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-   -   Converting Single Speed MU Uno to Double Speed (http://www.bikeforums.net/folding-bikes/928733-converting-single-speed-mu-uno-double-speed.html)

keyven 01-05-14 08:23 PM

Converting Single Speed MU Uno to Double Speed
 
My wife is getting a Bromptons soon, so I thought I'll splurge a little and upgrade my MU Uno to a two-speed so I'd have less trouble keeping up.

I'm pretty much a complete newbie to mods, so I'd like to know what are cheap and/or reliable options in this case?

Thanks in advance.

fietsbob 01-05-14 08:27 PM

how about a kickback coaster brake 2 speed.. new wheel..

non mechanical ? have a bike shop do the order & swap.


with out a fixie kit, to slow with resisting pedal rotation,
there needs to be some rear brakes..

keyven 01-05-14 08:40 PM

[h=3]Sturmey Archer S2 Duomatic Kick Back Hub ?[/h]
Just did a quick google and this sounds good, especially since my Uno is outfitted with front hand-brakes as well. From the review it sounds a little worrying if you have to rely solely on backpedaling to brake and gear-shift.

fietsbob 01-05-14 08:44 PM

SRAM has 1 too.

keyven 01-06-14 02:28 AM

Quote:

Originally Posted by fietsbob (Post 16385759)
SRAM has 1 too.

Will any of these hubs affect the fold? I walked into a random bike shop carrying Dahons and they said they can do it (using a hub whose brand I can't remember), but they said it may make the bike difficult or impossible to fold.

Joe Remi 01-06-14 03:31 AM

Quote:

Originally Posted by keyven (Post 16386233)
Will any of these hubs affect the fold? I walked into a random bike shop carrying Dahons and they said they can do it (using a hub whose brand I can't remember), but they said it may make the bike difficult or impossible to fold.

You might want to have a chat with www.thorusa.com. He offers a SRAM Automatix wheel for your UNO.

keyven 01-06-14 07:09 PM

Can the item be exported to Singapore? How difficult would it be to install?

fietsbob 01-06-14 07:13 PM

Ever owned a bike with a coaster brake?

Reaction arm has a strap that wraps around the left chainstay.. 1 small bolt connects the 2.

that and the axle nuts,, is all there is ..
buy it from Thor who sells Dahons and it will fit.

He will quote Shipping cost.

BruceMetras 01-06-14 08:02 PM

Quote:

Originally Posted by keyven (Post 16388479)
Can the item be exported to Singapore? How difficult would it be to install?

It's easy to install.. drops right in .. If I'm in Singapore, I'd hunt up my favorite Dahon/Tern bike shop and have them build up another rear wheel with the SRAM automatic 2 speed hub.. here's mine.. with belt drive added.. but chain drive is easier to set up ..

http://i181.photobucket.com/albums/x...psd6550f2e.jpg

keyven 01-06-14 08:48 PM

Quote:

Originally Posted by BruceMetras (Post 16388622)
It's easy to install.. drops right in .. If I'm in Singapore, I'd hunt up my favorite Dahon/Tern bike shop and have them build up another rear wheel with the SRAM automatic 2 speed hub.. here's mine.. with belt drive added.. but chain drive is easier to set up ..

Very nice. Thanks for the info guys.

jerrysimon 01-07-14 05:51 AM

I started by upgrading with a SRAM A2 with coaster brake but have since put the rear cable brake back on and gone for a SRAM A2 freewheel/no coaster brake.

I just could not get on with the coaster on my city commute.

Its a worthwhile upgrade to the Uno for sure.

http://farm3.staticflickr.com/2845/1...d6704ff2_o.jpg

Jerry

mconlonx 01-07-14 08:25 AM

I'm surprised fietsbob didn't also mention the possibility of a 2sp crank.

Truvative does the Hammerschmidt, but I don't think it will fit without specific bb mounting hardware the Mu does not have. They used to make a 2sp crank called the Metropolis, which was the non-mtn bike version and would fit right up -- if you can find one of these on closeout somewhere, it might be a great deal and quite possibly cheaper than a new wheel.

There's also Schlumpf 2sp cranks, but they are a bit pricey...

OP, if you go with the Sturmey Archer S2C or S2, keep in mind that you get stock gear ratio plus an overdrive geared ratio. Meaning, if you set up your bike with the same sized sprockets you have stock, the gear you gain will be higher. Most people doing gears want them for an easier gear, so the trick to these is to adjust the drive cog out back and chainring up front to where you want the shifting to end up.

keyven 01-07-14 09:46 AM

Quote:

Originally Posted by mconlonx (Post 16389646)
I'm surprised fietsbob didn't also mention the possibility of a 2sp crank.

Truvative does the Hammerschmidt, but I don't think it will fit without specific bb mounting hardware the Mu does not have. They used to make a 2sp crank called the Metropolis, which was the non-mtn bike version and would fit right up -- if you can find one of these on closeout somewhere, it might be a great deal and quite possibly cheaper than a new wheel.

There's also Schlumpf 2sp cranks, but they are a bit pricey...

OP, if you go with the Sturmey Archer S2C or S2, keep in mind that you get stock gear ratio plus an overdrive geared ratio. Meaning, if you set up your bike with the same sized sprockets you have stock, the gear you gain will be higher. Most people doing gears want them for an easier gear, so the trick to these is to adjust the drive cog out back and chainring up front to where you want the shifting to end up.

My eyes just kinda glazed over at the tech-speak lol. So far the Sturmey Archer S2 and SRAM 2 (assuming they are different) keeps popping up. I'm just going to call a few stores and ask them about these. They seem to be relatively safe and popular choices. I'm more a visual kinda guy so I'll learn better once they're showing me the parts.

smallwheeler 01-07-14 11:08 AM

Quote:

Originally Posted by keyven (Post 16389899)
My eyes just kinda glazed over at the tech-speak lol. So far the Sturmey Archer S2 and SRAM 2 (assuming they are different) keeps popping up. I'm just going to call a few stores and ask them about these. They seem to be relatively safe and popular choices. I'm more a visual kinda guy so I'll learn better once they're showing me the parts.

1. you don't want a coaster brake. one of the great things about not being 9 years old is that we no longer have to ride bikes with coaster brakes.

2. Singapore has great bike shops that can build any wheel your heart desires. no need to order a wheel from the US that's built using parts manufactured in Taiwan or China. that would be silly.

3. "stock gear ratio plus overdrive" as mentioned above means that whatever gear you currently have, a two-speed conversion will give you a second gear that's higher, i.e., more difficult to pedal. you and your bikeshop can adjust the 2 resultant gear ratios to your liking by choosing the size of the rear cog- the larger the rear cog, the easier it is to pedal. the range of cog sizes for the sturmey archer 2 speed hub is 14 teeth to 22 teeth.

fietsbob 01-07-14 12:17 PM

Yea Sclumpf, made in , Swizerland , cannot be made as cheaply, as the Asian countries do ..
the CHF , being the home of numbered accounts of every despot and tax evader, around the world,
has a hard time in Manufacturing because of Strong Currency Valuations, too.

SRAM , shifted production , on Taiwan, has some 1.6x overdrive cranks,
though aimed at the Hardcore MTB market

and The Patterson Metro are also the same sort of small chainring ,
turning faster than the cranks sort of thing .

more easily used on Hybrids with bigger wheels.

BruceMetras 01-07-14 03:36 PM

Quote:

Originally Posted by keyven (Post 16389899)
My eyes just kinda glazed over at the tech-speak lol. So far the Sturmey Archer S2 and SRAM 2 (assuming they are different) keeps popping up. I'm just going to call a few stores and ask them about these. They seem to be relatively safe and popular choices. I'm more a visual kinda guy so I'll learn better once they're showing me the parts.

Big differences between the Sturmey S2 and the SRAM Automatix ..

The Sturmey shifts by you back pedaling a few degrees, and then proceed forward.. if you are in high and backpedal, you are in low .. if in low and backpedal, then in high .. if you have a coaster brake hub, whenever you engage the brake by backpedaling, you also shift from what ever gear you were in.. they also have many reported problems since their introduction across the web..

The SRAM Automatix shifts automatically with wheel revolution, and at a pre-determined point .. stock, on a 406 wheel it would shift around 6 to 8 mph.. the A2 can be modified to shift later (mine shifts at around 14mph) .. but that is a usually done by the mechanically inclined, whether an individual or shop.. I happen to love the Automatics and coaster brake setups ( I have two that I run frequently) I also use a Moulton TSR-5 (SRAM P5 5 speed, belt drive, coaster brake) bike as my daily ride .. although some can't get on with a coaster brake, they do have distinct advantages for me.. the SRAM also has an excellent reliability record ..

dynaryder 01-07-14 04:35 PM

Reviews of the auto-shifting 2spd hubs:
http://mccraw.co.uk/sram-automatix-review/
http://mccraw.co.uk/sturmey-archer-s2c/

If you search around in this forum,there's also been a couple postings on converting Dahon Uno's to 2spds.

smallwheeler 01-07-14 04:45 PM

Quote:

Originally Posted by dynaryder (Post 16391486)

ugh...

jerrysimon 01-08-14 04:59 AM

Quote:

Originally Posted by BruceMetras (Post 16391259)
.. but that is a usually done by the mechanically inclined, whether an individual or shop.

If you use the SRAM A2 on a smaller wheel i.e. 20" or lower this is almost mandatory or it will change too quickly. I have mine set to change about 12mph. As stated for the mechanical minded only as you do have to open up the unit and adjust the spring. Details of how are on the links already posted I think.

I MUCH prefer the SRAM offering over the S/A having tried both.

Jerry

smallwheeler 01-08-14 01:22 PM

Quote:

Originally Posted by jerrysimon (Post 16392675)
If you use the SRAM A2 on a smaller wheel i.e. 20" or lower this is almost mandatory or it will change too quickly. I have mine set to change about 12mph. As stated for the mechanical minded only as you do have to open up the unit and adjust the spring. Details of how are on the links already posted I think.

I MUCH prefer the SRAM offering over the S/A having tried both.

Jerry

what was your experience with the SA hub on your moulton?

jerrysimon 01-08-14 03:26 PM

Quote:

Originally Posted by smallwheeler (Post 16393946)
what was your experience with the SA hub on your moulton?

It was rubbish :p

Seriously the first ones seem to lock up and kick back gear changing was unpredictable. I think the later ones were better but by then I had moved to using the SRAM A2.

Jerry

smallwheeler 01-08-14 03:36 PM

Quote:

Originally Posted by jerrysimon (Post 16394353)
It was rubbish :p

Seriously the first ones seem to lock up and kick back gear changing was unpredictable. I think the later ones were better but by then I had moved to using the SRAM A2.

Jerry

sucks. i just bought one a couple of weeks ago and was preparing to lace it to a rim that just arrived. bummer. usually, i am a very research intensive type, but for some reason i just bought this hub on impulse as it seemed perfect for what i wanted to do. dammit..

jerrysimon 01-08-14 03:46 PM

I think they have sorted out the problems now :)

Their advantage over the SRAM is you choose when you want to change gear. The disadvantage over the SRAM is that the SA is always in the higher gear when you brake to stop.

Jerry

smallwheeler 01-08-14 03:51 PM

Quote:

Originally Posted by jerrysimon (Post 16394418)
I think they have sorted out the problems now :)

Their advantage over the SRAM is you choose when you want to change gear. The disadvantage over the SRAM is that the SA is always in the higher gear when you brake to stop.

Jerry

thanks for that encouragement :P

yes, i didn't like the idea of automatic shifting that's why i chose the SA. also, i didn't opt for the kick-brake version for the reason you've mentioned. now, i just wonder if it is going to worth the effort of ordering spokes and lacing this thing up. well, i guess if it sucks i can always replace it with a SA 3 speed hub. i think the hub flanges and spacings are the same...

jerrysimon 01-08-14 03:58 PM

I sold my SA easily and also the SRAM A2 with the coaster when I replaced that with the freewheel one. People snap them up, even quicker when they are already laced into a rim :)

Jerry


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