NYCDahon

Ok -- I changed the rear gear to a 14T and after one week and 80 miles I LOVE the change -- but I would still like to go further -- maybe two gears harder yet again -- the front is now a 39T -- should I go with a 47T or a 52T? I added one of these to my old folder and really liked it.

Litepro MTB Folding Road Bike 170mm Crankset BCD 130mm Chainring 45/47/53/56/58T

Also what about a 175 vs 170?

https://www.ebay.com/itm/BICYCLE-BLAC...G/150867627148

https://www.ebay.com/itm/Folding-Road...-/262992043027

badmother

Rule of thumb :

If you buy it too small (not enough teeth) there is nothing you can do- expect buying a bigger one.

If you buy it too big (too many teeth) you can just put a bigger cog at the rear to compensate.

fietsbob

Sturmey/sachs/shimano 3 spline drivers , cogs start at 13t, 16t is the smallest dished cog.

NYCDahon

Thanks!

I got a 54T 130 crank set winging its way from china -- and I now already have a new rear 14t cog -- so I will just see what happens once I get the 54T on -- I can always put back the 18T that was there -- or just get some other size.

Likely this new setup will have a top gear (7) that will be too hard unless downhill or with strong wind to my back -- since it will be 54T front and 14t rear with my Nexus 7 internal hub.

The crank arms I ordered are 170mm and the tires (Dahon) are 20" x 1.75"

Thanks again -- I am much happier with the new 14T cog on the back! I'm no longer just effortlessly spinning gears all the time.

NYCDahon

Can you put a 13t on a Nexus 7 internal hub? I tried a 14t and it is great -had to remove the dust cover as stated in the Youtube I posted above. In any event - I am changing the front to 54t - should give me 2 more gears higher than what I now have.

Rick Imby

My minimum high gear on a road bike with 2.0 tires would be 90 gear inches. If you are running narrower tires I would try to get to 100 gear inches.

NYCDahon

Thanks Rick
So with my 20" - 1.75 tires this new 54T crank might turn out to be just about right - the top gear might just be for down hills or when wind is at my back.