Which suspension design is better? Rising rate linkage or shocks only?

[meepmeepmayer]

See title. Which one is better?

Marty said in a video (forgot which one) that he thinks the rising rate linkage approach is better. Is there a reason for this? Does it depend on the implementation? Can the linkage do something the shocks alone cannot?

I do like the simplicity and robustness of the shock-only designs, so I'm wondering if there is a good reason for one or the other.

• Linkage suspension has the linkage in the back of the wheel, where one shock sits, providing the suspension action.
  Example wheels are the EX30, Master, T4, S22.
  
• A shock alone suspension has two suspension shocks directly between the motor+tire assembly and the rest of the wheel.
  Example wheels are the Sherman-S, Commander Pro, V13, V11 (a little different but fundamentally the same approach).
  (Sherman-S without battery packs)

[Eucner]

If you want to have a good mechanical suspension the linkage system is only option.

If you want to be sure to have spare parts after years of usage the linkage system is only option.

[Freeforester]

 

30 minutes ago, Eucner said:

If you want to have a good mechanical suspension the linkage system is only option.

If you want to be sure to have spare parts after years of usage the linkage system is only option.

 

What is to stop someone just buying a spare strut or two, financial considerations aside? it’s not as if proper linkage systems or decent shocks are free?

[level9]

Considering where we are at in EUC development.. the system that's the easiest to work on/maintain/upgrade would be the better one. That means linkage.

Once there is an EUC dealer around every corner that I can take my wheel in for a suspension tuneup and at low or no cost, then perhaps the other. Maybe.

[techyiam]

4 hours ago, meepmeepmayer said:

Is there a reason for this? Does it depend on the implementation? Can the linkage do something the shocks alone cannot?

Let say you like to ride on forest service type roads, but you also like do a drop here or a jump there. But you still want a comfortable ride and not bottom out. This can be accommodated perhaps by having extra long travel. However, an alternative could be to use regular suspension travel with rising rate links. Many prefer not to ride on too high pedal height. Generally speaking, longer suspension travel means higher pedal height. So a suspension with properly designed rising link suspension could be the route to go here.

On the other hand, for riders who only ride to only commute around town, many may be happy riding on suspension with fixed spring rate and normal suspension travel. (It could even be enhanced by putting in a progressively wound spring. But the end result is that it won't be able to compete with a competently designed rising rate link suspension system that can offer good small bump compliance and no bottoming out action on bigger drops or jumps at the same time.)

What we have seen since the arrival of suspension wheels, is that manufacturers have been struggling making sliders that have low stiction, low maintenance, and are also durable.

It is understandable, since this a tall order, especially under tight budgetary constraints. Look at MTB history and see how they have evolved over the decades from elastomer front forks to Marzocchi's, to now.

To be economically feasible, the cost effective approach would probably to borrow technology from another application, like mtb. 

Over the next years, perhaps the roller sliders in the S22 could prove it can go far, but only time will tell.

But for now, many are singing praise to the Sherman-S suspension. 

Edited January 23, 2023 by techyiam

[Roadpower]

Prior to owning a suspension wheel I would have said a mechanical linkage system but once I got a V11 and I was reading/watching the issues with mechanical I've come to the opinion that the basic issue with spring suspensions on a EUC is that they need more space than they are being given in order to have enough suspension travel, fluidity, lack of stiffness, and granularity of adjustment & capacity. A pneumatic system has some question marks about lifespan but I think that depends on whether or not you can refresh them with seal kits.

If I'm going to have a suspension wheel, I want it absorb as much of the harshness of the road as possible. Getting a suspension wheel that rides like a sports car isn't why I am buying a suspension wheel.

[Rawnei]

11 hours ago, meepmeepmayer said:

See title. Which one is better?

Marty said in a video (forgot which one) that he thinks the rising rate linkage approach is better. Is there a reason for this? Does it depend on the implementation? Can the linkage do something the shocks alone cannot?

I do like the simplicity and robustness of the shock-only designs, so I'm wondering if there is a good reason for one or the other.

• Linkage suspension has the linkage in the back of the wheel, where one shock sits, providing the suspension action.
  Example wheels are the EX30, Master, T4, S22.
   
• A shock alone suspension has two suspension shocks directly between the motor+tire assembly and the rest of the wheel.
  Example wheels are the Sherman-S, Commander Pro, V13, V11 (a little different but fundamentally the same approach).
  (Sherman-S without battery packs)

I like the idea of a linkage as long as it's well designed and have well thought out sliding mechanism, I think it makes maintenance and customization of the shock easier, with shocks only in middle it there are other challenges to consider.

[meepmeepmayer]

Thanks, everyone!

So as I understand it (and read a bit about linkage), they allow for fine-tuning the suspension resistance curve from the mostly linearly behaving shocks. So you can have a more sophisticated suspension if it's done right.

I'm surprised you guys prefer linkage from a maintenance standpoint. You'd think shock-only would be seen as better there? Less parts and all?

Anyways, the real critical part seem to be the sliders, and both suspension mechanisms depend on those, right?

So I guess the wheel and its particular implementation seem to count more than what type of suspension it has (with the wheels right now!), though a good linkage system seems to be the best in theory.

Edited January 23, 2023 by meepmeepmayer

[meepmeepmayer]

4 hours ago, Roadpower said:

If I'm going to have a suspension wheel, I want it absorb as much of the harshness of the road as possible. Getting a suspension wheel that rides like a sports car isn't why I am buying a suspension wheel.

That's a good argument! If shock-only has a glass ceiling kind of limitation, we might end up with linkage suspensions winning out long term.

Edited January 23, 2023 by meepmeepmayer
spelling

[meepmeepmayer]

New questions:

Are there nonlinear shocks?

Could you do an electromagnetic shock? Maybe even with adjustable/programmable resistance curve? Ideally with no/low power use. Would be cool to set the suspension in the app and have one (or two) otherwise no-maintenance shock(s).

[Rawnei]

4 minutes ago, meepmeepmayer said:

I'm surprised you guys prefer linkage from a maintenance standpoint. You'd think shock-only would be seen as better there? Less parts and all?

With linkage it's easier to access and remove the shock and even replace it for a proven, well known and well reviewed MTB shock if you prefer, otherwise you will have to trust the quality of in-house developed ones and be completely at the mercy of the EUC manufacturer for everything.

[Rawnei]

2 minutes ago, meepmeepmayer said:

New questions:

Are there nonlinear shocks?

Could you do an electromagnetic shock? Maybe even with adjustable/programmable resistance curve? Ideally with no/low power use. Would be cool to set the suspension in the app and have one (or two) otherwise no-maintenance shock(s).

Yes, air shocks are inherently progressive and you can install volume spacers to fine tune the progression, for spring shocks you can have progressive springs, linkage itself can be progressive.

[Paul A]

Maybe active suspension one day for EUCs...

[Eucner]

18 hours ago, Freeforester said:

What is to stop someone just buying a spare strut or two, financial considerations aside?

You would be well covered with two pairs of spare shocks and several seal kits. Begode brings new models and versions on the market such a fast pace, that it is good to purchase spares with the wheel. Inmotion, Veteran and Kingsong have longer product life cycles, so you can do it also later.

[Freeforester]

7 hours ago, meepmeepmayer said:

Thanks, everyone!

So as I understand it (and read a bit about linkage), they allow for fine-tuning the suspension resistance curve from the mostly linearly behaving shocks. So you can have a more sophisticated suspension if it's done right.

I'm surprised you guys prefer linkage from a maintenance standpoint. You'd think shock-only would be seen as better there? Less parts and all?

Anyways, the real critical part seem to be the sliders, and both suspension mechanisms depend on those, right?

So I guess the wheel and its particular implementation seem to count more than what type of suspension it has (with the wheels right now!), though a good linkage system seems to be the best in theory.

A good linkage system - is that currently available (stock) as a ‘thing’ on the wheels that run this type of system? From what I’ve read, they all seem to either have inherent design shortcomings and/or require a fair bit of tinkering, time which could otherwise be used as er, riding time? 

[Freeforester]

7 hours ago, Rawnei said:

With linkage it's easier to access and remove the shock and even replace it for a proven, well known and well reviewed MTB shock if you prefer, otherwise you will have to trust the quality of in-house developed ones and be completely at the mercy of the EUC manufacturer for everything.

How much easier, in your estimation? Sorry to play devil’s advocate, but, again, the tear downs I’ve read about for most of the linkage type wheels (Begode, KS S22) seem to show quite a bit of messing about trying to get shock units in and out of their respective linkages. As a prospective S ‘S’ rider in the next month, I have only a passing, academic interest in this, but have to say I personally see the prospect of swapping out a strut on the ‘S’ as a fairly straightforward fit job, ie not involving any pre-compression of the part or modification of shims, spacers, etc in order to implement a changeout. Genuinely interested, even though I’m unlikely ever to need to do so on a linkage unit, I think the processes as shown may even have subconsciously steered me toward settling on the ‘S’, not that any of the current Begode lineup nor the KS S22 were ever on my radar as possible next wheels.

[Rawnei]

42 minutes ago, Freeforester said:

How much easier, in your estimation? Sorry to play devil’s advocate, but, again, the tear downs I’ve read about for most of the linkage type wheels (Begode, KS S22) seem to show quite a bit of messing about trying to get shock units in and out of their respective linkages. As a prospective S ‘S’ rider in the next month, I have only a passing, academic interest in this, but have to say I personally see the prospect of swapping out a strut on the ‘S’ as a fairly straightforward fit job, ie not involving any pre-compression of the part or modification of shims, spacers, etc in order to implement a changeout. Genuinely interested, even though I’m unlikely ever to need to do so on a linkage unit, I think the processes as shown may even have subconsciously steered me toward settling on the ‘S’, not that any of the current Begode lineup nor the KS S22 were ever on my radar as possible next wheels.

S22 is the easiest wheel I ever worked with, removing the shock is very easy 5 (10 tops) minute job and I'm not exaggerating, same with the motor, again super easy, of course will take more time the first time since you are learning, video tutorials I've seen online are often not great as they disconnect more things than you have to.

Begode Master is a bit more work, assuming you already removed whatever fairing system you might have there are two options, either play it safe remove all 4 battery packs then it's pretty easy to remove the whole linkage and when that's done you have to remove the shock from the linkage, faster but not as safe is to put the wheel upside down and unscrew the two rear battery packs so they lay on the floor still connected to the wheel and then removing the shock, I don't know about the stock linkage as I only fiddled with it once but my Kuba linkage requires some fiddling with two very annoying screws to remove the shock from the linkage, all in all for me also removing the Grizzla fairings (which in itself is a bit fiddely diddely) I'm looking at maybe 10-15 minutes of work for that.

Installing everything back in is about the same amount of time once you are done with whatever you are doing.

Edited January 23, 2023 by Rawnei

[Tawpie]

I've not torn a BG wheel apart, but shock removal on S22 is as easy as it is on a MTB... lay it on its side, extend suspension, relieve pressure on coil, undo top and bottom shoulder bolts and it's out. You still have to press out the bushings from the shock itself, but that's no different than any other MTB. Spring change you only need to remove the bottom bolt and press out the bushings. Very simple.

[Planemo]

Linkages aren't 'better' or 'worse', it all depends what you are asking from your suspension installation in the available packaging you have.

Linkages and rising rate all came about due to motocross bikes needing more and more travel, and running 2 super long coil shocks each side of the swingarm just became messy, heavy and cumbersome. Linkages allowed all that travel to be condensed into a much shorter distance, allowing a small single shock to be mounted just ahead of the rear wheel, tucked away behind the engine. All of a sudden you had the entire rear end free from clutter, massively reduced weight and what weight you did have was now not only very low but also close to the CofG and henceforth it transformed motorbike suspension. Of course, road bikes don't really need the same system but its used mainly to free up the rear end for the massive exhausts and luggage/passenger capability that many do need.

The downside with linkages is that you now have many more moving parts. Each of those parts needs to have a roller bearing (or should do - unlike the crappy begode offerings), the whole shebang needs to have minimum friction and the entire setup themselves needs to be strong - theres an awful lot of leverage force being transmitted.

As with most engineering 101's, simplicity is king. Theres absolutely nothing wrong with either conventional coil/air shocks or indeed telescopic forks which is why if you can rely on them alone to solve your suspension requirements then it will always be the best solution. Less parts, less friction, less things to go wrong.

Taking the Sherman S, I think I would have preferred to have air in those forks mainly to allow rate adjustment (with tokens) but the overall idea is the best implementation I have seen thus far on EUC's. My only concern at the moment is torsional and fore/aft strength leading to undue wear on bushings/seals/stanchions but that concern could be proved wrong (I hope so).

I have no doubt that Veteran went coil simply because it's cheaper. Manufacturing costs to provide a reliable, low friction airtight seal for many 100's of miles aren't to be sniffed at. It's far easier to leave the internal surface of the stanchion rough-finished and just chuck a cheap coil spring in there.