what size cog and chainring is best for a Nexus 3 speed?

[GTCOMA]

I am debating on what ratio would be best to use with a nexus three. I'm trying to figure out the balance to get the best all around gear range. I would want ti to tend toward the faster side on the top gear so 1st isn't a wasted gear.
I have three size cogs right now: a 16t, 18t and 22t. And right now the bike has a 52t front chainring, but that could be changed to a 48t or 42t easily.
So which ratio would you choose?

 

[mesome]

My Specialized Globe came with 42t chainring and I think the back cog is 19t and it's been fine so far. That being said, if you already have the parts go ahead and try it out with what you have. Maybe put the 22t cog on the back and see if you like it.

 

[GTCOMA]

I initially had the 22:52 setup and it was pretty good. The only problem was it took every link of a 112 link chain and it was at the front of the dropouts.
And I don't really want to add any links to the chain. So I put the 18t on the back, but it was a little too steep with the 52t up front. So I thought if I went with smaller gears all around it would give some play in the dropout placement and it might give it a more updated look. But I don't have. A 42t to experiment with right now. And I hate to break a perfectly good chain if the smaller gears don't work how I like.

Too many variables...

 

[thatismytruck]

My Specialized Globe came with 42t chainring and I think the back cog is 19t and it's been fine so far. That being said, if you already have the parts go ahead and try it out with what you have. Maybe put the 22t cog on the back and see if you like it.

I have a Sturmey 3 speed with a 22 on the back and a large Murray chain ring (I wanna say 52). the gearing is sweet for me. Note: I am an out of shape 46 year old man so keep that in consideration.

mesome - I love your avatar. great album and apropos since you are from Kansas

 

[deorman]

I'm not familiar with Nexus gear spacing, but this may help you compare various ratios without a lot of swapping or that icky old math.
http://www.machinehead-software.co.uk/g ... ble26.html

 

[hubgearfreak]

if it's like an SA AW, ie. -25%, DD +33% then there's a holy trinity of gear ratios. ie, 46", 62" & 82"

one for up steep hills, two for up gentle hills and head winds, three for tail winds

as you haven't mentioned tyre size, you'll have to put the numbers in to the brilliant sheldon's brillaiant calculator yourself.

http://www.sheldonbrown.com/gears/

 

[yeshoney]

I have the nexus 3 Speed on my Bud Truck and it is 22/52, which essentially is a waste of 2nd and 3rd gear. If I could redo it i would go 48 up front. THis way first is a stump puller, second is good cruising and 3rd is the need for speed gear.

Joe

 

[GTCOMA]

if it's like an SA AW, ie. -25%, DD +33% then there's a holy trinity of gear ratios. ie, 46", 62" & 82"

one for up steep hills, two for up gentle hills and head winds, three for tail winds

as you haven't mentioned tyre size, you'll have to put the numbers in to the brilliant sheldon's brillaiant calculator yourself.

http://www.sheldonbrown.com/gears/

That calculator is amazing!

 

[GTCOMA]

Well, I've got it set up with 16:48 right now. I'm gonna run it like this for a bit and see how i like it

 

[Exocet98]

My Flying Sue came stock with the 22-42t setup which I'm satisfied with. I'm thinking of installing the rear cog to a 16t, this is the cheapest way to improve the top end. :mrgreen:

 

[GTCOMA]

Well, I've got it set up with 16:48 right now. I'm gonna run it like this for a bit and see how i like it

Ok, so the 16:48 combo is a little too strong. 3rd gear is super tough. I feel like the chain is going to explode. I'm going to try the 20:48 combo next to see if that moves the gears down enough.

 

[bigj]

Wheel and tire size(i.e. overall diameter) play a lot into it. I'm running a 46:22 with a S/A 3 speed. Wheels are 700c and tires are 32. To me this is a perfect combo. I think it is way too easy to overgear.

 

[hubgearfreak]

To me this is a perfect combo. I think it is way too easy to overgear.

42", 57" & 75" is near enough the perfect combo.

and you're right - it is easy and such a shame to overgear

 

[GTCOMA]

Ok, so I think I have found the perfect combo for this bike.
It now has. 48:20 setup with 26" x 2.10 tires and 180 mm cranks.
It feels perfect now. Plenty of flat land speed with a decent low gear for moderate inclines.

 

[hubgearfreak]

Ok, so I think I have found the perfect combo for this bike.

yep, you've got what i told you a week or two ago :wink:

there's a holy trinity of gear ratios. ie, 46", 62" & 82"