e-bike, only 7.66 kg including battery !

[kfong]

Wow, he's got money then. Can't take it with you when you die and at his age anything that makes a bike light is worth going after. I bet he feels like superman on that setup. As much as I like my ebike for the trails, it's still a heavy monstrosity in my eyes. My new DH build is heavier yet, and already not my choice for single track riding.

I'm guessing this engineer did hid own layup work and I'm sure he is confident that it will hold up.

It's a "thin-walled Scott Scale Carbon frame"...

 

[Chalo]

I'm guessing this engineer did hid own layup work and I'm sure he is confident that it will hold up.

It's a "thin-walled Scott Scale Carbon frame"...

Ah, so one of these, then.


Very confidence-inspiring.

Chalo

 

[kfong]

Even steel frame bikes break, but usually in a safer way. I was lucky that my jump wasn't larger.
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=6348&start=120

 

[spinningmagnets]

I can see a CF frame for a commuter in a city with smooth and well-maintained roads. I have to agree, though, about using CF on off-road, and streets with potholes and curbs I am forced to jump without warning (teen drivers texting).

I am sure if we look, we can find downhill CF frames available, ones that are MUCH stronger than the "Scott Scale" featured. Because of the power limits for E-bikes on the road, I think I caught a hint of a smirk in the article. "I only use the 400-watt mode when I am off-road (wink)". This bike is his third Guinness Book entry...this build was more about getting the award, rather than something he wants to spend the rest of his life riding.

If someone threw a boatload of cash at me to make a variety of frames for different types of E-bikes to sell to the public...I think I'd make them all Cro-Mo.

 

[Kin]

There are some rather robust CF mountain bike frames. A guy I know at work has a beautiful one, it's around 20 pounds (About the same as my 20" Alu folder), which blows my mind because half that weight has to be the tires and suspension. I wish I remembered the exact weight, but I do remember picking it up and just not believing the visual contrast between such a serious bike and the weight I felt. He says he's not sure if it was worth it though, because mountain biking you expect to fall a lot, and the frame doesn't deal well with compression as you smash into a rock (for reasons Chalo has detailed.) And it's like $16,000 .

 

[spinningmagnets]

The original writer of the article (Martin Platter) posted another pic:

 

[Lebowski]

the guy should write a follow-up article about my e-bike, a prime example of an e-bike everyone
can build in their garage using only a simple saw and drill

 

[fizzit]

Here's a test of carbon frames showing how well they hold up to stress in the various forms of impact that a frame can take in a crash.

[youtube]xreZdUBqpJs[/youtube]

They also try to destroy the frame by smashing it against a concrete block and this doesn't work out very well for them. I would say that the fact that this eBike has a carbon frame is not a strike against it.

 

[Chalo]

Here's a test of carbon frames showing how well they hold up to stress in the various forms of impact that a frame can take in a crash.
[...]
They also try to destroy the frame by smashing it against a concrete block and this doesn't work out very well for them. I would say that the fact that this eBike has a carbon frame is not a strike against it.

You know, or I guess you probably don't know, that the frame in the favorable video (tests contrived by the manufacturer, after all) weighs over six pounds without a fork. The Scott frame used by old German dude weighs less than two pounds without a fork.

That's exactly like comparing a sub three pound chromoly steel frame to an over nine pound chromoly steel frame. The latter, if well designed, should be approximately indestructible. The former would be disposable, if not outright dangerous to ride.

An e-bike built on a six pound carbon frame, with appropriately matching components, would be nice and strong. The typical build of a Santa Cruz Nomad bike weighs about 32 pounds or 14.5 kilograms without any e-assist equipment at all. That's close to double the weight, before any e-assist is added.

CFRP has some terrible intrinsic qualities that I have already described briefly. Its saving graces are excellent strength to weight ratio, relative immunity to fatigue cracking, and superb resistance to corrosion. But a sub two pound carbon MTB frame has all the shortcomings and scary fragility besides. It does not matter how good the material's strength to weight ratio is, if you simply don't have enough weight of material to make it strong.

Chalo

 

[Green Machine]

More information about the drive train of the bike posted on www.electricbike.com from author Martin Patter.

Yo`re right. There`s no freewheel at the crankset. It needs a little
practice to ride this bike according to the sense of its builder Mr.
Jean Pierre Schiltknecht. That`s the reason why the drivetrain only
starts by pressing the thump button (aka. throttle control) at the bell -
and not by pedaling like a common «pedelec». Without motorsupport the «Volta Montanara» rides similarly easy like an usual (very) lightweight Mountainbike. Beside the very low weight is that the reason for minimum power consumption.
For Schiltknecht it doesn`t make any sense to use the e-motor on flat or
downhill offroad sections - except in difficult lowspeed singletrails.

 

[Ypedal]

from author Martin Patter.
snip..
... it doesn`t make any sense to use the e-motor on flat ... snip...

Say whaaaaaa ? :lol:

 

[Hillhater]

I assume the motor pinion must have a free wheel, if it to be at all useable without power ?
Are we any wiser as to the make /type of motor which presumably has an integrated planetary reduction g'box ?

 

[deepfraught]

Yeah the motor/reduction seems to be the million dollar question.
I wouldn't mind direct drive on a mk1 to avoid complexity and quick test, using one single 6S 8Ah 1.1kg pack if it will do the trick, as it fits in a water bottle and weighs about as much as a large one.

I think he's riding with a one-crash body, so I don't think the carbon fibre is his biggest concern.
I don't think this electric kit in weight or power is pushing the frame more than a strong rider. Combined would he be doing this kind of output?

Wattbike Ranking

The Wattbike ranking is a good place to log scores and look at comparisons with other Wattbike users.

The current peak power ranking has a number of male entries over 1750W with a few over 2000W, for females there are a few entries in the range 1000-1250W.
For 60 minutes there are a limited number of entries so far but for males a few in the range 300-350 W.
We expect the 60 minute score to improve dramatically as more people attempt 60 minutes on a Wattbike.
We will shortly be amending the rankings data to include power to weight [P/Kg] as a ranking feature.

 

[deronmoped]

I have to agree with Chalo,

Not a very good bike at all. Well, except for bragging rights.

One poster mentioned that it's a good bike because he can ride it all day. Not if you use the power all the time. The only way you can ride it all day, is if you do almost all the work. Running the motor off road is going to burn through the watts really quickly. Were talking mountain biking here, hills, mud, soft soil... It's not like riding down a paved street.

I built a E-MTB and I would never dream of riding something that light. Suspension is really nice to have, a good seat to sit on is a must if your going to do a all day ride. A rack to carry a repair kit, drinks, lunch, lock... A substantial motor and drive train that will take years of abuse. A price tag that allows you to enjoy doing other things with your money.

 

[deepfraught]

There are two conversations going on here in circles that will not converge.
1. A Guinness Book world record holding lightest e-MTB reported in a positive way without critique.
2. People talking about practical bikes they would use, weighing up costs, maintenance, failures.

If I was competing with his record, I would be stripping it down to bare bones, take the win, then ride home on a massive Cloud9 seat, riser bar, stereo and all the things I use for comfort =D

Chalo has his opinions and credit is interesting discussion, but not as whimsical as the 74yo who has pulled this off, and has a history of similar.
He would fit in very well here. We don't debate the obvious unsuitability of 106kph e-bikes with 16sec 1/4 mile times or rain on parade of class winning bike at Pikes Peak with oiled direc drive budget hub.
This record inspires me like a Racquel Welch wet dream kind of way, while Chalo is the drill seargent at 4am throwing a bucket of cold water on the wet dream before sunrise telling you to rise in a different way and ride your steel horse up the mountain towing a septic tank while reciting notable sections from an official military charter =P

 

[kfong]

Don't forget the rider is 74yrs old, how hard can he still hit the trails. I'm sure it holds up well for his type of riding.

 

[Chalo]

I think you meant to say "world record trolling", not "riding".

That's a single-purpose vehicle.

 

[Dauntless]

Someday people will get over the obsession of building hollow frame carbon fiber. Might add close to a pound to some of these bikes to avoid some of those breaks such as Chalo illustrated. If you're NOT trying to win the Tour de France, it doesn't make sense to complain about the slight added weight.

As deepfraught says:

There are two conversations going on here in circles that will not converge.
1. A Guinness Book world record holding lightest e-MTB reported in a positive way without critique.
2. People talking about practical bikes they would use, weighing up costs, maintenance, failures.

Are the people with tunnel vision for the lightest bike going to get upset at the idea of that bike weighting a pound more and breaking less?

 

[neptronix]

Being the opposite of a weight weenie, this scares me

How 'bout a tiny 200-350w rear geared hubmotor on a carbon fiber frame with panasonic cells? Could make for a nice 27-30 pounder..

But i like heavy and durable when i'm going fast. Even if you could build such a thing on a decent budget, i'd not suggest anyone do it!

 

[deronmoped]

There are two conversations going on here in circles that will not converge.
1. A Guinness Book world record holding lightest e-MTB reported in a positive way without critique.
2. People talking about practical bikes they would use, weighing up costs, maintenance, failures.

If I was competing with his record, I would be stripping it down to bare bones, take the win, then ride home on a massive Cloud9 seat, riser bar, stereo and all the things I use for comfort =D

Chalo has his opinions and credit is interesting discussion, but not as whimsical as the 74yo who has pulled this off, and has a history of similar.
He would fit in very well here. We don't debate the obvious unsuitability of 106kph e-bikes with 16sec 1/4 mile times or rain on parade of class winning bike at Pikes Peak with oiled direc drive budget hub.
This record inspires me like a Racquel Welch wet dream kind of way, while Chalo is the drill seargent at 4am throwing a bucket of cold water on the wet dream before sunrise telling you to rise in a different way and ride your steel horse up the mountain towing a septic tank while reciting notable sections from an official military charter =P

Did you read the article?

He was bragging all about how nice the bike is, like it was his daily rider. Not something he built to break light weight records. Were just pointing out the downsides to sacrificing everything else to be lite.

Did you see the seat, that was the first thing I noticed. Damn, my seat weighs about as much as 1/3 of what his bike weights. I choose a seat according to what my ass was telling me over my years of bike riding. Not some record.

I looked real hard at trying to lower the weight of my bike. But there was just no practical way of doing it, on a budget. And keeping in mind, what made the bike practical.

I could of gotten rid of or changed these things: Rack, a pound or two. Nice comfy seat, a few pounds there. Suspension, five or six pounds there. Battery box, a pound or two there. Half my battery capacity, a few pounds there. Less substantial motor a few pounds there.

Anyways, when you have electric assist, the added weight is not that big of a deal. Not unless your so worried about lifting it over a cattle guard.

 

[deepfraught]

No, I didn't read the article

What you are saying is everything already said with 'i' and 'my' in front, and fits into #2 clearly (and I don't mean you taking a dump).

You may not have noticed the bike is pictured in record breaking minimalist spec. How I photograph my bike for global view, and how you see me on it any day of year, are two different things. I don't have all the girls from thefixfixfix carrying me on it like a Polynesian King for instance, but may have the man bag strap on.

 

[deepfraught]

Also, metal is about equally strong in any direction (anisotropic). Carbon is only strong in the direction the fibers are laid, meaning you're really riding an epoxy bike when it encounters any force it was not designed to withstand. Lack of off-axis strength and lack of ductility are why carbon bikes do this when they fail, and metal bikes don't:

Chalo

PS: It's material technology not religious opinion, you left out this bit of context for the off axis failure example:
"From Jeff:
after incident with a car at 35mph my bike is in pieces an I have multiple broken bones as result
Ouch."
http://www.bustedcarbon.com/2011/07/s-works-sl.html.

I was actually looking up this fork specs below for my Voodoo Sobo frame, found the alloy sheered steerer, after just mentioning to a friend heathyoung's alloy handlebar failure at 55kph+ on a pot hole, while considering what material to choose for a rigid front end that may take a hiding. It is half the weight of a more versatile Voodoo steel 29/26 vee/disc fork.
http://www.bustedcarbon.com/2009/09/specialized-tri-cross.html

After looking reviews of this flexible bendy plush alloy fork and wondering about the strange characteristics it has since I never had the feeling those qualities went with aluminium alloy, but couldn't see "Flubber" in its specs, makes me curious to want to try it.
http://www.chainreactioncycles.com/Reviews.aspx?ModelID=15348

Now just finding it hard to swallow that extra 700grams of steel goodness, I think the fork may have gone down sideways like a chicken bone =P

 

[Chalo]

Aluminum is 1/3 as stiff as steel, and also 1/3 as dense. (It tends to be about 1/3 as strong, too.) To make an aluminum fork just as stiff as a steel one, you either have to make all the tubing 3 times thicker walled (in which case, you lose any weight advantage), or you have to make it a different bigger shape. Since steer tubes are fixed in outside diameter and are already pretty thick where it matters, an aluminum steer tube is always less stiff than a steel one.

Carbon fiber itself is a lot stiffer than steel, but that's just along the direction of the fibers and it doesn't count the plastic matrix. So it can be stiffer or less stiff than steel or aluminum, depending on how the fibers are laid.

Metal bikes fail in many of the same situations that CFRP ones do, but they tend not to fly into splinters. They also tend to absorb some energy in the process.

 

[deepfraught]

Bringing this up as SpinningMagnets was disparaging my hero in the Bafang mid-drive thread.

Speaking of that guy, I'm still not following why use carbon crank arms

He was going for a Guinness Worlds Record, to be listed (for at least one year) as the lightest electric mountain bike. He got it. Light, yes, but...no suspension so it makes the claim of "mountain bike" a bit stretched.

Suggesting that it's not really a mountain bike and so less justified for its record because it doesn't have suspension didn't really make sense to me,
He lives in mountains.
He rides up mountains.
If you ride uphill, you often want to lock out suspension.
Suspension design works hard to stop pedal power losses through suspension... so no suspension isn't strange for a mountain bike.
In Switzerland the "offroad" is very strongly protected by harsh fines, so offroad motorcycling and offroad mountain biking across rough all-mountain terrain is not allowed, probably what you would be thinking of.
Like the picture of him below, their mountain biking is more like what we know as cross country mountain biking, light duty and not much more than adequate tyres required, someone else mountain biking similar looking surface and inclines:
http://en.wikipedia.org/wiki/File:Mountain-biker-climbs.jpg
Him

We have forum owners championed for their weight weenie home built builds just as this guy does (Kepler the latest greatest build thread I've noticed and seen widely championed by posters, that I also champion).
This guy shows it off with a Guinness World Record and gets a global golden shower. I think if he had posted it as a build thread to the forum he'd be cheered. I'd be disappointed if he was pointed to the thread and found a bad case of http://en.wikipedia.org/wiki/Tall_poppy_syndrome
Personally I think the same kudos and respect shown for fellow custom home grown hand made creations should be afforded to this guy, without the detracting remarks.

Taking off that fanboi groupie hat, Spinningmagnets is also a champion of ES so no disparaging sentiments intended from me to your tireless efforts on ES and your site

 

[fabiograssi]

This thread is about carbon fiber or about the bike?

Trying to return to the topic, who suggests something in million dollar question:

- motor kv?
- this setup has a motor reduction?
- what is the chain reduction?
- the motor sprocket has a freewheel?

I just love this setup. We have thousands of 70's bikers that loves to ride and have some kind of dificulties nowadays. But they have money and love the low weight bikes (not necessarilly CF).

Any oppinions?

- Fabio