Sound of ATS Speed Drive 2-speed


What is this click/scratch sound made by the ATS Speed Drive 2-speed? Is it normal?


Hi Alex,

with this drive there is something wrong, definitely.
(I couldn’t tell what exactly without disassembling, but for my meaning this does sound like a broken/damaged ball bearing - there are several in there.)

Can you tell for how much kilometres/what time that drive was used?
Was it lubed yearly?



It is my strida I acquired in 2010 if I remember correctly.

For the mileage question - I have no idea, as I ride it sparingly. Some times it is every day commute, some other months complete absence. When I coummute I do in any weather like rain, snow, etc. My road has at least 2 hills of about 15min each. If it is dirty when arriving home I routinely do shower or other running water.

I never lubed it. I only lubed it a few weeks ago with a lube spray called ‘3-in-1’. I never added grease like MoS2.

The belt never derailed, except once in snow uphill: there was so much snow accumulated that it locked.

Whenever I push very hard in 2nd (fast) speed, and against wind, it skips. I am not sure what skips: the front bracket, the freewheel or the inner speeddrive.

What are my options? Must I extract the speeddrive? Open it? Replace it? With a 3speed? With a 1speed (presumably lasts longer)?

I would like to do as little work as possible, with as little as possible dedicated tools.


Thank you.

Unfortunately this seems to be a major issue, you have a problem.

Well…maybe first of all:

  • You can’t simply switch to the EVO three speed drive because single speed and 2 speed (Ø 60 mm) bottom bracket housing diameters are different to the EVO (Ø 95 mm)!

  • You also can’t simply replace the ATS drive - because you won’t be able to get a “naked” drive in hands; you are forced to buy a complete kit like that from bikegang/UK
    (Look below Carry Me.)
    This is some kind of region protection for Europe; here you must choose a Schlumpf drive (if you insist on drive only).

  • You should not even think of disassembling without knowing exactly before what to do -
    except you like, perhaps 30 or 50 little steel balls over/under your workbench.
    The bearing balls of all these drives are not caged.

Just a few days I’ve stumbled upon this solution to change to an EVO drive, suitable for all Strida versions:

…and alternative the efneo three speed drive for single/dual speed Ø 60 mm bottom bracket.

Ok single speed will be more durable…but do you really want that?

On a sidenote I want to add here that I’m very interested into the ATS drive, so much that I’d even buy a defective one like yours, just for education purpose.
The one I have here had a completely different behaviour in comparison to yours, therefore I’d be very curious to figure out why.

I’m considering the ats set you indicated at bikegang, hoping I would replace it myself with little work.

Hoping it will last longer.

Two hints for a possible bikegang order:

  • Caution; the goods come from Taiwan, depending on your local bureau for customs duty there may be additional costs.

  • At the same page, a little bit hidden, you can find the link “this listing” - below specifications of the kit. Here you can order special tools; you need at least that for the kickshift buttons, perhaps a 60 mm hook key (if you can’t find it cheaper locally).

For more detailed information I’d highly recommend to download the original Schlumpf manual:

Installation and adjustment of the gear shift buttons - please study chapter B-5.

For maintenance go to chapter C-1 :wink:

The installation process was shown in this old thread:
Re: Has anyone retrofitted a schlumpf on their strida?

The schlumpf manual is under study.

The additional tools at bikegang - noted.

The pointer about retrofitting schlumpf is great. If only I knew the photos earlier, it would avoid me risks when extracting the belt with bike upside down and two hands; now I know how.

I hope the ats set comes with instructions to uninstall old ats set, before installling new ats set.

I hate to disappoint you - but I don’t think that any installation info will be supplied with the ATS kit which is dedicated especially for a drive exchange.
But if you follow the retrofitting Schlumpf thread (and just imagine that the single speed excenter would be your old drive) it will be most likely no problem.

Anyway, here are again the main special tools, don’t forget the little steel roll “C”.
Instead of “D”, the Allen bit, you can use of course a common 1,5 mm Allen key:

Strida workshop tool guide

Morover that you need a crank extractor tool “L”.

Don’t worry, think relaxed about the operation and if there are questions - just ask :sunglasses:

Is the L tool needed? (“Crank extractor tool, for example the one of BBB Powerpull BTL-14”)

They dont list it at bikegang.


Yes it is because you have to unmount at least one crank.
I guess they don’t list the extractor tool cause it is much too common.
You should be able to find this, or a similar one, locally for about ten Euros.
There are several of different companies on the market - the prices do vary a lot, be careful where you buy.

Well…there are so much search results…however - you are searching for a crank extractor (tool) for square taper.

The little steel roll is required to be pushed over the kick shift axle before crank extracting - it will protect the thin axle from bending!

Noted for the crank extractor tool. I will look for the BBB version on Amazon.

For the little steel roll ‘C’: if I look at the tools offered by bikegang I find a ‘Small Tube for disassemble crank’; the photo shows a small shining (steel?) cylinder of two sizes whose dimensions seem to correspond to the little steel roll. I hope it’s a tool for the same purpose.
(Open in new tab/window)

Yes, that thing with letter H.

Regarding choice between hook key F and box spanner G;

G is suitable for a torque key.

F is more versatile - you can use it later also to adjust belt tension.
(That would be impossible with G without removing the crank logically.)

B and D are required to mount/adjust the kick shift button.
(You have to mount/unmount at least one.)

C is a replacement kick shift button.

E is a grease syringe.

All letters above refer to the above linked image only.
The letters do not correspond with that of my tool thread.

I received the ATS SpeedDrive, ordered to bikegang, shipped from Taiwan.

I unpacked the box and tested and recorded the sound. The sound is much lower, but one can hear very faintly the same kind of sound.

Well…acceptable delivery time from Taiwan I think.

I’d not take care of this faint noise you hear, you can’t expect that such a gear drive will run completely silent.

You wrote at youtube “not oiled” - was there any advice supplied with the drive which does indicate that?

I do believe that the drive was already greased at the factory ready to use.

I wrote ‘not oiled’ because the package came with a syringe with oil to apply. I did not apply it. I do not know whether the drive is already oiled at the factory, probably yes.

The package also contains 3 A4 sheets with instructions in English, and an Asian language written left-to-right. They are titled ‘Installation’, ‘Caution: Before assembly’ and ‘Maintenance’. In the Maintenance sheet there is an instruction called ‘Lubrication’ with a photo how to use the syringe. I did not use it.

Ok…in doubt, the solution would be easy, either ask Bikegang (as far as I know is their connection to ATS pretty good) or just take a look inside via the lubcrication bolt.

ATS themselves linked at their page to the original Schlumpf drive manual;
I’d recommend also to refer to this, much more detailed, real workbench manual.
Here’s an alternative link: / Speed Drive manual engl.pdf

Mentioned “ATS maintenance” document was found here / ATS Speed Drive maintenance manual.pdf
but sadly nowhere the other two :neutral_face:

Thank you very much for the pointers.

For information, I still have to find time to make the replacement. The current ATS makes noise only when in low gear (no multiplication). In high hear (multiplication) there is almost no noise. So I can still live with it for a few weeks.

For information, this is the pdf with the pages that came in the box. It includes English and Asian language. … 5VBelakguP