I’m currently running 1×10 (slowly)

32 front and a 11-36 on the back. Hard work on the steepest of climbs, but I spin out when its flatter.

So I’m going 1×11 and an 11-42 on the back. But the choice I cant make is what front ring. 32 or 34 ?

Sheldon’s Gear Ratios tell me:
With a 32 I get a ratio of 5.9
With a 34 I get a ratio of 6.2 = that’s only about half a cog difference.

Will I really notice that on the flats where I used to spin out ? Or do I need more of a difference to notice it in the real world ?

I may just buy both front rings – if I do would the same chain fit ?

Get an xd driver and a X1 10-42 cassette (it will work with shimano 11sp).Then you’ll get an easier and a harder gear.

Many years ago the old mechanic at my LBS told me that with an 11 tooth on the back, the number of teeth on the front is roughly the speed in MPH that you spin out at.
I’ve found it to be pretty much true.

Will I really notice that on the flats where I used to spin out ?

I did the same thing from a 36T to a 34T and as you say the mathematical difference is half a cog i.e. not even a gear change at the back

It does feel different but not much.

with an 11 tooth on the back, the number of teeth on the front is roughly the speed in MPH that you spin out at.

wouldn’t that depend on wheel/tyre size?

Is a double not an option? I’ve recently moved from x9 9 speed triple (which to be fair was more or less faultless) to 2×10 XT on the new bike and the few grammes of weight extra seem well worth it. Doubles also seem to work better and require less faffing than the old triples, I’ve not looked at it in 6 months.

I don’t want a double – that space on the bar is taken up by the remote dropper and the remote lock out for the suspension.

Any more cables and birds will be nesting. Not to mention my thumb getting way too confused as I drop the post for a sprint and change up for a drop off 🙂

So, half a cog difference is slightly felt, but probably not enough to stop me feeling like I spin out all the time…………… Is that what people think ?

Assuming a 26” wheel with a 2.3 tyre.

With your old 32 and 11 – 36

Easiest gear you were travelling 23.7 inches per pedal stroke.

Hardest gear you were travelling 77.4 inches per pedal stroke.

With 34 and 11 – 42

Easiest gear you’ll travel 21.6 inches per pedal stroke.

Hardest gear you’ll travel 82.2 inches per pedal stroke.

With 36 and 11 – 42

Easiest gear you’ll travel 22.9 inches per pedal stroke.

Hardest gear you’ll travel 87 inches per pedal stroke.

If you are spinning out at a cadence of 140 then the rule above applies.

32 – 11 = 32.25mph
34 – 11 = 34.24mph
36 – 11 = 36.24mph

There… clear as mud.

Mmmm, so I reckon I will probably need to go up more than a 34 then.

Sod it, I will just buy two front sprockets and test them. It shouldn’t require a longer chain. (hopefully)

Mbnut, Gear inches is the effective diameter of the wheel, not the distance traveled. You need to multiply by pi to get the distance.

http://www.gear-calculator.com/?GR=DERS&KB=32&RZ=11,13,15,17,19,21,24,27,31,35,40&UF=2160&TF=90&SL=2.6&UN=MPH&GR2=DERS&KB2=34&RZ2=11,13,15,17,19,21,24,27,31,35,40&UF2=2160

Try that.

Ah… the mud is clearing. Thanks

Oooh, that’s better than Sheldon’s gear calculator web site.

I run a 32T oval with a 10-42 cassette and I’m finding I still spin out on tarmac and loner (smoother) off road descents, going to put a 34T oval (also with a 10-42 cassette) on my new HT build which I hope will sort it out, if it does I’ll post here, will be after 18th Dec as that’s when my new HT frame is due in 🙂