Surly Big Fat Dummy with L-R Big Block Mid Drive

[Ecyclist]

That broken rubber mount is not making that sound.

I wasn't suggesting the mounts themselves were causing the sound. (Hadn't even occurred to me...)

I was going with your instructions to look around for some unintended shift or movement...

Other possibilities for unconstrained movement are these types of dual-sided threaded stacks:

No clinch means no preload torque (for retention, load-spreading, etc.)

Plus, the unsupported sections can fail under shear.

Actually, crumbling rubber mounts is the big part why you have a noise problem. If you think about it, you will see it.

 

[kickaha]

Did you find the culprit?

Hi larsb,

You nailed it! The output shaft bearing is toast.

> I guess the root cause is a misaligned bearing or sprocket causes wobbling/grinding movement on an axle. <

 

[mechanistic]

Actually, crumbling rubber mounts is the big part why you have a noise problem. If you think about it, you will see it.

Hi Ecyclist,

I completely agree.

BTW, I love your work! Beautiful battery holders, awesome drive, great stuff!

 

[Ecyclist]

Hopefully, single bearing is your only problem. Unfortunately, I have this sinking feeling that the problem is in the way the drive is mounted to the bike's frame. These clamps are pulling the drive to the bike's frame and, most likely, distorting both structures. Custom adjustable clamps would do the trick. I assume that your bike's frame is made of steel so you should be OK, but just in case, check for cracks near welds.

 

[mechanistic]

Hopefully, single bearing is your only problem. Unfortunately, I have this sinking feeling that the problem is in the way the drive is mounted to the bike's frame. These clamps are pulling the drive to the bike's frame and, most likely, distorting both structures. Custom adjustable clamps would do the trick. I assume that your bike's frame is made of steel so you should be OK, but just in case, check for cracks near welds.

Hi Ecyclist,

The frame is 4130. I assume you are referring to potential frame damage due to drive torque, added weight, etc.?

No problem in this case - I haven't even been able to test ride it, due to the noise, unsafe motor mounts...

 

[mechanistic]

To clarify: Mike shipped it to me with the broken motor mounts.

Here are pictures Mike posted of my bike in his driveway:

Here's a crop from IMG_8813.jpg:

This is how they looked out of the box -- L/R side views of the two mounts shown in IMG_8813.jpg:

 

[TOLM]

Frame mounts.. Ouch ((

 

[mechanistic]

5,760 watts with the battery at it's nominal 72V. 6,720 watts HOC.

+

= unsafe

 

[larsb]

That's at least easy to fix! How it wasn't noticed before shipping is hard to understand; both the noise, the cracked mounts and the loose screws should be hard to miss..

If all depend on the mounts (which is possible) then maybe they cracked during/after the first test drive at lightningrods.

Hope you get it fixed and can start to ride!!

 

[mechanistic]

Hi larsb,

You make excellent points. It's awesome how much you have been able to intuit from 5000+ miles away

On a related note: I wanted to thank you, as I have learned a lot from your posts these many years.

Best,

Erik

 

[larsb]

Thanks, we all have some possibilities to learn here. I often search for an answer to some ebike question and find that it was already answered by someone in an ES thread back in 2012

 

[mechanistic]

Thanks, we all have some possibilities to learn here. I often search for an answer to some ebike question and find that it was already answered by someone in an ES thread back in 2012

I know, right? There's sooo much info here! I can think of more than a few times when I've found someone already answered after I figured it out :lol:

 

[mechanistic]

Hi Mike,

Checking in to see if you have any input?

The noise persists:
[youtube]rdI7mB0PpAc[/youtube]

I would really like to get this resolved so the drive is safe enough to road test.

Mike,

It appears that you are choosing to ignore this situation?

I received the bike 8/2.

Got it running on the stand 8/26 - reported the noise, motor mounts, etc.

Now 10/4 and no response from you.

What is your warranty policy on Defects in Materials and Workmanship?

 

[mechanistic]

I was really looking forward to riding the ____ out of that thing

 

[larsb]

It's weird, you have problems with a brand new bike but no help?

He's been on here today but i guess he doesn't spend a lot of time on ES checking threads. Do your mails and calls get answered? ES isn't the best for communicating..

 

[mechanistic]

It's weird, you have problems with a brand new bike but no help?

Hi larsb,

Sorry for the late reply - I intentionally took a week away from this project. Coming back to it this morning, I was happy to see your post.

I find it remarkable that you chose the word "weird" to describe this situation! It has indeed turned weird.

Mike has not reached out by email, or phone. The last email I received from him didn't offer any solutions to the problems I have reported. He was more concerned that I not post to ES.

 

[mechanistic]

I mentioned that this project has turned weird, here is an example:

For reference, we are now 49 days after I reported the broken motor mounts.

The only action Mike has taken is to remove my name from this post:

…and delete mention of the fact that I sent him the 3D in this post:

Deleted my name from posts. The day after I reported the broken motor mounts.

Weird, right?

 

[mechanistic]

Here’s another example of behavior that strikes me as weird:

Mike took photos that I posted to this thread, photoshopped out the loose wires, etc. then posted them to his Facebook page:

FB post

vs.

vs.

Modified my photos to make my bike look more complete/finished for his FB post. The day after I reported the broken motor mounts.

Weird? Ethically questionable?

 

[mechanistic]

For reference, my notes from 8/2:
Unpack notes:

1. Front tire both beads broken all around
2. Front tube flat
3. Headset parts loose in box
4. Motor Mounts fragmenting
   a. Material? UV stability, etc?
5. Pedal chain run tensioner hits frame
6. Center stand cable exit blocked
7. Unclinched fastener/spacer stacks
8. Secondary chain tensioner spring tab loose
9. Rear chain tensioner push down spring installed (need push up spring)
10. Second Beam? Brackets? Programming software?
11. Speed sensor airgap looks big
12. Primary belt shield retaining bolt loss/rattling

Assembly notes:

1. PAS ring
   a. runout (~0.5 - ~4.3 -ish)
   b. cast? Hub – survive BB torque? 54
   i. one ear broken
   ii. mounted in BB stack - ~2.5 flange thk
   iii. spacers still in place on spider side
   c. confirmed recurring intermittent PAS signal (due primarily to warpage/runout WRT proximity)
2. BeamTS
   a. Mount deflects with load (looks close to 1:1)
   b. Load testing confirmed output unstable (due to unconstrainted sensor)
3. Speed sensor
   a. Magnet installed spanning two spokes
   b. Pickup position is static – no adjustability
   c. Speed signal laggy/erratic
4. Rear wheel harder to assemble – something changed!
5. Makes loud creak/squeak from the drive when rolled backwards (thus rotating the drive)
   a. bearing noise? belt noise?
   b. primary pulley?
   c. Motor pulley flange runout

 

[mechanistic]

To recap, Mike shipped my bike with broken motor mounts.

First reported here.

Also here.

And here.

 

[mechanistic]

Mike shipped my bike with a failed output shaft bearing.

Examples of the LOUD grinding noise from the bad bearing:

[youtube]LBjCy-N7h50[/youtube]
[youtube]eCeflGUi5qs[/youtube]
[youtube]t_95z2DJUAk[/youtube]
Location of the failed bearing:

 

[mechanistic]

Mike shipped my bike with a broken PAS sensor ring adapter hub.

Here is a picture Mike posted of my bike in his driveway:

Slightly higher res version of IMG_8825:

detail crop:

video of broken PAS ring adapter hub:
[youtube]KqsjWH5jE5M[/youtube]

Here’s how it looked when I received it:

 

[mechanistic]

Mike shipped my bike with a defective Torque Sensor mount.

As reported here (the BeamTS did not provide a stable signal due to excessive deflection of the mount under load.

Here’s how it looked out of the box:

Video showing excessive runout:
[youtube]7pvg4Xharc0[/youtube]

 

[mechanistic]

Mike shipped my bike with the front chain tensioner grinding on the frame.

Here is a picture Mike posted of my bike in his driveway:

Slightly higher res version of IMG_8807:

detail crop

here’s how it looked out of the box:

 

[mechanistic]

Mike shipped the bike with several loose fasteners.

The primary belt shield fixing bolt was rattling around:
[youtube]wAQRPEQ5rU0[/youtube]

Motor mount fasteners were loose: