Kalkhoff Gearing Modification Question

[Allan Rudwick]

Hi! I'm thinking of buying a Kalkhoff pro connect sport 27-G dual drive. I have ridden it on several test rides including one 20 mile ride where I noticed that there is a problem with the gearing. Specifically, when I am trying to go fast, I notice that I need to shift for the motor to a higher gear before my legs are ready for it, so essentially my maximum comfort pedalling speed is noticably faster than the motor's maximum power output speed. I am wondering if anyone else has had this problem with Kalkhoff bikes and has fixed it by changing the gearing. Is it easy/hard/impossible? Are there kits or instructions + parts that make this a piece of cake? Without this modification I will not be buying the bike. The folks at Kalkhoff USA have told me that this modification will void the warranty. Is there a simple process that doesn't require permanent modifications to the bike? Thanks so much for your help.

 

[JuicyBike]

VOID THE WARRANTY?
Are you kidding?
It's a bike!!!

Or at least it's supposed to be...

Change the front chain wheel for one with a few extra teeth. And keep the old one in case they seriously expect you not to make any change to stay within the warranty.



Bikes are all about modifying and personalising.

Oh, and welcome to these forums Allan.

Muttering under breath... void the warranty my ass... is this the litigious future awaiting the uk... "will it be ok if I put a Who sticker on my cross bar?"... Grrr!

 

[banbury frank]

Hi If you where to buy one off our bikes and de restrict it to do 30 mph Strictly for use on Private land with the land owners permission I would be very annoyed and VOID your warranty He He He He

Just Joking As long as you don't open the electronic and start soldering Its your bike

You can customize the Gears Just BUY the right part from the suppler I sure he will supply so it is a Genuine part

Frank

 

[Allan Rudwick]

It seems like I'd need a smaller chain-wheel or a larger toothed gear on the motor drive shaft to make the change I am hoping for. Has anyone made these modifications? Who is the part supplier -- does Kalkhoff sell these or is there a vendor that is 'approved' for these sort of changes?

 

[banbury frank]

Hi 50 Cycles are and do

Electric Bikes | Kalkhoff E-bikes | Best Electric Bicycles UK

Frank

 

[NRG]

You can increase the motor sprocket size to provide assistance to a higher speed. Not sure what the bike you tested will be fitted with but the largest I've come across is 12 tooth. 50cycles sell these or they can be bought from eBay...



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[flecc]

To make your cadence (pedal speed) faster at any given motor speed, you need to reduce the chainwheel size. Normal bike chainwheels do not fit, only the Panasonic spline mounted ones from the makers will. There are only two sizes available, 35 tooth and 41 tooth.

Most S models have the 41 tooth as standard, if so and you change to the 35 tooth, your pedalling speed relative to motor speed will increase by 15%.

This change can affect the warranty since the change affects the motor drive relationship, so the makers will not be liable for any difficulty caused by that change. Users have had more transmission problems with the 35 tooth chainwheel and solved that with the 41 tooth instead, the opposite of what you need.