Which gear in a 3 speed hub is strongest?

gogo

gogo

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If I wanted utilize either 1st or 2nd in a 3 speed hub as an acceleration/hill climbing gear, which would be able to handle the most torque from the motor without breaking?

Also, can 3rd gear handle more motor torque than the other two? This is assuming that 2nd gear is the 1:1 gear.
 
gogo said:
If I wanted utilize either 1st or 2nd in a 3 speed hub as an acceleration/hill climbing gear, which would be able to handle the most torque from the motor without breaking?

Also, can 3rd gear handle more motor torque than the other two? This is assuming that 2nd gear is the 1:1 gear.
Click to expand...

The short answer is the bigger the gear the stronger the gear. However, that's not always the issue when hill climbing or accelerating.
 
I have been told 2nd gear is by far the strongest in the 3 speed Sturmey Archer hubs

KiM

EDIT: p.s 2nd gear in the Sturmey Archer is 1:1
 
AussieJester said:
I have been told 2nd gear is by far the strongest in the 3 speed Sturmey Archer hubs

KiM

EDIT: p.s 2nd gear in the Sturmey Archer is 1:1
Click to expand...

Wouldn't that be because 'second gear' is just a locked state between input and output. I suspect therefore that these Sturmey 3 speed hubs really only contain 2 selectable planetary gear stages with the middle 'gear' (2nd) just being a locked state of power transmission from the axle to the hub via a sliding selecter pin/s in a keyway/s, and therefore 2nd definately being the strongest 'gear'. This has the benefit of allowing quite wide gears and pinions within the constrained hub width compared to higher count multi geared hubs. This should allow torque to be spread across a wider contact/surface area of teeth compared to a internal hubs with far more gears.
Hence i suspect 3 speeds would survive far more abuse than an Alfine8spd or an I-Motion9. Rohloff is a different league though, both price and quality wise. Even though the gears in those are narrow, they are much tougher heat treated steel (hence the off road MTB rating).
 
boostjuice said:
]

Wouldn't that be because 'second gear' is just a locked state between input and output.
Click to expand...

Pretty much how my Mate said it too be, hes pulled a handful of 3 speeds down now including Shimano and Sturmeys and both are similar as far as 2nd gear goes, give it hell in second take it easy in 1 and 3rd rolling on the power and we "should" be good too go ...His 1st and 3rd are shot but second works like new.

KiM
 
It might be that low gear (1st) has the best ability to reduce shock loading (and less likelihood of breaking), by its nature of spreading work across time. It uses most of the same internal parts as the other gears.

1st gear: driver contacts the ring gear, which moves the planet carrier engaged to the shell .75
2nd gear: driver contacts the ring and engages the ring to the shell 1.0
3rd gear: driver contacts the planet carrier which drives the ring engaged to shell 1.33
SturmeyParts1.jpg
There are only two pawls engaging in any speed in a Sturmey AW. The teeth are machined into the inside of the shell.

The bit that actually does the gear-changing is the 'clutch' [30] (more of a selector; no slipping) which moves along the axle, connecting the driver [16] to the gear-ring or planet carrier. When the clutch is closest to the sun, the planets are driven; when it's furthest from the sun, the ring is driven; in the midpoint, the ring is driven and the ring's pawls extend out to the shell.
 
I think 2nd is the stongest, because like others have said it is just a direct lockup like a free wheel.
My Sturmey Archer is now making horrible mechanical noises in 3rd and particularly bad noises in 1st but continues to run well in 2nd.
I will open it up soon and investigate, I will post what I find out.
Cheers,
Matt.
 
AussieJester said:
^^^ Looks nothing like the Shimano i have in pieces here...

KiM

EDIT: Best pics i have of the 3 speed Shiman

internal_3_speed_hub_pics.jpg
Click to expand...
is that the 333 hub? i could never find a sturmey archer with all of its parts intact on ebay so ive always settled for the shimano hubs because they were always together. from what i hear, the shimanos are not as strong as the sturmey archers. i have a shimano 3-speed on my bmx and its working flawlessly so far. i guess ill find out when i put some power from an electric motor through it...lol
 
1000w said:
I think 2nd is the stongest, because like others have said it is just a direct lockup like a free wheel.
Click to expand...
It is 1:1, but not 'direct lockup' where the driver would have pawls.

The sprocket connects to the driver, which contacts the clutch, which contacts the gear-ring which has pawls that engage the shell.
 
The answer to the question:

Depends on the individual hub design.


It seems as though it would be most simple to make whichever gear is 1:1 into the strongest gear, but it entirely depends on the manor in which they make the gear lock 1:1. It could very well have all the weaknesses of the other gears, plus it's own unique failure points.
 
Looking through Sheldon Browns site it appears there has been more the 40 different models of the Sturmey Archer rear hub so im sure there will be differences from one to another. Ill be staying in second gear for any 'aggressive' riding with my Extra wide 3 speed SA if it has worked for Matt :: fingers crossed:: it'll hold up for me...

KiM
 
I was unable to locate the 'other thread' discussing using 3 speed hubs in non hub drive setups, so ill post here instead...

I reported on the 'other' thread that Matt.P (1000watt) Had issues with 1st and 3rd in a Extra Wide Sturmey Archer 3 speed hub but 2nd gear was trouble free... I spoke with Matt 2 days ago and he reports that 2nd is shot anow also :-( He is pulling it down in the coming days to inspect what has gone wrong with it, he mentioned he would be taking detailed pics for me too look @ if he doesn't post them i will up them on his behalf for all too peruuuuse over... This was a bit of bad news for me as i have this same hub and will likely be putting a lil more strain on it than Matts setup (he is running a Cyclone 1000watt setup 70amp controller 48v 20ah Headway pack)

KiM
 
Kim here is that thread:
http://endless-sphere.com/forums/viewtopic.php?f=28&t=14382&start=15

That is dishearting news. I really have high hopes for these 3 speed huds. I don't know what what your friends riding stye is....I hope he was rodding the hell out of it! & it was out of adjustment with defective factory parts made on a friday after lunch.......& all the rest we test with are bullet proof.
Any input there Jester? he a power shift guy ? (like gary banging gears in his video)

If he cracked a tooth of one of the gears without a teardown, I would expect the shrapnel to take out the other speeds pretty quickly, trannys never seem to heal on their own :cry: I would really like to see the tear down photographed in sequence to see what failed. I will still test my shimano unit with a cush drive on the final reduxtion.

enough till we learn more. Thanks for the update. T
 
As a boy, I was regaled with the story of how my father tried to make a 3 speed hub work on a Whizzer bike. He would break the hub and then repair and strengthen it only to find the next weakness. He finally gave up, deciding the hubs were only good enough for pedal power. The pulses from the Whizzer engine might have been part of the problem.

It may turn out that geared bicycle hubs have a power limit, but the lower power ebikes are the ones that need them the most.
 
Thud said:
Any input there Jester? he a power shift guy ? (like gary banging gears in his video)
Click to expand...

I recall Matt mentioning he did do some 'power changes' but no, he doesn't tear around
munching the gears everytime he rides it, it is from the torque thats done it im afraid. I spoke to Matt ~2 hours ago on the phone and he hasn't pulled the hub down as yet, I'm hoping he might make it
buy my place today actually unfortunately though his lil daughter is ill so he is taking care of herso he may not make it.. I Shall remind Matt to take the pics, i did mention tohim i posted in this thread RE: the failure though. (i will link him now to the thread so he will prolly pop in himself also)

It is unfortunate though, having seen the insides of these hubs i was never overly confident of them being durable. I will stick to my plan of using the 2nd gear pretty much exclusively, my bike is geared low enough to pull hard in second and max out in the mid 50's in 2nd gear needing 3rd only for 65km/hr my shire has a max speed on 95% of the roads of 50km so i wont be using it alot either way. :: fingers crossed:: it
will hold up for awhile...Ill still be lacing up a extra wide hub to fit an Eno/pulley too, with the planned
second motor (6500watt Turnigy) being added there is no way on this earth the 3 speed will take the abuse ill throw at it...

KiM
 
Ok guys, I opened up my hub today and looks clear that the sun gears are not upto Ebike power loads.
Here is the hub.
hub1.jpg


Here is the main shaft showing tooth damage where the sun gears run.
hub2.jpg


Here are two of the sun gears and a couple of teeth.
hub3.jpg

I don't think there is much future for this hub!
Cheers,
Matt.
 
Shit that was quick Matt only just hung up the phone hahaha...that is certainly rooooted...

So...whats the deal with the multi speed Sram hubs the fellas are popping dual eno freewheels on, are they going to go BANG like this too peoples? all the efforts to broach the enos will be pointless if these hubs have similar internals...


Thanks for the pics Matt...glad i got you to grab me a back up freewheel extra wide hub from ChoppersUS too i unfortunately I forsee it will be in use alot sooner than anticipated..

KiM
 
Gary has been dumping some serious power through an SRAM hub. I've got one I've been meaning to open up and take some pictures of for weeks now. lol

I will open that thing up finally and we can see what makes them stronger.
 
That is the failure I would expect.....bummer. :(

I am still optomistic. :| I know these things are potentialy fragile. But with a proper cush drive on the driven sprocket & a careful (I know...what fun is carefull????? :mrgreen: ) shifting tecnique.
I will become a pessimist once I break my 3rd one under normal use.
(still need to break the 1st one...I am starting to hate winter)
either way, damn shame on the unit 1000w....always sad to see death in such a nice mechanical assembly...
 
That damage is not encouraging.

I'm wondering if there is any other internal failure... I vaguely recall some comments about damage to high or low gears; then broken pieces getting jammed into the planetary section.
 
TylerDurden said:
I'm wondering if there is any other internal failure...
Click to expand...

I do recal Matt mentioning on the phone today the Pawls were all in good condition still TD...pretty sure the components hes shown are the only ones damaged though...

Thud you dont need to be messing with this off the shelf garbage anywayz you have your L337 2 speed reduction unit!!! :mrgreen:

KiM

edit: OH and yes TD, the 1st and 3rd gears were the first to go 2nd remaind working until.....well....^^^^
So i guess it could be possible the 'broken pieces' from this failure would have contributed to the ultimate terminal failure of the entire hub :-( MAYBE in future soon as a gear starts making noises pull the frocker apart clean it out get the loose bits out re-grease re-assemble...(after replacing broken part obviously) Would have to extend the lifetime of the hub but still IMHO its just a band aid solution they simply arent upto the power we will put through them.
 
In the SA, the planetary is always meshed and rotating during operation, but it has no load when 2nd gear is engaged.

1st and 3rd require the sun to be intact to operate; so with a stripped sun, 2nd can still work, but there might be some noise from the planetary.

If a broken tooth from the planets or sun gets into the ring, 2nd will jam.
 
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