Relatively long commute on gravel

[Saratoga Dave]

An 800 wh Giant battery? Is it reverse compatible with their other 500 wh bikes if you know?

And good lord, what does that thing weigh?

 

[DaveMatthews]

An 800 wh Giant battery? Is it reverse compatible with their other 500 wh bikes if you know?

And good lord, what does that thing weigh?

Hi Dave, it is compatible with "some" bikes. They are the ones that use the battery that mounts at the front of the downtube, not behind.
So it couldn't go on my previous Fathom, but does on the Stance.
The weight penalty is minimal as the cells are newer/more compact. Might be 1.5lbs more?

 

[Saratoga Dave]

Thanks Dave! Too bad for the Toughroad, we keep on at 500.

 

[Jeremy McCreary]

Then there's the gravel/dirt roads where the gravel size is larger and is often looser and accumulates in bunches. Older roads often have longer stretches of hard surface but are also pocked with pot holes or the really nasty washboard surfaces. Here there's a real tax on riding distance (probably adds 20% to the battery usage) and where front suspension certainly makes a big difference, both in terms of comfort and controllability at higher speeds.

Surprised to read in Bicyling Science (Wilson and Schmidt, 2020) that suspension also reduces total resistance on washboard.

The resistance added by a washboard surface can be huge. Suspension helps in 2 ways here — (1) by limiting the total mass raised on each on upstroke, and (2) by reducing the vibrational energy dissipated in the rider's body. Less dissipation within the rider+bike system means more energy recovered on the downstroke, and the body is the biggest sink by far.

 

[Stefan Mikes]

Surprised to read in Bicyling Science (Wilson and Schmidt, 2020) that suspension also reduces total resistance on washboard.

The resistance added by a washboard surface can be huge. Suspension helps in 2 ways here — (1) by limiting the total mass raised on each on upstroke, and (2) by reducing the vibrational energy dissipated in the rider's body. Less dissipation within the rider+bike system means more energy recovered on the downstroke, and the body is the biggest sink by far.

Certainly, it is true in the scientific terms. However, gravel cyclists would laugh at you if you even tried to tell them so (I was laughed at when I said "suspension stem" to my club members). Gravel cyclists are for 9 kg rigid bikes with the sole suspension provided by wide lowly inflated tubeless tyres. (Of course, e-bikes are not that lightweight).

 

[mclewis1]

Even the hyper weight conscious pros have dabbled with front suspension. There have been front suspension setups used on the pavés in the Tour de France and Paris Roubaix classic.

 

[Stefan Mikes]

Even the hyper weight conscious pros have dabbled with front suspension. There have been front suspension setups used on the pavés in the Tour de France and Paris Roubaix classic.

Which are road races, yes, involving cobblestone in the case of Paris Roubaix. If I were to ride cobblestone daily, I would get me a FS e-MTB for sure

Now, what suspension are you talking about? The Specialized Futureshock? Trek Isospeed? Cannondale has used a suspension fork in their Lefty for gravel bikes but the travel is just 20 mm there!

A smart idea indeed for over €1100

P.S. Specialized Roubaix is using Futureshock 2.0 which is indeed the suspension for handlebars.

 

[Jeremy McCreary]

Certainly, it is true in the scientific terms. However, gravel cyclists would laugh at you if you even tried to tell them so (I was laughed at when I said "suspension stem" to my club members). Gravel cyclists are for 9 kg rigid bikes with the sole suspension provided by wide lowly inflated tubeless tyres. (Of course, e-bikes are not that lightweight).

I live to be laughed at by gravel bikers.

Wilson and Schmidt also say that suspension is a net power loss in other circumstances I don't recall. Whether it's a net benefit energetically apparently depends on the ride, but there many other pros and cons to consider.

 

[Sparky731]

Electron range can be dramatically influenced by riding style. I have a class 3 Bosch motor with a 625w + 500w Range extender. The attached pix show the ECO vs. TURBO ranges on a full charge. Note: 6,700 miles on the batteries.
Gravel vs. pavement has little range effect per my experience.

 

[Stefan Mikes]

Wilson and Schmidt also say that suspension is a net power loss in other circumstances I don't recall. Whether it's a net benefit energetically apparently depends on the ride, but there many other pros and cons to consider.

I think the net power loss with the suspension is when there is the "pedal bob". Related to poor rear suspension.
Jeremy, the suspension can be locked in some situations: for instance it is beneficial to lock the suspension on the ascent. Does your book explain why?

 

[Jeremy McCreary]

I think the net power loss with the suspension is when there is the "pedal bob". Related to poor rear suspension.
Jeremy, the suspension can be locked in some situations: for instance it is beneficial to lock the suspension on the ascent. Does your book explain why?

Wilson and Schmidt had lot to say about vibration in cycling — with many practical implications. I recall seeing pedal bob, suspension lock-out in ascent, and suspension type and tuning but should reread before repeating.

What I can say now is that bike suspension (including that provided just by the tires and wheels) can make a lot of sense in certain settings.