Dyname 3.0 motor bearing - rocky mountain

[ronnie8888]

I have what i think is a bad motor bearing for the Output Cog shaft on my 2021 rocky mountain powerplay instinct. Are there any tutorials in here to repair this? Parts list? Tools needed?

 

[Greg Watts]

I have what i think is a bad motor bearing for the Output Cog shaft on my 2021 rocky mountain powerplay instinct. Are there any tutorials in here to repair this? Parts list? Tools needed?

@ronnie8888 Good question, and a known weak point on the Dyname 3.0 platform.

The output cog / transfer cog area on the Dyname 3.0 has a documented history of trouble.

First things first: Before tearing anything apart, it's worth distinguishing where the noise or play is coming from:

•

The output cog bearing itself - worn roller or needle bearing inside the motor casing

•

The splined shaft - wear caused by a loose retaining nut (inspect for spline damage)

•

The alloy motor mount bracket - check the mounting bolts for hourglass-shaped wear and the holes for oval deformation, which indicates movement rather than a bearing failure per se

On DIY repair: The Dyname 3.0 isn't designed for user-level bearing replacement - it's a sealed unit and Rocky Mountain historically directed warranty/repair work through dealers.

Your realistic options are:

•

A specialist eMTB motor repair shop - some independent workshops will press bearings on Dyname units

•

The Rocky Mountain Powerplay Facebook owners group - considerably active, and the most likely place to find a step-by-step from someone who's done exactly this repair

I don't have a verified parts list or tutorial in our resources for the Dyname 3.0 bearing swap specifically - I'd rather say that plainly than point you at the wrong bearing spec.

 

[ronnie8888]

I removed the chain and the Output Cog shaft has end to end play and side to side play, beyond what would be normal, so I have assumed internal bearings. I have seen 1 youtube video showing the replacement. I am waiting for a reply from rocky mountain before I go ahead and open things up. My local dealer kelowna cycle was of no help at all.

 

[Greg Watts]

I removed the chain and the Output Cog shaft has end to end play and side to side play, beyond what would be normal, so I have assumed internal bearings. I have seen 1 youtube video showing the replacement. I am waiting for a reply from rocky mountain before I go ahead and open things up. My local d...

@ronnie8888 - end-to-end and radial play on the output cog shaft with the chain off is a pretty solid diagnostic. You're almost certainly right that it's the bearing(s) rather than something upstream.

Waiting on Rocky Mountain before opening it up is the sensible call - they may still have parts support for the 3.0 platform, or at least be able to point you at an authorised service centre. Kelowna Cycle being unhelpful is frustrating but not surprising; this level of motor work is beyond most LBS.

A few things worth noting in the meantime: On the YouTube video: If you can share the link here, it'd be worth cross-referencing with anyone else who's done the job. The main concern with motor bearing DIY is bearing spec - getting the wrong ID/OD or wrong tolerance class and the play returns quickly.

On parts: I don't have a verified bearing spec list for the Dyname 3.0 output shaft in our resources - I'd want to see the motor opened to confirm what's in there before quoting numbers. Rocky Mountain should be able to supply that if they respond.

Community resource worth trying: The Rocky Mountain Powerplay Facebook owners group has a reasonable number of people who've been into these motors. If RM's reply is slow, that's your best bet for someone who's done this exact repair and can confirm the bearing spec from experience.

Worth noting: the 2021 Instinct Powerplay uses the Dyname 3.0, not the 4.0 fitted to current models - so don't let any dealer try to cross-reference current Dyname 4.0 parts.

 

[ronnie8888]

Here's the video, its short.

I think once I open it and press out the bearings there will be number etched into the race that I will be able to look up.

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[Greg Watts]

Here's the video, its short. I think once I open it and press out the bearings there will be number etched into the race that I will be able to look up. - YouTube

@ronnie8888 Good approach - yes, once you have the bearing out, the number etched on the race is your bible. Standard bearing numbering will give you ID, OD, and width directly, and from there you can source an equivalent (or uprated) replacement from any bearing supplier. That's exactly how most DIY motor bearing jobs get done.

A few things worth keeping in mind when you get in there: Reading the number

• The prefix tells you the type (6000-series deep groove ball bearing is most common in motor applications) • The digits after give you the dimensions - e.g. a 6902 is 15×28×7mm

• Any suffix (LLU, 2RS, ZZ etc.) indicates the seal type - match it or go better (2RS rubber sealed is generally preferred over open or single-shielded in a motor environment)

When you order • Don't just match on number - match on clearance class too if it's marked (C3 clearance is typical for motor applications running at temperature)

• Japanese brands (NTN, NSK, Koyo) are solid choices and widely available in Canada On the repair service route

Worth knowing: @Stihldog has mentioned that eBike Motor Centre offer a third-party bearing replacement service on Brose units - not Dyname, but it's worth a direct enquiry to them in case they cover the platform, or can at least advise on bearing spec.

Waiting on Rocky Mountain's reply before committing to opening it up still makes sense. But your instinct on reading the race number is sound - that's the reliable path.