2x vs. 3x Chainring Differences?

[emicen]

Putting the TL:DR version first: would a 3x outer ring work as a 2x outer ring?


My gravel bike came with Claris 2x8, running 48/32 up front.

Now I’m back to using it in winter I’m finding it annoying being stuck between gears. I mostly wind up in the 48t ring and 4/5/6 at the back but often find the lower gear a bit too spinny and the higher gear a bit to stiff.

Excel monkey calculations suggest reducing the front 48t ring down to a 44t will bring 7 in to play and give me better ranges 4-7.

Trying to find a 44t ring that isn’t narrow wide for 1x is a royal PITA. Have found Acera 3x parts which are obviously designed for shifting between rings, albeit 9sp over my 8, but is there any difference in alignment between 3x and 2x?

Edited by emicen on Sunday 8th November 15:55

[Barchettaman]

By the sound of things you need a different cassette, not a 44 chainring.

What’s the range of your current 8-speed cassette? 12/30?

Maybe go to 13/25 or get a junior geared one with a 14 big sprocket?

[smifffymoto]

For all things gearing have a look at SJS cycles,they are primarily a touring shop but tourers love a big gear range.

[DP1]

You may find this handy as well

https://www.bikecalc.com/gear_speed

Also Spa Cycles do loads of gears, rings etc

[emicen]

Barchettaman said:

By the sound of things you need a different cassette, not a 44 chainring.

What’s the range of your current 8-speed cassette? 12/30?

Maybe go to 13/25 or get a junior geared one with a 14 big sprocket?

The ultimate (correct?) answer would be I need more gears, but this bike was cheap and I want it to stay that way, getting to 10/11 speed from Claris seemingly requires an everything upgrade and 9sp isn’t really worth it from the gear spreads I have calculated.

Current set up is 48/32 chainrings with 11-34 cassette [34-28-24-21-18-15-13-11].

I don’t want to lose anything at the low end. There are roads on my rides with inclines which have me in the granny ring and 34/28/24 at the back.

The main issue is on the flat or slight grades, I’m usually running big ring with 21/18/15 at the back. The issue is I want to be in the middle of those ratios and short of creating a seriously bizarre custom cassette range, shrinking the big ring is the better bet.

That’s why I’m wanting to go smaller big ring rather than change cassette. This same issue bugged me before I got my TCR, but now I’m used to running 11sp and being able to always find the right gear, it’s feels way more noticeable now.

As a footnote, looks like my current chainrings BCD (110 x 4) is different to the Acera (104 x 4) I had found and 110 options are sparse so the answer may well be to just suck it up.

[Barchettaman]

emicen said:

Current set up is 48/32 chainrings with 11-34 cassette [34-28-24-21-18-15-13-11].

I don’t want to lose anything at the low end.

The main issue is on the flat or slight grades, I’m usually running big ring with 21/18/15 at the back. The issue is I want to be in the middle of those ratios and short of creating a seriously bizarre custom cassette range, shrinking the big ring is the better bet.

That’s why I’m wanting to go smaller big ring rather than change cassette.

That makes sense.

Having said that, I‘ve made ‘custom’ cassettes before in the past and they’ve worked without issues.

My first thought was to look for a 13/34 cassette but they don’t seem to exist. So I would consider getting a 13/26 (or similar) cassette and marrying it with your current one.

Again, I understand why you don’t want to do this, but if you can’t find a chainring that works it may be the only option....

Best of luck whatever you go for!

Edited by Barchettaman on Monday 9th November 11:52

[frisbee]

Claris is a 4 arm funny Shimano chainset? Even if you can fit a smaller ring it is likely to be close to the price of a complete chainset. I don't think you'll find a generic ring that will fit.

[frisbee]

frisbee said:

Claris is a 4 arm funny Shimano chainset? Even if you can fit a smaller ring it is likely to be close to the price of a complete chainset. I don't think you'll find a generic ring that will fit.

Actually maybe only about £25 but impossible to actually find one anywhere and 44t might be the smallest anyway.

I used a 42x12-21 7 speed for a while. That wasn't bad, as long as you avoided any big hills.

[emicen]

frisbee said:

frisbee said:

Claris is a 4 arm funny Shimano chainset? Even if you can fit a smaller ring it is likely to be close to the price of a complete chainset. I don't think you'll find a generic ring that will fit.

Actually maybe only about £25 but impossible to actually find one anywhere and 44t might be the smallest anyway.

I used a 42x12-21 7 speed for a while. That wasn't bad, as long as you avoided any big hills.

Should have said, its Claris but not a full group set, chainset and bottom bracket aren’t Shimano, or even FSA. The best solution to the whole situation is to fling a Tiagra or GRX group set on it, but that’s double what the bike cost, so not happening!

I live at essentially the highest point between Glasgow and Edinburgh, granted there’s no TDF style categorised climbs I’ve stumbled over yet, but I wouldn’t fancy my chances

[lufbramatt]

Maybe find a cheap chainset 2nd hand such as an FSA Gossamer that comes OEM on loads of bikes and are worth pennies, that takes 5x110mm BCD generic rings and then mix and match chainrings to find what works. What bottom bracket type does the bike have?

https://www.sjscycles.co.uk/110-bcd-5-arm/?order=p...