ebike to keep up with road bike for 40 miles

[tillson]

Tom, there will always be some who wish to travel faster that a wheelchair.

You keep repeating yourself, is this a medical issue or just an attempt to get people to listen to you?

Actually, oldtoms's post was factual, unbiased and not at all repetitive. His words provided the sort of information that a potential new entrant into the world of electric bikes needs to hear. Pointing out the pros and cons of illegal bikes thus allowing the OP make an informed choice whilst in possession of all the facts is entirely sensible.

When you eventually stop your insignificant posting on this forum and quickly fade from memory, which you will, someone is going to have some really big clown shoes to fill.

 

[tillson]

The Pro Connect i8 Alfine is perfect for this - it has the range, the reliability, the power.

If this bike is as good as the old 2008 Pro Connect (I expect that it has improved over the last 6 years), then it has to be worthy of consideration. If you are serious, it is definitely worth a trip to Loughborough to try one out. The same goes for any bike, don't buy it without trying first.

Looking at the specification on 50c's website, it will give you a good level of performance by intelligently exploiting the regulations to keep you legal.

I have only ever owned Kalkhoff electric bikes, so can't compare them with anything else, but I have travelled thousands of miles commuting on my Pro Connect and it has been virtually faultless. (The motor has now died, but I'm not in the least disappointed, I have easily had my money's worth out of it).

50c have been around for a long time, so the back up is there. From my experience their service ranges from diabolical to outstandingly good. Taking an average, they are ok, and if I wanted another bike (which I don't), I'd go back to them. They generally try to help but occasionally have a brain fart and undo all their good work.

 

[jackhandy]

When you eventually stop your insignificant posting on this forum and quickly fade from memory, which you will, someone is going to have some really big clown shoes to fill.

Totally disagree with you, Tillson:
The amount of potificating on the legality of bikes & builds is becoming tiresome. It's a matter of personal choice.
Anyone taking the trouble to read the forum for a while before posting will have found all the legal/non-legal information without it being preached every time.

 

[trex]

if speed is what you want, then it's easy to get high speed with crank drives because it is limited only by your cadence.
For example, with 26" wheels, 23mm tyre size, 44 teeth in the front and 12 in the back, 15mph = 58 RPM, 52 RPM with 700C wheels.
http://www.bikecalc.com/cadence_at_speed
The cheap Chinese crank motors from TCM, XOFO and 8-Fun can assist up to 80-83 RPM at 36V. The BBS01 and XOFO MMT/MMS can be used at 48V assisting up to120RPM.
What you need at high speed is extra torque to overcome greater air resistance, the motor can only supply a set amount, the rest must come from your legs.
I personally feel that 250W assistance is enough, there is no need to buy a more powerful motor and run a much bigger risk of endangering yourself and others.

 

[mountainsport]

Totally disagree with you, Tillson:
The amount of potificating on the legality of bikes & builds is becoming tiresome. It's a matter of personal choice.
Anyone taking the trouble to read the forum for a while before posting will have found all the legal/non-legal information without it being preached every time.

Hi jackhandy good point taken, and as john had also said it is all down to personal choice but please bare in mind there are new members that have just signed up today for the first time oblivious to the rules and regulations of the ebike world.
Therefore going on and on.......... maybe a good thing for the extra green or wet behind the ears new members and STILL like myself .

MS.

 

[mountainsport]

Sorry, jackhandy it was you who had mentioned about personal choice, again sorry for skimming through your reply

MS.

 

[cwah]

My dahon jetstream can do your 40 miles at 20mph NO PEDALLING with the 1440wh (72V20AH) battery pack:

I'm considering getting a bigger bike. Heavier and with more acceleration. So if you want to get it just tell me.

 

[drsolly]

What is the way out then? I see people arguing a 36V 15A standard motor is not enough to cope with hills, and even a lycra guy could beat them.

But a watt is a watt, and 36V 15A provides for 540W. Ok, take 30% due to losses, but you are still at Tour de France performance levels.

I cannot understand how a kit able to provide continuously 36V 15A is not able to go up any hill, no matter how steep, if a Tour de France biker can, too.

The only possible explanation is the kit is not giving 36V 15A support, but much less.

Or is there another possible explanation?

Yes, there's another explanation.

As well as not taking into account the reduced efficiency of the motor when it runs slowly, you might also be confusing watts and watt-hours.

The 36volt, 15 battery is 15 amp-hours, not 15 amps. That tells you the total amount of energy in the battery.

To go up a hill, you don't use watt hours, you use watts. Your street-legal engine is rated at 250 watts. It can do more for short bursts, but on the other hand when going up a steep hill, it'll be running slowly, so it'll give you less power. So if the 250w motor can do a burst of, say, 500w, but it's efficiency is only 20% because you're going slowly up a steep hill, then you're only getting 100w of power at the wheel.

 

[drsolly]

That Dahon Jetstream looks terrific. And when eventually the time comes to replace the batteries, they're an easy buy from Hobbyking.

 

[Arbol]

Yes, there's another explanation.

As well as not taking into account the reduced efficiency of the motor when it runs slowly, you might also be confusing watts and watt-hours.

The 36volt, 15 battery is 15 amp-hours, not 15 amps. That tells you the total amount of energy in the battery.

To go up a hill, you don't use watt hours, you use watts. Your street-legal engine is rated at 250 watts. It can do more for short bursts, but on the other hand when going up a steep hill, it'll be running slowly, so it'll give you less power. So if the 250w motor can do a burst of, say, 500w, but it's efficiency is only 20% because you're going slowly up a steep hill, then you're only getting 100w of power at the wheel.

Yes, I know a battery capacity is quoted in Ah. But I was referring to 15A as a current, being the max current the controller is going to provide to the motor.

Luckily, I still remember some applied physics from high school

 

[D8ve]

Retread thread.
Arbol was talking 15 amps and 540 watts available .

Drsolly was also saying efficiency falls as motors slow before stalling.

Hence only 100 watts of push up hill.
This is the argument for crank drive that gearing allows you to carry on up very steep hills.
My personal experience says it did work up hill.
Never tried a hub drive in bath so can't comparing but I understand the maths and you will flat the battery or smoke the motor doing that.

 

[Artstu]

My crank-drive bike allowed me to ride 36.2 miles yesterday, climbing 3207 feet, and an average speed of 20.1 mph, I did however use about 650 wh of battery.

 

[Arbol]

My crank-drive bike allowed me to ride 36.2 miles yesterday, climbing 3207 feet, and an average speed of 20.1 mph, I did however use about 650 wh of battery.

Quite impressive.

Have you had to change your chain yet? I have heard one of the (few) shortcomings of crank drives is chain consumption.

 

[Artstu]

Yes I changed the chain at about 1,000 miles, I also put an adjustable chain tensioner on at the same time, it's hub geared, the higher spec KMC chain seems much better than the original lower spec KMC chain. I also brush grease on the chain these days.

I've also gone from a 21T rear sprocket to a 19T for a while, and now have a 16T one, which has upped my speed a fair bit.

 

[rippedupno1]

I think you should put a 30 T on to give us slow coachs a chance lol

 

[Artstu]

I think you should put a 30 T on to give us slow coachs a chance lol

I'll tell you what, if it turns out I'm really that much faster I'll run on 3/4 sport. and with your higher powered bike that should even things up

 

[rippedupno1]

My lord i have a cunning plan. ......i could use one of my elastic training bands and hook it round your seat post and I could easily follow you all day.....he he he he

 

[gryffe1974]

Perhaps I'm missing something here Geebee or it may be I'm just really thick. Correct me if I'm wrong but in order for an EAPC to comply with European legislation, the motor assistance must cut off at 15 mph although a marginal tolerance is permitted which could conceivably allow a smidgin more than that.

If you are telling me that an Ezee bike can permit 20 mph with next to no pedalling, that suggests there is still electrical assistance at work therefore the bike must be illegal? Last time I looked, most Ezee machines were of the order of 26-28Kgs including battery.

I note your address is Australia so perhaps different power limits apply there.

Tom

Oldtom,

You seem to get really offended everytime someone mentions illegal bikes and while i applaud your law abiding attitude you really need to chill out pal do you think the uk's finest really care if a few punters are cruising around on slightly over powered ebikes?

 

[Artstu]

I've been running on no higher than Tour setting for a few rides now, my battery is giving a range of around 30 to 35 miles now, up from my normal 15 to 20 miles in Turbo mode.
I was hoping it would prevent me from getting any KOM's , alas I've just picked one up. I'm amazed how well the bike goes on what is supposed to be 1/2 power.

Average speed is still pretty good considering.