sethimus
😠 Donald Duck 😠
because there is still some pedal kickback? less than with other designs, but still there. hence why i built a rear wheel with the sidekick hub for the velduro
Anyone use Anti-Pedal Kickback Tech on EMTB?
- Thread starter slickrock
- Start date
In what way does the kickback actually matter ? We've all been riding without the devices OK for decades... is it really a game changer ?
I tried one, i REALLY disliked it.... it was horrible to ride.
sethimus
😠 Donald Duck 😠
i ripped out my derailleur once and rode chainless down and want to recreate that feeling as much as possible, but with a chain.
with my current bike, a kenevo sl, i optimized suspension to the max, the most tiring thing is actually the hits i feel in my feet, which i suspect are coming from the chain. it got already better with a stfubike, but is still there
with my current bike, a kenevo sl, i optimized suspension to the max, the most tiring thing is actually the hits i feel in my feet, which i suspect are coming from the chain. it got already better with a stfubike, but is still there
mhueschen
New Member
adding a wrinkle to the pedal-kickback convo:
I'm noticing that during auto-shift (Avinox + AXS extension cord, hitting the shift pod button while coasting), the system seems to spin the chain/cassette fast enough to take up the deadband and engage the hub (audible engagement/buzz/clunk) on choppy terrain. if that’s real, it seems like it could "neutralize" hub-based PK devices.
crank-based devices with springs or elastomers might be more resistant to "motor takeup of slack", but probably would be impacted also?
anyone else experiencing this?
it's not a huge issue in the grand scheme, but seems unfortunate. on analog I often shift by pedaling half-speed, so that the ratchet is still buzzing but half as fast as it would be with fixed pedals. it seems like the motor could do the same, but perhaps they've just programmed it to "match cassette to rear wheel speed" for simplicity.
I've been experimenting with auto-shifting when I know I'll need to be in a different gear soon, e.g. steeper corner where I'll accelerate thru it and want to be in a smaller cog to stomp out the exit.
I'm noticing that during auto-shift (Avinox + AXS extension cord, hitting the shift pod button while coasting), the system seems to spin the chain/cassette fast enough to take up the deadband and engage the hub (audible engagement/buzz/clunk) on choppy terrain. if that’s real, it seems like it could "neutralize" hub-based PK devices.
crank-based devices with springs or elastomers might be more resistant to "motor takeup of slack", but probably would be impacted also?
anyone else experiencing this?
it's not a huge issue in the grand scheme, but seems unfortunate. on analog I often shift by pedaling half-speed, so that the ratchet is still buzzing but half as fast as it would be with fixed pedals. it seems like the motor could do the same, but perhaps they've just programmed it to "match cassette to rear wheel speed" for simplicity.
I've been experimenting with auto-shifting when I know I'll need to be in a different gear soon, e.g. steeper corner where I'll accelerate thru it and want to be in a smaller cog to stomp out the exit.
John_likes_bikes
Well-known member
You're not wrong but for me the amount of time auto-shift is counteracting a KB device is very short and any negative effect is minimal compared to overall positives of auto-shift. Nothin' is perfect i guess.
Compared to a mtb, it's difficult to even pedal to shift in chunk and chatter, I'd take the ability to auto-shift then anyday. Even then on a mtb you'd have to pedal through the deadband to get the cassette moving fast enough to shift, negating the KB device (right, that's how my brain is seeing it?). For me, I've wanted autoshift capabilities since 1995 so I'm a big fan!
Pre-hub engagement is a bigger enemy of any KB device because the instant it feels a crank movement forward it spins the motor, which eats up deadband. If you have this on you should defintiely turn it off.
mhueschen
New Member
totally agree, I'm quite enjoying having it
it's definitely a minor gripe about the momentary extra-KB window while autoshifting. just a tradeoff I noticed while getting auto-shift-happy the other day, that it can reduce bump-tolerance in exchange for having the right gear when you want it.
slickrock
Well-known member
- Thread starter
- #157
I was considering do the very same thing with my bike, but then came to realization that the entire bike suspension design mostly dependent on the chain as the primary mechanism to create anti-squat, at least with lower pivot designs. The corollary that AS is meaningless without a chain because there is no force vector (human or motor) to drive the suspension other than COG dynamics. IOW, the suspension is operating in way it was never intended, as liberating as it is.
But what you did is really the only way to fully understand what it's like to experience both no kickback and no chain-whip on your bike. It creates a baseline from which work from, which is a good way to look at it.
The other good thing is the the Velduro will be much better than the Kenevo here because the Velduro is a mid-HP with idler, so you get a good chunk of AS capability from the higher pivot location rather than from chain growth vector, so actual kickback will be less, not to mention potentially less chain whip because of the shorter distance from the idler to rear sprocket.
AS is only a factor when pedalling, and a chain damping device is only active when you aren't pedalling, so it is an ideal solution. I've tried o chains on a few high pivots and universally found them to not be as noticeable, or worth the weight/maintenance.
slickrock
Well-known member
- Thread starter
- #159
I take it the first sentence refers to STFU or similar anti-chain-whipping devices? If so, I agree. What's telling is you make no mention of kickback, which is happening whether you pedal or don't; if the suspension is articulating, kickback is happening. The qualitative call is how much kickback is actually there paired with felt experience. With HP+idler bikes, I'm not surprised in your case that kickback on such bikes don't experientially rise up to the point of needing a technical remedy.
I'm referring to the ochain, e13 hub, or the like. These devices are primarily chain dampers, rather than pedal kickback eliminators, regardless of marketing..
What I was getting at is that such a device has no effect on AS as designed by the manufacturer. The suspension will operate exactly as designed. You had commented that suspension will not work as designed without a chain, or by extension, a chain device.
The lower chain run, and it's associated mass, is where most of the perceived chain whip/pedal kickback comes from, I've only ever found the stfu to be effective at quieting bikes with subpar chainstay protection. And even then, it quiets them, but doesn't calm them, as does an o-chain.
I wouldn't own another low pivot without an ochain on it.
Definitely useless device on HP for sure. Outside the HP I would also definitely recommend ochain or rimpact.
Now people have also to be honest with themselves, depending on how and what they ride, these can be close to useless.
But like @ntm95 said, I ride HP 50-75% of the time and my upcoming park bike has not but will require an ochain/rimpact, once you are used to some feeling and predicting behavior it is harder to switch back when riding aggressively, at least to me.
Now people have also to be honest with themselves, depending on how and what they ride, these can be close to useless.
But like @ntm95 said, I ride HP 50-75% of the time and my upcoming park bike has not but will require an ochain/rimpact, once you are used to some feeling and predicting behavior it is harder to switch back when riding aggressively, at least to me.
slickrock
Well-known member
- Thread starter
- #162
Your statement is the hot take I've been pushing for a while here: It's mostly chain whipping effects being addressed by this tech. The reason I was being specific about STFU is that nothing about the product addresses kickback, while the other products are marketed as addressing kickback. Also, STFU's loops are too large to fully address the swings from chain whipping, but perhaps just keeping the chain from slapping on the chain stays is seeming enough for it be considered part of the PB's collective pedal kickback tech review.
Regarding AS, I think you misunderstood my assertions. What I was saying is:
- Every MTB suspension, as varied as they are, are designed as they are mainly to address create a specific anti-squat curve ( and to lesser extent also to decouple AR and target an LR)
- Kickback is primarily as side-effect of AS design, often because designers don't want to push HP too high and often push their instance centers low.
- Removing the chain, while eliminating kickback (good for baselining) and liberating the suspension means you are riding a suspension not designed for that purpose. IOW it would be designed very different if there were no concerns about AS (because you wouldn't be pedalling in first place) without a chain. Perhaps this last point is bit too quixotic to ponder, as it seems to have caused confusion.
Ah, that's a bit more clear.
I'd agree that "pedal kickback" is indeed a byproduct of more aggressive AS, as anyone would. One would expect e-bikes to be better in that regard since AS isn't nearly as critical, but I've not noticed that myself. Perhaps it's an evolution yet to come, as per your point number three.
A part of the hp bikes exhibiting a calmer feel through the feet is almost certainly related to the lower chain guides. When removed from the slash, claymore, or dreadnought, the bikes become noticeably noisier in terms of actual acoustics and feedback through the feet.
An ochain with no bottom roller guide still felt only on par, if not slightly worse, than a hp with a lower roller and no ochain. No bottom roller, and no ochain was certainly still better than the average low pivot, but it starts to loose some of the magic in terms of that calm feeling on the feet.
All shades of grey, but it adds up.
mhueschen
New Member
Rimpact eMTB Chain Damper is taking preorders. currently only 34t, and for Bosch and Avinox. I just placed my order y'day. hoping when it arrives in May it'll alleviate some of the eDruid PK on low/mid-speed chop (rather common here in Bellingham)
for the record, I'm in no way affiliated w/ Rimpact. just seems like they're the best and only option rn!
they gave me a referral link for 10% off: www.rimpactmtb.com/referral/UhykLsUCfici?utm_source=referral_program (hope this is kosher to share)
for the record, I'm in no way affiliated w/ Rimpact. just seems like they're the best and only option rn!
they gave me a referral link for 10% off: www.rimpactmtb.com/referral/UhykLsUCfici?utm_source=referral_program (hope this is kosher to share)
mhueschen
New Member
unless they changed stance since I last heard from the Ochain rep, they won't support Avinox... otherwise I'd prob go with Ochain.
You on the vivid air ?
I'd look there first before a chain damper.
On my dreadnaught, the chain damper did little, but changing to the ext coil was a massive improvement. Calmed the bike considerably.
John_likes_bikes
Well-known member
With the 1 million Avinox bikes hitting the market I hope that stance changes. I'd take a chainring style over hub any day.
slickrock
Well-known member
- Thread starter
- #169
One thing that can be said about Rimpact is at least their marketing posits their product as a "chain damping device" rather than an anti-pedal kickback device. In their FAQ, I found this one the most telling:
Does it work on a Hardtail too?
Yes, and arguably offers even more benefit due to the harshness of the solid rear end on Hardtails.
Needless to say their ain't much suspension-induced kickback with a hardtail.
Still would prefer Ochain's elastomers over Rimpacts springs, but we all know about SRAM's stance on ceeding to Avinox.
Wouldn’t the chain pulling on the chainring from chain slap and/or suspension travel cause “pedal kickback” either way. So really the term anti pedal kickback applies to either situation and is what these devices are looking to eliminate.
slickrock
Well-known member
- Thread starter
- #171
Perhaps we should use the term Pedal Feedback instead of Pedal Kickback.
Agreed, in that sensation at the pedals is sensation at the pedals, no matter what it comes from. The problem is that the sources could be many and the sensation itself is subjective. This is why some people insist that these devices help with kickback while others say its nominal or not worth it at all, depending on their bike suspension design (pivot location, chain length, chain growth), size, geometry,travel, riding terrain, shock choice and setup, whether you they the brakes, and of course their sensitivity feeling at the pedals.
But term "pedal kickback" is less subjective, as it's tied to an actual kinematic effect that shows up in kinematic graphs, specifically "kickback graphs" what are shown along with AS, AR, LR, and wheel path graphs. The kickback graphs show the direct consequence of kickback activation over it's travel, so this is real. There is also rotational kickback, having to do diameter differences between front chainring and rear sprocket, but this tends to be much smaller than suspension kickback. So at least this much we can hang our hat on, but then again, how much does this really affect the sensation at the pedals, or are chain whipping effects a larger or at least shared factor. My callout was just that Rimpact is pushing the latter to the top.
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John_likes_bikes
Well-known member
The clutch on the new SRAM XX DH derailleur looks magical, little to no chain whip. WIsh I could get away with a DH cassette range.
mhueschen
New Member
hey thanks for the suggestion. I'm running a Vorsprung Telum. it's impressed me a lot and is quite smooth. maybe has had the opposite effect of inducing me to chase that last bit of pedal feedback!
for me it really just seems to be the kickback from a 72t DT 240 DEG hub on low/moderate speed chop. whipping effects feel minimal with the idler. but I can hear the ratchet engage and clunk when slow-clanking over stuff
John_likes_bikes
Well-known member
I don't know if where I ride a max 24t ring DH cassette would cut it without sucking battery life but a boy can dream. The XD slim driver is interesting for a potentially stronger rear wheels. I don't know if the jumps are possible with a short cage but a 12-50t, 7 speed would be the bee knees for a emtb
Has anyone tried. DEG DF system with an avinox motor yet? I’m leaning in that direction as ochain doesn’t support dji probably due to the insane torque and likelihood to destroy it and I tried a sidekick in a parking lot and it felt horrible and I just prefer reliability of DT
I guess that’s fair, I’m not sure which setting it was on. Just pedaling felt really sloppy since I’m used to high engagement hubs but I guess that slop is going to be present in any of the hub systems depending on the float it’s set to.
mhueschen
New Member
just a guess - it's possible you were experiencing the gear ratio effect of hub based PK solutions.
if you're on a 52t granny with a 34t chainring, 12deg "float" at the hub turns into 18ish degrees at the cranks. in smaller cogs it will have less float at the cranks.
thanks.Could always use DT 240 or 350 hubs' DF Technology.
after looking into hub-based anti-PK solutions a bunch this week, my current feeling is that a crank-spider PK solution is more preferable for me:
1) hub-based degrees of freedom (DF) need to be multiplied by the gear ratio to determine crank-based degrees of freedom. a Sidekick with 12deg at the hub turns into 18deg at the crank in a 52t granny on a 34t chainring. that is a huge amount in my experience - having run an Ochain I found I liked 6deg and...
