern doesn't work out with your new cassette, it will still be plenty usable if you just shift up and down the cassette on a particular chainring, as you would a regular bike. No downsides, really.