Changing to smaller chainring gap

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Twilkes

Twilkes

Guru
Looking to drop from 50 to 46 too, gear calculator showed that 46/11 is the same as the 50/12 top gear I had on my previous bike and which was fine, so it's like I'm losing the 11 cog and gaining something more usable further up, all good.
 
I used to use 38/48 for everyday riding. With a large 44 ring you may need a different front mech radius/profile or put up with tricky shifting. The std advice on vertical position above the teeth may need to be ignored when you use incorrect radius mech.
Try it and see. Move the existing mech up and down for best operation.
 

Ajax Bay

Guru
Location
East Devon
Is there any need to match brands/models of chainrings, or will any replacement chainring that fits do? I'm sure I read about Shimano chainrings being designed to work together to improve shifting smoothness, with the way the teeth are shaped etc, but is that absolutely necessary?
BCD, 5bolt, inner/outer specific and speed within 1: otherwise it's cosmetic (see 4 bolt normally). Browse the Spa Cycles offerings.
 
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Twilkes

Twilkes

Guru
Looking to drop from 50 to 46 too, gear calculator showed that 46/11 is the same as the 50/12 top gear I had on my previous bike and which was fine, so it's like I'm losing the 11 cog and gaining something more usable further up, all good.
Fitted the 46 (so 46/34 chainrings) and wish I'd done this a while ago - the best difference is that when I get to a hill, if I change from the big to small ring I'm generally already in the gear I need, rather than having to shift down a cog or two at the same time.

As per above, it's the equivalent of losing the 11 cog off my cassette (the old 50-12 is the same as the new 50-11) and getting some more useful mild-incline gears on the big ring, so probably reducing the number of times I have to shift to the small ring anyway.

There's still a bit of a gap where a 13 cog would be useful, but in practice I'd just work around it by upping cadence on the 14 cog for a while.

1648644540848.png

The standard 46/30 on gravel bikes might be another reason why they're getting popular, seems a long way from the days of standard 53/39 12-25 gearing. :smile:
 

Ajax Bay

Guru
Location
East Devon
12t to 14t is an unacceptably massive jump. These cassettes would be better as 12-13-14 -..... The 11t is not needed for normal riding, unless of course the rider has decided to change the large ring from 50t to 46t.
 
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Twilkes

Twilkes

Guru
On my previous bike I did switch out the 11-12 cogs for the 12-13 cogs from a 12-28 cassette to achieve basically what you wrote, gets expensive if you don't have a spare cassette lying around though! I'd have kept doing it but the 12-13 cogs were on a bike that got nicked, I reused them a few times as they never wore down as much as the middle of the cassette.

There doesn't seem to be a (10 speed) 12-32 cassette out there, without trying something custom from Miche and I've read mixed things about their cassettes so never went down that route.

edit - turns out there are some SRAM and Sunrace MTB cassettes that might be suitable.
 

Ajax Bay

Guru
Location
East Devon
I did switch out the 11-12 cogs for 12-13 cogs
I've done exactly the same, wanting a 30t for a hilly 1000km but wanting a 12-13-14 too. Worked OK. If a 13t 'outer' was economically available, I'd have gone 13-14-15, but they aren't. For that ride I swapped my inner 30 ring for a 28t too, many double chevrons (all ridden) including Hardknott and Wrynose, Rosedale Chimney and others on N side of the North York Moors, and several going north across the Dales from Hawes to Hexham. Was 'ard.
 

Ming the Merciless

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Inside my skull
The standard 46/30 on gravel bikes might be another reason why they're getting popular, seems a long way from the days of standard 53/39 12-25 gearing. :smile:

It would be, 53/39 as standard fitment disappeared decades ago.
 
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