Head or heart – a comparison of Kalkhoff and Cytronex bikes

[tagray]

At the end of last year with retirement looming, I wanted a reliable e-bike to see me through the next few years whilst I am reasonably mobile and to go on longer rides into the Derbyshire Peak District. I have used Trek Cytronex bikes for commuting a hilly 16 miles a day through Sheffield but the bikes needed a lot of maintenance and I wanted to try a different system. I specifically wanted shock absorbers to deal with the rotten roads locally, and a hub gear system. I had originally had these with a Giant Twist Comfort with a 5 speed hub gear which was great for getting me back to cycling but the bike was slow, heavy and rather cumbersome, but I knew that the new panasonic powered bikes were better. So I took the plunge and bought a Kalkhoff Pro-Connect disc with the alfine 8-speed hub before VAT went up.

I have attached a zipped word document with my thoughts on the relative merits of the two bikes. I can’t justify having two bikes so I had to decide which to choose.

To sum up the choice in a few sentences, the Kalkhoff oozes quality, it is heavy but looks bomb-proof and does everything without fuss but is so low geared it runs out of steam (or at least I do) over 20 mph. The Cytronex on the other hand can go as fast as I can pedal downhill at any cadence I choose and still brings me back with my pulse racing. The Trek bike is probably less robust but the cycling position is right for me to get the best out of the bike and it is the original stealth bike whilst the Kalkhoff shouts e-bike. However, the Cytronex has limited battery range whereas I have tested the Kalkhoff battery out to nearly 30 hilly miles without problems. The accompanying document gives a performance comparison and a few photos are linked below. So do I go with my head which says the Kalkhoff is the better long term bet, or my heart which gets a kick out of each session on the Cytronex?

Trek 7500 Cytronex | Flickr - Photo Sharing!

 

[HarryB]

You don't say whether you have changed the gearing on the Kalkhoff - this gets round the gearing problem and/or the cadence problem can be cured with an 11 tooth sprocket. The Kalkoff would then make mincemeat of the Trek but of course be slightly illegal...

 

[tillson]

I can't open your word document because I'm away from home and can only access the forum on my iPhone, so forgive me if I have missed something in that write up.

I noted that you thought the Pro Connect to be slow. Have you tried altering the gearing by changing the rear sprocket to something smaller, say 18 or 19 teeth?

My colleague commutes to work on a Trek FX 7.3 (non electric) and I have borrowed it on a few occasions, to be honest, the fastest I can pedal that is to about 37mph which is about the same as my PC with an 18 tooth rear sprocket. I too live in a hilly part of Derbyshire and haven't come across a hill that the modified PC can't cope with.

Ps crossed with HarryB. Agree with his comments.

 

[flecc]

I'd say first try the gearing change suggested by Harry and Tillson.

If that isn't a decider, I think your fitness should be.

In other words, if you can at all times enjoy the challenge that using the Cytronex entails, go with your heart.

If on the other hand there are times when you don't feel up to the prospect of the Cytronex, or your spirits are flagging by the end of some Cytronex journeys, go with your head. Those occasional adverse feelings won't get any better or less frequent with time.
.

 

[tagray]

Cadence on crank drives

Thanks to all for comments. As those who can open my document can see, I have considered changing the gearing but that does mean that the bike would not stay within the regulations as I understand them. With the hub gear, cadence and speed can be varied at the riders whim and ability. Being unable to match the Trek's downhill speed on the Kalkhoff has nothing to do with fitness - there is such a disparity in gearing with the Kalkhoff on its standard gearing that my legs simply won't go round fast enough! (A simple calculation shows it has to be nearly 50% faster). I can reduce the disparity using a smaller rear sprocket but that would put the bike outside the regulations.

 

[Scottyf]

Follow your heart, because if you always trust your mind, you'll always act on logic, & logic doesn't always lead to happiness.

Thats my little quote for today.

Besides nothing every fun came out of being sensible.

 

[EdBike]

Follow your heart, because if you always trust your mind, you'll always act on logic, & logic doesn't always lead to happiness.

Thats my little quote for today.

Besides nothing every fun came out of being sensible.

Exactly! Who says you have to 'justify' having two? You've already got both?

It'd be a different issue if you were living in a skip and they were your last two possessions, right?

 

[tillson]

Thanks to all for comments. As those who can open my document can see, I have considered changing the gearing but that does mean that the bike would not stay within the regulations as I understand them. With the hub gear, cadence and speed can be varied at the riders whim and ability. Being unable to match the Trek's downhill speed on the Kalkhoff has nothing to do with fitness - there is such a disparity in gearing with the Kalkhoff on its standard gearing that my legs simply won't go round fast enough! (A simple calculation shows it has to be nearly 50% faster). I can reduce the disparity using a smaller rear sprocket but that would put the bike outside the regulations.

Yes, reducing the rear sprocket size does, technically, put it outside the regulations and if you want to stay on the right side of them, then the modification isn't for you.

 

[Biged]

Change the Kalkhoff front chainring to 42T, works wonders
They did it for free when i purchased my Agattu

 

[eTim]

Flecc's advice is good, if your fitness is up to it, stay with the Cytronex for the fun reward. Otherwise, go with the practical solution.

 

[fishingpaul]

The bikes are very different,one can make you feel as though you are speeding along,and you can also also enjoy riding it without power,the other can take you greater distances,handle inclement weather and make hills a breeze,if you sell either i think you will have some regrets,so i think this justifies keeping both bikes.

 

[HarryB]

I understand your point about the kalkhoff looking like an obvious electric bike - I think most of that is down to the ugly chain guard and I wish they would reduce the size. The emotion sport looks much less electric and is better looking IMHO. More expensive and not nearly so well equipped though.

 

[fishingpaul]

I think the placing of and colour of the battery sticks out like a sore thumb, not everybody wants to shout that the bike is electric powered,if it came with a stealth option and blended in with the frame i am sure they would sell far more.

 

[tagray]

Sorted

Change the Kalkhoff front chainring to 42T, works wonders
They did it for free when i purchased my Agattu

Thanks to all who replied. I contacted 50 cycles who kindly changed the front sprocket to a 41 tooth ring giving a much more normal cadence. The bike is transformed and I found it much easier to cycle around the top of the power band as I usually do on the cytronex. Apparently Derby cycles have recently been shipping them with 35/19 as opposed to 41/22 (similar ratio but would need the controller to be tweaked to give similar speed characteristics to the power band with the smaller rear sprocket). This gives the opportunity to change the front sprocket to change the cadence whereas when delivered with a larger set of sprockets (and presumably controller to match) the only way you can change the cadence is to reduce the rear sprocket size which takes you outside the regulations.
So thanks for the advice and for good service from 50 cycles and I am really looking forwards to some great rides in Derbyshire soon.

 

[flecc]

Apparently Derby cycles have recently been shipping them with 35/19 as opposed to 41/22 (similar ratio but would need the controller to be tweaked to give similar speed characteristics to the power band with the smaller rear sprocket). This gives the opportunity to change the front sprocket to change the cadence whereas when delivered with a larger set of sprockets (and presumably controller to match) the only way you can change the cadence is to reduce the rear sprocket size which takes you outside the regulations.

The controller wouldn't need to be changed since it's speeds relationship is only with the motor's chain drive sprocket.

Changing the size of the motor sprocket also changes the cadence in the same way that changing the chainwheel does, but it also has to be compensated by a change in the rear sprocket for legality to be kept.

Changing the rear sprocket only doesn't change the cadence, it just changes the overall gearing.
.