Chalk and cheese

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
This doesn’t really come under the category of a ‘bike review’ – maybe a two-bike review! Anyway, my apology if it’s a bit too long (I had to split it into two posts because there’s a message length limit) and I hope the moderators will let me off – I promise not to do it again – for a while at least.

So – Part 1....

I’ve had a Wisper 905Se since New Year 2009, and it’s still in use – despite the fact that the battery is getting somewhat tired after all this time. I’d considered putting it onto Ebay but whoever bought it would need to buy a new battery so I doubt I’d get a good price for it.

Anyway, the point is I’ve been riding a Kalkhoff Sahel Pro since April (no, not the S model) and although I thought that would become my exclusive ‘ride’ I find I still use the Wisper, though not anywhere near as much.

I’ve more or less decided that I’ll get a new battery for the Wisper next year – and probably I’ll keep it. Both bikes have lots to commend them, and I thought I might share my observations on both and what I like (or not) about each of them.

The Kalkhoff is slower under power – it cuts out completely at around 16.5 MPH. There’s no way to fiddle it either – the speed is measured by a magnet on the rear wheel and a frame-mounted pickup. The system will assist you from rest just as soon as you apply some weight to the pedals – but the power is fed in sensibly as the speed builds up – so if you disconnected the pickup you wouldn’t get much help at all. Quite clever. The latest Panasonic system is a quantum leap ahead of what was being fitted three or four years ago. It’s 36 volts (at last) and you get a 14 amp hour battery – coincidentally, the same spec as the Wisper. However, that’s about as far as it goes if we’re talking about similarities. The ‘famous’ torque sensor is still a feature of the Panasonic drive, so you get assistance in direct relation to how much effort you put in. However, the level of assist available is now (up to) three to one if you select ‘high’ assist mode – which means you don’t need to pedal too hard to get lots of help.

The Wisper, being in effect four years older, is nowhere near as sophisticated. This is not a complaint – it was also less than half the price when I bought it. One shortcoming of the rear hub motor setup is that it’s just fine on the flat or downhill, but if you’re climbing anything much above a moderate incline you have to work damn hard to keep the speed up so the motor is not too far out of its ‘sweet spot’ of performance. The seven speed derailleur only applies to what effort you’re putting in to turning the pedals. In the case of the Kalkhoff not only your effort but also that of the motor go through the gears – in this case a nice eight speed Alfine hub gear. No matter how steep the climb, you can find a gear which makes both you and the motor happy, and you can get maximum power out of the motor under pretty well any circumstances. You may not realize that an ebike motor doesn’t deliver a lot of power until it’s running at some 70-80% of its rated top speed. You can certainly appreciate that fact if you allow the Wisper to drop below about 10-12 MPH on a hill, because the motor speed relates directly to the speed you’re travelling. On the Kalkhoff you just change down and if you’re pedalling comfortably the motor is comfortable too. It’s not just the principle of the thing which feels right – it hangs together beautifully. You have to approach it differently when it comes to changing gear though – you need to ‘feather’ the pedals to get the power off so that the gear change comes easily. It’s less forgiving than a derailleur to being shifted with the power on – and not forgetting that if I were being clumsy I could be hitting that hub gear with well over double the power a fit and much younger rider could produce. Of course you can change right through the box when stationary – I can’t do that on the Wisper and I find myself forgetting that with a derailleur you really need to be in the right gear to pull away before you come to a stop.

The Wisper affords two methods of motor control – a pedal sensor and a throttle. I’ve never been particularly happy with the pedal sensor system on the Wisper as it’s ‘all or nothing’. By that I mean that you do get a ‘low/high’ switch box on the left of the handlebar, and ‘low’ is probably about 20% power, with ‘high’ giving about 80% power. I leave mine on low all the time and use the throttle to regulate the amount of power in real time. The 20% assist setting gives very little help, but the 80% setting comes in with a bang after about one turn of the pedals – which can give rise to some tricky situations. The Kalkhoff doesn’t have a throttle control, but the pedal assist system is splendid – it does just what you expect and with almost no lag at all. You can pedal away from rest and get just as much assistance as you may need according to how hard you pedal.

I’m led to believe that current Wispers don’t give you the option of getting the motor to assist above about 16 MPH. Mine has that useful green button by the left handlebar grip – it’s a ‘push-on push-off’ switch and when it’s on you get assistance to somewhere near 20 MPH. Of course there’s a price to pay, in that if you rely on it too much and are a bit lazy, or unfit, your range takes a nose dive, but I’ve found it’s good for around 35-40 miles the way I ride, though I suspect by now 30 miles is about the limit because of the battery’s age and the fact that I’ve used it quite a bit.
 
Last edited:

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
Part 2

Because the Kalkhoff encourages you to work harder, and also in no small measure because of the non-variable cut off of the motor, it has a much more generous range – I’m getting around 60 miles on ‘high’ and if I used the ‘standard’ mode more I think I could probably double that. When the battery indicator drops to one bar I have about 20 miles left – when it starts to flash I have 10 miles left. What happens when it runs out? Well, obviously, you have to do all the work, and it’s interesting that although the Wisper with a flat battery feels to be a heavy lump (I’d rather walk with it than ride it) and there seems to be quite a bit of drag from the hub motor, the Kalkhoff is still eminently rideable. No discernible drag at all from the Panasonic system. When I ride the Kalkhoff down one of the steepest hills around here I can hit 45 MPH (coasting of course) by the time I’m approaching the bottom (other traffic permitting) but I can only get around 35 MPH out of the Wisper on the same hill.

Brakes on the Kalkhoff are hydraulic disk front and rear. You can get as much braking as the tyres will handle with just finger pressure. The Wisper has a rear calliper and a front disk and they’re cable operated as you would expect, but they stop just as well – it just takes a good squeeze on the levers.

With the Wisper electronics is minimal – probably just the controller. You have the red/amber/green LEDs on the right handlebar but of course they only reflect the real-time battery voltage, and as that ages they don’t mean much at all as the green and amber lights go out as soon as the throttle is opened, and the green light gives up entirely within some 5-10 miles, and you’re down to permanent red by around 20 miles. The red light stays on even if the battery reaches the cutoff point – obviously a function of the controller. On the Kalkhoff the comprehensive LCD on the left handlebar acts as a dashboard for the electronics, incorporating all the control switches as well as comprehensive information on anything you might like to know – speed, distance, battery charge state, an indication of the power you’re drawing, etc.

Some purely engineering points here relating to the way the batteries on the two bikes are charged. With the Kalkhoff you need to remove the battery and drop it into a charging cradle – the Wisper will charge in situ. The actual way they charge is interesting though – the Wisper charger gets the battery up to around 75% charge and then starts to tail off as the BMS limits the charging current. Obviously this benefits the battery which gets an easier time as the charge is reduced approaching ‘full’. The downside is that from flat it takes a good four hours to get a full charge, and even when the charger light goes green to indicate the battery is full, charging continues at a slow rate for a good while longer. In fact I don’t think it ever stops completely unless the charger is switched off. The Panasonic charger operates in a different manner altogether – it goes full steam until the battery is fully charged and then it turns off – and I mean OFF. It draws less than a watt if there’s a fully charged battery in the cradle and nothing at all if the battery is removed. The power factor of the Wisper charger isn’t magic, but the Panasonic charger hits 0.95 most of the time. Most users won’t appreciate these finer points, but in terms of good ecology a power factor approaching 1 is A Good Thing. Time from flat to fully charged is under three and a half hours. In spite of that Kalkhoff reckon the batteries have a good life – so progress, progress.....

The Kalkhoff comes with Busch & Muller lighting running off a Shimano hub dynamo. It’s all LEDs – no bulbs to blow – and the lights incorporate ‘supercaps’ which can best be described as low-capacity short-term batteries. The significance is that after two minutes of riding with the lights on the supercaps are fully charged – and when you stop the lights maintain full brightness for more than four minutes. In effect that means fully functional lights at all times whether you’re in motion or not. Also the front light is impressive. There are no doubt brighter lights around – but for most of us the lights fitted to the Kalkhoff do the job splendidly.

If you’re wondering why they run off a dynamo instead of the bike battery, it’s to do with German law – cycle lamps have to have dynamo power. It removes the problem of people who ‘forget’ to replace flat batteries. You can have batteries as well – or supercaps – but the main lighting supply must be a dynamo. The ‘S’ version does run the lights off the bike battery – because it’s no longer a ‘bicycle’, of course, so different rules apply. The hub dynamo is very efficient – I can’t detect any drag when it’s working. Nothing like those old 6 volt Lucas jobs that ran off the side of one of your tyres and were really hard work!

No lights on the Wisper – at least, not on my model.

If it sounds as though the Wisper is coming a poor second in this comparison, it’s worth remembering that it’s in a different price range and a huge amount of development has taken place in the four years since that model was introduced. Back then I wouldn’t have entertained the Panasonic system – 24 volts, small batteries, and limited assistance seemed to be the order of the day. The Wisper was at the time one of the few ebikes with a seriously large battery. I took a chance in buying it to see if it would keep my interest – and it’s done that in spades. I’d never have bought the Kalkhoff if I hadn’t owned the Wisper. I know a new battery will transform it, and I suspect I’ll be even more reluctant to sell it when I do that. The Kalkhoff comes in a choice of sizes, and as I’m 5’ 7” the medium one suits me perfectly. The Wisper one-size-fits-all would really be better for someone three or four inches taller – but then again, at barely 140 pounds weight (me, not the bike) there are advantages in being a short ‘un.

No faint praise here therefore! I have no experience of current Wispers. What I bought was just about the best thing around four years ago, and it still stands up well against the opposition now. In my opinion, of course.

Rog.
 

indalo

Banned
Sep 13, 2009
1,380
1
Herts & Spain
Nice report Rog and I agree entirely with your point about one-size-fits-all bikes. So many bikes require one to shape one's body to conform with the bike's geometry whereas others provide a range of adjustment sufficient to allow anyone, well almost anyone, to find a comfortable riding position. Generally, bikes which offer several frame sizes and provide ample adjustment tend to cost a bit more, not unreasonably in my mind.

I suppose custom-fitting is probably a good idea but I shouldn't think many could be bothered. Most cyclists unfortunately have only ever known bikes which they had to adjust themselves to so they probably don't know any better.

Indalo
 

eddieo

Banned
Jul 7, 2008
5,070
6
more apples and pears I think, both very different bikes and very good in their own way. Things have most definitely moved on, but have very fond memory's of our 905 & 705. Still very sort after, if you look at ebay auctions wispers always in demand and sell well
 

Martin1

Finding my (electric) wheels
Aug 29, 2012
16
1
TW13
Very intresting comparison, for the last month i was was torn between the Wisper 906 Alpino and a Bosch crank drive bike such as the KTM Macina race (lucky enough to have received a windfall to at last be in position to buy one) . Never having owned any e-bikes before I spent a lot of time on this forum researching the pro's and con's of hub drives and crank drives. Test rode the Alpino and was very impressed by the power and feeling of effortless cruising, but without power not a bike i would like to try and ride very far. I had briefly ridden one of the early Panasonic drives some time ago and liked the idea of a crank drive but found it had a uninspiring power delivery and suddenly tailed off at what seemed a low speed, like many others i found a lot of sites advertising bikes such as the KTM actually had no stock or demonstrators so I ended trying a Kalkhoff to see if Bosch had improved much on Panasonic. The bike I tested was the Pro-Connect BS10 (seemingly the Devils Spawn to some on this site!), Yes I have to agree the bike if not registered with DVLA is effectively not legal on British roads, but I am certain if Rog tried one he would be puttting both his bikes on e-bay, it certainly addresses the issue of power fading away to early as it will power up to 28mph in speed mode (that also requires some fairly serious effort from the rider as well) and is also a pleasant free running bike to ride even without power. The smooth and intuitive power delivery, obvious build quality and fact that it turned a cynical 55 year old into a grinning schoolboy after tearing past every cyclist I met on the test ride did it for me and I put my order in there and then!
 
Last edited:

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
I did consider the S version of what I ended up buying, but in the end decided against it. Although it's likely that riding an S bike won't attract unwelcome legal attention, there have certainly been a couple of cases recently when owners have been less fortunate. One story I heard was of someone who had been involved in an accident with a bus - allegedly not the rider's fault - but he was none too pleased when the consequences of riding an S-class bike started to pile up - including the bus company's refusal to compensate him. I stress that it's only a story I heard and I can't vouch for the facts, but something to bear in mind especially if you ride in heavily-populated areas. Cyclists in general seem to be vulnerable, and assuming 'it won't ever happen to me' might be less than wise.

Anyway, to get away from that, I realized I didn't really want an S-class bike. I like to work at it and I don't need a high top speed. I have a motorbike for such purposes. I find I'm actually covering up to 50 miles at a time on the Kalkhoff when I go out - much to my surprise - and the idea of riding a bicycle but with some help is what appeals to me. It gets used more than the motorbike (as did the Wisper). I never enjoyed cycling so much when I was a kid. It seemed there were too many hills going up, not enough coming down, and the wind always seemed to be blowing in your face rather than at your back. A standard ebike removes that, and it's pure fun.

Rog.
 

eddieo

Banned
Jul 7, 2008
5,070
6
I can assure you (from an unfit (medical problems) 18 stone very late 50's vintage) that the legal 250 watt Bosch drive is very impressive..have just bought our second one. These moped riders who still think they are riding a bike are either in a terrible rush (leave earlier) or lazy...

I have also noticed that the proverbial rock of ages, the ever popular Kalkhoff Agutta is now also available with Bosch drive!
 

Martin1

Finding my (electric) wheels
Aug 29, 2012
16
1
TW13
Lazy?
Not sure about that, I am working harder on my commute on the BS10 than I do on my unpowered hybrid, I just get there a lot quicker. As for moped, just as with your 250 watt version I only get back what i put in, to my mind the Wisper was more like (a very slow) moped as no rider effort was required to maintain momentum.
 

flecc

Member
Oct 25, 2006
50,676
28,509
One story I heard was of someone who had been involved in an accident with a bus - allegedly not the rider's fault - but he was none too pleased when the consequences of riding an S-class bike started to pile up - including the bus company's refusal to compensate him. I stress that it's only a story I heard and I can't vouch for the facts,
This is not apocryphal, it's perfectly true.