gear ratio choice for 1x conversion for whyte 905

jonnya777

hello :-),

i have just decided to strip my 2x 905 2017 whyte (orange) of its front mech and shifter to go 1x.

The frame is size large with an extended 50mm stem and longer seat post. I should have ideally chosen an xl, being 6 ft 3 inches. But the bike felt so right when i tried it out. It has 11-36 (10gear) cassette (which i'm keeping on), and a 36 tooth chainring.

What tooth chainring should i choose. I ride trail and need a ratio to climb occasionally although im a reasonably stong climber so the front chainring doesnt need to be too small...I just need to know the right chain ring!!! for the 11-36 cassette.
Answers and thoughts greatly appreciated.

cheers, jon

cooldad

Depends on you, ride up a hill and see what ratio you need.

jonnya777

Im looking for suggestions for number of teeth for a chainring to buy that will be suitable/good for the rear cassette ratio. Im not planning on buying several to fit and try. Cheers bud. Thanks for your reply.

cooldad

You already have chainrings. Two of them.

Ride up a hill and see what the lowest gear is that you need using those. Use the small ring and a some of the midrange cogs at the back. Decide the lowest you need, and convert the ratio assuming a 36 cog and see what the chainring size comes out as. It's simple maths.

No one knows what you need, but 32 would be common - some cranks will not allow smaller rings, so you don't have a huge choice - 32 or 34, possibly 30.

Kind of depends if your hills are tiny humps or the Alps.

cycleclinic

No can tell what chainrings you should be using. It something you should figure out for yourself. If you want to be told, pay a shop and you'll get the standard answer a 32t front.

steve_sordy

You will be reducing the range of your gearing. You have to decide whether you want to ride up every hill but spin out on the fast bits, or to be able to go as fast as you normally do, but accept that you will have to push up some hills. Unless you have thighs of steel you cannot have both. Unless you go 1x12 of course!

Your clue is in the front gears you already have. If in doubt and you can't work it out, go in between.

JBA

I’d go for a 32T chain ring.
If you struggle on uphills with that then consider swapping the cassette for a 10-speed 11-40 or 11-42.

swod1

JBA wrote:

I’d go for a 32T chain ring.
If you struggle on uphills with that then consider swapping the cassette for a 10-speed 11-40 or 11-42.

I'd agree with this, not had any issues riding with this setup. cant see me ever needing bigger than 42t.

The shimano hg500 11-42 cassette is a good choice if you can get one.

billycool

What they said ^^^^^

There is no absolutely correct answer - you need to work out which of your existing front rings (and/or combination of gears) you use the most and roughly work out which front ring size would cover most eventualities.

I'd agree that 32T would be a good place to start. If you end up with too many easy climbing gears, then maybe go to a 34T.

jonnya777

thanks, thats really good input.
I was always planning to keep the 11-36 on the rear, My biggest concern was, would loose the granny gear if I needed it. From what Im gathering is 34 will be a good compromise to go with that will give me something close to a granny gear, as 32 would give me too many climbing gears, Billy cool?

swod1

Jonnya777 wrote:

thanks, thats really good input.
I was always planning to keep the 11-36 on the rear, My biggest concern was, would loose the granny gear if I needed it. From what I'm gathering is 34 will be a good compromise to go with that will give me something close to a granny gear, as 32 would give me too many climbing gears, Billy cool?

Just try it out chain rings aren't expensive what £25 ish?. I did actually at one point run an oval 34t chain ring with an 11-36 cassette worked quite well until it worn out and i replaced it with a 11-42 cassette and 32t chain ring up front.

Depends on your fitness etc, we can only advise what might work for you until you try it out.

bobbydigital

11-36 can be converted to 11-40t with an expander.

My favourite set up for 1 x 10 is 34t chain right with 11-40t cassette. So I'd probably go 32t if I had a 11-36.

billycool

Bobbydigital wrote:

11-36 can be converted to 11-40t with an expander.

My favourite set up for 1 x 10 is 34t chain right with 11-40t cassette. So I'd probably go 32t if I had a 11-36.

11-40T would give you a better range and I'd probably use 34T based on that.

Jonnya777 wrote:

thanks, thats really good input.
I was always planning to keep the 11-36 on the rear, My biggest concern was, would loose the granny gear if I needed it. From what Im gathering is 34 will be a good compromise to go with that will give me something close to a granny gear, as 32 would give me too many climbing gears, Billy cool?

I'm 1x11 and run 11-42 on Shimano XT cassette with 34T up front. That gives me enough range to get up stuff but also have some gears for the flat and DH stuff. I've tried 32T and I have too many climbing gears. It is personal preference though and depends on your bike/terrain/fitness.

I've got Uberbike chainrings from their eBay shop for £19.99 each so it's not the end of the world to have 32T and 34T. If you want a granny gear, then 32T is obviously smaller than 34T.

Based on your gear range, 32T might suit you better to start with.