Gearing: How close is 24 teeth front/28 teeth back to a 44 front/46 back? (edited title)

[Lovacott]

My 21 speed or 3x1 gives me a low gear which I used to use a lot but rarely use now (although, I do use it now and again).

My current set up has a low gear with 24 teeth on the front and 28 teeth on the back.

I'm looking to buy a 1x10 with a single 44 tooth chain ring driving a maximum 42 tooth cog on the back.

Does anyone have a "ready reckoner" which could calculate a % difference in effort required between the two groupsets?

 

[matticus]

If you google "online gear ratio calculator" you can probably answer this exactly with little effort:
I can confidently tell you it would be a slightly higher gear

 

[iandg]

Bicycle Bike Gear Ratio Speed and Cadence Calculator (machars.net)

 

[Darius_Jedburgh]

Bikecalc.com

 

[CXRAndy]

My 21 speed or 3x1 gives me a low gear which I used to use a lot but rarely use now (although, I do use it now and again).

My current set up has a low gear with 24 teeth on the front and 28 teeth on the back.

I'm looking to buy a 1x10 with a single 44 tooth chain ring driving a maximum 42 tooth cog on the back.

Does anyone have a "ready reckoner" which could calculate a % difference in effort required between the two groupsets?

The gear inches for your triple lowest gear is 22.75"

The gear inches on the propsed single crank is 27.78"

The triple has it by quite a margin

Bikcalc.com. for seeing ratios, percentage, gear inches, speed at cadence etc. Ive used it many times to work out setups and its pretty accurate

 

[Lovacott]

The gear inches for your triple lowest gear is 22.75"

The gear inches on the propsed single crank is 27.78"

The triple has it by quite a margin

Bikcalc.com. for seeing ratios, percentage, gear inches, speed at cadence etc. Ive used it many times to work out setups and its pretty accurate

I think you've answered my question.

Just under 20% harder but, the bike I am looking at is for weekend pleasure use rather than commuting.

I won't be carrying my work stuff and I won't have the MTB spring forks and the knobbly tyres.

Going from three chainrings to one will also save a bit of weight and drag.

At worst, I'll just have to go 20% harder up the last dregs of the hills on which I currently use the bottom combination of the MTB.

 

[Cycleops]

1x drive trains are fashionable right now and should suit you as far as high/low goes but maybe try it it out first if you can as there will be bigger steps between them.

 

[Lookrider]

Are the wheels the same size on the bikes
Are the cranks tbe same size on the bikes
Wheel size makes a big difference
Crank lenght a little

 

[Ajax Bay]

My 21 speed or 3x1 gives me a low gear which I used to use a lot but rarely use now
24 teeth on the front and 28 teeth on the back.
1x10 with a single 44 tooth chain ring driving a maximum 42 tooth cog on the back.

http://www.gear-calculator.com/?GR=...21,24,28&UF=2215&TF=90&SL=2.6&UN=KMH&DV=teeth
http://www.gear-calculator.com/?GR=...32,36,42&UF=2150&TF=90&SL=2.6&UN=KMH&DV=teeth
1.9m development (distance travelled per chainset revolution) on the triple; 2.35m for the 1x (lowest gear).
Power saving from either weight saving or reduced drag will be negligible, given type of riding described and likely speed.
Crank length makes no difference to the gearing question, per se (I am about to shift from 170s to 165s (-3%) so I know where you're coming from, @Lookrider - I will drop all three rings by 2 teeth (-4%) on the new chainset).

 

[Darius_Jedburgh]

Slightly off topic...1x drive must lead to extremes of chain lines when in top/bottom gear.

As the cognoscenti scream about cross chaining why is this unimportant on 1x drive trains?

 

[Lookrider]

What About Crank Length?
All of these systems share a common inadequacy: none of them takes crank length into account! The fact is that a mountain bike with a 46/16 has the same gear as a road bike with a 53/19 only if they have the same length cranks. If the mountain bike has 175's and the road bike 170's, the gear on the mountain bike is really about 3% lower

SHELDON BROWN begs to differ about crank length not been taken I to account ...I didn't see how it give different "inches" but as in his example the 2 bikes with different gears have same inches BUT take into account crank length ..then one if them becomes easier to pedal..I guess as its further away from the BB ...making sense ...ie you can turn a wheel by the tyre with your fingers with little effort
Try turning at the hub is a different matter

 

[Lovacott]

Are the wheels the same size on the bikes
Are the cranks tbe same size on the bikes
Wheel size makes a big difference
Crank lenght a little

I've thought about all of the above and I've concluded that the road bike will have harder gearing up hill but it will be compensated for in other ways.

 

[Ajax Bay]

Slightly off topic...1x drive must lead to extremes of chain lines when in top/bottom gear.
As the cognoscenti scream about cross chaining why is this unimportant on 1x drive trains

Contrary to general wisdom, cross chaining only loses about 0.5% power, whereas large/large (eg 52/26) is much (eg 1-2%) more efficient than middle/middle (42/21 and certainly small/mid-small (30/15) (reputable reference available). So it's "unimportant".
A 1x10 can manage both top and bottom gear with a chain angle of 2.4o which is not much.
A compact 2x10 (as an example) on 2.4o loses the extreme cross-chain (large/large and small/small).
HTH

 

[SkipdiverJohn]

1x drive trains are fashionable right now

1 x gearing is all a load of marketing shite designed to sell more bikes and more expensive cassettes. Stick with a triple, especially in a place as hilly as Devon. Only mugs pay more cash for a worse choice of gearing. The "almost duplicate" ratios inherent in many triple set-ups are very useful if you are familiar with your gears. A difference of two or three inches between two different front/rear combos on a triple might not sound much, but sometimes it's very handy. You need to do the maths though, and know what all your ratio inches are

 

[Archie_tect]

My 21 speed or 3x1 gives me a low gear which I used to use a lot but rarely use now (although, I do use it now and again).

My current set up has a low gear with 24 teeth on the front and 28 teeth on the back.

I'm looking to buy a 1x10 with a single 44 tooth chain ring driving a maximum 42 tooth cog on the back.

Does anyone have a "ready reckoner" which could calculate a % difference in effort required between the two groupsets?

Is the 44 chain ring a typo... should that be 34?