Spring seat suspension bouncing - is elastomer better?

[bananu7]

Yeah i don't want to go the tire route, you trade improvements in NVH for range.
I want a bike that's smooth with narrow tires on high pressure, and unfortunately we can't buy 750D rims yet.

That's an interesting statement considering that a lot of recent research is pointing to much less efficiency penalties for human riders than expected, on wider tyres in real world conditions - to the point where road racers are starting to use 40mm tyres on suboptimal surfaces. This is for pedaling, though, and not electric motors.

Would Your Road Bike Be Faster With Massive 40mm Tires? New Testing Challenges Old Assumptions.

A recent lab test suggests wide road tires outperform traditional options on most real-world surfaces.

www.bicycling.com

Isn't getting a more capable battery an option for the range? I would assume that wider, but slick tyres with moderate pressure could perform reasonably well in the efficiency department.

 

[neptronix]

I can see how slick + wide tires could be better, but i can't run those in my area, these are also way too lightweight for the terrain ( tons and tons of things that want to puncture your tire )

The bike is usually pedal powered and occasionally offroad, so a balance of grip, efficiency, strength, and low weight is most desirable.
I run a 38mm kinda-puncture proof gravel bike tire on the rear currently and it is a hair faster on pedal power than the similarly patterned 29 x 2.3" tires ( with much thinner rubber BTW ) that the the bike came with. That's why i think narrower tires are faster.

Ideally i'd use 750D wheels and 1-2mm narrower tires, because it's the diameter that's responsible for the extra speed, but this combination don't exist yet.

Battery technology is not up to my expectations of distance still, i have a 52v 20ah battery and it is not enough, so i'm all about choosing the most efficient components. I have big distances to cover out here at high speeds in the suburbs.

I also live in an environment where goatheads are common ( up to 11mm ) and the most efficient way to handle this is something akin to stans no-tubes. The wider the tire, the more of it i need, the more efficiency penalty i get. So my penalty for wide tires is higher.

In this thread i'm looking for the ultimate suspension addon in spite of my existing preferences + challenges.

 

[neptronix]

You probably want one of the runnier flavors for that application. The really thick stuff, like on the toilet seat, would probably be like glue and stop the travel altogether.

Oh really... i did not know they made grease that thick!

 

[bananu7]

Suspension and tyres aside, 20ah is what, 14s4p with 5000mAh 21700? In your large frame triangle you'd probably fit at least double that.

 

[neptronix]

True but i want to lower the size of fire i could potentially have since the bike must be parked in an apartment and also contains today's potentially flammable cells.

If i could get my hands on some early solid state or exceptionally high energy density sodium ion, it'd be a different story. I'm waiting for that day to come, hence the preference for large triangle

 

[AZeBikeGuy]

....So hey Thundbuster LT owners.. i don't know what the motion of this seatpost looks like but i'm wondering if it travels too far backwards on big hits.. or is it just fine?

Any gotchas? if not, i'll just order one

Long time (~10Kmi) on LT and that's not even remotely an issue, the direction of travel is ideal for me

 

[Chalo]

Long time (~10Kmi) on LT and that's not even remotely an issue, the direction of travel is ideal for me

It's worth noting that the rotation of the bike around the front hub (more or less) when the rear wheel hits a bump, makes the Thudbuster's suspension travel direction approximately tangential to the bike's movement. This is the way in which it's an improvement over a telescoping seatpost suspension, which moves at a very different angle than the impulse the bike gets from a rear wheel bump.

 

[neptronix]

Thanks!

 

[AZeBikeGuy]

It's worth noting that the rotation of the bike around the front hub (more or less) when the rear wheel hits a bump, makes the Thudbuster's suspension travel direction approximately tangential to the bike's movement. This is the way in which it's an improvement over a telescoping seatpost suspension, which moves at a very different angle than the impulse the bike gets from a rear wheel bump.

Good way of expressing it

 

[DingusMcGee]

Whine, whine, whine. If you need more cushioning from hitting pot holes, then stand up on the pedals just before the ass would get the impact. These isometric maneuvers will do more for lowering your blood pressure that hours of discussion about thud busters, elastomers etc.

 

[marka-ee]

I have a thudbuster seatpost on my hardtail bike as well. It really helps a lot, turns it into basically a halfway full suspension bike. I only do street riding with it, but it made a big difference. The rearward travel of the seat as it hits bumps takes a little bit getting used to, but then you don't notice it anymore. I highly recommend these devices.

 

[99t4]

If you need more cushioning from hitting pot holes, then stand up on the pedals just before the ass would get the impact.

Sure, that is obvious, but a rider cannot do that in all instances (poor visibility, hidden obstacles, other vehicles unexpectedly forcing rider into hazardous path). And not all riders are capable of timely weighting/unweighting manuevers.

 

[lnanek]

Technically, AirSeat does have a lump of rubber in the middle of the rear spring to act as a dampener. So it isn't all springs.

Re the lose weight comments, there's definitely more things that suspension can help with than brief bumps you can see ahead of time and stand up for. There's a 3 mile stretch of road that's had the smooth top layer of pavement removed for years on my commute, for example. Without various suspension hacks like a Spank SPIKE 800 Vibrocore Bar, I have to traverse it at half my full speed.

Otherwise my bike feels like it's shaking itself to pieces. I'm not going to stand up for 3 miles, and it wouldn't keep my steering as steady and electronics as damage free as suspension techniques anyway.

 

[neptronix]

Whine, whine, whine. If you need more cushioning from hitting pot holes, then stand up on the pedals just before the ass would get the impact. These isometric maneuvers will do more for lowering your blood pressure that hours of discussion about thud busters, elastomers etc.

Try my ride before you call me a wuss. Come visit me in Salt Lake.
35mph on roads with random 1-3 inch variances, just the crappiest roads you've ever seen ( unless you've been to Detroit )
On a hardtail bike.
You'll never be able to anticipate bumps, not even standing on the pedals will help, since you can't engage your muscles fast enough at this speed.

Why do i do 35mph? there's close to no bike lanes. You're holding up traffic if you don't go at least that fast. That's the minimum speed for >90% of the roads.

$100 says you'll be vey sore after and won't be able to go a second round.

A bonus $30 if you manage to not get a flat tire over this mileage because all of the goatheads and other pointy road hazards.

 

[harrisonpatm]

unless you've been to Detroit )

I ride in Detroit. Nep, do whatever you need to make your ride softer, lol

 

[neptronix]

I ride in Detroit. Nep, do whatever you need to make your ride softer, lol

Oof. Is a full suspension fat 29er even enough?

 

[harrisonpatm]

Oof. Is a full suspension fat 29er even enough?

I'm on a full-sized motorcycle with recently-rebuilt front forks and an upgraded rear mono suspension that comes from a 750cc sportbike... and its still rough.

 

[neptronix]

I imagine that the largest wheel size available on any motorcycle isn't big enough for these roads:



This looks like more of a job for a 32"-48" tractor wheel!

 

[amberwolf]

This looks like more of a job for a 32"-48" tractor wheel!

At 10mph.


If you would just stop sending out the 50 foot tall Pikachu to stomp pawprints into the asphalt when it's hot, it probably wouldn't be so bad.

 

[bananu7]

I imagine that the largest wheel size available on any motorcycle isn't big enough for these roads:

View attachment 368026

This looks like more of a job for a 32"-48" tractor wheel!

In my experience those kinds of roads do smooth out once you go a bit faster, as the motorbike starts flying over some of the holes. Needs a long wheelbase platform with good suspension you can trust, though.

Overall it seems that for your use case a small motorcycle could indeed be a more comfy and safe option, if you're getting mixed with both traffic and avoiding potholes. I really wouldn't want to a be a cyclist there.

 

[amberwolf]

In my experience those kinds of roads do smooth out once you go a bit faster, as the motorbike starts flying over some of the holes. Needs a long wheelbase platform with good suspension you can trust, though.

As long as you are going in a straight line...but maneuvering, such as traffic avoidance of morons, doesn't work out so well at higher speeds when your wheels aren't in continuous contact with the ground. :/

 

[bananu7]

As long as you are going in a straight line...but maneuvering, such as traffic avoidance of morons, doesn't work out so well at higher speeds when your wheels aren't in continuous contact with the ground. :/

Yeah, obviously I don't recommend that around traffic. It's a strategy that only works on long open straights. Still, a heavier vehicle will generally be more comfy and planted on such roads, I generally like looking out for damaged ones because cars avoid them and they're typically going around more scenic places. As long as there's noone else around it can be pretty fun dodging the potholes too.

But yeah, on a hardtail bicycle, mixed with traffic? Hard pass. I'd probably rather just ride parallel gravel/fire road even if that was slower.

 

[peadar]

Has anyone tryed small air bags to replace springs

 

[DingusMcGee]

Neptronix,

To your point about inferring that my post was claiming you were a “wuss’.. I said, “ whine, whine, whine” which is applicable to a complainer but I do not see such wording to imply you are a wuss?

I have owned and used Thudbusters. One of these TB’s was used on a “full suspension bike”. But even then that Cyclone 4k motor installed on their MTB was a one of a kind lousy MTB. Any other Full Suspension MTB offers a better ride that it did with the Thud buster mounted on the Cy4k.

I have seen the road photo of the potholes you ride over, daily? What are the circumstances that keep you from building a FS ebike? The early steel frame WalMart Hyper MTB likely maybe as cheap $$$ and as good as many of them out there would be for the conversion.

I have considered your offer of some $100 + to come to STL and ride your roads. My edirtbikes will handle that terrain at 35+mph. Rather than visit you and take your $$$ please invest your $$ in a good FS ebike build rather than whine and simply put a band-aid (seat cushion mechanism) on your ebike.

 

[bananu7]

Has anyone tryed small air bags to replace springs

Air-spring suspension is very common yes. Virtually all hi-end and midrange modern mountain bikes use air springs. Exceptions are entry level bikes and downhill bikes.