Trek Cytronex - First Impressions.
- Thread starter Chris_Bike
- Start date
The label on the motor says 180W and 175 rpm, but I think I remember Mark saying it was 190 rpm on the other thread. I've just tested the speeds off ground but this was with a warm fully charged battery: 15.5mph on low and 18.2 mph on high. I find these translate to about 12.5 and 16 on the road.
Chris
ps. I have just looked in the other thread and it was Flecc who mentionned a 190 rpm motor, so I guess it's 175 (unless this and the 180W are marked as "rated" for legal reasons in various countries). If Mark reads this, perhaps he can say?
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The size, weight and capacity suggests sub-C cells to me John, some of which claim a 35A max discharge current (~8C): Mark or others will be able to say for sure.
It sounds like its a 190rpm motor if the wheelsize is the same as the Trek 7.3FX spec (700 x 32c) - that would give a top motor-only speed of ~16mph on the road, as Chris said.
Stuart.
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When does yours arrive Andy?Thanks Chris, everyone of your posts so far has me glad I've got one on order
Chris
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With the greatest of respect Chris, the figures just don't seem to add up to me as I've said and, just in case you consider me to be one of the 'cynics' you refer to, I have never for one second doubted either your sincerity or your genuine happiness with & infectious enthusiasm for the bike.
I don't doubt that its a great bike to ride, but I do strongly question how much power output you are accrediting to the bike, and not your legpower, for your results.
Stuart.
I don't disagree about the motor's ease of riding and if my assessment of your level of input on is wildly inaccurate and the bike instead performs far beyond expected then I will gladly retract my statements to the contrary.
I calculate that the motor output is approximately half the 800W required for the 15% climb at 10mph, which means the remaining 400W power is rider input, which would be no small feat - equivalent, for example, to climbing about a 13-14% gradient in a Torq1, when the often-stated normal limit is 10%, or climbing a 10% (1 in 10) slope on an unassisted bike at around 7mph.
I don't doubt that its a great bike to ride, but I do strongly question how much power output you are accrediting to the bike, and not your legpower, for your results
.Stuart.
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175 rpm sounds right and makes sense. The 190 rpm motor gives you a 20 mph unloaded speed and around 17 mph on the road.
How much leeway is there with the motors' rpm? Even on a fresh charge, 190rpm in 700 x 32c wheels/tyres is barely 16mph? 175rpm would give about 15mph maximum, less than Chris has measured? Unless the speedometer is incorrectly set for the wheel size, perhaps.
Stuart.
Stuart.
I'd refrained from commenting on this, but I'd already seen that Chris is a far more powerful rider than he feels he is. The Tongxin motor simply isn't capable of miracles, the motor technology is quite normal and the Nano only gains over others fractionally due to it's roller drive efficiency gain. Most e-bike riders using the bike in the way they usually do, power all the time, wouldn't get to 10 miles on the battery and would complain it wasn't brilliant on hills. The majority certainly wouldn't be able to climb 1 in 4, since many of them can't do that on the most powerful very large batteried hub motor bikes.I calculate that the motor output is approximately half the 800W required for the 15% climb at 10mph, which means the remaining 400W power is rider input, which would be no small feat - equivalent, for example, to climbing about a 13-14% gradient in a Torq1, when the often-stated normal limit is 10%, or climbing a 10% (1 in 10) slope on an unassisted bike at around 7mph.
I don't doubt that its a great bike to ride, but I do strongly question how much power output you are accrediting to the bike, and not your legpower, for your results
Stuart.
Of course it's not meant for the run of the mill e-bike users who ride in moped mode, and in the hands of the keen cyclist it's intended for to help a bit on hills, it can perform well and I've no doubt it's a delight then.
My only concern is if Chris's obvious enthusiasm gets the wrong people to buy and be disappointed, and it's important that everyone understands the limitations of this kind of system. We saw this problem on the Torq 1, with many buyers misled by enthusiastic reports from capable cyclists and subsequently terribly disappointed. The result was a string of sales of nearly new Torqs at less than half of the new price in many cases.
.
Chris,
The decision was a bit of a change of direction as I was going to get an Ezee hub for my Yuba cargo bike. I was quite excited to notice that the new UK distributors listed the Ezee kit, but 2 unanswered email enqiries and a phone enquiry when someone was going to get back to me and didn't, left me less sure. (In complete contrast to ebike in Canada who responded very quickly and helpfully to several queries.) I was going to wait until ebike had them back in stock and then read your posts on Cytronex.
Thinking it through some more I acknowledged that 90% of useage would be for commuting 15 miles each way to work. If it'll help with pulling a child trailer occassionally as well I'll take that as a bonus. Mark was helpful and responsive, I'd prefer to go for UK based supplier and your enthusiastic posts clinched it for me.
I don't have a specific delivery date yet, but I'm hoping days rather than weeks. I'm up in Perthshire and all but the last couple of miles is country lanes. I'm really looking forward to being able to get in some quality riding time, which is quite difficult with a littl'un, and it be under the guise of doing something I have to anyway ie get to work
Andy
The decision was a bit of a change of direction as I was going to get an Ezee hub for my Yuba cargo bike. I was quite excited to notice that the new UK distributors listed the Ezee kit, but 2 unanswered email enqiries and a phone enquiry when someone was going to get back to me and didn't, left me less sure. (In complete contrast to ebike in Canada who responded very quickly and helpfully to several queries.) I was going to wait until ebike had them back in stock and then read your posts on Cytronex.
Thinking it through some more I acknowledged that 90% of useage would be for commuting 15 miles each way to work. If it'll help with pulling a child trailer occassionally as well I'll take that as a bonus. Mark was helpful and responsive, I'd prefer to go for UK based supplier and your enthusiastic posts clinched it for me.
I don't have a specific delivery date yet, but I'm hoping days rather than weeks. I'm up in Perthshire and all but the last couple of miles is country lanes. I'm really looking forward to being able to get in some quality riding time, which is quite difficult with a littl'un, and it be under the guise of doing something I have to anyway ie get to work
Andy
Much of what flecc posted is really all I was trying to say, especially the last part: the hard learnt lessons of the Torq1 for many who found it wouldn't climb their hills (too steep at over ~10%) in particular on my mind. The enthusiasm is refreshing but as always its important it doesn't cloud accurate information about performance: I hope the added clarification of what type of riding & terrain the bike will suit will help prospective owners choose a bike, and the experiences of others should add to whats known about its range of use.
And I'm relieved I'm not going mad, I was beginning to wonder!
Happy cycling everyone!
Stuart.
And I'm relieved I'm not going mad, I was beginning to wonder!
Happy cycling everyone!
Stuart.
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I think that 10 miles is probably reasonable to expect for 36V/4Ah battery, but not too much more for 'normal' commuting, for an efficient setup like this one.
The setup is probably one of the better hill climbers, judging form my 260rpm in 26" wheel going up moderate hills nicely. Having a full range of gears does help the rider to always be able to provide an efficient input.
I can see people getting carried away with Chris's enthusiasm. I am still more concerned about reliability. It would be nice to learn from TongXin that they had learned how to glue magnets on at least and perhaps a run of 6 month without people reporting major problems.
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I just remembered, I took my bike on holiday recently on a track with the kids and came to a 1 in 8. I can just about tackle this in bottom gear (of 24) just pedalling and adding motor power helped enormously even though the motor couldn't have managed it on its own. I think one of the issues with the Torq1 was that it didn't have any low gears.
C
Cyclezee
Guest
Personally, I think what is needed in this thread is a bit of balance, fairness and an open mind rather than pre judge the Cytronex before it has really hit the road.
Not everyone wants a heavy 'electric moped'.
Sure Chris is very enthusiastic and enjoying the bike, but there is a lot of negative stuff from people who have not even seen the bike let alone ridden one. Why can't we just wait until there are a few more Cytronex owners out there and allow them to comment before writing it off.
J hn
Not everyone wants a heavy 'electric moped'.
Sure Chris is very enthusiastic and enjoying the bike, but there is a lot of negative stuff from people who have not even seen the bike let alone ridden one. Why can't we just wait until there are a few more Cytronex owners out there and allow them to comment before writing it off.
J
hn
Reviews
It should not perhaps be a surprise to us on introducing an innovative new product there will be others in the industry that will be worried by the competition. I notice the same few names keep appearing in threads about our product with negative comments every time something positive is said, yet none of these names have ever been on our bikes! Shame that they feel they have to knock a British design.
Regarding torque, I am 43 years old and was the only Cytronex bike entered in the Presteigne races - I came third in the hill climb, and 5th equal (out of 100 ebikes) in the race on Sunday. I was up against proper cyclists fielded by some of the big names in the industry. I have never been in any cycle race before and yet I beat a great many Torq, Heinzmann, Kalkhoff, Giant, etc.. However, they are all good bikes and I am certainly not going to detract from them – in fact I want us all to sell as many as possible to get more cars off the road.
We certainly do want people to pedal, our bike is designed for the enjoyment of cycling, it is not intended as a moped substitute. Yet Cytronex can give any of the big names a run for there money in hill climbing due to its excellent power to weight ratio, and real bike geometry.
I would urge people to judge for themselves or read the reviews from those who have actually tried the bike. We have only just started so these will come out as soon as we can ship the bikes.
Regarding other questions: motor is 175rpm, 180 watts is rated for China. We are not using AA cells or C or sub C cells. Our battery is an innovative product and we have been working directly with the cell manufacturer. The result is a small battery that packs a big punch!
It should not perhaps be a surprise to us on introducing an innovative new product there will be others in the industry that will be worried by the competition. I notice the same few names keep appearing in threads about our product with negative comments every time something positive is said, yet none of these names have ever been on our bikes! Shame that they feel they have to knock a British design.
Regarding torque, I am 43 years old and was the only Cytronex bike entered in the Presteigne races - I came third in the hill climb, and 5th equal (out of 100 ebikes) in the race on Sunday. I was up against proper cyclists fielded by some of the big names in the industry. I have never been in any cycle race before and yet I beat a great many Torq, Heinzmann, Kalkhoff, Giant, etc.. However, they are all good bikes and I am certainly not going to detract from them – in fact I want us all to sell as many as possible to get more cars off the road.
We certainly do want people to pedal, our bike is designed for the enjoyment of cycling, it is not intended as a moped substitute. Yet Cytronex can give any of the big names a run for there money in hill climbing due to its excellent power to weight ratio, and real bike geometry.
I would urge people to judge for themselves or read the reviews from those who have actually tried the bike. We have only just started so these will come out as soon as we can ship the bikes.
Regarding other questions: motor is 175rpm, 180 watts is rated for China. We are not using AA cells or C or sub C cells. Our battery is an innovative product and we have been working directly with the cell manufacturer. The result is a small battery that packs a big punch!
Mark,
I am not quite sure which comments you are referring to, perhaps a quote or two would be useful.
Speaking of my own comments, some of which could be described as 'negative', they are always balanced by at least as many positive. They also only refer to the TongXin components which I am very familiar with (inside and out).
As for the rest of your bike, I have not tried one but from the details I have read I am very impressed. It is indeed refreshing to see a company make a really serious effort to source the best quality components and put them together in very thoughtful way.
Keep up they good work!!
John
Hello everybody........ Oh dear, I do seem to cause so much trouble
Can I say from the outset that I hope I have never given the impression that I think you should ride this bike without pedalling. I wouldn't want to and I can't imagine that anyone who would want to ride like this actually buying one. This is a bike for those who love cycling. Btw. I would describe the Kalkhoffs the same way - by definition, the rider pedals - and I greatly enjoyed riding those bikes at Presteigne too. But, if you want a moped to do all the work for you - buy a moped.
Thanks to Mark for the clarification on the motor. Whatever it says on the label, I think it is clear that it is delivering more than 175 rpm most of the time (on full power). I have just been out and measured the circumference of the wheel + tyre. The result is 86.6 ins, to deliver the 15.5 mph it certainly does on high power, that wheel should be going round at 190 rpm.
With respect to the computer Stuart. Trek computers insert the tyre size rather than an accurate circumference, which would be better as tyres vary. The computer is set correctly but could be a little out as a consequence of this variation in actual tyre size. I will accurately callibrate it against a local RTTC time trial course when it stops raining and post the result.
Now we come to the vexed question of my power output. I'm afraid this is a subject that I do know something about. I'm a Biochemist not an physicist and I'm not going to try to calculate the wattage required to climb a hill right now. It's more than 20 years since I did mechanics. However, I have a lot of experience of the power outputs of elite cyclist, let me explain.
My 2 sons are both competitive cyclists. The oldest is also a sports scientist currently working in Oxford. He regularly measures the power output of elite cyclists, including members of the national squad. My youngest was a member of British Cycling's Talent Team for 3 years, during which he was tested for power output every 6 months at least.
The best way to measure endurance output , such as required for hill climbing is via a "ramp test". Essentially the resistance is progressively increased in steps every 3 minutes and the system measures (usualy via SRM cranks containing strain guages) the power output by the cyclist over the last 3 minute period completed before they "blow".
A cyclist does NOT have to put out 800 watts to climb at 15% hill at 10 mph lasting a mile. There are probably a very few elite cyclist in the world who could sustain this sort of power output for more than a few minutes. If you google, you'll probably find some examples on the web, but I haven't looked. My youngest son, who is a very good hill climber probably manages about half this when climbing Forhill and he gets up it a lot faster than I do with a motor.
I'm an experimental scientists who deals in experiments that yield data, which we all try to interpret. That is what I have been trying to do in these posts and I stand by the data that I have reported.
Chris
Can I say from the outset that I hope I have never given the impression that I think you should ride this bike without pedalling. I wouldn't want to and I can't imagine that anyone who would want to ride like this actually buying one. This is a bike for those who love cycling. Btw. I would describe the Kalkhoffs the same way - by definition, the rider pedals - and I greatly enjoyed riding those bikes at Presteigne too. But, if you want a moped to do all the work for you - buy a moped.
Thanks to Mark for the clarification on the motor. Whatever it says on the label, I think it is clear that it is delivering more than 175 rpm most of the time (on full power). I have just been out and measured the circumference of the wheel + tyre. The result is 86.6 ins, to deliver the 15.5 mph it certainly does on high power, that wheel should be going round at 190 rpm.
With respect to the computer Stuart. Trek computers insert the tyre size rather than an accurate circumference, which would be better as tyres vary. The computer is set correctly but could be a little out as a consequence of this variation in actual tyre size. I will accurately callibrate it against a local RTTC time trial course when it stops raining and post the result.
Now we come to the vexed question of my power output. I'm afraid this is a subject that I do know something about. I'm a Biochemist not an physicist and I'm not going to try to calculate the wattage required to climb a hill right now. It's more than 20 years since I did mechanics. However, I have a lot of experience of the power outputs of elite cyclist, let me explain.
My 2 sons are both competitive cyclists. The oldest is also a sports scientist currently working in Oxford. He regularly measures the power output of elite cyclists, including members of the national squad. My youngest was a member of British Cycling's Talent Team for 3 years, during which he was tested for power output every 6 months at least.
The best way to measure endurance output , such as required for hill climbing is via a "ramp test". Essentially the resistance is progressively increased in steps every 3 minutes and the system measures (usualy via SRM cranks containing strain guages) the power output by the cyclist over the last 3 minute period completed before they "blow".
A cyclist does NOT have to put out 800 watts to climb at 15% hill at 10 mph lasting a mile. There are probably a very few elite cyclist in the world who could sustain this sort of power output for more than a few minutes. If you google, you'll probably find some examples on the web, but I haven't looked. My youngest son, who is a very good hill climber probably manages about half this when climbing Forhill and he gets up it a lot faster than I do with a motor.
I'm an experimental scientists who deals in experiments that yield data, which we all try to interpret. That is what I have been trying to do in these posts and I stand by the data that I have reported.
Chris
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Speed
Yes Chris you are undoubtedly right that the rpm speed does not correspond to the top speed of the motor. This confused us no end when we were trying to choose the right speed. Our working assumption (though I have never actually asked) is that the rated speed is that at which it supplies the maximum continuous power. It is certainly not the no load speed of the motor.
Yes Chris you are undoubtedly right that the rpm speed does not correspond to the top speed of the motor. This confused us no end when we were trying to choose the right speed. Our working assumption (though I have never actually asked) is that the rated speed is that at which it supplies the maximum continuous power. It is certainly not the no load speed of the motor.
I've just tried to put Jack's data into this calculator but it refused to calculate: The data are: 28" wheels, 6.75 cranks, 15mph, bike weight 18 lb, rider weight 125 lb, resistance 3%, gear 0.435 (39 x 17), straight arms, racing clinchers (some a bit arbitrary).
Added later:
I've now got this site to work and it claims a rider input of 729 Watts. I'm afraid I don't believe this number and neither would British Cycling. Jack, who was highly amused, reckons his tests show he achieves about half this output
Chris
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