Abu Mahendra

you conveniently avoid the issue by ad hominem. the issue is why attempt an unnecessary hack when the thing is already solid? your veiled vitriol does not replace reasoning or answering the question. i listened to you, to your post. i am sorry if i asked a thorny question for which, evidently, you have no answer by the looks of your response. the plain fact is that i have a bit of experience with SDD. i even own one, and have used it extensively, unlike you. good luck with that hack...

BruceMetras

I have both the Sachs 3x7 and the SRAM Dual Drive.. I like the chain more for aesthetics reasons than anything else..and, I've yet to have a problem with a click box... but I did toy with seeing what I needed to do to convert a DD to chain.. there are some immediate problems .. as you can see from the picture the IGH internal attachment is in a completely different position.. more towards the drive side with the Sachs, and more towards the non-driveside with the SRAM by almost 3".. that's where I stopped .. wasn't going to be worth the effort for my purposes.

badmother

That is a huge difference for sure! I think maybe I would do what you did, just use the clickbox. I found the discussion about converting to chain when I searched for info on shifters. I found Aron saying all the Shram 3 speed IGH shifters was interchangable but still not sure if the Sachs/Shram 3 speed shifters are, that is why I am thinking of buying a SA shifter. I know from experience (and from the info on the IN) that you can use SA 3 speed IGH shifters with Sachs hubs but not Sachs 3 speed IGH shifters on SA hubs.

I think the guys discussing the clickbox conversion wanted to get rid of the clunky clickbox and get a more "old scool" look, some of them are close to Sheldons level so "they just have to find out if it is possible..."

I think what I did with the Surly brake hanger and the cable splitter I copyed from a picture you posted of a
Moulton you have set up this way so that invention may be yours!

BruceMetras

My plan to convert a DD to chain pull was going to be to cut the DD long rod, flatten and drill the end, and attach the chain.. lot of other projects ahead of that though.. I use a SA bar end shifter for the Sram IGH.. no issues.. the SRAM/Sachs 3 speed shifters will work with SRAM/Sachs hubs, but they shift in reverse of each other .. Sachs defaults to high gear when relaxed, SRAM to low gear..

Harhir

Slight correction: SRAM not equals SRAM.
SRAM also sold the older style 3x7 hub (Sachs) and branded it as SRAM Spectro 3x7. They have a different housing but are almost identical inside expect the clutch which had 6 claws in the older Sachs model and then 4 claws in the newer SRAM models.
But agreed the SRAM dual drive is completely different from the SRAM/SACHS 3x7. They are not compatible.

One more thing: The chains for the 3x7 are no longer available. I even can no longer find them in Germany. One can still buy the chain for the 3 speed where the pin is too short for the 3x7 or the chain for the 5 speed (left side) where the pin is too long. I need to try if I can use a 2mm die to extend the thread on the longer pin and then cut it to the correct length.

BruceMetras

Not sure what you mean there, but I'm pretty sure we're on the same page


Let me know what length pin you need.. I have a reasonable collection in the drawer.. maybe I can mail you what you need..

badmother

I have not yet found anything (numbers or letters) to identify my hub but I guess I could post pictures and I am sure some of you can identify it.

About the chains (chain/rod combo) not being available: If you have the pin its self it should be possible to atatch a new chain to it, I did this some time back after buying my B with the old scool two chain 5 speed hub. It did not take me long to crush the chain on the left side and I managed to repair it. Removed the crushed chain carefully and just used a chain from a different pin/chain combo. I actually think I used one from an old Sachs 5 speed hub as that was what I had at the time. I used a small brass coloured nail as a rivet, cut it to lenght and carefully hammering it to hold the chain. I remember taking a amall nail or two as a spare on longer rides but never had to repair it. Also with this kind of drivetrain (as with the B SA two chain hub) all is not lost if half of the system can not be changed. You always have at least three gears

ofgow

>I eventually learned that I could use a Sturmey Archer 3 speed bar end shifter on the Dual Drive
Aha! Thank You!

Tourist in MSN

Yup. For several years I used a friction bar end shifter on my Dual Drive until I learned that a Sturmey Archer shifter worked, learned that at post number 16 at this thread back in 2016 when someone said they were using the Sturmey Archer.
https://www.bikeforums.net/folding-b...ding-bike.html

Photo of my folder with a Sturmey Archer shifter on left and the Shimano rear derailleur shifter on the right back in 2018 below.

bikebikebike

Sturmey Archer 3x9hubs going for ~$90.
With ~$25 for a rim and ~$20 for spokes, that makes it competitive with a FD for cost & weight
(1090gm vs ~200 gm per chainwheel+ FD ~100gm + rear hub ~300gm, so what? 400 gm heavier?)

The wide gear spacing on my 6 and 9 speed foldies needs something and I really like the SDD on my Bike friday

Clearly not weight weenie racer, but for touring city bike, not a bad move.

tomtomtom123

One problem is the gear range. The sturmey has 177%. Dual drive had 186%. The 44/24 double crank that I use now is 183%.

Reddleman

Has anyone found a source for the 28 hole Sturmey Archer dual drive hubs, either the CS-RF3 or the CS-RK3? All I can track down are 32 or 36 hole versions, and I’ll quite like to be a cheapskate and reuse my existing rim.

tomtomtom123

I could only find this site with 28 holes, but it's pretty expensive.
https://foldingbike.biz/Dahon/Tern-N...ar-Unit-28Hole

You might as well contact a shop closer to your location, and ask them if they can order it. I see other places with 32 or 36 holes for around $100.

Reddleman

Other suppliers in Europe say that the regional importer doesn’t ship in the 28h model which partially explains why it hasn’t turned up other than a Tern branded version at a Tern and Dahon parts specialist in that corner of the world. Hmmmm. The extra £35 to reuse the existing 28h rim is probably better spent on a new 36h one and getting a stronger wheel into the bargain.

Numerozero

I installed a SRAM DD on my Xootr Swift. No cassette, just the three internal gears. It’s geared as per Sheldon Brown’s suggestion - low gear is for going up hills, so I spin out going down- which doesn’t bother me.

But that clickbox looks vulnerable. So I fitted a derailleur protector. It worked. Then, I replaced it with a titanium version. Weight went from 80 to 32 grams.

Titanium derailleur hanger from EBay.


Just the right amount sticking out!


Barely clears for removing clickbox.

bikebikebike

I found replacement clickboxes only after a big search and had to get them from Holland
$$
The guys here that have them guard them jealously

Tourist in MSN

When i heard that the Sram Dual Drive was no longer going to be produced a few years ago, I ordered a spare click box and one or two of the rods that threads into the hub for gear changes in anticipation of difficulties ordering them later. When I disassemble my folder to pack it in my S&S case for travel, I remove the rod and wanted a spare in case it got lost.

I considered trying to make a guard for my click box like the one shown above, but never got around to it. I have not toured on my folder, but I thought that if I put a rack and panniers on the back for touring that the pannier might not play well with the click box, thus I thought I might need a guard for the click box in that scenario.

pakeboi

What tires are you running ?

onbike 1939

Damned if I can remember as I've had to give up all my bikes for health reasons and it was some time ago.....probably something by Schwalbe though.