← Back to context

Comment by molsongolden

1 day ago

This bike booster will probably come in at less than half the cost but the Bimotal kit is another option that doesn't have the tire wear issue, offers better performance, and the form factor is much nicer.

https://bimotal.com/products/elevate

Wow, $2k? You could get a decent ebike for that money. And the installation doesn't look any easier than a hub motor... Only seems worth it if you already have an extremely nice bike. I think of friction drives as being aimed at budget-conscious commuters, not serious mountain bikers.

  • I think in nyc I'd prefer to lock my $100 dumper of a bike on the street and be able to take the expensive component with me, if this thing is as detachable as it seems

    • It may just be that I’m comparing to the Bay Area, but I’ve never been that concerned about bike theft in NYC. If you lock your bike with a good lock and leave it somewhere with plenty of foot traffic, it’s quite unlikely to be stolen. Most people don’t even bother locking the wheels! Just a U-lock through the frame.

  • I was shocked by the price, too. I mean a motor and a battery can't be so expensive, especially such a "small" battery (300Wh).

    That being said, having driven electric bikes for a while, here in France they're ridiculously limited in speed and power. 25km/h limit on flat land usually makes sense (except on long straight lines), but when you get climbing even slightly you get down to ~10km/h and have to provide more effort. I guess that's where the 750/1250W 70Nm unrestrained motor comes in handy, and if you live in a place with lots of small hills the choice is either that kind of motor or a car, not the 1000€-total Decathlon/Carrefour electric bike.

    • The whole European Union has that limit. Without it it's not an electric bicycle anymore, it's a moped or electric motorcycle, that sort of thing, and you have to register it, have a driving license and so on.

      7 replies →

    • In my experience the issue is one of torque, not of power. Most cheaper electric bicycles (including most Decathlon models) have a hub-mounted motor which cannot deliver power effectively at low speeds -> it stops assisting when you most need it. For hilly terrain you need a motor that's mounted on the crankshaft so that it can take advantage of the gears.

      To compare: a tour de france runner outputs 400-500W on mountain climbs while keeping up to 20-25km/h. So a 500W motor (plus 100W power output from yourself) should be enough for smaller climbs!

      3 replies →

    • I have a heap of ebikes, all 250w and 25km/h limited. A Bosch performance line motor on a MTB going up a steep hill is effortless compared to a budget shimano motor where it can barely make it up no matter how much effort you put in to pedalling. Torque makes a big difference.

      2 replies →

    • Not a single country in the EU limits a speed or power of the EV motorcycles. They do limit these vehicles to an appropriate places which are called "roads" and do require a proper vehicle license and registration. A person can ride their Suicide Killer 9000 Pro Max with any motor power and any speed in the whole EU area really, no problem. On. A. Damn. Road. Where. It. Belongs.

      2 replies →

    • I climb hills at 25km/h with zero effort (with a strong wind) on Ecoride Ambassador.

    • > but when you get climbing even slightly you get down to ~10km/h and have to provide more effort

      I've ridden bikes with Bosch 65Nm motors and with a 80kg rider plus 20kg of cargo they're perfectly fine even up steep hills. As in 18kmph or more with only a moderate amount of effort from the rider. Your bike was really underpowered (50Nm?).

  • Mountain bikes one level down from professional tier start at 6-8k. If I could pay 2k and get a nice electric bike from my nice muscle bike it would be a bargain.

    However bimotal is not that nice - adding a motor to rear triangle alters weight distribution and adds unsprung weight. Also unlike actual nice MTB e-bikes it cannot use chain/casssete for gearing, so gearing is fixed at the factory. If you’re used to nice bikes you will want your ebike to be dialed in just right.

    One place where it makes sense is as an alternative to shuttling on forest roads / lifts for downhill-focused riding. F you’re going strictly downhill you can move the motor to the backpack after finishing the climb to reduce unsprung weight. This opens up a large number of trails where forest roads are blocked to car traffic. It also allows dh riding on trail where motor bikes are prohibited.

  • > Only seems worth it if you already have an extremely nice bike

    How nice should one's bike be that you'd rather turn it into a mediocre ebike for the price of buying a good ebike?

    • Your existing bike hopefully fits you great rather than having to modify a low-mid grade ebike. Perhaps you don't have space for more bikes. Perhaps you want a bike made of good components that are easy to repair. It's a significant amount of money but there are absolutely reasons.

      I have a ebike that cost ~1500 in 2018 and is probably comparable to what $2k would buy you these days. It's very heavy and while the drivetrain is repairable, there are important pieces of it that I would struggle to repair/replace if they died today.

      I have a steel touring bike that's significantly lighter, has standard sized parts that can be repaired, replaced and upgraded (many of which I have already upgraded in the last 15 years) and fits me like a glove. If I didn't own an ebike and you asked me whether I'd rather spend $2k buying something like my ebike or adding a 750W motor to my Surly, I'd upgrade my touring bike.

    • It really depends on your standard for "good." Some people spend $5-10k+ on their mountain bike. If you're looking at getting an ebike of similar quality, then I could see this being an attractive alternative.

  • $2k makes sense only if the bike underneath it is valuable enough that you specifically want to keep riding that bike

    • If the bike underneath is valuable enough you dont want to strap a motor and battery to it.

  • Bike equipment is ridiculously high margin. Motorcycles and mopeds are extremely common commuting vehicles in much of the world, yet i'm surprised motorcycles aren't more popular since they offer much more capability and are a better value.

  • You can get a nice ebike for that money if you're even slightly patient in waiting for a sale to hit.

  • Bimotal is removable after the installation: the motor and battery can both be taken off in under 30 seconds and you're left with just the cables and a specialized brake disc. I'd say that's its main differentiator. It is definitely more for premium bikes though and even then isn't for everyone.

As a mountain biker I don’t see the appeal of this. Yes, this rather expensive solution could transform my nice bike into a shitty e-bike, but the point of having a nice bike is to avoid a shitty experience.

A proper e-bike needs to be designed as an e-bike from the beginning.

  • Shuttling? Once you remove the motor and put it into a backpack downhill riding should be quite decent. Decent enough I think to make it worth it for the space and cash saved.

    • Personally I’m not doing any downhill riding with the motor in my backpack. Or really anything hard with sharp edges. I like having a working spine.

      Either it’s unsprung mass or a liability, and, well, actual e-bikes have converged on BB motors for a number of reasons.

Oh I like this idea. Looks simple and lightweight.

Expensive as f though. Also the gear-thingy looks proprietary (=expensive).

That's a terrible kit that should never be considered. You can get 6kW monster kits like the CYC X1 Pro, and battery, for that price!