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Kalkhoff Impulse vs Bosch electric bike comparison

Kalkhoff Impulse vs Bosch –  Who Wins?

The Kalkhoff Impulse and Bosch motor systems debuted around the same time several years ago and both have gone on to dominate the high-quality electric bike market.

They’re both highly versatile e-bike systems, powering commuter e-bikes, power-assisted mountain bikes and comfortable town bikes.

Both systems are into the second and third generations now, with increases in power as well as functional and ergonomic improvements. The latest versions even offer onboard navigation systems.

Kalkhoff Impulse Evo components.

Kalkhoff Impulse Evo Components – motor, integrated battery back, smart LCD display with navigation. Source: Kalkhoff.

The Impulse and Bosch electric bike systems have proved to be a hit with hundreds of thousands of owners across Europe and the UK. 

As UK importer we do have access to a variety of Kalkhoff’s Bosch-powered pedelec bikes. So why don’t we import any Kalkhoff models fitted with a Bosch motor?

Kalkhoff Endeavour BS10

2013 Endeavour BS10 electric bike with Bosch Performance Speed motor. Source: Kalkhoff.

Well, for a couple of years, we did. We had one of the first HaiBike FS xDuros in our Richmond shop way back in 2011.

Then there was the Kalkhoff Endeavour BS10 fitted with Bosch’s 350 Watt Speed motor, coupled with a 10-speed derailleur and first a 300Wh then a 400Wh battery.

We also had a few of the Pro Connect B10 which was powered by the 250 Bosch Performance Line motor. In fact, the Pro Connect B10 was the least expensive Performance Line e-bike available in the UK.

However, they sat stubbornly in our showrooms until we slashed the price in a clearance sale. Why? They just did not compare well with Impulse bikes on test rides – lacklustre, slow, noisy was the feedback at the time.

So, we decide that, despite its merits, not to offer Kalkhoff Bosch ebikes alongside Impulse ebikes as they just do not sell as well. They are constantly eclipsed by the greater power, range, ease of use and lower noise levels of Kalkhoff’s Impulse system.

When you take this into account, as many customers evidently do, Bosch-powered ebikes offer less value, bang for buck, pedal for pound than Impulse-powered ebikes.


Impulse 2.0 gives assistance up to 70 Nm of torque and the new 2016 Impulse Evo system boosts this to 80 Nm. Bosch meanwhile offers a range of maximum torques depending on the spec of the motor and bike.

So, the most common Active Cruise motor provides 50 Nm of torque in the maximum Turbo mode for bikes with derailleur gears but only 48 Nm for those fitted with hub gears.

The Bosch Performance Line motor can supply up to 60 Nm for bikes with derailleurs, but only 50 Nm for hub-geared bikes. Even Bosch’s new 2016 Performance CX motor has a maximum of 75 Nm, but you’ll only find that on bikes starting about the £3,000 mark.

Now maximum torque isn’t everything, but it is important to consider if you live in a hilly area or expect lots of stops and starts along your journey. More torque makes for happier electric cycling when you most need strong assistance.

Battery Capacity and Range

Let’s just say that the smallest capacity battery you’ll find on an Impulse bike is the largest you’ll find on all but the most recent Bosch bikes.

Kalkhoff Impulse bikes come with 11Ah, 14.5Ah or 17Ah battery packs. Most of our models have the largest 17Ah pack, giving up to 205 km or 127 miles of assisted cycling in Eco mode, a good 60-80 miles with normal levels of assistance in mixed terrain.

Bosch started out by offering a 300Wh power pack back in 2010-2011, moving up to 400Wh in recent years. Some Bosch Performance powered bikes will take a new 13.4Ah / 500Wh power pack in 2016, but this is still short of the 612Wh offered by the Impulse 17Ah battery pack.

You’ll also want to consider how long your battery is likely to last. Bosch batteries come with a 2-year warranty or for up to 500 charge cycles, whichever comes first.

All Impulse batteries come with a 2-year warranty and up to 1,100 charge cycles before the battery is down to 60% of its original capacity. So your Impulse battery will both take you further and last longer.

Value for money

Let’s take a look at two very similar Raleigh and Kalkhoff models. Both offer similar battery capacity and have decent brakes, gears and lights.

Raleigh Motus Electric Bike

Raleigh Motus Bosch Active Line Electric Bike with 11Ah battery, £1,999

Kalkhoff Pro Connect Impulse 9

Kalkhoff Pro Connect Impulse 9 Electric Bike with 11Ah battery, more torque & disk brakes, £1,695. Source: Kalkhoff.

Both have battery packs of around the same capacity and 250 Watt motors, along with lights, luggage rack, kickstand. The Kalkhoff comes with disk brakes, but they’re broadly the same.

2016 Kalkhoff Pro Connect 9

For the same money at the Raleigh Motus, the 2016 Kalkhoff Pro Connect 9 with 14.5Ah battery. Source: Kalkhoff.

However, at £1695 the Kalkhoff Pro Connect is fully £300 cheaper than the Raleigh Motus, yet offers a touch more power for climbing hills and beating headwinds. It’s also made in Germany to the highest standards.

The same money spent on a Kalkhoff Pro Connect means it comes with a 14.5Ah battery pack, giving greater range and upgraded lights.

Or you could spend £1995 and buy the Tasman Impulse 8, with whopping 17Ah battery pack and 8-speed Shimano hub gears.

Kalkhoff Tasman

Kalkhoff Tasman Impulse 8-speed with 17Ah battery pack. Source: Kalkhoff.

Again, this bike comes with a much greater battery capacity, giving up to 127 miles range, significantly greater torque and Kalkhoff’s unbeatable build and ride quality.

How Impulse compares to Bosch

There are several centre motors like the Impulse 2.0 system on the market now. Bosch have recently offered their own pedal-assist electric motor for bicycles, with manufacturers such as Raleigh, KTM, HaiBike, Moustache and others fitting it to their new electric models. But how do the Impulse 2.0 and Bosch systems compare?

Kalkhoff Impulse  vs Bosch comparison

  Bosch Active Impulse 2.0 Impulse Evo
Motor power (Watts) 250 W & 350 W 250 W & 350 W 250 W & 350 W
Maximum torque 48 Nm/50 Nm 70 Nm 80Nm
Maximum battery capacity 400 Wh (36V 11Ah) 612 Wh (36V 17Ah) 612 Wh (36V 17Ah)
Climb Assist No Yes Yes
Charge cycles (battery lifetime) 500 1100 1100
Gear shift detection / Shift Assist Derailleur only Both derailleur & hub Both derailleur & hub
Multifunction LCD with remote Yes Yes Yes + Navigation
Motor weight “less than 4kg” 3.8kg 3.8kg

The Impulse motor system comes out as the clear winner:

  • Far longer battery lifetime (your battery can be recharged more than twice as many times)
  • Far greater battery capacity (the 17Ah pack will assist you up to 125 miles in ideal conditions and up to about 85 miles in more realistic conditions, compared to about 50 miles for Bosch)
  • Greater motor power output for tackling hills and headwinds
  • Integrated rear light that shows following traffic you’re slowing
  • Gear shift optimisation for hub gears, not just derailleur. This is important as it’s hub gears that actually benefit most from this technology.

When you consider that the bikes Impulse 2.0 and Impulse Evo motors power what would be some of the best-equipped, most comfortable and well-constructed bikes even without a motor, Kalkhoff e-bikes are way ahead of the competition in every respect.