High performance & durability Cannondale Semi Recumbent

[neptronix]

Oof, that is a very small bike.
I can't imagine how wiggly such a bike would be with such a short wheelbase.
I've tested out a few bikes like that before and came back feeling that even the large ones don't feel confident even at lower speeds.

The real thing that keeps me hooked on the idea of using a CLWB is the long wheelbase and how they ride/steer like a car. It's very hard for the bike's balance to be disrupted by anything. Just needs bigger wheels so that potholes don't disrupt the front..

 

[maiz]

Oof, that is a very small bike.
I can't imagine how wiggly such a bike would be with such a short wheelbase.
I've tested out a few bikes like that before and came back feeling that even the large ones don't feel confident even at lower speeds.

The real thing that keeps me hooked on the idea of using a CLWB is the long wheelbase and how they ride/steer like a car. It's very hard for the bike's balance to be disrupted by anything. Just needs bigger wheels so that potholes don't disrupt the front..

did you ever ride the bacchetta Cafe? designed by Mark stonich, who also came to the conclusion that clwb bikes were the answer. I keep an eye on craigslist, hoping I luck out

 

[neptronix]

No, and looking at the bachetta, i see why i haven't ridden it, no suspension. That'd be no fun to ride in pothole/mud/irregular road surface/1 inch curb lip country

Tell me more about this Mark Stonich dude.


I'm over here coming up with a good plot on how i can free up 50 sq ft in my office to put another ride together. It's been way too long.

 

[maiz]

No, and looking at the bachetta, i see why i haven't ridden it, no suspension. That'd be no fun to ride in pothole/mud/irregular road pattern/suddenly you have no road and must ride in the dirt and rocks country

Tell me more about this Mark Stonich dude.


I'm over here coming up with a good plot on how i can free up 50 sq ft in my office to put another ride together.

kind of a pioneer in the short crank for recumbent space.

https://bikesmithdesign.com/

you're right about suspension tho.

 

[qwerkus]

Oof, that is a very small bike.
I can't imagine how wiggly such a bike would be with such a short wheelbase.
I've tested out a few bikes like that before and came back feeling that even the large ones don't feel confident even at lower speeds.

Actually it's 100cm on that bike which is the same as most tour/trekking bikes. If it's too wiggly, you can always go for a steering stabilizer, but I would not recommend it: https://www.kidscab.be/en/kidscab-child-transportbike-accessories/1703-cargo-bike-steering-damper.html
It think a great deal of stability is conferred to those bikes just by lowering the center of gravity in comparison to upright bikes. Also, on bikes like the toxy, weight distribution is better balanced between the two wheels, which mean better handling on loose or steep ground.

 

[neptronix]

Ahh but both my cannondale and maxaraya recumbent have a 57 inch ( 144cm ) wheelbase, so 44% more wheelbase. That's a big difference, and equivalent to the wheelbase of a mid sized motorcycle. Now we're not far from the ~200cm wheelbase of a smart car :lol:

TBH i absolutely love the handling quality of the large wheelbase, it always feels solid and safe. I just can't do a short wheelbase anymore.

But a non-compact wheelbase is just a little too far in the direction of being long!!



Too short of a wheelbase however, can be quite bad. I don't trust my standard size bikeE beyond 30mph, it just isn't stable enough, but also, a 6 foot tall person shouldn't be riding such a small bike anyway.

 

[neptronix]

kind of a pioneer in the short crank for recumbent space.

https://bikesmithdesign.com/

you're right about suspension tho.

Thanks for the link!

 

[qwerkus]

TBH i absolutely love the handling quality of the large wheelbase, it always feels solid and safe. I just can't do a short wheelbase anymore.

Agreed; on my utopia bike it's also 144cm. Yet I have to agree with Atos62 when he writes about weight distribution vs handling on those semi recumbent. It's just terrible. On a steep hill with 20+ kg luggage and a battery, I can almost feel the front wheel leaving the pavement. Hence my search for something with a better weight distribution. So far the best I found are the german flux s900 with 115cm wheelbase: https://flux-fahrraeder.de/produkte/s9-ol-ul-sm/ and the spirit with 125cm http://www.sinnerbikes.com/pdf/Spirit%20specificatiesDE.pdf

Though I muss say that I love the fold ability of the toxy!

So you're up to 3 semis ? And not one fulfills all requirements ?

EDIT: How about this one:


Funny how many of those semi and recumbents the germans make...

 

[neptronix]

I have to agree with Atos62 when he writes about weight distribution vs handling on those semi recumbent. It's just terrible. On a steep hill with 20+ kg luggage and a battery, I can almost feel the front wheel leaving the pavement.

It's to be expected when any amount of your storage is behind the wheel axis.
Unfortunate, but.. that's going to compound the weight distribution problem.

So you're up to 3 semis ? And not one fulfills all requirements ?

2 require machining to get things right ( i don't have the time/space/tools/people willing to do it ), 1 is too small.

EDIT: How about this one:


Funny how many of those semi and recumbents the germans make...

Bad:
+ That front fork is at quite the angle and i don't expect it to survive a Utah pothole.
+ The weight balance looks worse than our CLWBs.
+ The use of a chain guide is a hack that makes up for some poor design choices.
+ No seat back?
+ Looks like riding it involves hunching over?

Good:
+ It has a front rack.

 

[Warren]

Ahh but both my cannondale and maxaraya recumbent have a 57 inch ( 144cm ) wheelbase,

But a non-compact wheelbase is just a little too far in the direction of being long!!

Yeah. My Linear, and RANS Screamer, are both too long for anybody not living out in the boonies, like us. For most uses, including city, I think 58"-62" WB is about perfect.

Back in the 1990's, a German engineering professor had his students design the perfect recumbent. This was a multi-year project. Their final answer was a 60" WB with a 406 mm front, and a 559 mm rear. The cranks were directly over the front axle, for better front wheel loading, and zero pedal steer.

Here is the design for an electric recumbent motorcycle, from Royce Creasy the British FF motorcycle guru.

https://bikeweb.com/node/3434

 

[qwerkus]

Bad:
+ That front fork is at quite the angle and i don't expect it to survive a Utah pothole.
+ The weight balance looks worse than our CLWBs.
+ The use of a chain guide is a hack that makes up for some poor design choices.
+ No seat back?
+ Looks like riding it involves hunching over?

Good:
+ It has a front rack.

I wouldn't be so quick to dismiss it. The guy building them has been doing so since 1986. He won multiple prices for the fastest and sturdiest semi-recumbent. Here is the classic model with less aggressive steering:



Front fork is hand welded cromoly with elastomer suspension. Apparently it's sturdier than many modern air/oil stanchion forks. Here is an example of tandem use: same frame, same fork - no issues.



The unloaded frame is balanced in a way that if you carry it by the handlebar, front and rear weight the same so you can quickly flip it. Once you sit on it, the front rack is planned to be loaded such as to balance the weight of the riders body. Ideal place for a battery and luggage.

Seat choice is governed by the idea of a quickly dismountable bike that fits into a car. The low handlebar has racing in mind. I agree that I would never ride on such a thing. Fortunately, there is a possibility to mount a full fleged seat. A different seat will also change the riding position and I think a longer Handlebar support tube would also be more comfy.

And finally the chain guide tubes: I'm no fan of those either, but it seems all performance recumbent now use them. I had a nice mail exchange with a guy from velomo.eu (they hold the current title of the lightest and fastest recumbent) who explained me that those tube are actually more efficient than pulleys or a 2 axle system like on the easy rider. They allow for some flex in the chain and if correctly setup, there is very little noticeable drag. Though I have to admit that this "correct setup" can be a pain, like on my utopia.

I don't want to sell you a bike I don't know personally. Just pointing that keeping an open mind might actually result in unexpected solutions. My plan for the next months is to try a many non orthodox bike geometries as possible, hoping to find the best one for my body and its limitations! If you're interested and have some spare time/cash next year you can visit the https://spezialradmesse.de fair in Germany. It hosts the largest concentration of unusual bikes in the world. IIRC even the ebikes.ca team once exposed there.

 

[neptronix]

Yeah, poorer weight bias is built into the bike, and that's a huge problem.. install an aftermarket seat and tilt it back and you've got a serious wheelie problem on even pedal power. You're about a foot behind where i sit on my bikes.. that's bad.

The backwards tilted position is super comfortable and improves the aerodynamics, so i wouldn't be able to give that up.
Elastomer suspension is nice, but not up to the duty of handling my roads at high speeds.
That fork looks a lot less like it'd snap on a high speed pothole.

The constant noise from the chain guide would drive me bonkers even if it is a little more efficient.

Thanks for the suggestion, but i know the bike wouldn't work out for me.

Honestly i have no hope for a bit longer CLWB with proper full suspension; i think the bike i want doesn't exist and has to be fabricated or created from an existing one.


I'd consider a front hub motor on the cannondale since it has a chromoly fork with no functioning brake currently. But i've only seen one person doing that and being happy with it. My last experience with a front hub motor and a bike with bad weight distribution involved lots of front wheel slippage.

 

[qwerkus]

Honestly i have no hope for a bit longer CLWB with proper full suspension; i think the bike i want doesn't exist and has to be fabricated or created from an existing one.

Do you have a drawing ? Would be interesting to see if it can be built.

I'd consider a front hub motor on the cannondale since it has a chromoly fork with no functioning brake currently. But i've only seen one person doing that and being happy with it. My last experience with a front hub motor and a bike with bad weight distribution involved lots of front wheel slippage.

I have the sx1 up front on my utopia an can confirm that handling improves up to a certain rack load and/or slope steepness. Than it starts slipping. It works better than expected though, especially in terms of battery mileage.

 

[neptronix]

I want the cannondale with a 1ft longer rear swingarm. That's it :lol:


Yeah i figured the front motor was only a partial fix. Maybe the ideal CLWB motor to help rebalance the weight is a 30mm leafmotor ( 15lbs ), plus a motorcycle tire ( +3lbs easily ).

Unfortunately for safety, we'd have to go with a chromoly front fork instead of suspension though. And it is a bummer to lose that high speed potential for the sake of a front rear hub.

Normally i'd pick the grin all axle motor ( very light ), but we want the heavier 30mm wide leaf because that extra metal is good insurance against heat exhaustion, and good ballast

I think the Atos62 way of mounting the battery here is on the right track.. maybe we get closer to CLWB nirvana with that plus a front DD hub.

So take that 15lbs 1000w rated front hub ( probably underrated and more like ~1100w )
...then add a 12lbs battery ( 1kwhr ) as far forward as you can get it.
..30lbs so far
...then add on:
+ Bigass headlight ( 1 lb )
+ Your controller and other electronics stuff ( 1lb? )
+ A metal structure for mounting a fairing in the future ( 3lb )
And we're +35lbs up front which is pretty decent.

So, handling wise..
I've ridden the bikeE ( no front suspension, but chromoly front fork and great rear suspension ) and with it's 16" wheel, the front end starts to have bad NVH @ 30mph.

I'm thinking that the cannondale with a 20" front wheel, chromoly fork, motorcycle tire, and hub weight should reach at least 35mph before NVH gets bad due to the extra rubber up front acting as a suspension in itself + the larger wheel diameter.

35mph is OK, because 45mph can be reserved for short bursts when i need it ( the ever frequent sudden disappearance of the bike lane in my area ), and i usually cruise along at 30mph, so the ride should be smooth 75% of the time and that's 'good enough for now'.

This might be feasible but i still don't like the idea of a front motor :lol:

 

[uhmwpolyethylene]

.

Estimated completion date is fall of this year, maybe earlier.. depending on how the surgery goes.

Reading from your first post to this was a real saga. Did you ever find lightweight 16" fattish scooter tires. Was thinking of some odd ideas like a non folding hyper narrow bike custom fabricated , or a full size bike with long forks and either with 20x2.3 or 20x4 for the narrow one to disassemble and put in a trunk or bus. Only 20x4 puncture protection though are heavy ahh tannus armor inserts although you can run those tubeless. Some type of 20x2.3 tire that just fits on a bus rack slot and has integrated lightweight foam guard would be good but schwalbe doesn't make them that wide , idk about some kind of Enduro BMX tire designed to handle burrs and thorns. I'm afraid of that and city micro glass shards. Jackrabbit uses 1.9 and 2.5. Maybe I could custom fabricated something with a real low double diamond titanium or steel shape with a reinforced downtube for a mid drive, wide forks that accommodate BMX or fat 20 tires, and some type of long stable telescoping seatpost and handlebars . Something with a strida ride geometry and not a piece of junk with plastic 18" wheels that accommodates a tall rider. Maybe aero bars to accommodate the geometry

Love your semi recumbent idea too, something that slots onto a bus would be good

The chimera eBMX is pretty impressive too 24" not sure if it fits schwalbe but the motor is 8lb and puts out 1000x4000w Electric BMX on Instagram: "Ryan Williams backflips electric BMX"

 

[neptronix]

Reading from your first post to this was a real saga.

Yeah i'm sorry there wasn't an awesome ending!

Did you ever find lightweight 16" fattish scooter tires.

They come in all shapes and sizes, almost like bike tires.
Check treatland.tv for a good supply.

Only 20x4 puncture protection though are heavy ahh tannus armor inserts although you can run those tubeless. Some type of 20x2.3 tire that just fits on a bus rack slot and has integrated lightweight foam guard would be good but schwalbe doesn't make them that wide , idk about some kind of Enduro BMX tire designed to handle burrs and thorns.

I don't know, dude, everything i have tried in the bike tire arena just hasn't worked. The goatheads in Utah are often longer than the maximum protection layer, and it just goes right through.

I have never ridden a tannis armor but i hear the ride quality is not good at high speeds from a bunch of local mountain bikers, so given we're building an ebike i feel like that's possibly rickety and disappointing.

The only cure for such a hardcore situation is:
1) more rubber
2) harder rubber

I've kind of considered just building an upright bike with a 22" BMX rim ( with a 18" moto tire = 23" equivalent ) in the rear and 26" up front and getting on with life because the semi recumbents have been such a huge pain in the ass; just not conducive to building a really killer ebike unless you have fabrication abilities i think.

The really frustrating part is that the handling and comfort on them is *killer*

Love your semi recumbent idea too, something that slots onto a bus would be good

A semi recumbent on a bus seems like a pipe dream for the most part, hehe. They're just so long.

BMX bikes.. for me.. just have too short of a wheelbase to feel confident at the high speeds i like to travel

 

[uhmwpolyethylene]

Yeah i'm sorry there wasn't an awesome ending!



They come in all shapes and sizes, almost like bike tires.
Check treatland.tv for a good supply.



I don't know, dude, everything i have tried in the bike tire arena just hasn't worked. The goatheads in Utah are often longer than the maximum protection layer, and it just goes right through.

I have never ridden a tannis armor but i hear the ride quality is not good at high speeds from a bunch of local mountain bikers, so given we're building an ebike i feel like that's possibly rickety and disappointing.

The only cure for such a hardcore situation is:
1) more rubber
2) harder rubber

I've kind of considered just building an upright bike with a 22" BMX rim ( with a 18" moto tire = 23" equivalent ) in the rear and 26" up front and getting on with life because the semi recumbents have been such a huge pain in the ass; just not conducive to building a really killer ebike unless you have fabrication abilities i think.

The really frustrating part is that the handling and comfort on them is *killer*



A semi recumbent on a bus seems like a pipe dream for the most part, hehe. They're just so long.

BMX bikes.. for me.. just have too short of a wheelbase to feel confident at the high speeds i like to travel

I guess only their MTB ones run tubeless also. And they don't make 16". 16x4 seems so ideal but moped tires are far too heavy. I think there is one company making 20x4 tubeless dunno about rims.


I guess tubeless acts like slime and seals up glass type stuff. They say also Tannus shreds up your inner tube and ruins your tire. My friends fatbike chaoyang type tires with Tannus armor and inner tube are heavy as hell but you need schwalbe,Tannus, or tubeless latex imo

 

[amberwolf]

And they don't make 16". 16x4 seems so ideal but moped tires are far too heavy.

They're heavy because they're thicker...which means greater flat protection because the stuff has to go thru more tire thickness.

This one thing has saved me many flat repairs on the SB Cruiser's heavily-loaded rear wheels over the years, using the Shinko 2.25x16 SR714's.

I also use thick MC/moped tubes (Bikemaster, which so far have all been CST-made, the best rubber brand I have found so far), and use a old one slit circumferentially on the valve-side seam, minus the valve and thicker rubber dome around it (to make room for the actual tube's valve stuff), between the actual tube and the tire.

Very little has made it thru so far, and even a roofing nail has not gone thru; it was deflected out the sidewall!

I've actually had more problems from tube failures (tiny splits at the seam) than punctures. I had a >half-inch long mesquite or paloverde thorn that was just a slow leak until I pulled it out; the thickness of all that rubber held it in place pretty well like a plug. PIece of glass took a chunk out of the tread all the way thru to the "outer" tube but dind't make it to the actual innertube with the air, so caused no problems. Etc. Whenever I examine the tread, I find quite a few steel wire pieces (out of car tires) embedded in it, but none make it thru to the actual tube.

Without all that thickness of rubber (and weight), I'd've had probably dozens of flats in those years instead of a handful (most of which did not require a roadside stop to fix, as they leaked slowly enough to let me get home (or to work) to fix them there.


But how you choose to deal with flat protection (if you need it) is up to you.

 

[Papa]

I have also considered a 20" no suspension chromoly fork up front.. my only concern is that i see a lot of long rakes on recumbent forks.. from what i understand, the more rake, the twitchier the bike is. The less rake, the more stable it as at high speed ( what i want! ).

Actually... high speed handling stability involves much more than just 'rake'.

1. CWB & LWB Recumbents benefit from a moderate amount of positive tiller - i.e. grips rearward 4-6" aft of the steering axis. This alone reduces sensitivity and improves steering self-centering by the rearward weighting (pulling) of the rider's arms on the grips, induced naturally because the rider is lower and further rearward of the steering axis. On MTB and road bikes, it's just the opposite because the rider is upright and usually pushing forward on the grips, necessitating negative tiller (note the forward extended goose-neck onmost bikes, which places the grips forward of the steering axis).

2. Rake alone doesn't mean much without considering "trail". A knowledgeable fellow by the name of Archibald Sharp stated that 'trail' was employed solely to allow hands-free riding - and I agree with him. That said, on my builds I generally try to eliminate 'trail', but if I do decide to add, it's never more than 0.5" (12.7mm). I'm NOT an hands-free advocate. First, I design-in the required amount of steering axis angle, based solely on the egronomics of the primary rider, then dial-in just enough fork rake to minimise or eliminate trail completely.

3. Increasing wheelbase (WB), generally improves handling at elevated speeds. Why?... because It requires MORE steering input to initiate a defined rotational arc, given the same speed compared to a short wheelbase, which requires LESS steering input (making it more sensitive to control at speed, but easier than the LWB to maintain balance at slower speeds).

4. Weight distribution. This gets a little tricker, because a two wheeled bike is a 'tilting' single-track-vehicle, requiring different design parameters. Optimum is usually close to 50f/50r, but generally requires a higher placed, vertical CoG than a non-tilting multitrack-vehicle. Placing the CoG too far aft, say 70r/30f for example, forces the rider to initiate more exaggerated and abrupt steering correcctions to maintain balance (because the CoG is further from the front tire's contact patch). Rearward bias WD also reduces the front tire's contact patch grip, potentially causing complete steering loss on sub-par surfaces.

 

[Chalo]

Rake alone doesn't mean much without considering "trail". A knowledgeable fellow by the name of Archibald Sharp stated that 'trail' was employed solely to allow hands-free riding - and I agree with him. That said, on my builds I generally try to eliminate 'trail', but if I do decide to add, it's never more than 0.5" (12.7mm). I'm NOT an hands-free advocate. First, I design-in the required amount of steering axis angle, based solely on the egronomics of the primary rider, then dial-in just enough fork rake to minimise or eliminate trail completely.

Fork rake (more accurately, fork offset) and head angle are a system. The slacker the head angle, the larger the wheel, the more offset you need to achieve neutral handling. Trikes need zero to very short trail such as you suggest (a topic in its own right), but bikes need some, so that bumps don't apply reverse caster and dump you suddenly.

"Low trail" for a bike is typically 35mm or so. It works very well at low speeds and with high front wheel weight, but gets vague and squirrelly as speeds increase. The rougher the surface, the higher the speed, the more trail is necessary to maintain stability. But this comes at the expense of low speed manners.

Excessive trail, like modern mountain bikes have, also prevents no-hands riding just like inadequate trail.

Recumbents all handle so atrociously compared to real bikes that they are a poor laboratory for variations in steering geometry. But the same general principles apply, just with less reward for getting things right.

 

[Papa]

.... (a topic in its own right),..

Much of the dynamics I stated previously, were aimed primarily at recumbents, However, I agree... and to include, that most, if not all, of the topics discussed, justifiably deserve their own cozy thread. Lemme know... I'll be more than eager to pull-up-a-chair.

Recumbents all handle so atrociously compared to real bikes that they are a poor laboratory for variations in steering geometry.

No doubt... yet another opinion - and I lack the foolishness to try and convince you otherwise.

I ride recumbents exclusively... because I physically cannot tolerate a 'real' (in your words) bicycle for longer than 5 minutes tops. At age 14, I pulled a stupid stunt (on a 'real' bike, no less) that damn near cost me my life. It took some time, but I was finally able to regain my reckless attitude... except for one diminutive detail, no more bicycles, no more motorcycles - the discomfort was just too severe. To say I was perturbed, would be a monumental understatement. Then the discovery... you know, those weird looking contraptions referred to as 'bents. At my tender age, the cost of admission was much too steep, so I crafted... because I knew I could.

Not only has 'bents resurrected my love for pedal powered wheels, but they have also spawned many, many souls,.. suffering from similar past experiences. I know, because they cross my threshold daily. And yes... they have 'opinions' too.

 

[AnthonyC]

Recumbents all handle so atrociously compared to real bikes that they are a poor laboratory for variations in steering geometry. But the same general principles apply, just with less reward for getting things right.

Some 'bents I cannot ride but... have you actually tried a Streetmachine with USS? It's stable to around 50mph and my wobble speed is well under 2mph, it's good in sidewinds, on cobbles, gravel and fist-sized stony tracks. What evils await me? The Greenmachine is another, it's pitched as a stylish commuter but on demo it handled superbly.

 

[Cowardlyduck]

Yeah, we can all ignore Chalo's comments on recumbent's I think...he clearly has something against them while the rest of us enjoy using them without issue.
I also have a number of semi-recumbents with both long and short wheel bases, one of which is setup for very rough terrain and regularly gets over half a meter of air without issue.

Cheers

 

[nicobie]

regularly gets over half a meter of air without issue.

 

[neptronix]

I second what cowardlyduck has to say, my cannondale is the most confident thing i've ridden on two wheels.

Full recumbents and semi recumbents are totally different beasts. You can still use your upper body/torso to control a semi recumbent. It's also very forgiving if you start to lose control over the front wheel. Your turn radius sucks, but on the other hand, you have an advantage in the much lower center of gravity.

What i wouldn't want to do, while changing the fork, is to modify the original design too much since i don't know what i am doing with bike geometry. The stock ride is great - with the addition of wide BMX handlebars.