Abu Mahendra

What are your thoughts and feedback?

Yan 

Interesting concept. Had not heard of this before. Does it only work with the supplied flat bar shifters? That would be an issue for a lot of people.

rifraf

I don't remember which drop bar shifters are correct but have seem them utilised with a Dualdrive.

My last bike was a Moulton APB Landcover which I had for many years and only recently sold. It had a Sram Dualdrive as an upgrade from its original Sachs 3x7.
Sram bought Sachs if I remember right and the DualDrive was the evolution of the 3x7.
The Dualdrive is still popular on small wheeled bikes and recumbents.
Due to relocating to Western Australia where the distances between towns can be large and the Moultons limited luggage capabilities (water), I changed to a more suitable, for the local conditions, Surly Ogre with IGH.

Sturmy Archer also produces an IGH three speed with exterior cassette in the CSRK3 series and the CSRF3.

Sturmey Archer | CS-RK3 Black

Sturmey Archer | CS-RF3 Black

AusTexMurf

I have ridden SRAM dual drive setups on both pedicabs and on my bike friday triple family traveler. Have worn them out in pedicab applications due to torque and constant heavy use. I have noticed on pedicabs that there is some drag in hubs with wear, particularly in smallest gear/cog under load. Be careful not to bend shiftng rod when puling rear wheel for flat or repair. I also run a drum brake on the non drive side of bike friday triple. Complicated heavy setup but rolls surprisingly smoothly. Never any problems with this hub

I would recommend the Dual Drive for touring application.
I would also be interested in putting the Sturmey Archer to the test. I am a fan of their 3 speed internals in general.

Abu Mahendra

No, it works with some Shimano triple crank shifters. I shift my SRAM DD with a Shimano SLX shifter.

Abu Mahendra

I'll say that I ask because my experience with SDD has been quite positive and uneventful on my light tourer, a 20" folding minivelo. I like it for its ability to shift much more quickly and smoothly than a FD with a triple crank.

VT_Speed_TR

I've had a Sram DD on my Dahon Speed TR for 10 years & have had no issues. I've done some light credit card touring with it utilizing Amtrak trains and taking it directly with me; as its a folder allowed as carry-on. I really like the concept for my folder, since it provides a nice gear inch range. I don't think I'd select it as my power train option for a bike I was building up myself, I'd either go straight internal hub; Shimano 8 or 11, or a Rohloff 14.

Pukeskywalker

Seems like the worst of both worlds: You still have a RD, but you also have the risks of a failed IGH

Abu Mahendra

Except that the SDD is quite sturdy and not likely to fail. A comparison to multi-speed IGH is apples and orangutans. SDD is its own different thing. My 20" wheel bike has a range of 20-119 gear inches due to the very reliable SDD.

Tourist in MSN

I have not toured with a dual drive, but have one on my foldup bike. When I bought the frame I thought I would be able to fabricate a front derailleur mount for it, but to make a long story short decided that a front derailleur was not going to work on that frame. Then I bought the Dual Drive to get the range of gearing I needed.

I am running a Sturmey Archer bar end shifter with the Dual Drive. And a bar end shifter for the eight speed cassette on the other side of the handlebars. I have maybe 5 miles at most with that combination, only installed the bar end shifter a few months ago during a lull between snow storms. More information at this thread: https://www.bikeforums.net/folding-bi...l#post18569533



I would be hesitant to carry a really heavy load on the back with that hub, but otherwise I would be confident in using it. Since the rear is nutted instead of quick release, you are looking at carrying more tools than you would with a derailleur bike. A spare click box and a spare rod (I do not recall what it is called, it is the rod that is threaded into the hub for shifting) might be on your list of spares to bring on a bike tour.

I do not know if the pannier would hang over the click box, but if it did I think that is not a problem as long as your shifter stayed in adjustment. My point is that the window in the click box might be obscured by your pannier. I do not know if the pannier rubbing on the click box could be a problem, you might need to consider that too if it is on a small wheel bike.

The spring in the Dual Drive for shifter operation is pretty weak, I have had a few issues of too much cable friction in my cable housing to make it shift well. But, I have a very long cable with full length outer housing, thus this problem may be unique to my setup. I have to buy tandem length cables.

The Dual Drive has a constant noise from pawls clicking. I got used to it, but just be advised that there is some noise. Not too loud, but on a windless day out in the country you will certainly notice it.

I think that Bike Friday was installing Shimano brifters to shift Dual Drives, but I have not seen such a setup. But it might be possible.

You need a 135mm spaced frame for the Dual Drive. If you can't put a 135mm hub into it, I think you can't use it.

fietsbob

Bike Friday owners , ask them ..

Read CGOAB , lots of Bike Friday touring riders got that dual drive hub.



Yes, as a Popular Bike Friday option, check the Company hosted bike owner/user's forum through their web link..

the 3 speed bar end, + the 8+ speed derailleur shifter may both be satisfied by Micro shift..

& Gevenalle combines on brake levers may be a suitable drop bar brake/shifter if that is what 'floats your boat'

Sram wants to focus on high end stuff they dropped dual drive production and all IGH, recently.

now Sturmey Archers left to own that market segment, without competing sources.





.......

AusTexMurf

Uses SRAM X7 RD and equivalently spec'ed parts, equivalent to Shimano Deore LX probably.

Abu Mahendra

Actually you can run any RD for the hub does not know or care what cogset it's got on. I run Shimano SLX RD and cogset on the SDD, and I shift the SDD with Shimano SLX too.

Tourist in MSN

I have the Sram 11/32 eight speed cassette, a Shimano low end derailleur (do not recall which model, but it was cheap) and a KMC chain. Shifter is the BS64 eight speed bar end shifter.

As Abu noted above, there is a wide range of options since any Shimano eight or nine speed compatible cassette will work.

Abu Mahendra

10 speed works too. No reason why MTB 11-speed should not work either.

Tourist in MSN

Ok, I am using eight speed, I did not want to guess about newer options that I was not familiar with and I have never used a cassette with 10 or more speeds.

Thanks for posting, I was unaware that there was an option other than Sram Dual Drive.

Looking at the documents for the Sturmey Archer, it appears that both are almost identical in how they are used and fitted, but the Sturmey Archer uses a indicator chain for gear shifting like they have used for many decades, Sram uses a different design. The only real difference to a user is how the cable is fitted to the hub, as the outer housing runs to the click box on the Dual Drive, you would need an outer housing stop on the chain stay with the Sturmey Archer.

And the Dual Drive has a slightly wider gear range, but it is so slight that most users would not notice the difference. My lowest gear with the Dual Drive is 20.7 gear inches, with the Sturmey Archer it would be 21.3 gear inches, that is so small a difference that I would not notice it.

With the Sram eight speed 11/32 cassette, the Sturmey Archer would also have a few more redundant gears than the Dual Drive but otherwise there is almost no difference.

The paperwork for the Sturmey Archer is silent on a cassette with 10 or more speeds, they only cite 8 or 9. Abu indicates above that the Dual Drive can be used with 10 or MTB 11 speeds.

AusTexMurf

I have used the SDD on at least two different pedicabs that carry up to 4 people with rider, battery, lights, food, water, tools, and gear. The SDD is original equipment on Cycles Maximus pedicabs. The SDD was also original equipment on my Bike Friday Triple Tandem touring bike with front/rear racks rolling on 20" wheels. I use a rear rack specifically designed for 20" wheels. I run Ortlieb Front Roller Classics on the rear rack and can use either front or rear Ortliebs on the front rack. The smaller front ortliebs attached to the rear rack fit and keep from interfering with the SDD click box. I actually prefer to load up the front wheel as I often have two other human bodies behind me, weighing us down. I am running Ultegra brifters on the Bike Friday Triple and use a Microshift bar end shifter to control the supplemental rear drum brake. On pedicabs, shifting with any rear shifter and use the SDD grip shift on the IGH. Running dual BB7 disk brakes in the rear and Magura hydraulic rim brakes up front. Point is, seems to me, this hub is used frequently in heavy duty applications. To quiet pawls, could consider oil bath for the IGH. I also pull the shift pin and straighten and lube as needed.

Tourist in MSN

Thanks for posting. I had been nervous about using the Dual Drive for touring because Sram clearly states: "Caution:Not suitable for tandems, trademen’s delivery bicycles and similar."

Thus, I was worried about loading it up, as I did not know how strong the axle was. But I am sure you have put much more weight on it than I ever could if I do loaded touring on my fold up bike.

Abu Mahendra

One scenario. SRAM DD with a single 30T chainring and a 11-36T cogset. The hub costs only about $160, the clickbox $15. In essence you get the gear range of a triple crankset without the FD, chainline and cross chain issues and really crisp, RD-like shifts among 0.73, 1.00 and 1.36 multipliers on the single chainring.

Tourist in MSN

With my eight speed 11/32 cassette on my fold up bike with 24 inch (507mm bead diameter) wheels with Schwalbe Marathon 1.5 width tires and Sram Dual Drive, using a 39 tooth chainring, my gears are as follows:



X axis is gear number 1 through 24, Y axis is gear inches.

My spreadsheet was set up for a triple crank, so I am essentially forcing the spreadsheet to think that there is a chainring of 53.1 teeth and another of 28.6 teeth to reflect the gear ratios in the Dual Drive. The color for each gear indicates if it is low, medium or high Dual Drive gear range based on the equivalent chainring tooth counts.

I think this would be a good range for loaded touring. Maybe slightly high but close.

Abu Mahendra

Another scenario, resulting in a cool 16-114 gear inches...

rifraf

I have kept a spare DD hub and click box on the off chance that my Rohloff ever gives any trouble.
A couple of years down the track now with no issues but its there if I ever need it.
I toured from East to West across Australia towing a trailer on my 406 wheeled Moulton APB without issue and wouldn't hesitate to take a DD installed bike on any journey.
I do prefer the derailleur free IGH I currently run as its virtually maintenance free but doubt I'd outlay the expense should I be forced to start again.

rifraf

Yes, I ran a Shimano XT on mine

rifraf

I was so confident in the durability of the DD that I decided on a high spec wheel build for my bikes then upcoming across Australia tour.
Lacking confidence in my LBS ability to do a decent wheel build, I got in contact with the Team at Wheelbuilder.com in sunny California.
I sent them a Sram DD and a SonDelux dynamo hub and requested they supply Velocity Aeroheat rims and customs shorten some Sapim CX-Rays with an overkill of 36 spokes per wheel.
The job was done promptly and shipped to me in Aussie and I was very happy with the outcome.

Abu Mahendra

Yes, Rohloff vs SDD is a bit of a mismatch for they are different beasts in function and price. The former is 8x the price of the latter.