dwells

I'm getting to the point where I'm considering an e-road bike, and I'm looking for the lightest possible bike, with carbon frame, etc.

The bikes I've seen from the European brands are too heavy and too powerful, weighing ~ 10 lbs more than the non-electric versions, and with way more power than I need. A lot of bikes show specs of 40 Nm or 50 Nm of torque assist; this is more than double what I can make on my own FTP.

Has anybody seen a light-assist system with maybe only 10 - 20 Nm assist, and an added weight of ~ 5 lbs? With a removable battery, this would be a great option for a lot of aging road bikers.

Thanks!
DW

Rick_D

Mine is programmable to any amount of boost and assist you choose, three discrete modes selectable while riding. Powertrain total weight is 8 pounds, bike is 30# and rides like a normal bike when powered off. No 50# behemoth.

Zehus says they have thirty companies using their system, which contains everything in the back hub. Maybe check out some of these makers.
https://eventure-bikes.webflow.io/our-partners

Tomm Willians

One of the lightest e-bikes on the market with completely removable battery and motor rendering it a perfectly normal bike. Full carbon Pivot E Vault with the Fazua motor system. Mine weighs in at 21.1 lbs with the motor removed, 7.5 lbs more with it attached.
Power profile is adjustable to a near infinite number of possibilities giving you whatever you want. My last ride gave me 40 miles with 5300’ of climbing. If I just use it on flats it can easily go 60-70 miles. But that is a profile where I’m doing 90% of the work.

Warning …. It’s not cheap.

john m flores 

Lemond's new ebikes are carbon fiber and are supposed to be light.

john m flores 

Lemond Prolog, 28 lbs

https://bikerumor.com/lemond-all-roa...c-gravel-bike/

Wildwood 

Have not heard of what you seek.
Ribble had a lightweight bike rear hub motor, but not as light as you seek and they may not ship to USA.

Mine is 2020 Orbea Gain = 30 pounds in CF and size XL, Ultrgra Di2. New Orbea models have a newer Mahle rear hub motor so not sure of weight. At 72yo and a 4 decade cyclist I need help on hilly & Cascade mountainous roads.

I have regular bikes for most rides, but this one is better suited for rest day rides, long rides and mountains.

Wildwood 

I will follow this thread to see what you and others can find. I think the market demand is for bikes with more power than you seek.

Actually, the '2 bike' solution has worked well for me. Ebike, pedal bikes.

Polaris OBark

If money is no object, some of the Trek Domane+ e-bikes are very light.

Wildwood 

Trek's aluminum framed Domane+ AL5 in size 56 = 31 pounds per Trek site. Shimano 105 = $3500 if your size is available.

2020 Orbea Gain - CF in size XL = 30.2 pounds incl heavy pedals + 1 bottle cage. UltegraDi2 for $3700.

Both of above are hub drive systems.

Domane+ with carbon fiber frames start @ $8500 for 105. Weight from website for size 56 = 27.3 pounds and with more power than above hub motors

late edit: advice for all who desire what does not exist beyond prototypes, but is technically feasible with leading edge stuff.

So if I subtract accurately, 31 to 27 pounds on Treks - costs the buyer (assuming selling price holds) $5,000.

and the original poster wants a 22-23 pound bike. So the answer is: add another $5-$6k for further weight reduction, then take your $14K dream to a specialty builder. Calfee, Parlee, or something in titanium. Probably lightest weight rear hub on lightest weight frame. Or what a certain Swiss rider was accused of using years back, but that one was astronomically expensive, if you could even buy it. Money buys nice toys.

Leisesturm

The reductio ad absurdum of the o.p. grailquest is not far off. I can't see much point to a motor that is weaker than the rider. At what point does it make more sense just not to have a motor at all? And, trust me, I have read on BF of riders that are very proud of the fact that they do not use their e-assists.

roadcrankr

I rode my Swytch e-assisted conversion today. My typical ride with it involves significant pedaling.
Normally, I average 24 miles with their Max battery - sometimes achieving nearly 40 miles.
Lots of climbing today, yet still managed thirty miles of assist. Front hub power of about 250 watts.
It takes my 18 pounder to about 25 lbs. I carry a second Max, so it requires lugging around 28lbs.
But enables me to easily cover fifty miles. If I chose to constantly use the assist on a flat route, I might only get thirty miles.
Most people wait months for Swytch to deliver. That's their biggest downside.

Rick_D

Closest to my BMC is the Domane+ SLR9 XLS. A 56cm is said to be 12.15 kg / 26.79 lbs. Uses the TQ drivetrain.

Jklotz

You might want to look at the newly released Specialized Creo 2. It's geared more to the gravel crowd, but a swap of tires and it would be a fine road bike. I've got a Trek Domane+ SLR. It's been great so far, however it's over priced IMHO.

Keep in mind almost all of them have an app that lets you tailor the power to your liking. Most also have 3 modes, the first being just enough assist to make your 30lb bike ride like a 15lb bike, so you are still doing most of the work.

dwells

Thanks for the excellent replies, everyone!

I need to do more research, but this week I've found a new(ish) Mahle 20 rear hub system, with 23Nm torque, and a little lighter weight.

I've got another few years before I really need to pull the trigger. Most of my riding is solo, but I do ride with a few cyclists who are 20 - 30 years younger than me, and keeping up with them on climbs is the issue.

Thanks again!

DW

Bob S

My Specialized Creo, XL frame, weighs the same 30 lbs as my prior custom Titanium, fully equipped.

rm -rf

I think crank motors are more responsive than the rear hub motors, just based on reading, not experience. Less lag when the rider starts pedaling.
The lightest e-bikes right now add about 7-8 pounds over the equivalent non powered bike. I think the weight limit is the battery, not the motor. My all-day, non-powered adventure bike is around 23-24 pounds, compared to 18 with my road bike. It seems "wow, heavy" when I pick it up, but after riding a few minutes, I don't notice the extra weight. So a 26-28 pound road bike would be fine.

Harmonic drive motor!
These tiny motors use an offset toothed ring to reduce the fast spinning motor rpm down to the crank rpm. And it's all concentric, in a small, lightweight module. They seem very expensive now, and I'd want to wait a couple of years for "version 2" with perhaps some durability and/or size improvements.

For example
Promo video

3D expanded views.
The harmonic drive operation is at 1:50. This motor has a 17.5 to 1 speed reduction (and corresponding torque increase).


The Trek Domane+ bikes are extremely expensive now. But that will change, like all new tech.
Aside from a thicker downtube, a slightly fatter bottom bracket, and a small control panel, they look like a normal road bike.

I'm 70 now. I think that in 5 years, I might want a similar e-bike. Just an assist to keep up with the group on hills or at the end of a longer ride. Now, I can maintain 200-220w on a one mile hill, so a 100w effort with 100w boost would easily be enough.

Class A limits!
Class A e-bikes have a sharp cut off to the assist at 20 mph. That's too slow for my group rides, even though our pace is more like 17-19 mph on the flats. I understand why these regulations are made -- bike trails, etc. A gradual rolloff of boost would make more sense to me, but I doubt if they will change the regulations.

Other bikes can keep the assist up to 28 mph.

Wildwood 

There are rides where power level above minimal may prove useful!


All uphill to 6400’ elevation, later in the ride to be followed by 6 miles up without a flat road.

No throttle, but I like the three power options. What’s the downside? about 4 pounds. IMHO, no ‘one bike solution’ does it all, without compromises. N+1 always suits best.

CrimsonEclipse

Read the title and thought solar sail or laser propulsion.

Rick_D

I would so buy that.

JohnJ80

It's additive to your power output. Most of the lightweight e-bikes (i.e. trek domane for example) put out around 250W of power to 300W peak. You can adjust them to that scales to your output, very common to have it add a watt for every watt you supply up to its max. Having to put in 250W and getting out 500W is pretty nice. IIRC, when Chris Froome did his breakaway to win the 2018 Giro, he was putting out 397W average. So the boost from the lightweight e-bikes is significant. A rider with a middling FTP of 250W could conceivably get to those sorts of overall power numbers.

Leisesturm

I'm still not convinced. I'm also not understanding the obsession with weight for an e-bike. A light e-roadracer is frightfully expensive. These bikes can set you back $10K at minimum, and for that you get a pig of a bike that weighs what my totally noncompetitive road race replica (carbon fork) does (~20lb+) but my bike cost less than $1K. A lot less. To get what the o.p. wants, you have to spend over $13K and the bike is no faster going downhill or on the level than anything else! Most of the time spent riding will be at speeds no faster than anyone else able to afford a full carbon racebike replica. A $10K premium just so you can sprint up hills like a frightened Mountain Goat.

JohnJ80

You sound a lot like me before I got my lightweight e-bike (an mtb this one) last year. We live at around 700' ASL and we frequently ride at high altitude of 9,000-11,000 feet in the mountains. It takes longer than we have available to acclimate to those altitudes. Getting the e-bikes allowed us to dramatically expand the terrain available to us in terms of both miles and grade and turned out to be a really smart idea. In the process, we also discovered how much fun they are to ride in general and especially on recovery days. Riding an e-bike on a recovery day gives your legs and body a rest but you still keep the training up for core, bike handling etc..

Because I'm a bike geek and an engineer, and because I wanted to see how much the e-bike mattered, I mounted a power meter pedal set on my e-mtb and then I also rode with an HRM. Surprisingly, I hit my target and max heart rates quite frequently. I found that typically I was running at about 50% of my FTP while riding flat terrain but generally at higher speeds. I'd max out going up the steeps just like I would on a regular bike - albeit on steeper grades or terrain that i might have struggled with before. Greg Lemond once said, "It doesn't get easier, you just go faster." Strikes me that applies here - you don't ride much differently from an FTP or power output perspective, but you do wind up going faster or tackling more difficult terrain. That, especially for me not being a youngster anymore, is a big benefit. I plan to get a road e-mtb (probably the Trek Domane version) just for the ability to ride every day regardless of recovery status and as an alternate to my standard "acoustic" bike.

As for light vs heavy - It's like riding any other bike. The heavier bike is not as nimble or responsive. A light e-bike is what I would choose. I don't want to ride a 50lb behemoth anymore than i would on a non electric bike.

I take it you probably haven't tried one? If not, you should. Bottom line - it's a ton of fun.

Rick_D

Heh, I refused to ride one because I was afraid I'd like it too much--even as my neighbor kept offering me rides on his.

Sure enough, one once I tested some I was hooked and added an ebike to the fleet. My early thoughts of a commuter-centric model had passed and I opted for better performance and lighter weight. The actual cost of an advanced model is a fraction of $13k for CF frame & fork, e-shift, CF wheels, top-tier drive system, etc. Real money still, to be sure, but also a LOT of technology packed into the bike.

Calsun

My Specialized Creo road bike weighs under 27 lbs with the motor and battery installed. It is a Class III bike that provides pedal assist when pedaling up to 28 mph. The 35 nM from the motor is more than enough for me the steepest of grades. Very natural feel to riding the bike on hilly terrain or in windy conditions. I can adjust the amount of power assist provided and have 3 presets that area programmable with my Smartphone. It also takes a 160Wh range extender battery that fits in a water bottle cage on the seat tube to gain.

JohnJ80

.... and besides that, it's a lot of fun.

I'm looking at the Trek Domane road e-bike. It too has a 160Wh extra range battery. Interestingly enough, Delta allows one to carry 2 160WH max batteries in your carryon luggage. My plan is to to take out the main battery in the downtime (fairly simple) and then to get two of the range extender batteries and then take the bike along on the airplane. The internal battery is 360WH, so the two extender batteries are almost the same.

So, one of the places I wanted to do this was to take the bike to the EU. For me, that requires Delta to AMS and then KLM from there to my destination. KLM has a similar policy but you need to get approval in advance for the battery. I wound up having this continual circular discussion - KLM says they can approve the battery once I have a ticket. I keep telling them that I'm not buying the ticket until I know I can do this. Round and round we go....

J.