ArmChairRider

I'm thinking my 1st gear is pretty much useless here in Florida.
I use it to roll down toward a dead-end about 100 feet for my flight-check to see if something is going to fall off on the first part of my ride, then I never use it again. I'm going to get a bigger front sprocket to slide the gear ratios taller half way between each gear. I'll probably need a good wind and sail before I can use 3rd (and a half) haa ha But I've ran out of 3rd before at about 19mph.
If I find myself on a hill I'll just walk the bike.
Having a choice to hover halfway under or halfway over what is now 2nd gear seems idea.
Bye bye Granny.

ArmChairRider

The math(s)
What I got now
https://bike.shimano.com/content/sac-...1-inter-3.html

***gear ratio Nexus 3 speed shifter hub
Gear Ratio Total Difference 186%
Gear Ratio 1 = 0.733
Gear Ratio 2 = 1.0
Gear Ratio 3 = 1.360
****************************
The sprockets on my bike now... 18 tooth rear sprocket and 40 tooth front sprocket***
(18/40 = every .45 revolution of front sprocket = 1 complete revolution of rear sprocket (good to know))
18t Rear/40t front/Nexus gear ratio
18/40/0.733 =0.614
18/40/1.0 =0.450
18/40/1.36 =0.331

ArmChairRider

The seat of the pants wish list...
1st gear is too low, 2nd gear almost okay until the dreaded feeling that I might have to go to 1st or 3rd gear.
So I want a ratio that is halfway between 1st gear and 2nd gear and a ratio that is halfway between 2nd gear and 3rd gear.
*********************************************************
Halfway between 1st and 2nd gear is (0.614+0.450)/2 =0.532
So...
18/0.733/0.532 =46.15905384
~~ A 46 tooth front sprocket will bring me to my desired range of halfway between the gears

ArmChairRider

With an 18 tooth rear sprocket and a new 46 tooth front sprocket***
(18/46 = every .39 revolution of front sprocket = 1 complete revolution of rear sprocket (good to know))
18t Rear/46t front/Nexus gear ratio
18/46/0.733 = 0.534 (the halfway between 1st and 2nd gear)
18/46/1.0 = 0.391 (the halfway between 2nd and 3rd gear)
18/46/1.36 = 0.288 (May the winds be with me)

ArmChairRider

Oh yeah, this guy...
https://www.youtube.com/watch?v=picMxSwpXH0

SkunkWerX

I am a fan of gear changes, whether a rear cassette or front chain ring to achieve your best ratio, for your strength and your terrain. Looks like you are doing the research and have a game plan.

Good Luck, tell us how it works out, please.

ArmChairRider

I will, thanks.
I'm hoping my perception of my riding efforts equals reality.
It would be nice to only have to rock between 2 gears at cruising speeds.


I should be receiving the sprocket sometime this weekend or next week.
They are cheap enough, plus I got some extra chain and I'm confident I can deal with adjusting the chain guard for the fit.
The actual removal is going to take some muscle though. When I was looking at the right hand of the crank during my recent grease packing, it looked like the threads on the crank had no exit strategy. Maybe the crank just gets smaller at that critical stage of unthreading the cone though.


46t sprockets for 1/8 chains are hard to find and most likely unavailable (at this time) (unless it is an old Schwinn sprocket on eBay).
But Harris Cycle was selling a 46t for 3/32 chains and had a footnote it was okay for either chain.
If it looks like I'm going to have problems with the thinner sprocket, I'll just put in a wait for the 1/8 chain sprocket and wait it out.

Philphine

i haven't done it nearly as often (i've changed more clusters that a single one), but you can change the rear sprocket too.

fietsbob

You Move the set of 3 Up or down By the ratio of the teeth of the sprockets..

Higher? 3 lobe 3 speed sprockets are from 13 to 22 T


One piece crank? there are Adapter Spiders to Use 110 BCD sprockets on your crank..

check eBay




./.

prathmann

I agree with them that either type of sprocket will work fine with your 1/8" chain. We've used 1/8" chain for the captain-stoker connection on our tandem for many years together with the thinner sprocket designed for 3/32" and never experienced any issues.

ArmChairRider

Thanks, that is good to know. I have a suspicion that my original 40t front sprocket on my bike right now, thin as it is, is for a 3/32 chain as well. I've had no problems with it. I did notice one "Schwinn like" 4 big hole design, 46t sprocket that had an indentation ring all the way around it right below the teeth. That would be pretty good for strength, probably not so good for dirt though. Or maybe it can trap dirt before it gets to the chain, who knows.

ArmChairRider

Yes thanks, it would be somewhere between a 15t and 16t rear sprocket.
I would probably opt for the 16t, a little cushier.
I'm a little hesitant to mess with the 3 speed hub, just yet.
I'll give it time, until I realize I'll have to lubricate the insides of it or something.
But there is supposedly a trade off with wear when going to a smaller sprocket.
(Probably not much of a big deal on a bicycle.)
Besides, my rear axle is a busy headache with flipped fender braces and filed down chain adjusters right now.
I like the simplicity, price and ruggedness of the one piece crank for right now.
A little periodic maintenance is good for my hands on needs.
mmm grease.

fietsbob

I pry the wire snap ring off the Driver and the cog comes right off

I have a 3 speed on my small wheel folding bike it came with an 1/8" 13 t

I changed it to a 15t ..

the that type have become a standard used by Sturmey Archer Shimano And Sachs

by laying the bike on its left side and removing the shift Box on the right, You got the Bell crank kind i guess..

there is a hollow axle to squirt a little oil in to the Hub.

the oil seeps out oiling the bearings and you wipe it off, the outside , occasionally

ArmChairRider

Okay thanks.
My rear hub has never weeped oil out, that might be a problem.
I'll have to check into that.
I hope they didn't short me on lube.

sail

Yep, on three speeds I've always changed the rear sprocket to get to where I want to be.

ArmChairRider

Test 1 scrubbed.
Got out the gate really great.
Then it started getting a little tougher to pedal... then a little more tougher.
Rear tire was totally flat halfway through a 2 mile loop.
Bike makes a good armrest while walking..

SquidPuppet

46t sprockets for Ashtabula cranks are readily available almost everywhere.

https://www.amazon.com/Sprocket-Circ...s=46t+sprocket

ArmChairRider

Yes, I got that link saved now. Wish I had gotten that one, seems a little sturdier than the flat design small chain sprocket I finally wound up with. But this one seems sturdier than my OEM, (scratches head).
My search prowess wasn't quite up to snuff at the beginning of my search. And I was including the 1/8 chain dimension which probably threw the search engine off. Plus I think I was using "46 tooth" instead of "46t".
I got the SunLT one, looks pretty good.
Put extra links in my chain.
I had to revisit filing my chain adjuster for my flip-flopped fender brace screw clearances so I could slide the axle back a little further. (My tactile for my fingers is about 50 percent of what it used to be, really hard time with small items, so I didn't cut the screws flush.)
Now there is a circle around the axle hole and then the clearance goes straight out to the other side where there is another rise before the rear adjuster ends, like half a dog bone. Looks good.

SkunkWerX

Sounds like you have something there. pics if you get a chance.
Then let us know how the gearing "feels" in use. Nice job.

ArmChairRider

Yes, I will, thanks.
My inner tube got a bite from a spoke nipple access hole (double walled aluminum rims). I can see where my liner was sitting right on the edge of the hole. The inside of my tube has these small impressions now, oblong like an old 'Esso' fuel station sign running all along the inside of the tube. The bite was right on the edge of one of those. This liner is too thin and too narrow. (20mm x 0.5 mm)
I was thinking about truing this wheel but I wanted it trued and with good tension on the spokes. Don't know what kind of rim it is, maybe Weinmann Excelsior. Can't find the specs. So I'm going to go ahead and tension it as if I were tensioning aluminum spokes that were one size bigger than the steel spokes on them now. Only thing I can think of. Aluminum shavings trapped inside the rim at the spoke nipple access.
Really thinking about tossing it if it doesn't behave. haa ha
I probably need a steel one anyway.

ArmChairRider

Whoops, so much for truth in advertising. Bike is suppose to be for tall and big men. Spokes are aluminum and they are 2.28 mm (the smallest ones on the chart I'm looking at). This is a game changer. Looks like I'll be perusing the Clysdale threads, thinking how I'm going to swing this one for an all steel back rim and spokes.
Got it trued and tensioned. Still a little micro aggression around the weld area.
Hopefully I can find my box full of inner tubes and make me another rim liner.

SquidPuppet

Aluminum spokes? Are you sure?

fietsbob

You used a Magnet?

ArmChairRider

Yes.
Makes sense in an engineering point of view. (weakest link as an acceptable loss)
Also at 2.28 mm I doubt if they are customized titanium spokes. Regular 2.0 mm titanium spokes cost $2.06 apiece at bulk rate.
My bike is just skirting the edges of box store prices.

fietsbob

Boutique wheels ?

Some stainless steels are not magnetic

FWIW Sky Way Tuff wheels Are molded 'Mag' Glass or Carbon fiber reinforced Nylon
not offered with more than 1 speed or coaster brake.

Though maybe a good Machine shop can Modify them.



./.