Blackstrida_A_

Please could you tell more exactly what had happened to the Schlumpf drive?

And you were talking to "Haberstock mobility", but not "Schlumpf innovations" - is that correct?

Jipe

Haberstock took over the commercialization of the 3 Schlumpf drive types. The Schlumpf company doesn't sell the Schlumpf anymore.

iveywill

One of the buttons sprang off whilst I was cycling along a flat/level road - gear then slipped into mountain drive - I couldn't change back into normal drive. Fortunately I found all of the bits on the road including a small threaded locking screw. I tracked the drive manufactures via google search (earlier this year) assumed it was Schlumpf innovations - but whoever - was helpful with very precise advice on refitting all the parts - number of turns of the screw etc. Seemed like a poor piece of engineering to me, if it could fall apart so easily.

Jipe

Yes, the problem you encountered is very common with all Schlumpf, Speed Drive, High Speed Drive and Mountain Drive.

Its good practice to regularly check the tightness of the tiny screw on both sides.

Reddleman

So it seems that the main issues with the Vello relates to its chosen rear wheel motor and the bottom bracket mounted gear box. Does anybody know what the acoustic version is like to ride and fold?

Jipe

For the Schlumpf, if you do not like the push buttons, there are also kickplates that cover part of the crank.

Blackstrida_A_

Thanks for your reply!
Well, "falling apart" and "loosing a button" are two different things for someone who is familiar with the drive's components.
Principially, there is just one thing to watch at the kickshift buttons - the torque at the small set screws of 110 cNm (0.8 lbft)!
(Yes, there are special, pretty small, torque keys and one more unusual tool required.)
"If the button is tightened correctly, youŽll never lose it." -> (Refer to workshop manual chapter B-5)

Inappropriate installation at the factory...

In emergency situation, you could still switch down manually, by pushing the rod in the centre of the cranks straight inwards.
With a piece a wood for example, that should be feasible without damaging the thread or bending the shifting rod.

Mate, jfyi - I'm from Austria, we are direct neighbours of Germany (that's where the Schlumpf drives are made) and Suisse (where the drives were made before).
So, it's not really amazing that I do know Mr. Haberstock even personally (just unfortunately I can't get along with him - it's a sympathy thing).
But I had many, very nice mail exchanges with Mr. Florian Schlumpf, the founder of this drive, back then - that's quite easy because we are all speaking German here, you know?
It is correct that Mr. Schlumpf is "detached from bike business" nowadays, but anyway, a while ago I've got special drive parts still from Suisse - but not from Germany.
The production moved to Germany in 2011, before that time I've installed my first, Swiss made Schlumpf drive...and a few more since then...chamfering is more easy than most people think
florianschlumpf.swiss

What are you talking about???
There is one post regarding this theme at Stridaforum, just a single one - and this user had a tool problem!
Shift button coming loose on the Schlumpf Speed Drive
So, where are all the other problems?
But certainly, you will share your wisdom and show us articles which are proving your claim, right?

Yesterday I've visited my local folding bike store; the owner told me that he has installed over 20 Schlumpf drives during the last twelve years.
Not a single one of those was ever reported to be faulty.
dasfaltrad
Schlumpf drives are - sadly - totally underestimated regarding liability and durability, that may have something in common with mixing up ATS and Schlumpf drives.
Both drives are principially identical - but by far not the same!
And overestimated is the "difficulty" of heel shifting...
Last but not least; mostly also overlooked: No need to run a cable somewhere, no additional lever at the bars - an advantage especially for folders.

Show me an offer for a used Schlumpf drive...can't find any?
That's because many Schlumpf (or Rohloff) owners move their drive from the old bike to the next one.
Such drives are expensive - but usually they will accompany you for your whole life.

No guys, sorry, I don't believe that the problem is the Schlumpf drive - but the parts around it, likely...

Jipe

I am in Belgium and I know many people having a Schlumpf, its very common on recumbent and velomobile. I have myself a SD on one bike.

Losing one button is very common even when correctly fastened. Its good practice to very it regularly.

For the rest of the drive, its indeed very reliable and need very little maintenance.

But both MD and HSD have the drawback of a noticeable lower efficiency on the 2.5 times overdrived for HSD, 2.5 time reduced for the MD position. They have also the drawback that a difference of 2.5 time between the two positions, its very big, it force to change simultaneously several gears to maintain a similar pedaling cadence which isn't easy with a cassette+derailleur (its easier with an IGH like the Rohloff).

The SD is better because the difference between the two positions of 1.65 is relatively close to the difference between the two chainrings of a compact 50-34 or 52-36 and the loss of efficiency on the overdrive position is smaller.

Vellonaut

ignachete7 PM'ed me having had a similar catastrophic failure with a Vello Bike+. IMHO, these bikes are deathtraps as sold.

To stop the Vello Bike+ folding while in use, I used a dyneema loop. They are sold at any climbing store and designed to take massive jolts. By removing the seat post, it is possible to loop it around fairly tightly, and secure the loop where the seatpost fits.