Is my bike too heavy for my air shock?

[Transit Artist]

This is my first air shock. It's compressing well past the marked indicators as shown by the red elastic band's placement. I could't find much writing on DownHill/Trail shocks for heavy electric bikes but research within, (really over), what I could afford led me to RockShox Super Deluxe Ultimate (lock-out) RC2T Air Rear Shock 230 x 60 -C1. I have it filled near it's 300psi capacity, though the brief hiss upon releasing my pump valve likely loses more than I think. By RockShox calculator the red band shouldn't be moving below the middle markings so this is more than twice as much travel. The bike weighs 115, myself 180 pounds, top speed 28, sometimes jumps small mounds.

1. Is this dangerous? Can it pop mid-ride if I bottom out? Can that happen? I think it did once but it may have been the front I felt.
2. Should I have gone for higher psi or a different type of shock? The spring it came with was too rigid and these knobby wheels were hell on pavement. My focus is on a smooth ride through generous dumps, which it now has, so the feel is fine. Just too much range.
3. Are there less expensive options and/or shocks geared toward off-road ebiking for heavy frames? Being my first purchase and, at times, high stakes riding the generic options frightened me.

 

[neptronix]

You have 22" effective wheels, so any shock is going to articulate a lot more than if you had 26" or above, due to the small wheel diameter.
You need the longest shock you can fit. Luckily you have numerous mounting points that allow you to do that.

 

[PaPaSteve]

Just guessing ... judging from your pictures the swing arm leverage ratio looks rather extreme.
A typical ratio on a mountain bike is between 2 or 3 to one.
How to measure ?
Distance from the swing arm pivot to the shock mount bolt = "X"
Distance from the swing arm pivot to the wheel axle should not be more than "X" times 3

 

[OlderGiantFan]

300 PSI, right at the edge of the envelope and still it's bottoming out. Time to upgrade, definitely.

 

[offGridDownUnder]

Umm...

Who says this frame is built to handle jumps? What is the authority behind this, and are they reputable on that question?

If you can answer that, then you can ask them about what to do. If you can't answer that, are you so sure you want to do this?

I would not worry about "popping" the air-shock, I would be worried about jamming metal into my crotch if something breaks.

 

[gromike]

Yeah, if that bike is a stump jumper there appears to be many problems with that frame.
What's the model and make of your bike?

 

[Transit Artist]

Distance from the swing arm pivot to the shock mount bolt = "X"

Top or bottom mount? T'is extreme @ 180mm of travel.

You need the longest shock you can fit. Luckily you have numerous mounting points that allow you to do that.

I don't see how that addresses my concerns but to change the angle. Fill me in?

300 PSI, right at the edge of the envelope and still it's bottoming out. Time to upgrade, definitely.

Any recommendations made for heavy ebikes or just less expensive? According to RockShox calculator I should be at 30% sag not 90% where I'm at. I also misspoke, while I'm at 300psi, capacity may be 360. Been a minute since I installed it.

Umm...

Who says this frame is built to handle jumps?

I did. Month 7.

Yeah, if that bike is a stump jumper there appears to be many problems with that frame.

What are your perceived problems with the frame?

 

[gromike]

Biggest one is the rear "triangle". It looks wimpy.
This is what a decent rear end unpowered mountain bike looks like:

 

[Transit Artist]

Biggest one is the rear "triangle". It looks wimpy.

Still not gauging your concerns. Are you thinking it'll break? I have absolutely no concerns about the frame's strength.

 

[gromike]

Yes, if you ride technical. Average trail riding, maybe not.

 

[Transit Artist]

Yeah, I'm in a major metro so inner-city parks are best I get and things are relatively tame. I'm jumping piles of chipped christmas trees and buried logs, eating some ditches and bunny hopping off of tall curbs. Urban off-road. I do however wonder about maintaining the metal hinge. Things get squeaky back there and I've been hitting all three of the hinging screws visible here with WD's spray lithium grease.

 

[gromike]

And a true mountain bike:

 

[Transit Artist]

And a true mountain bike:
View attachment 387971

Looks far flimsier all round but for my center hinge's metal/material.

 

[OlderGiantFan]

Biggest one is the rear "triangle". It looks wimpy.

I don't even see a triangle. It looks more like a monoshock motorcycle swingarm. Such arrangements have roller bearings or the like, pushbike suspension has dedicated bearings too with neoprene bosses.
@Transit Artist You say "I've been hitting all three of the hinging screws visible here with WD's spray lithium grease." That doesn't sound like a proper suspension system at all? Are there any bearings back there? Did someone build this bike as a homemade or is a recognized brand?

 

[scianiac]

I mean I've seen worse designed suspensions but that one is up there. I would not be hitting anything very hard with it. As mentioned it's bottoming out because the leverage ratio is absurdly high, the shock mount is way way too close to the pivot. Also that whole swingarm is on that, what looks to be pretty small and narrow pivot point.

Bikes often use a swingarm which pivots at two points meaning you can make the whole setup lighter with small bearing joints because there isn't the leverage on the swingarm is spread over a wider base. Something like a dirt bike and some bikes use a swingarm that pivots in one place like that bike but the pivot is real wide, again to reduce leverage, just in the opposite axis. And those pivots are really beefy to deal with the stresses.

 

[PaPaSteve]

Yeah, I'm in a major metro so inner-city parks are best I get and things are relatively tame. I'm jumping piles of chipped christmas trees and buried logs, eating some ditches and bunny hopping off of tall curbs. Urban off-road. I do however wonder about maintaining the metal hinge. Things get squeaky back there and I've been hitting all three of the hinging screws visible here with WD's spray lithium grease.
View attachment 387968

This picture provides 2 clues :
1) Diameter of the spring wire appears enormous for a light vehicle . . . why ?
2) Distance between the swing arm pivot to shock bolt appears short.
The leverage ratio is too high for a bicycle rated shock.
Measure the distances to confirm.
Pivot to shock.
Pivot to axle.
Divide the large number by the smaller number, if it's higher then 3 then mechanically your shock choice won't work.

 

[OlderGiantFan]

@PaPaSteve Which shock? The one in the pic above is completely different to the one in the first post. Thread needs some explaining.

 

[PaPaSteve]

 

[gromike]

One picture is worth a thousand words.

 

[99t4]

Clearly not a serious offroad contender. No amount of fancy shock replacement can solve this suspension geometry design failure. The bike sure does look rad though! Maybe that's what it was designed for?

 

[OlderGiantFan]

Yeah, it's a Beast alright, it sorts says, "Get out the way or I'll stomp on you"