Sturmey-Archer 5-speed hub, it's real!

I agree wholeheartedly, SA has a very good design for a robust 5-speed IGH, perfectly suited for ebike use and they have completely misread the market by only offering it in traditional widths. It's as though they had never heard of a fat or +type bike nor any of the wider dropout widths: 170mm & 197mm. I can understand financing all your R&D on a new design multi speed hub by OEM pre-orders and introducing the 135mm version for them first, but to omit even mention of a wider model indicates an engineering dept that has no communication with the marketing department at all. A 5-speed rotary IGH with a DD 3rd gear could be built in a 197mm version to withstand an easy 50% more torque than the current C-50 unit, itself a major improvement over their prior 5-speed model.

With all the chatter about imminent chainwheel options for the BBSHD, can a two ring system with front deraileur be too far off? Paired with a bulletproof 197mm 5-speed IGH one would have the ideal drive system short of adding a Gates belt! IGHs, BBSHDs and fatbikes were made for each other: the sum is far greater than the total of the parts, just ride one and see. Personally my heart belongs to a 10-speed full suspension fatty, but nothing is a nimble as a Karl Replica with an IGH!!

I am running mine on a BD Deadeye Monster and I shamelessly copied Karl at electric-bikeblog.com's installation in every particular. It is just about the only actual Fatbike that can run 4.25" tires on the rear and a 4.7" on the front available with a 135mm reared: maybe why it's only $399! Being a direct copy of a developed design it was a simple plug and play installation with no surprises, just as Karl figured out and put online for guys like me. The bike was a singlespeed and when I added the original Nexus 3, the gear sensors were unavailable in the US. So I trained myself to backpedal approx 1/8 turn as a sort of clutch, as I use the immediate pause in power to slide the cogs onto the next gear, the delay on the PAS is just long enough for the internal cogs to be seated before the machine torque inputs which gives a quiet up shift. Downshifting, I use the same process, but the grip shifter is able to jump several gears and get settled before the power arrives. I feel confident that I could train a novice how to operate this type bike smoothly in a matter of moments, a deraileur transmission, maybe not so fast? The swapping of the Nexus 3 for an SA 5-speed haven't changed that one bit. Just being able to shift at a dead stop is an important part of making a new rider comfortable with an ebike.
 
John in CR wrote:
Any motor can be rigged up as a mid-drive motor. Multiple stages of reduction always add noise and cost efficiency. Higher rpm comes with more noise too, both in terms of the motor and the front sprocket or pulley. I'm not into 1-2kw drives and don't know all your requirements, but that's enough to get you started, since investing all that weight in motor instead of a bunch of gears and multiple planetary gearsets is the route to spinning the motor slow enough for near silence.

I can't tell the difference between John in CR and LFP. They both talk like everyone is a motor designer and why don't you just design
a proper motor to fix your issues. I think I read that LFP limps around with a car that has a Zero motor in it that without a tranny couldn't
even function. Yeah, so he has a 180 lb. 'bicycle' with a 65lb. Zero motor that can get down the drag strip that doesn't need gears, so
now the rest of us are always wrong including BMW for not designing a proper motor for our application. Sorry, we live in the real world
fellows, and we are not motor designer like you are with all the motors the both of you have designed and brought to market. Oh, you
haven't designed any successful motors that have proven functional? Well, golly gee fellas, I guess you just love to hear yourselves talk
and make the rest of us wrong in the proccess, like killing two birds with one stone. You certainly 'is' some sharp fellows.
 
Great observations from WoodlandHills regarding the lack of IGH fat bike hub options in the wider widths. I would love to swap my Boris the Brut Sprung rear cassette and hub for a 5 spd IGH in 197mm. Belt drive would be the proverbial icing on the cake.
 
stayleft said:
I would love to swap my Boris the Brut Sprung rear cassette and hub for a 5 spd IGH in 197mm. Belt drive would be the proverbial icing on the cake.

Your bike couldn't support any kind of internal gear hub, no matter the width, because it uses through axles. And of course in order to use a belt drive, your frame has to split somewhere to install the belt.

Sounds like you got the wrong bike.
 
FWIW, rode the Porteur S which has a front hub motor and 5-speed SA IGH and it was a great combination for a 20 mph bike. Power delivery was smooth, and acceleration acceptable for street use. Overall, a really fun bike if one doesn't mind low speed conveyance.
 
So far so good. I have over 500mi on mine and the only thing I don't like is the internal friction. It seems like there is more drag than with my previous Nexus3: I have to keep it one PAS setting higher out of the nine available than with the Nexus in all conditions. It also does not coast quite as fast either. Having said that, I really like it and haven't seen any range reduction. It is easy shifting and totally silent in operation, some have reported a clicking sound from the freewheel when coasting, but I haven't heard it yet.

I'm running a 34t rear sprocket with the Luna Mini 30 on the BBSHD which is the same combination I used on the Nexus3. This allows a direct comparison since the SA has a direct drive middle gear (3rd) and the Nexus3 is also direct in its middle gear (2nd) and they both have 25% gear steps, that means the SA is just a Nexus3 with an added 25% lower first gear and an added 25% higher top gear. Anyway combined with an IGH GearSensor it seems to be bulletproof and especially suited to new riders who might be hard on a derailleur gear set.
 
was this hard to fit ? does it need a torque arm?

Do you have a 5 spd twist or trigger shifter ?

would this fit a normal mountain bike wheel ?
 
Sounds interesting Woodland!

Can you show us pics of the rear gear (34T) on the IGH? I am guessing you had to make a custom cog to sprocket adapter?

I am seriously thinking of using this hub for my next build, thanks for all the info so far!

Also, what speeds to you have it geared for particularly in 3rd (IIRC that is the 1 to 1 fixed speed?) I would probably want to gear mine for around 35 MPH since you need to over-shoot top speed a bit to figure in losses.
 
This bike is class 1 legal so it has a top speed of 20mph on the flat on motor alone. To make the sprocket I took a 34t BMX steel chain wheel and welded it to the SA 18t cog. The chainline is improved by the width of the cog and my "eyeball engineering" resulted in about 3/32" of runout at the chain which does not seem to hurt anything. I use a Surly Singulator as a chain tensioner and that has no trouble keeping up with the eccentricity.

The internal drag that concerned me earlier seems to have gone almost entirely away as I have added the miles. Still no clicking sounds from the freewheel either!
 
WoodlandHills said:
This bike is class 1 legal so it has a top speed of 20mph on the flat on motor alone. To make the sprocket I took a 34t BMX steel chain wheel and welded it to the SA 18t cog. The chainline is improved by the width of the cog and my "eyeball engineering" resulted in about 3/32" of runout at the chain which does not seem to hurt anything. I use a Surly Singulator as a chain tensioner and that has no trouble keeping up with the eccentricity.

The internal drag that concerned me earlier seems to have gone almost entirely away as I have added the miles. Still no clicking sounds from the freewheel either!

Good to hear! :D

Would you mind taking some pics of the rear hub with 34T sprocket attached? I am curious to see how much space you have in there. :)

I wonder if I would be able to get something in that same space similar to what goes on my NuVinci N171B (27T sprocket with built in freewheel threaded adapter)

3274.jpg


(Only using this as an example, I would of course make one to match the splines of the SA IGH)

I am very excited that now that speed pedelects are being more and more common here in Oregon, and I love how the BBSXX kits are so user friendly! No one really thinks twice even when you'r approaching 30 MPH as long as you're pedaling. :wink:

I still prefer my hub motor, but also the different classes of electric bikes make a lot more sense, hopefully we will get the higher powered but speed restricted (under motor power alone) class officially here as in California.

That way a cargo bike wouldn't suffer from total wattage restrictions.
 
Chalo said:
stayleft said:
I would love to swap my Boris the Brut Sprung rear cassette and hub for a 5 spd IGH in 197mm. Belt drive would be the proverbial icing on the cake.

Your bike couldn't support any kind of internal gear hub, no matter the width, because it uses through axles. And of course in order to use a belt drive, your frame has to split somewhere to install the belt.

Sounds like you got the wrong bike.
Rohloff have through axle versions of their Speedhub in several different lengths: https://www.rohloff.de/en/products/speedhub-xxl-fatbike-a12-197mm/index.html
 
I just purchased an Sturmey IGH RX-RK5 for my bike, however I'm having trouble with the chain slipping on the front kog. What kind of kog do you use on the front? I know the RX-RK5 uses thicker chain, because we could not use 9-Speed bike chain on it. However, the new chain we're using keeps slipping on the front kog. I've got a new front kog meant for 7 speed chain on the way, and we've got the rear derailleur tentioned nice and snug. Do you have any suggestions? I'm curious about your setup.

I noticed that the thicker chain seems to float on the front kog, so I'm hoping the new kog will be thick enough to alleviate the slipping problem.
 
You're probably right on the money, if the chain isn't severely stretched or otherwise worn, it's probably just not being carried properly on the narrower ring.
 
I just watched this video here: [youtube]SeO9bvQ-Ut0[/youtube] demonstrating the compatibility of 3/32'' and 1/8'' chain on single speed chain rings. Obviously the 3/32 doesn't fit, which is strange considering how many people online say that 1/8 chain is interchangeable.... Looks like I need a single speed chain ring around 40t with 104mm bcd.
 
Harold25 said:
I just watched this video here demonstrating the compatibility of 3/32'' and 1/8'' chain on single speed chain rings. Obviously the 3/32 doesn't fit, which is strange considering how many people online say that 1/8 chain is interchangeable..

There are 3/32" and 1/8" chains, and there are 3/32" and 1/8" chainrings. Single speed freewheels, coaster and gearhub sprockets, and fixed gear cogs also come in thick and thin versions. However, multi-speed freewheels only come in 3/32".

For a single speed chain drive, you can't use a thin chain with a thick sprocket, but you can use a thick chain with a thin sprocket. So 1/8" chains work with both sizes of single speed sprockets. Multi-speed cranks and freewheels only work with thin chain.

When you get more than 7 speeds on a freewheel or cassette, you have to use a chain rated for that many speeds or higher. 8-speed and up chains get successively thinner on the outside, while still remaining roomy enough on the inside for any 3/32" sprocket. So yes, a 10-speed chain will work just fine on a single speed setup as long as the chainring and rear sprocket are 3/32". But then, so will a 1/8" chain or the much less common 3/16" chain.

For these reasons, I always go for 3/32" sprockets when I have the choice. They give me the option of using any chain available. I use 1/8" chain when it works, because it's cheap and it lasts longer than 3/32" chain.
 
Messy stuff.

I did spot a simple noob relevant fact? tho recently.

Above 7 sprockets on a gear cluster, you have to switch to a finer chain.

Given strong chain on mid drives is good, then ideally, use a 7 gear cluster derailleur, rather than get tempted by more gears.
 
Chalo said:
Harold25 said:
I just watched this video here demonstrating the compatibility of 3/32'' and 1/8'' chain on single speed chain rings. Obviously the 3/32 doesn't fit, which is strange considering how many people online say that 1/8 chain is interchangeable..

There are 3/32" and 1/8" chains, and there are 3/32" and 1/8" chainrings. Single speed freewheels, coaster and gearhub sprockets, and fixed gear cogs also come in thick and thin versions. However, multi-speed freewheels only come in 3/32".

For a single speed chain drive, you can't use a thin chain with a thick sprocket, but you can use a thick chain with a thin sprocket. So 1/8" chains work with both sizes of single speed sprockets. Multi-speed cranks and freewheels only work with thin chain.

When you get more than 7 speeds on a freewheel or cassette, you have to use a chain rated for that many speeds or higher. 8-speed and up chains get successively thinner on the outside, while still remaining roomy enough on the inside for any 3/32" sprocket. So yes, a 10-speed chain will work just fine on a single speed setup as long as the chainring and rear sprocket are 3/32". But then, so will a 1/8" chain or the much less common 3/16" chain.

For these reasons, I always go for 3/32" sprockets when I have the choice. They give me the option of using any chain available. I use 1/8" chain when it works, because it's cheap and it lasts longer than 3/32" chain.

I'm using a brand new chain ring and rear sprocket with brand new chain. The chain is 1/8" and it's slipping on the front chain ring which is 3/32". We've checked alignment and everything but it's still slipping, so I'm just going to get a 1/8" chain ring.
 
I'm thinking bad chainline, insufficient wrap, insufficient/inconsistent tension, or a combination. Whatever it is, it's not likely related to chain width, so it'll probably reoccur with a different chain.

That said, there's no harm at all in matching the chain width to the sprockets.

Edit:

Be sure to let the B tension adjustment on your derailleur all the way out, to maximize wrap. The chain should be shortened compared to that of a multi-speed cassette, but not to the very minimum. Leave enough length to get your wheel in and out without a fight. That should result in a good balance of wrap and tension.
 
Harold25 said:
I just purchased an Sturmey IGH RX-RK5 for my bike, however I'm having trouble with the chain slipping on the front kog. What kind of kog do you use on the front? I know the RX-RK5 uses thicker chain, because we could not use 9-Speed bike chain on it. However, the new chain we're using keeps slipping on the front kog. I've got a new front kog meant for 7 speed chain on the way, and we've got the rear derailleur tentioned nice and snug. Do you have any suggestions? I'm curious about your setup.

I noticed that the thicker chain seems to float on the front kog, so I'm hoping the new kog will be thick enough to alleviate the slipping problem.

What motor and what chainwheel are you using?

My front chainwheel is a Luna Mini 30 for the BBSHD and I am using a heavy duty single speed chain by KMC. With 180 degrees of wrap around the chainwheel, I cannot see how you would get a slip with new parts..... The only time I ever had a front chain derailment was using the Luna Eclipse, the long gear teeth did not get along with my setup, all my other chain issues were at the back and were due to the misalignment between chainwheel and IGH cog. Adding a chain tensioner/guide fixed everything by guiding the looser lower chain onto the cog on the hub. A Surly Singulator is what I used.image.jpegimage.jpegimage.jpegimage.jpeg
 
I ended up just going without a tensioner or derailleur. It's a 1600 watt cyclone kit basically, and 44t chainwheel up front.



WP_20161104_17_38_55_Pro.jpg
 
Harold25 said:
I ended up just going without a tensioner or derailleur. It's a 1600 watt cyclone kit basically, and 44t chainwheel up front.





How much wattage are you running through that 5-Speed? Also love to see more about your build, do you have a build post? Sounds like lots of fun! 8)
 
LI-ghtcycle said:
Harold25 said:
I ended up just going without a tensioner or derailleur. It's a 1600 watt cyclone kit basically, and 44t chainwheel up front.





How much wattage are you running through that 5-Speed? Also love to see more about your build, do you have a build post? Sounds like lots of fun! 8)

Sorry no build post. I think it runs 60 amps peak at 48 volts. It's a 1600 watt kit though.
 
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