Enviolo automatic - vibrations + cadence + 22T + tension

[leifg]

Hi everyone,

This is a great forum with a lot of helpful members. I'm hoping to leverage some of your expertise as someone new to ebikes!

Some background:
I have a new Vado 5.0 IGH that is generally great except for some questionable vibrations coming from the Enviolo hub at times. I've read through various threads regarding Vado / Como 5.0 IGH as well as Enviolo automatic hubs in general, and it's still not apparent what is normal and not. Apologies if I missed some info!

The concern is that I feel vibrations or rumblings in the pedals when at low gear indexes (ie 2-4). This occurs when effort to pedal is low, and when cadences are fairly high (standard/fast). Effort almost feels like being on the verge of ghost pedaling, but pedaling is still productive and necessary to maintain speed. Vibrations are not consistent.
A typical scenario would be eco, cadence of 75-80, speed 8-12mph. Vibrations go away if I pedal harder. There are no issues at the lowest cadences, and susceptibility increase as higher cadences are selected and lower gear indexes are shown in display.

It doesn't matter what assistance level is as it happens when assistance is OFF. I tried a different IGH 5.0, and it did it a bit as well...but that doesn't mean it's expected and okay behavior.
Other then this, bike seems fine. I can reach 28mph with a cadence in the mid to upper 90's (I know that is a concern). Belt tension *seems* okay per app (~50), and there are no apparent signs of belt rubbing. I haven't tried Calibrating Enviolo. It feels like what I would expect a vibrating belt to feel like, but I have no evidence to support that.

Any thoughts on whether or not it's normal for Enviolo automatic would be appreciated, thanks!

 

[xsp6000]

I have a new Vado 5.0 IGH that is generally great except for some questionable vibrations coming from the Enviolo hub at times. I've read through various threads regarding Vado / Como 5.0 IGH as well as Enviolo automatic hubs in general, and it's still not apparent what is normal and not. Apologies if I missed some info!

The concern is that I feel vibrations or rumblings in the pedals when at low gear indexes (ie 2-4). This occurs when effort to pedal is low, and when cadences are fairly high (standard/fast). Effort almost feels like being on the verge of ghost pedaling, but pedaling is still productive and necessary to maintain speed. Vibrations are not consistent.
A typical scenario would be eco, cadence of 75-80, speed 8-12mph. Vibrations go away if I pedal harder. There are no issues at the lowest cadences, and susceptibility increase as higher cadences are selected and lower gear indexes are shown in display.

It doesn't matter what assistance level is as it happens when assistance is OFF. I tried a different IGH 5.0, and it did it a bit as well...but that doesn't mean it's expected and okay behavior.
Other then this, bike seems fine. I can reach 28mph with a cadence in the mid to upper 90's (I know that is a concern). Belt tension *seems* okay per app (~50), and there are no apparent signs of belt rubbing. I haven't tried Calibrating Enviolo. It feels like what I would expect a vibrating belt to feel like, but I have no evidence to support that.

hey, I also have this with the Como 5.0 IGH, at a lower cadence eg. I don't experience this slow! But for me it cycles best on standard

 

[leifg]

Thanks, good to know. I'm starting to think it's the belt vibrating. I recently viewed the belt with a strobe light (just a dimmable led flashlight) while pedaling on a stand and saw standing waves on the belt during vibrations.

I tried a couple different belt tensions and checked alignment, but so far it hasn't made a huge difference (much lower tension is better, but tension was way below recommended min).

I bought a 22T rear sprocket to replace 24T (I have a 2022 Vado), but turns out I've been happy with cadence so I haven't swapped it yet. But now I'm curious what 22T will do here..so I might swap sprocket afterall.

Do you have a 2022 or 2023 Como?

 

[leifg]

I have a fairly lengthy update for pedal vibrations and some other ancillary improvements -- I swapped to a 22T rear sprocket and all pedal vibrations are gone(!). I wonder if this holds true for everyone. Swapping out was much easier than expected and without issue. Lack of vibrations could also be because I did a better job aligning the wheel...but I'm a bit doubtful because I followed a similar process to my past wheel alignment efforts, and overall riding feel is so much improved (at low speeds, more below).

In addition to pedal vibrations being eliminated, the pedal cadences are also vastly improved -- sort of a long story there as I found that the gear ratio appears to be linked to the belt tension on my bike (at lower tensions it appears that I can get a better gear range for hub...even with 24T). I also found the RH hex nut on hub was over-torqued, I'm not sure if related but FYI since it may compress the automatiq, etc.

One thing I'm not sure about is if the cadence targets are dependent on rear sprocket, I now suspect so. I would have thought the cadence sensor was on the cranks and not the hub, but the hub does have a sensor on the rear sprocket, so maybe that's where cadence is measured.

So I now have the following after swapping to 22T at ~35lb belt tension + recalibration:

Before:
Cadence target per 2022 manual w/24T.

After:
Eyeballing average in Rides after stepping through cadences, each measurement on a ~1/3 mile straight @ ~18mph..slight elevation changes involved

Before -> After
slowest 65 -> 53
Slower 70 -> 58
Slow 75 -> 65
Standard 80 -> 70
Fast 85 -> 75
Faster 90 -> 80
Fastest 95 -> 85
28mph in the 80s

This is a very welcome change and now ALL cadences are useful to me. Especially given that all pedal vibrations are gone. I can now ride at any speed without any weird sensations from belt resonance. I tend to ride in "fast" now. Previously I was not super happy with sub 10mph speeds because I was prone to ghost pedaling and vibrations and had to ride at slower/slowest. Perhaps the new gearing keeps belt under tension and prevents vibrations, or maybe it also has to do with belt length being ~3.5mm longer from smaller diameter gear. Many variables.

In any event, the other big takeaway is to check belt tension if you are not happy with the cadence, as your high gearing may improve. I stumbled upon this by accident as I was playing with belt tension to eliminate the vibrations. I had belt tension way below spec at one point and didn't recalibrate..and actually had hub slip on me twice. I was pedaling about 75rpm/25mph (yes, with 24T it's possible...), then I pedaled hard and crank dropped. No bad sounds or crunching, it just dropped. So perhaps I was operating above intended "overdrive" as Enviolo says, and there is not enough contact area in planetary gearing and balls slip at higher torque. So be careful.

But a "trick" to lower cadence may be to calibrate at higher tension and then reduce tension a bit without recalibrating...but this may be a very bad idea so proceed with caution. I didn't do any tricks with calibration after switching to 22T, calibration was done at final tension of ~35lbs / 44Hz (used both carbon drive app and krikit gauge)

I also added a cliq pro for fun. I haven't spent a lot of time with it, but it seems to work well.

 

[xsp6000]

Thanks, good to know. I'm starting to think it's the belt vibrating. I recently viewed the belt with a strobe light (just a dimmable led flashlight) while pedaling on a stand and saw standing waves on the belt during vibrations.

I tried a couple different belt tensions and checked alignment, but so far it hasn't made a huge difference (much lower tension is better, but tension was way below recommended min).

I bought a 22T rear sprocket to replace 24T (I have a 2022 Vado), but turns out I've been happy with cadence so I haven't swapped it yet. But now I'm curious what 22T will do here..so I might swap sprocket afterall.

Do you have a 2022 or 2023 Como?

Hey, it's a Como 2023

 

[leifg]

Okay, so the 22T/2023 vs 24T/2023 alone doesn't explain the vibrations.

While I did change a fair amount, I was able to get lower cadences/no vibrations with the 24T as well by reducing belt tension below spec (which seemed to increase available geat ratio)...so I guess too much tension could perhaps hurt the 22T on 2023 as well. By "too much" tension, still within spec, just at the upper end like ~43lbs/55Hz vs 32lbs/40Hz....at least based on what I saw. (And I clearly I had too little tension without a recalibration at one point because hub was slipping)

I'm also curious what sensor inputs are used in hub's decision to upshift or downshift, and if they could be a factor in automatiq leaving belt under higher or lower tension.

 

[McCorby]

Can you please explain how the tension of a cogged belt would affect/change the IGH‘s gear ratios? That makes absolutely no sense to me. Also, the Enviolo should not require a re-calibration when belt tension is adjusted. Again, that makes no sense.

As to your question regarding if the belt tension changes when the IGH changes gear ratios, the answer is no, they are totally separate from one another.

 

[leifg]

I'm not sure if you have other sources, but I read that it should be calibrated twice a year, whenever wheel is removed, "repaired", etc. Documentation is open enough that I wouldn't exclude tension adjustments.

Also, I didn't ask if belt tension changes when gear ratios change -- but I disagree with your answer that they don't. Take a bike with a chain that's parked and stand on the pedal -- the chain is under more tension. The belt tension changes constantly when pedaling under different loads, cadences, and gear ratios. If it's hard to pedal then there is more tension on the belt, and Enviolo can influence this with its gear selection by selecting a slighting higher or lower gear and cadence.

Back to your question, I don't think that either of us can really say whether or not it makes sense from a hub perspective, but here goes...

You've probably seen the internals of the hub -- there is a lot going on and with tight tolerances. Everything is concentric to the axle, so I'm guessing that if something is out of alignment then things may not work quite right.

The cog is connected to the input side and is not independent of the hub as you suggest. So the belt tension is indeed transferred to the hub. I could imagine that a high tension belt pulling on the cog could cause a slight misalignment on a bearing or other surface, which in turn increases the amount of force needed to transition through min/max gear ratios (and maybe automatiq doesn't have enough force to overcome). Similarly wheel alignment is important and could be a factor, but was not evident with changes I made.

Likewise, the hub interface that is responsible for changing gear ratios is physically close to the cog; maybe there is some localized interaction or binding, and when it happens we lose some range on available gear ratio because the interface can't move through entire range.

We also know that some Enviolo manual shifters stiffen up at high gears or when shifting under load -- maybe there is a similar phenomenon happening there.

Whatever it may be, we know that each hub must be calibrated on the bike and recalibrated whenever changes are made to the drive train, so there is an intended dependency. Part of the calibration could be the hub setting the low/high limits for gear ratio which may have a non-obvious dependency on the belt tension.

From my perspective, the data I have clearly shows a relationship between tension (or the process of changing tension), and the gear ratio. On two occasions I calibrated at high tension, reduced tension, and gained significantly higher gearing. And in one instance I had hub slip, presumably because gearing was so high that maybe there was not enough contact area in planetary balls to input/output and they slipped. While I don't know what's going on, there is enough evidence for me to conclude that there is a direct or indirect link.

 

[McCorby]

I'm not sure if you have other sources, but I read that it should be calibrated twice a year, whenever wheel is removed, "repaired", etc. Documentation is open enough that I wouldn't exclude tension adjustments.

Can you please point to where this documentation is located? Their website lists only 3 reasons calibration is required. I found nothing about twice a year or whenever the wheel is removed.

 

[leifg]

Are you trying to figure out when / why you should calibrate? There is not a lot of interesting detail on calibration. Basically they tell us how to do it, and then a few bullets with a common theme of calibrating whenever something changes.

Nuvinci (before they were enviolo)

https://www.r-m.de/media/filer_public/07/e6/07e6ab59-9907-41bf-b74d-7af316be753a/bbp377x_pt750_my22_us.pdf

"On the first set up or after system maintenance
or incorrect functionality the system has to be
calibrated."

Serial 1

https://support.serial1.com/hc/en-us/articles/4406863070228

"All Serial 1 eBikes are correctly calibrated during assembly. However, it is recommended to re-calibrate your hub after removing the back wheel and disconnecting the AHI (Automatic Hub Interface) or when updating the Enviolo hub software. "

Specialized Vado 5.0 IGH
"On the first setup or after system maintenance or incorrect functionality the system has to
be calibrated."

https://faq.veloretti.com/en-US/how-do-i-pair-and-calibrate-the-enviolo-automatic-gear-shifting-device-238008

"We recommend calibrating twice a year and after a repair is conducted. Calibration can be easily done via our Veloretti app."