Gearing for a Nexus 7 speed

[Dr. Tankenstein]

I purchased a Nexus 7-speed coaster hub a while back and I'm looking to install it on my wife's 1950 Monark. The hub has a 21 tooth sprocket on it and the original Monark chainring (which looks pretty good after a week long vinegar bath and a visit from the wire wheel) has 44 teeth.
Now this bike will be pure cruisin', the 7-speed was an AWESOME deal that I couldn't pass up and should make the 'occasional' hill easy to climb.

I've always used the 2:1 ratio one single and 3-speeds for easy pedaling. This works on 3-speeds because 2nd gear is usually 1:1, so it's 1 click up for climbing or one click down for speed. While 44/21 isn't 2:1, I'm hoping it will be OK with the extra gears.

My question, does the same logic apply to the 7-speed? Is 4th gear the 1:1? Then 3 up, 3 down? I'd like to stick to a 44 tooth or smaller chainring because the bike is a 24" and I don't want to run into issues with a larger chainring hitting the chainstays.

Oh yeah, one more thing will a 410H heavy-duty chain have any issues on this hub?

As always, your advice and options are requested :mrgreen:

Cheers,
Dr. T

 

[user 135]

Re: Gearing for a Nexus & speed

4th is 1:1 Your gearing should be okay. That ratio should pedal easier on a 24" wheel.


24" 21/44 50.3

26" 21/44 54.5

You could always find a larger rear cog. I think you can find 22-24.

 

[Dr. Tankenstein]

Thanks Clancy, that's encouraging. Can't wait to lace this puppy into the Worksman rims I've got coming!

Cheers,
Dr. T

 

[mrfritz]

I haven't been able to find a cog larger than 22t. On the ordinary 26" cruisers it's worked great with the 44t. On the Onxy 29 first gear isn't low enough so I'm going to drop the chain ring to 36 and then adjust the rear cog if I need more top end.

 

[user 135]

http://sheldonbrown.com/harris/shimano- ... #sprockets

 

[expjawa]

Doc - just some reference information. My '09 Schwinn Classic Deluxe 7 came with the Nexus 7 hub. It has a 36T chain ring, 20T cog. With that combination, you get 29.5, 34.6, 39.4, 46.2, 53.5, 62.3 & 72.1 gear inches. My opinion is that first 2 or 3 gears are fairly useless on flat ground. On a 24" bike, that would be even shorter. I think that if you swap in the 21/44 combination with 24" tires, the end result is pretty similar to what I've got now.

I would go bigger than 44; in fact, on my bike I'm going to a 23/52 combo on my bike. Part of the reason for the choice is that I think a Phantom-style 52T sprocket is what looks most correct on my bike. The 36T looks tiny on it. 23T is as large as I can put on the Nexus7 to make up for the difference. That will essentially make my 1st gear comparible to the original 3rd gear, and shifts everything up accordingly. But, like I said, I think that'll make a good ratio combination. I will report back after I've actually made the change.

 

[Dr. Tankenstein]

Rick,
Thanks for the info, it sounds like I should be OK (at least to start). Now, I can't wait for the hoops to get here to try it out!

Cheers,
Dr. T

 

[B607]

I'm running 52T and the gear that came on the hub. It's hung up and I can't get to it to count the teeth. :roll: It's good for flat ground only with a 52T. Gary

 

[Dr. Tankenstein]

Hopefully, with the stock rear sprocket and a 44 tooth chainring, she'll be able to climb some slight hills easily. :wink:

The rider is only 5' 2", and ALMOST as old as me, so she doesn't generate a lot of torque. I'm hoping this gives her some versatility while being 'simpler' than a freewheel setup with hand brakes and derrailuers.


Cheers,
Dr. T

 

[kingfish254]

Good luck Tank.
I am bookmarking this thread for reference with my FlexLiner 7 build now that I am getting a Nexus 7 for it.

 

[Tychevelle]

Hey Doc

I swapped my 3spd to a 7spd nexus into my Electra ratfink its got a 44 up front and the stock 22 that came on the back. it also has 24" wheels but with 24x3's I took it for its first longer ride yesterday and theres quiet a few hills to get into town here one is a sharp short uphill the other is long gradual and of course there right after one another :roll: :lol: but anyways on the sharp short hill I found my self in 2nd gear most of the time once I got half way up I dropped down to 1st. the long gradual hill I used 2nd all the way. Even on flat ground I used 6th most of the time go to 7th and the thing flys! im very happy with how its geared. Also I built my girl a 26"AMF skyrider tanker and put a nexus 3spd into it it had 44/21 but she found it hard to go up hills and used 2nd more then 3rd to cruise I dropped the front down to a 40left the rear at 21 and now she loves it. shes obv not as strong as I am but it made her love the bike even more.hope this helps.

Ty