bosch bikes

[lemmy]

NOW if they get the Bosch powered Kalkhoff in that may sway me

Not having tried a Bosch bike myself, I'd be interested to know why you like their stuff better.

 

[eddieo]

Not having tried a Bosch bike myself, I'd be interested to know why you like their stuff better.

I just like the system and its performance, plus style and weight appeals as well. just think a 36v system makes more sense, Panasonic seem to now as well but at an astonishing price!

50 cycles had some recently....could try one on your home turf

 

[Kudoscycles]

Eddie...I am always looking to the future and would like to have a crank drive bike in our Kudos range but I suspect the market in the UK may be tiny,maybe only 50 bikes maximum....Bosch don't seem keen to let the Bosch crank drive motor to be included in bikes outside of Germany-I think they can sell all of their current production,they think they have a monopoly so can be arrogant about who they sell to.
We have settled down to a hub drive spec that works well for a lot of customers and can be adapted to suit a number of different styles and applications....the Kudos Eco bike photos are on our website- this bike suits a lady who would like a more sporty style but still with ease of access,the spec emphasises ease of maintenance and like all Kudos bikes uses the long life LifePo4 battery,current price £995.00 is I think good value. My ladies at work think it is a sexy looking bike and their favourite to date.
Dave
KudosCycles

 

[eddieo]

Dave, your ECO is probably the kind of frame my wife will end up with, infact she has an antique lightweight Raleigh with same style frame...

What has happened to the carbon bike, have you dropped it..now a girlie version of that would be of some interest

 

[Kudoscycles]

Eddie...we have had to put the Carbon bike to one side...it had potential but needed further development and there are easier designs which have more popular appeal. My job must be the dream of so many on this website-to conceive a new bike,design and develop the spec,then follow the progress through to production-there are very few engineering disciplines left in this world where you can view the process and evolve solutions throughout the build,we currently have 4 new designs to be released throughout 2012-I really enjoy my job.
Dave
KudosCycles

 

[gerryscott]

Thanks for the info eddio, a good looking bike.I'M not sure about range though with the 8ah battery,also the cost of replacement battery might be scary.

 

[lemmy]

I just like the system and its performance, plus style and weight appeals as well. just think a 36v system makes more sense

In what way its performance? How does it's performance differ? How does the style differ?

For myself, my Kalkhoff has 3 power positions and I use the 1:1 or .5:1. I've never used the higher power option even on the steepest hills because the gears obviate the necessity. If I wanted a fully powered machine with no pedalling I'd just go back to motorcycling, logically and be able to travel much faster and further.

I'm 67 and therefore not the strongest of riders but can't see that I'd need more power. The entire Panasonic unit including battery comes in at around 5 kilos, I'd have guessed, so presumably the Bosch can clip 2 or 3kg off this? That would be nice.

Is 36v automatically better than 26v? Wouldn't 48v - or 60v be better still then? I'm not technical so I'd like to understand these things.

The Bosch system seems to be a lot dearer - why would that be? Better quality components? Longer guarantee? Better battery technology?

It seems hard to get answers to these questions. The tech specs don't yield much difference between the two.

 

[eddieo]

Dearer? A good few Bosch bikes from around £1800. New Kalkhoff S class Bosch from £2400 New Panasonic 36 v around £3500. (2012 PC S 4.300 euro!) Even the new impulse drive bikes are heavy in comparison....That near enough every major European bike manufacturer has Bosch powered bikes coming out and they cant meet demand surely tells you something.

Gerry batteries are about 600 euro, about £520 at current exchange rate. The review I mentioned goes into range in detail.

 

[Deleted member 4366]

I tried a Haibike (Bosch) and an Emotion (Panasonic) back to back at Presteigne, The Panasonic felt dated, underpowered and agricultural compared with the Bosch. Technolgy has moved on now, so Panasonic needs to come up with something new. 36v systems are more efficient than 26v ones because of the high currents involved, which cause electrical power to be wasted as heat. These losses are more than twice as much in a 26v compared with 36v.

 

[flecc]

Panasonic have upgraded the unit and it's now a 36 volt system for 2012. However, with their new season prices high and trailing behind the competition at each step, they may have left it too late. Derby Cycles/Kalkhoff are their premier customer, but they now have their own up to the minute crank unit which could eventually displace their use of the Panasonic one completely.

 

[Miles]

36v systems are more efficient than 26v ones because of the high currents involved, which cause electrical power to be wasted as heat. These losses are more than twice as much in a 26v compared with 36v.

Errrrr, no. As far as motors are concerned, the voltage they are designed to work with makes no difference whatsoever to their efficiency.

 

[eddieo]

 

[Deleted member 4366]

Errrrr, no. As far as motors are concerned, the voltage they are designed to work with makes no difference whatsoever to their efficiency.

Yes , you're quite correct. I should have qualified my statement by adding the words "..... when delivering the same output power and assuming similar design characteristics".

 

[Miles]

Yes , you're quite correct. I should have qualified my statement by adding the words "..... when delivering the same output power and assuming similar design characteristics".

Hi d8veh,

I took that as read. For a given specification, it makes no difference if the motor is designed to run on 24 Volts or 36 Volts. A motor's velocity constant is the reciprocal of its torque constant.

Miles

 

[lemmy]

A motor's velocity constant is the reciprocal of its torque constant.

Seriously, what does that mean in less technical speak?

 

[Miles]

Seriously, what does that mean in less technical speak?

That if you rewind the motor to reduce the angular velocity per Volt, the amount of torque you get per Amp will increase proportionately.

If you have a motor wound to run at a given speed on 24 Volts and you want to rewind it so that it runs at the same speed on 48 Volts, you double the number of turns in the coils. If you do this the motor resistance will go up by the square [wires are half the cross-sectional area and twice the length]. However, the number of Amps required to achieve the same amount of torque is halved and the copper losses are proportional to the square of the current. Everything balances out and the efficiency remains the same.

Miles

 

[lemmy]

Thanks for that, Miles.

 

[NRG]

That if you rewind the motor to reduce the angular velocity per Volt, the amount of torque you get per Amp will increase proportionately.

If you have a motor wound to run at a given speed on 24 Volts and you want to rewind it so that it runs at the same speed on 48 Volts, you double the number of turns in the coils. If you do this the motor resistance will go up by the square [wires are half the cross-sectional area and twice the length]. However, the number of Amps required to achieve the same amount of torque is halved and the copper losses are proportional to the square of the current. Everything balances out and the efficiency remains the same.

Miles

Yes, your losses only increase if you are trying to pull the same power from the same motor at the lower voltage...

The move to 36v for the Panasonic motors is a marketing move as the perception is 36v is better than 26v...

 

[flecc]

The move to 36v for the Panasonic motors is a marketing move as the perception is 36v is better than 26v...

It seems to be a growing trend, 26 volts increasingly relegated to the low budget, low power sector such as the Cyclamatic.

If the trend continues it will at least be something standardised.

 

[Miles]

Yes, your losses only increase if you are trying to pull the same power from the same motor at the lower voltage...

Clearly, that wouldn't make sense.

So, although the voltage used is pretty much irrelevant, it's a handy marketing tool.... Starting at 18Volts would have given more scope...