fietsbob

S-A has a narrow and wide version in many offerings, and even some with a 28 hole hubshell

perfect for small wheels like 16"~ 349mm....

smallwheeler

its almost identical to this NOS 3 speed i have.

fietsbob

the AW3 shipped to Brompton's factory had 117 mm across the locknuts .. 28 hole..
now 2 ,BSR a new AW3 narrow .. and a wider ratio3 , the BWR, to take 2 cogs..

And the Sun Race made hubs ads the NIG safety feature.. .


https://www.sturmey-archer.com/produc...d/4/id/64.html 111 /119 wide

this one might offer 10 speeds,5x2.

singlespeedtwin

On the Uno can you raise the bars more than on the Uno speed? So this bike can have a different wheel which would not involve a coaster?

Derailed

I used a SA S2C for my Mu Uno two-speed conversion and was ultimately unhappy with it: the shifting is not consistent enough for my taste. To SA's credit, they sent new internals free of charge, but that did not produce an improvement.

I've gone back to the stock wheel. I enjoyed the project for its novelty, but I feel annoyed every time I see that wheel in my basement I'm not sure what to do with it. I don't think anything's wrong with it, but I'd feel uncomfortable selling it knowing that I don't find the shifting to be satisfactory.

If I were to do this over again, I'd definitely go with the SRAM -- my sense is that the reviews are consistently much more favorable, and few ever complain about the lack of on-demand shifting (the aspect that caused me to chose the SA).

keyven

1) SRAM 36h Automatix 2 Speed Coaster Brake Rear Hub

[h=1]2) SRAM 36h Automatix 2 Speed Rear Hub[/h]
Are there any difference? The description seems the same but the price is slightly more expensive with (1). I have a coaster brake installed so if I installed (2) does it mean there is no coaster brake then?

Would it make sense for me to order this and get a bike store to install? Or should I start looking at local bike stores first?

BruceMetras

With option 2 you don't get a coaster brake... if you install that option, you will have no rear brake.. since the Mu Uno does not have a rear brake bridge for a caliper brake, or bosses for a V-Brake, if you wanted to install a rear brake you would have to have the shop get creative.. one manner to install a rear caliper brake on the Uno is to mount an adapter plate on the kickstand boss, then buy a caliper, cable and brake lever.. if you already like the simplicity of your setup now, get option 1.. it's a simple operation, and the SRAM brake is very good, not grabby, powerful, and easy to modulate... I've been running an A2 coaster since the introduction of the hub.. since you seem inexperienced around this, I would locate a bike shop that you trust and tell them what you'd like.. having their support to fall back on will be worth more than the few bucks you might save by bringing in your own parts..

keyven

Thank you for the comprehensive reply. I like how the answer is so clear. SRAM 36h Automatix 2 Speed Coaster Brake Rear Hub it is.

bhtooefr

Going into vintage parts, there's a few more options.

Sachs Duomatic, which is just as nice as the SRAM Automatix (and the automatic version has the same drawback of having to open it up to manually adjust the shift point), and can be had in a manual version. I'm running one of these on my Boardwalk, and like it a lot. Shifting is quite reliable, the brake is easy to modulate, and it's just a nice hub to live with.
Bendix automatic hubs, although those are heavy.
Shimano AB-100, although I think that one's pretty rare, but it's an automatic shifting 2-speed with external adjustment of the shift point

pacificcyclist

I own the Sturmey Archer S2C hub that I bought from Bruce M. a while back for my Speed Duo. So far, it's working well with the new internals as the original one broke. I'm also lucky to have a IGH hub mechanic who is experienced enough working with SA stuff that he actually managed to make my S2C work better than when I got it originally from Bruce. It's shifts well and still shifts well today after the repair and the mech modification and I ride really hard. No breakage and he managed to get the hub turn with less drag. Much lesser drag than when I got it the first time.

Part of the reason I use the S2C is for the mechanical shift. I dislike auto shift as I am a spinner and I find that auto shifts even modified is too unpredictable in my kind of riding terrain. So far, I have a low and medium gear. I would see why it's a pain if you set it up with only medium and high gear, while most likely you'll end up at the high gear when you start the bike again. For me, low and medium no problem with hills and flats as I coast down the hill anyhow.

I'm still not sure if you really want to go to a dual speed option with your wife riding a Brompton; assuming she's getting a 6 speed version. You could probably go for the Shimano 3 speed IGH coaster hub which is a better choice for you to ride with your wife. You have low, medium and a high gear. This way, you can pace your wife on the uphill and the hub itself needs very little maintenance anyhow.

nichum

I've been following various posts about the Mu Uno (I finally just registered with the site today) and I'm wondering which would be the best front and rear Belt Drive sprockets to use for a Mu Uno. I've been meaning to order a custom wheelset and belt drive system for my Mu Uno with the A2 (coaster brake) hub.


I'm a complete newbie when it comes to this stuff but I am slowly trying to learn the ropes.

Nick

keyven

Man... I gotta admit, when I saw MU Uno and Nick in the same post I thought I was looking at my own post lol.

Not that many MU Unos floating around, my name is also Nick, and I'm a newbie as well.

keyven

How difficult would this be to do myself?

jerrysimon

Not so for the British market. My Uno came fitted with a rear brake/bosses for a V-Brake. Initially I installed an SRAM A2 with coaster and removed the brake. I then took that off and sold it, put the rear brake back on and went for a freewheel A2. I found the coaster uncomfortable to use in my city commute.

Regards

Jerry

jerrysimon

Not so for the British market. My Uno came fitted with a rear brake/bosses for a V-Brake. Initially I installed an SRAM A2 with coaster and removed the brake. I then took that off and sold it, put the rear brake back on and went for a freewheel A2. I found the coaster uncomfortable to use in my city commute.

Ps I also have the 28H version of the A2 freewheel fitted to one of my Bromptons. For both units I had to take them apart and adjust the change point which was too low for the 16/20" wheels.



Regards

Jerry

keyven

I called a local Dahon dealer and the guy insisted I will need to make some 'complicated' modifications to the wheel in order to add the SRAM A2.

Is that true? The way he makes it sound like a big deal.

jerrysimon

Nope not complicated at all except perhaps that you would need to get the hub built into the rim. He could of course mean the changes required to the hub itself to ensure it changes up/down gear at the right speed for you. There is a link posted in this thread, I think, of how to do that. Its not simple but anyone who can build a wheel/does bike maintenance should be able to do it. If you leave it as is then it will change at about 7-8mph which is fine for the flat but not so good when you have more hillier terrain.

The decision really is based on if you want the coaster or the free wheel. On the British (European ?) version then you can use either the coaster brake version or freewheel. Of course for the uno already fitted with a coaster brake then the only answer is to use a coaster A2 unless you can find a way of retro fitting a rear brake as discussed above.

Regards

Jerry

PS Here is the link to a review/instructions with pics showing you how to adjust the change point. Decide for yourself if its within your or the LBS ability to do it. Of course it may then invalidate any guarantee.

keyven

Unfortunately, noob that I am, I got the SRAM 36H A2 from online when my wheels are 28H. Is there any way to salvage this? Is it usable? From some posts on the forums, it seems unlikely...

BruceMetras

You could sell the 36h and buy a 28h .. buy a 36h rim ... or buy a 24h rim and lace 36h to 24h (lace two skip one pattern).. I've run 36/24 on numerous bikes through the years..

keyven

Sound advice as usual... thanks!

keyven

Can you recommend a solid 28H 2-speed hub? I only hear whispers of the existence of the SRAM 28H Automatix, but beyond that it seems impossible to find ANYWHERE.

Can someone point in the correct direction? Google seems to be out of ideas.

BruceMetras

They usually are found in Germany .. you could check EBAY .. I imagine there are other outlets, but the 28h is much harder to find than the 36h.

awakiju

I've got a very nice 451mm wheelset with Sach 2 speed coaster built up by Bruce that I'm thinking about selling. Excellent on the road, very fast setup but I've been doing more trail riding on my Mu Uno and looking to go back to 406mm where I can some fat tires, hopefully squeeze some knobbies on the Mu. I can be reached at awakiju@yahoo.com or 510-329-4563.

Mike

keyven

It's bloody ex... 160+ (including delivery) for the SRAM 28H vs the 70 I paid for my 36H. I rather get new rims.

mconlonx

Schlumpf being way expensive, and Hammerschmidt needing ISCG mounting tabs at the BB, anyone ever use or think about installing one of these?:



This is the 2sp Metropolis to which I referred previously, 1:1 and 1:1.6 ratios -- 28T chainring standard; equivalent of 45t chainring in overdrive. I'm seeing it online for $299.00 retail, as low as $225 ebay.

Unlike auto or back-pedal shifting, this does complicate matters a bit with handlebar mounted shifter and cable/housing setup.