So I want to be able to work out which ratio’s on my MTB I can ride in to simulate my SS on climbs:

SS is 32 / 18
HT is 28/40 front, 11-34 rear (XT 2×10 speed)

Cheers

Driven/driver.

http://sheldonbrown.com/gears/

divide the SS rear by the SS front and then multiply it by the each of the front rings you have on your geared bike and choose the closest match.

My free gear calculation software:

http://www.kinetics.org.uk/html/k_gear.shtml

ie: 18/32 = 0.5625

0.5625 x 28 = 15.75

0.5625 x 40 = 22.5

Which would suggest a 28 front, 16 rear would be close (but a tad easier)

or 40 front, 23 rear (bit easier again) or 22 rear (bit harder)

Also depends what your cassette has available of course.

Same wheel-size?

Yes, both 26ers

Then Andyl has it 🙂

Thankyou!

Chainring divided by sprocket multiplied by wheel diameter gives a figure in inches to allow you to compare ratios on different bikes. Rather quaintly it is the diameter of the penny farthing front wheel that would take you as far per pedal revolution as your new fangled geared safety cycle. <puffs on clay pipe>

Obviously if the bikes are both 26″ just divide the front by the back to compare the two.

I find it surprisingly hard to be disciplined about staying in one gear on a geared bike, so I don’t bother.