3x9 - 1x9. which chainring
Danieljephcott
Posts: 334
Hi all,
I have been looking at swapping my 3x9 to a 1x9 on my wifes bike. Seems fairly simple but before ordering the bits I wanted to double check what chainring to have and what gear would be equivalent to my 1x11 setup on my bike
So both myself and the wife aren’t the fittest so I want the best 1x9 setup for hills rather than top speed as this will likely be better. The cassette is a 11-34t and I’m thinking of having a 30t chainring. So if I was in first gear what would be the equivalent in my 1x11 setup which is a 10-42t cassette with a 32t chainring. Atleast then I can have a go in the relevant gear on my 1x11 so I know what first would likely be like in my 1x9.
Im thinking that 30t is probably the best.
I have been looking at swapping my 3x9 to a 1x9 on my wifes bike. Seems fairly simple but before ordering the bits I wanted to double check what chainring to have and what gear would be equivalent to my 1x11 setup on my bike
So both myself and the wife aren’t the fittest so I want the best 1x9 setup for hills rather than top speed as this will likely be better. The cassette is a 11-34t and I’m thinking of having a 30t chainring. So if I was in first gear what would be the equivalent in my 1x11 setup which is a 10-42t cassette with a 32t chainring. Atleast then I can have a go in the relevant gear on my 1x11 so I know what first would likely be like in my 1x9.
Im thinking that 30t is probably the best.
0
Posts
12-36 9-speed cassettes are available, Shimano Alivio, that would put here lowest gear at 22.5, in between your 2nd gear of 24" and your 1st gear of 20.6".
wow my brain just cant work this out haha.
Ok so if I had a 32t chainring on my 11-34 cassette first gear would be the same as my second gear on my 1x11 setup which is a 32t chainring with a 10-42t cassette?
ideally it would be great to keep the current 11-34 cassette on the bike so I only have to replace the chainring
Not quite. The calculation to use is front/rear * 27. This gives you the gear inches (27 is a nominal wheel size but is used by everyone when discussing general gear lengths). Crank length also alters the feel of a gear due to the change in leverage but that does not alter the length and most data seems to show it makes no difference with normal length cranks. They will vary slightly based on tyres etc. too. You need to remember that cassette spacings are different too. the 9 speed is 11-13-15-17-20-23-26-30-34 and the 11 speed is 10-12-14-16-18-21-24-28-32-36-42.
So for your examples:
32/34 * 27 = 25.4"
32/36 * 27 = 24"
Your 2nd gear is a bit easier than the lowest gear on the 9 speed.
If a wider range is wanted then a wide range 11-40 Sunrace would be a better bet in my opinion, lighter and wider range.
Only Dan knows the terrain they will ride but as climbing rather than top speed seems the priority a 30T seems a no brainer.
retired 9.6kg Carrera Kraken
The Carrera Hardtail combined thread - come on all you Carrera's!
The Sons Scott Genius RC20 build
I suppose the bit in red is what I was wanting, I think I get the calculations. so with fitting a 30t chain ring I will be getting 23.8" which is identical to my second gear on my 1x11.
fingers are crossed that I'm finally getting it
basically she will come with me to Cannock and ill be doing coed y brenin in a few weeks. she wont ride fast so top end isn't a worry. being unfit I want to simplify as much as I can so she enjoys it as much as possible.
changing to a 1x9 will stop the gearing confusion and I think a 30t front will allow her to peddle up most things. for instance I would use my second gear on my 1x11 setup for cardiac hill so her 1st gear should be the same if I use a 30t... I think.
Just the Dog or the Monkey as well? Apart from Cardiac there isn't really anything on the Dog that I used to use lowest gear for and at least cardiac is walkable without getting anyone's way!
retired 9.6kg Carrera Kraken
The Carrera Hardtail combined thread - come on all you Carrera's!
The Sons Scott Genius RC20 build
I only tend to do the dog however would like to try the full dog and monkey again now I'm fitter. the dog is no issues for me just cardiac which as said I'm in second on my 1x11. used to use 1st but realised that I'm putting more effort in rather than relying on leg power.
my wife fitness wise is where I was 6 months ago so for her doing the dog will be hard going but as said making things as easy as possible will help her enjoy it more.
even though ive got my biking life it would be good to get her into it for when we go away to wales which we do 3-4 times a year.
Ive just notice that sunrace 11-40 comment... that would work out amazing with a 30t giving her the best of everything. seen one on ebay for £30.
would that go straight on my hub? rear hub is a formula dc20
The Sunrace is heavier than the Alivio (500g vs 413g) and the those jumps at the low end are massive. Not sure I'd want to be shifting through them while climbing.
don't really want to spend much on this bike(voodoo hoodoo) so just some small changes. My spare reverb, a maxxis highroller II tyre on the front, changed the seat to a sdg allure (women) saddle and the 1x9 should make the world of difference.
lets hope she likes it
if not sod it ill go riding on my own haha
retired 9.6kg Carrera Kraken
The Carrera Hardtail combined thread - come on all you Carrera's!
The Sons Scott Genius RC20 build
Will have to go search the Sunrace.
retired 9.6kg Carrera Kraken
The Carrera Hardtail combined thread - come on all you Carrera's!
The Sons Scott Genius RC20 build
will try the standard cassette with the 30t front and see how we get on.
the plan really is to get her into it and then buy her a full sus if she keeps it up.
You would need to use a 10spd chain though, and the chainline will be shorter (which would be better if using the lower gears more), but this could be tweaked with a longer bottom bracket axle.
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