Kalkhoff Agattu Pedelec Review and Test
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The news over a year ago that the Lafree Twist Lite series was to be discontinued was greeted with widespread dismay, since that for many was the benchmark for what a good electric bike should be. The other contenders using the same Panasonic drive unit all fell short in one way or another, price, weight, poor performance, lack of representation in the UK. When this new Kalkhoff Agattu model was announced, I thought that at last it might be the long awaited successor.
I was not to be disappointed, as you will see.
I was not to be disappointed, as you will see.
The immediate impression on first seeing the bike was of the difference from the Lafree, that bike having a light, somewhat Gallic style, the Agattu having a far more imposing presence, more Germanic in style in keeping with it's place of conception. Here the construction appeared on a more epic scale, spacious and robust, yet the weight was no more than the similarly equipped Lafree Comfort models with less gears.
The Panasonic motor unit is the latest and best version with a high power mode and Li-ion battery with 54% higher capacity than the Lafree. At first sight the motor appeared larger, but it was an illusion due to the additional black covering case.
Motor control on the left handlebar has power on/off buttons with a three LED battery meter and a Mode
button giving three levels of power assistance, adding 0.5 times the rider input in Eco mode, 1 times rider input added in Standard mode and 1.3 times rider input in High Power mode. What this means in terms of rider contribution is explained later.
First Riding Impressions
With years of riding a Lafree Twist, I was immediately at home on this bike, despite the fact that it had a medium frame, too large for me. The wide handlebars are similarly confortably angled but more of a cruiser style shaping and giving excellent control, levers and controls all falling conveniently to hand. The frame is a big improvement on the Lafree, that bike in step-though form suffering from flexing only cured in the short lived final ST version. Almost universally unknown, it didn't just flex from side to side but longitudinally as well, the handlebar stem to saddle distance varying by as much as
With years of riding a Lafree Twist, I was immediately at home on this bike, despite the fact that it had a medium frame, too large for me. The wide handlebars are similarly confortably angled but more of a cruiser style shaping and giving excellent control, levers and controls all falling conveniently to hand. The frame is a big improvement on the Lafree, that bike in step-though form suffering from flexing only cured in the short lived final ST version. Almost universally unknown, it didn't just flex from side to side but longitudinally as well, the handlebar stem to saddle distance varying by as much as
5 mm on bumpy roads. No such trouble on the Kalkhoff Agattu, the large section down tube, strong cross brace, thick section motor unit mounting arch and large section widened rear "A" frame lower tubes seen in the photograph at the right ensuring that none of the rider's pedal effort is wasted through frame flexure and warp.
Shimano's well tried and trusted Nexus 7 hub gear at the left accepts the rider and motor drive, controlled by a right hand twistgrip changer and providing low gears for any circumstance met. The requirement to comply with the legal 15.5 mph maximum assisted speed means a top gear which many will find rather low, but this is easily altered by changing the 22 tooth rear sprocket seen left for a smaller one, readily available in a huge range of sizes. As expected, the gear change had all the usual slick precision that Shimano hubs have long been justifiably famous for.
From the same source comes the equally tried and trusted front hub dynamo which supplies a Busch & Muller front halogen lamp, this having a rear switch for Off, Always On, and Automatic. The rear light on the test bike was a temporary LED type, the standard one in future will be a Busch & Muller Selectra type with a standlight when the bike is stationary.
As usual with lighting included in a bike's specification, these are adequate for occasional use, but a regular cyclist on dark unlit roads will want to add some high intensity lighting.
Among the range of useful accessories provided there's the Abus rear wheel lock shown at upper left,
a skirt guard seen at upper right to protect clothing and keep little feet from trying to play harp music on the spokes,
a Pletscher prop stand shown lower left,
and a neat carrier mounted compact tyre pump shown lower right.
a skirt guard seen at upper right to protect clothing and keep little feet from trying to play harp music on the spokes,
a Pletscher prop stand shown lower left,
and a neat carrier mounted compact tyre pump shown lower right.
The remainder of the bike's equipment will be commented on in the test ride sections.
Test Rides: Rider: 70 kilos / 11 stones, 5' 6", 71 years, moderately fit.
Each ride is accompanied by a graph showing altitudes against distance. Below each graph is a link to the Sanoodi site page where you will be able to see the route in map form, satellite photo form or hybrid, or with contours appended to enable you to properly assess the test circumstances in detail. Scroll down and you will see the graph repeated.
Each ride is accompanied by a graph showing altitudes against distance. Below each graph is a link to the Sanoodi site page where you will be able to see the route in map form, satellite photo form or hybrid, or with contours appended to enable you to properly assess the test circumstances in detail. Scroll down and you will see the graph repeated.
29.11.2007 AM, overcast, damp tarmac, temperature 10 degrees C, very light winds.
This ride is a near 6 mile climb to almost the highest point of the North Downs, followed by losing all that height gained in a sudden drop down to The Weald.
Then turning round immediately and doing the very steep climb back up to the top, followed by the downhill fast run back. The high power mode was used only on the steeper sections outward bound and the steep initial climb on the return journey.
Then turning round immediately and doing the very steep climb back up to the top, followed by the downhill fast run back. The high power mode was used only on the steeper sections outward bound and the steep initial climb on the return journey.
The first 4.9 miles is my short test section and has been accurately measured, so I stopped there to check the cycle computer calibration, which was 4.69% slow, an adjustment then applied to all subsequent measurements. The average speed on that first 4.9 mile climb was 11.4 mph, this comparing with the Lafree at 10.1 mph. Across the whole 14.2 mile return journey the average speed was 12 mph exactly.
Between the five and six mile points there's an off road cycle path with a severely rippled surface, ideal for testing the response of the suspension forks at medium frequency vibrations. I'm not a fan of suspension on road bikes and rode the entire test with the preloads set fairly firm, but I have to admit that these Kalkhoff forks are amongst the best of their kind. The characteristic weave that sprung forks often exhibit when riding in straight lines on smooth surfaces was barely perceptible at any time, and the handling on corners was predictable and precise. That ripple test was successful, the ride being comfortable at any speed to 18 mph where it tends to be painful on rigid forks at anything over 10 mph.
On the drop of Titsey Hill down to The Weald there's a stretch of traffic calming rumble strip which again is very painful to ride fast on rigid forks, and this was an ideal test of the response of the sprung forks with high frequency vibration. The bike was quite comfortable across it, but the tyres and 700c wheel shared the vibration damping success.
29.11.2007, PM, overcast, damp tarmac, temperature 11 degrees C, still air.
Between the five and six mile points there's an off road cycle path with a severely rippled surface, ideal for testing the response of the suspension forks at medium frequency vibrations. I'm not a fan of suspension on road bikes and rode the entire test with the preloads set fairly firm, but I have to admit that these Kalkhoff forks are amongst the best of their kind. The characteristic weave that sprung forks often exhibit when riding in straight lines on smooth surfaces was barely perceptible at any time, and the handling on corners was predictable and precise. That ripple test was successful, the ride being comfortable at any speed to 18 mph where it tends to be painful on rigid forks at anything over 10 mph.
On the drop of Titsey Hill down to The Weald there's a stretch of traffic calming rumble strip which again is very painful to ride fast on rigid forks, and this was an ideal test of the response of the sprung forks with high frequency vibration. The bike was quite comfortable across it, but the tyres and 700c wheel shared the vibration damping success.
29.11.2007, PM, overcast, damp tarmac, temperature 11 degrees C, still air.
In this afternoon ride, the first 4.9 mile test route was repeated using the high power mode throughout, the average speed now 11.9 mph, against the 11.4 mph with power modes mixed. Then after a partial return, turning off onto the very steep downhill stretch of Hesiers Hill and climbing back up that again.
The reason for doing that was a further test of the suspension forks on a very variable severely broken surface of an ill maintained hill which you see below.
The reason for doing that was a further test of the suspension forks on a very variable severely broken surface of an ill maintained hill which you see below.
This is after road repairs, by the way! It's likely they didn't have a roller to hand that could cope with the steepness of this particular lane which is over 20% in places. The tarmac has parted and flowed downhill unevenly due to the braking of heavy traffic that uses it as a short cut. This shot was taken after riding down the section seen, the forks coping with the unevenly broken surface well and maintaining stability throughout.
Just before the 10 mile point there's a short winding fast downhill section which has a ridged surface due to trench works along it's length, a good test of resistance to "tramlining" and of rolling resistance. Letting the bike have it's head down there didn't reveal the slightest trace of loss of composure through the rippled bends near the end and the compulsion to use a touch of braking for the fast final bends so often betraying a lesser bike was absent. The terminal speed at the foot was 31.4 mph, exceptionally good for a very upright riding position and more than 4 mph faster than the Lafree.
On the more level parts of the 12 to 14 mile section on the Kent Gate Way cyclepath, the tarmac was very slightly damp and perfect for braking test adhesion, so I carried out a series of brake tests there. The brakes are basic Shimano V brakes, the front one very sensibly on the fork rear, not as in the old photo above, so acting in compression against it, rather than against the bolt heads as happens on a front mounted brake. The cables, like the electrical cables, are led unobtrusively through the frame via sealing grommets, making the bike much tidier in appearance and easier to clean than is usual.
The rear brake was easily controllable, not unpredictably locking the wheel whether used alone or in concert with the front brake. The front brake was very powerful and smooth acting with constant force and not the slightest trace of judder or snatch, this being also a tribute to the forks of course. Straight line stability under maximum braking was absolute without the slightest sign of sideslip from the Continental Cityride tyres, As well as the description on that link, you can read of the protection technology incorporated in those tyres on this link. Suffice it to say that the puncture protection did it's job over the very bad surfaces I incorporated into this test, and I will be mentioning the tyres again later in connection with rolling resistance.
The average speed on the afternoon test was 10.6 mph, but the reported average speeds on these tests are compromised by the stops for detailed tests of specific aspects and of course, the deliberately chosen very difficult terrain.
In between the morning and afternoon rides, I carried out a series of speed tests on a 1 in 7 (14%) hill and a 1 in 5 (20%) hill to use for determining the wattage inputs of rider and motor in various power modes, results in the Extra section at the end of this review.
With the bike received at 7.30 am, to maximise the riding time I'd started the day with the battery not reaching LEDs out at end of charge, so it would have been an estimated 10% short. Almost at the end of the day's riding the last meter LED started slow flashing, indicating 10% left, after which I rode a further half mile to complete the day. The total distance covered had been 31.4 miles, and with between 1.5 and 2.5 miles left in the battery, plus the shortfall on initial charge about the same, the true range under those conditions would have been between 34.5 and 36.5 miles. This is an excellent result.
My Lafree Twist with a 6.5 Ah battery and added 5 speed hub gear ridden on the same difficult routes would do 17 miles on a new battery, so the pro rata distance for the Agattu's 10 Ah battery would be 26 miles, the Agattu exceeding that by some 35%, an indication of the efficiency of this latest Panasonic unit. Add in the age decline factor, I was 67 when the Lafree figures were taken and 71 now, and that 35% is likely to be conservative. In more moderate territory the range could easily well exceed 40 miles, so the manufacturer's claim of "up to 80 km / 50 miles in ideal conditions" is correct since that may include use of the Eco mode.
I've not used that at all, the bike being so free running, even better than the Lafree in that respect, that I've merely switched between no power on easy going downhills and the two higher power levels for all adverse circumstances.
On the more level parts of the 12 to 14 mile section on the Kent Gate Way cyclepath, the tarmac was very slightly damp and perfect for braking test adhesion, so I carried out a series of brake tests there. The brakes are basic Shimano V brakes, the front one very sensibly on the fork rear, not as in the old photo above, so acting in compression against it, rather than against the bolt heads as happens on a front mounted brake. The cables, like the electrical cables, are led unobtrusively through the frame via sealing grommets, making the bike much tidier in appearance and easier to clean than is usual.
The rear brake was easily controllable, not unpredictably locking the wheel whether used alone or in concert with the front brake. The front brake was very powerful and smooth acting with constant force and not the slightest trace of judder or snatch, this being also a tribute to the forks of course. Straight line stability under maximum braking was absolute without the slightest sign of sideslip from the Continental Cityride tyres, As well as the description on that link, you can read of the protection technology incorporated in those tyres on this link. Suffice it to say that the puncture protection did it's job over the very bad surfaces I incorporated into this test, and I will be mentioning the tyres again later in connection with rolling resistance.
The average speed on the afternoon test was 10.6 mph, but the reported average speeds on these tests are compromised by the stops for detailed tests of specific aspects and of course, the deliberately chosen very difficult terrain.
In between the morning and afternoon rides, I carried out a series of speed tests on a 1 in 7 (14%) hill and a 1 in 5 (20%) hill to use for determining the wattage inputs of rider and motor in various power modes, results in the Extra section at the end of this review.
With the bike received at 7.30 am, to maximise the riding time I'd started the day with the battery not reaching LEDs out at end of charge, so it would have been an estimated 10% short. Almost at the end of the day's riding the last meter LED started slow flashing, indicating 10% left, after which I rode a further half mile to complete the day. The total distance covered had been 31.4 miles, and with between 1.5 and 2.5 miles left in the battery, plus the shortfall on initial charge about the same, the true range under those conditions would have been between 34.5 and 36.5 miles. This is an excellent result.
My Lafree Twist with a 6.5 Ah battery and added 5 speed hub gear ridden on the same difficult routes would do 17 miles on a new battery, so the pro rata distance for the Agattu's 10 Ah battery would be 26 miles, the Agattu exceeding that by some 35%, an indication of the efficiency of this latest Panasonic unit. Add in the age decline factor, I was 67 when the Lafree figures were taken and 71 now, and that 35% is likely to be conservative. In more moderate territory the range could easily well exceed 40 miles, so the manufacturer's claim of "up to 80 km / 50 miles in ideal conditions" is correct since that may include use of the Eco mode.
I've not used that at all, the bike being so free running, even better than the Lafree in that respect, that I've merely switched between no power on easy going downhills and the two higher power levels for all adverse circumstances.
2.12.2007
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