Kalkhoff latest impulse crankdrive system

[flecc]

Technically there are 4 types of chainwheel drive a la Panasonic.

1/ The crank drive. Works well but is prone to inconsistent power output and tends to be unreliable

2/ The warp drive. A clever idea but many question the use of an oval chainwheel

3/ The impulse drive. Technically ingenious but riders report a lack of urge at some points in a journey and a surfeit at others.

4/ The sex drive. Generally considered the most powerful but has a high failure rate with age.

Or in short, Warped Cranks have a Sex drive Impulse.

 

[piotrmacheta]

A question if I may, is this new Impulse drive back pedal brake work as a regen brake or friction pads? I can see the benefit of a regen brake all in one simple to use unit but otherwise it's just another crank drive - in itself a good idea.

Note to self - I must stop reading about all these new developments as I can't afford yet another ebike!

 

[flecc]

There can be no regen involved, the back pedal brake is integrated into the crank and not associated with the motor or a wheel hub.

Nor is it a friction pad brake, it's almost certainly a roller and ramp brake like the one Shimano make for bike hubs, so no maintenance needed.

 

[Artstu]

Sounds like a useful thing to have (the roller brake), I wonder why they've never been popular in this country.

 

[flecc]

Sounds like a useful thing to have (the roller brake), I wonder why they've never been popular in this country.

I don't know of any specific reason, but as long ago as 60 years our English customers disliked them.

They are more suited to leisurely utility riding like that more common on the Continent, and the traditional ones were never very effective. Originally based on brake drums, shoes and pads, car style, they often got oil soaked rendering them useless.

Even the modern Shimano roller and ramp incarnation is much weaker than any rim or disc brake.

 

[tillson]

I don't know of any specific reason, but as long ago as 60 years our English customers disliked them.

They are more suited to leisurely utility riding like that more common on the Continent, and the traditional ones were never very effective. Originally based on brake drums, shoes and pads, car style, they often got oil soaked rendering them useless.

Even the modern Shimano roller and ramp incarnation is much weaker than any rim or disc brake.

A friend of mine has the Shimano roller & ramp brakes on his Giant Escape R8. Granted, they don't have the power or feel of a decent set of rim brakes, but they aren't too bad. I think incorporating them into a pedal type brake is a good idea and I'd like to see the principle retained on the UK model. A low maintenance brake would compliment the low maintenance Alfine gears and hopefully low maintenance drive unit very well.

 

[flecc]

But most in the UK would dislike not being able to back pedal to get cranks into a suitable position for take of from lights etc, a major disadvantage of back pedal brakes. I sense that perhaps those asking for them here may never have ridden bikes with a back pedal brake and aren't aware of that.

I can't see 50cycles wanting to double up stock on the very large Kalkhoff range to give the ex-stock choice, but they have said they'll get back pedal brake versions to order. Just make sure you really will like it if you've never tried them before, I hate them.

 

[Tim]

But most in the UK would dislike not being able to back pedal to get cranks into a suitable position for take of from lights etc, a major disadvantage of back pedal brakes. I sense that perhaps those asking for them here may never have ridden bikes with a back pedal brake and aren't aware of that.

I can't see 50cycles wanting to double up stock on the very large Kalkhoff range to give the ex-stock choice, but they have said they'll get back pedal brake versions to order. Just make sure you really will like it if you've never tried them before, I hate them.

Anybody who has become used to cycling without a coaster brake is likely to find it a disconcerting when they idly back pedal when freewheeling to find themselves coming to a rapid halt. Happened to me cycling around Groningen and Cologne, on hire bikes, over and over again. It's great for the German market, Kalkhoff sold 5000 Impulse bikes with coaster brakes on one day last Spring, after the launch demo... we were pleased to find they're producing a freewheel version.

 

[tillson]

Maybe, but there must be something beneficial to the braking system if it is so widely used in other countries. We in the UK seem to in the minority, probably due to a touch of, "we've always done it this way" prevailing.

 

[mike killay]

I had them, one on a cyclemaster, the other on an NSU Quickly.
They were necessary because the left hand handlebar lever was the clutch.
Neither was very efficient in braking terms. On an electric or non powered bike they seem to be an expensive, difficult to repair unneeded addition.

 

[lemmy]

probably due to a touch of, "we've always done it this way" prevailing

Not in my case. They were not uncommon years ago but they had poor stopping power and gave little confidence. Given that rim and disk brakes work so well, it seems pointless to introduce a third type unless it shows some overwhelming advantage.

Presumably anyone who wanted them could retrofit.

 

[flecc]

Maybe, but there must be something beneficial to the braking system if it is so widely used in other countries. We in the UK seem to in the minority, probably due to a touch of, "we've always done it this way" prevailing.

Not that widely used, mainly the Netherlands and to some extent Germany and Denmark. All I can say is try a back pedal brake bike, there are a few around from such as the Dutch Bike Company. They really are the worst performing of all bike brakes, mainly suited to slow cycling.

The modern Shimano incarnation, which is usually lever controlled and not back pedal, isn't smoothly progressive. On first application it reacts slowly as the rollers gather up the ramps, then comes in more fiercely. This is very disconcerting on an emergency stop, first little response on hard application then fiercely cutting in suddenly and potentially locking the wheel, not at all what is needed. Again, they are usually only fitted on utility bikes of the sort used for leisurely riding.

 

[eTim]

Would somebody please explain to me what the sudden ramp down is on the Bosch system? I'm still waiting to experience it. I think there are a few reports of this, maybe I should ride around more in 3 Speed or do a back-to-back comparo with a Panasonic?

 

[flecc]

It's just full power to 15 mph Tim, then it cuts out almost immediately. It's not alone in this, many e-bike systems do the same.

The Panasonic system phases down power so smoothly as it approaches 15 mph that the cutting in and out at around 15 mph is impossible to feel when it happens, the transition is silky smooth. The experience of 100 years of them making bikes and over 12 years of making e-bikes shows. In fairness, this is the first venture by Bosch into anything to do with cycling.
.

 

[eddieo]

Would somebody please explain to me what the sudden ramp down is on the Bosch system? I'm still waiting to experience it. I think there are a few reports of this, maybe I should ride around more in 3 Speed or do a back-to-back comparo with a Panasonic?

Probably worth recognising Tim that all this criticism is from people that have probably not even bothered riding a Bosch powered bike, and have not got a clue as to how nice a system it is.....

I feel confident that you would still prefer the Bosch on a side by side evaluation as most European forum opinion backs this up...

 

[eTim]

It's just full power to 15 mph Tim, then it cuts out almost immediately. It's not alone in this, many e-bike systems do the same.

The Panasonic system phases down power so smoothly as it approaches 15 mph that the cutting in and out at around 15 mph is impossible to feel when it happens, the transition is silky smooth. The experience of 100 years of them making bikes and over 12 years of making e-bikes shows. In fairness, this is the first venture by Bosch into anything to do with cycling.

Thanks for the explanation Flecc

Probably worth recognising Tim that all this criticism is from people that have probably not even bothered riding a Bosch powered bike, and have not got a clue as to how nice a system it is.....

I feel confident that you would still prefer the Bosch on a side by side evaluation as most European forum opinion backs this up...

I don't want to get into a debate about it and I have no intention of changing my Haibike for something else (there isn't anything out there like it at this price range anyway). But I am curious about the ramp-down that is talked about as I hardly notice anything. There is a cut-off point when in the highest speeds settings, but I wouldn't say it is anything worth fussing about, however it sounds as if the Panasonic system is so smooth that Bosch have a little bit of work to do in refining the ramp-down. I shall try to observe it this evening on a ride out.

 

[flecc]

Bosch have a little bit of work to do in refining the ramp-down.

They may not even bother, they apparently have a healthy market for the system as it is and there are many other e-bikes with often very abrupt cutoffs in any power mode.

Some prefer the more obvious nature of the power appearance rather than the more subtle Panasonic approach, so there's a lot to be said for the choice to be there for consumers.

 

[james@justebikes.co.uk]

I haven't noticed sharp power-down. All crank drives seem to me 'agricultural' compared to Koga or Sparta hub drives. But I think Panasonic have perhaps the worst power-up I've come across. Way back when we were Flyer dealers we'd cringe when madame placed a foot on a pedal whilst adjusting her skirts... Whoosh/Yelp/and sometimes Bang! would follow as she was unexpectedly thrust forward. Scary.

FYI Bosch, Koga & Sparta motors power down at 17.2 mph (not 15 mph)

James

 

[flecc]

But I think Panasonic have perhaps the worst power-up I've come across. Way back when we were Flyer dealers we'd cringe when madame placed a foot on a pedal whilst adjusting her skirts... Whoosh/Yelp/and sometimes Bang! would follow as she was unexpectedly thrust forward.

One of the system's best features to many of us James, ideal for hill starts. Once aware of it there's no problem.

 

[tillson]

I think Panasonic have perhaps the worst power-up I've come across. Way back when we were Flyer dealers we'd cringe when madame placed a foot on a pedal whilst adjusting her skirts... Whoosh/Yelp/and sometimes Bang! would follow as she was unexpectedly thrust forward.

James

I have heard this characteristic mentioned by other people too but, I have to say that it does not exist on my 2008 Panasonic driven bike. It simply does not happen, so maybe they have revised the software.