Need help choosing a bike for 19 mile commute

[soundwave]

This average speed thing is widely misunderstood. Many people think that if they are cycling at - say 20mph much of the time then their average will be around 20mph. In fact it is more likely to be around 15mph. Consider that every time they stop - traffic, junctions, etc they will spend time slowing down and then stopped, then gradually accelerating to get back to 20mph.

There is also the effect of hills and headwinds. Lets take an example - say you come to a large hill - instead of doing 20mph your speed drops to 10mph, but on your way down you do 30mph. Then it seems as if you have kept up your 20mph average. ( average of 10 and 30 is 20?)

But no! Say the climb is 30 miles long. It will take you 3 hours to ride up, but only 1 hr to come down. So now you have done 60 miles in 4hrs - yes 15mph, not 20mph. Of course it makes no difference how long the hill is, the result is the same.

 

[anotherkiwi]

That makes no sense at all IMO. Of course its true that a dongle that removes the cut off limit will not increase the power. But a 350W motor is going to be more powerful than a 250W motor. Watts are a measure of power so more Watts equals more power! SO you will be able to go faster up hill etc. IMO!

A little high school physics refresher course:

W = A x v
250 W = 7 A x 36v

A Bosch 250 W bike probably has an 18 or 20 A controller and the 350 W one maybe has a 22 or 25 A controller. The 250 W and 350 W rating is what the motor can run at continuously for one hour without heating. Not over heating, warming by +2° Kelvin! It could peak at 1.5 kW for all we know. The only difference between the two Bosch motors is the controller and the rating printed on the label. The rating is there for consumer protection, insuring that your motor won't fry as soon as you get to the middle of the first hill.

Today I saw 688 W on my Wattmeter = 45v x 15.29 A with a 250 W motor purring along at 40 + km/h...

 

[Ryan Yorke]

Sorry 4bound I mustn’t have been very clear, I understand how average speeds work. I meant an average in the high 20’s as a hypothetical ‘dream’ figure, I realise that quite high top end speeds would be needed to account for the inevitable stops and slow sections to achieve that. I would however like a bike that could maintain a speed in the high 20’s to give me a reasonable average overall.

Oh I see, so it’s a case of the motors being under rated then? Are the s-pedelecs restricted to 45kph? Can they be derestricted too? Or after that point does it get unrealistic without changing standard gearing?

 

[Ryan Yorke]

Sorry guys, really need to refresh before typing! Thanks anotherkiwi, that does clear things up a lot. So I guess my question is, at a certain point does cadence become the limiting factor? And the controller obviously.

 

[soundwave]

under the 15mph speed limit the motor can use all of its power as 250w aint going to get you up steep hills or going 25-30mph on the flat with the speed limit removed.

dongle cut off is 35mph but to get to it takes a lot of effort as over 30mph the motor ramps down the assistance it gives until nothing.

i have 18t at front and 10- 42 at the rear but with a 20t at front you can hit 40mph but only for seconds as it cant be maintained as needs max rpm at the cranks of 120rpm

 

[anotherkiwi]

At 45 km/h air resistance becomes a real big thing... If you want to go faster you need to shave your legs, wear tights and ride in a egg shape positon. Not the most comfortable when going to work (and explaining to your new girlfriend why you nicked her wax...).

If you check the air resistance curves for cycling you will see what I mean:

 

[Deleted member 4366]

Sorry d8veh, I replied before your message had loaded! Thanks for the clarification. The Bosch motor on the RM is rated at 350W output, does that mean that the 45kph is unrealistic in the majority of circumstances too?

Yes. It's the cut-off speed, not how fast it can go. If you can pedal moderately hard throughout your journey, you should be able to hold a modal speed of around 22 mph, which would give an average of about 18 mph if it's relatively open road.

 

[Ryan Yorke]

Thanks everyone. Sorry if I’m being naive, I just want a realistic idea of what to expect. I’ve only had a short test ride of an ebike at Halfords.

- anotherkiwi, that’s fine, my legs are already shaved (kidding!) and I assume you say ‘new’ girlfriend as you tend to lose the current on after she finds out how much you’ve just spent on your new pushbike!

- d8veh, that seems reasonable, and I guess any faster than that is going to start getting quite unpleasant should you ever come off anyway.

So is there any benefit to getting an s-pedelec over a deristricted one then? Other than not voiding the warranty, but the money saved could easily cover the cost of a second Oxygen, let alone any repairs I should need to fork out for.
D8veh, you seem to have experience with the Oxygen, does derestricting it through the display ‘hack’ also void its warranty?

Thanks for being so patient with me!

 

[Deleted member 4366]

The 250 W and 350 W rating is what the motor can run at continuously for one hour without heating.

To expand on that, that's what the rating means, but what's stamped on the motor is adjusted to the legal requirement and not based on the motor's actual performance. The motor ratings have very little meaning in real life. As you say, there's very little difference between the 250w and 350w Bosch motors, so they should both be rated at 350w or 500w or whatever you want, but then that wouldn't be legal - in UK.

What we know is that using a dongle doesn't seem to do them any harm; however, it does give both the motor and the battery a hard time, so you have to be sensible about how you use one. Riding at maximum speed and power all the time is the nearly them same as continuously riding up a steep hill. A sensible rider would give it a rest from time to time to give it a chance to cool down.[/QUOTE]

 

[Woosh]

D8veh, you seem to have experience with the Oxygen, does derestricting it through the display ‘hack’ also void its warranty?

d8veh seems to avoid answering this question.

 

[Deleted member 4366]

D8veh, you seem to have experience with the Oxygen, does derestricting it through the display ‘hack’ also void its warranty?

Derestricting doesn't affect the motor in any way that would cause it to fail prematurely, so the dealer should have no reason to cancel the warranty, but some do. If I derestricted any bike, I'd keep it to myself and re-set the restriction if it ever went back to the dealer. The Oxygen takes seconds to restrict and derestrict.

I try to be fair with people. The battery will get a slightly harder time because it'll be providing power more of the time and using more charge during each journey, so if my battery started to wear out after 18 months instead of the guaranteed 2 years, I wouldn't be asking the dealer for another one under the warranty.

None of the cycle parts would be affected by going faster, except maybe you'll wear out the brakes and tyres sooner, but they're not covered anyway. If my frame snapped or forks seized, I'd expect them to be repaired under the warranty whether dongled or not, but some dealers will not pay if you've dongled/derestricted.

To summarise, don't tell anybody what you've done regarding derestriction. Don't even post anything on the forum. When questioned about how you use your bike, say nothing because the questions might be aimed at trying to avoid paying out on the warranty. There's actual examples of how forum members have posted about what they've done with their bikes, which their dealer or distributor read. Then, when they had a common failure that was nothing to do with their dongle, their warranty was refused.

I don't know the answer to your question, but for an honorable brand like Oxygen, I guess that it would come down to what the fault was.

 

[Deleted member 4366]

d8veh seems to avoid answering this question.

I don't seem to be avoiding anything. I am allowed more than 28 minutes between somebody posting and me posting a reply. Bear in mind that I'm working on at least four different forums.

 

[Danidl]

Derestricting doesn't affect the motor in any way that would cause it to fail prematurely, so the dealer should have no reason to cancel the warranty, but some do. If I derestricted any bike, I'd keep it to myself and re-set the restriction if it ever went back to the dealer. The Oxygen takes seconds to restrict and derestrict.

I try to be fair with people. The battery will get a slightly harder time because it'll be providing power more of the time and using more charge during each journey, so if my battery started to wear out after 18 months instead of the guaranteed 2 years, I wouldn't be asking the dealer for another one under the warranty.

None of the cycle parts would be affected by going faster, except maybe you'll wear out the brakes and tyres sooner, but they're not covered anyway. If my frame snapped or forks seized, I'd expect them to be repaired under the warranty whether dongled or not, but some dealers will not pay if you've dongled/derestricted.

To summarise, don't tell anybody what you've done regarding derestriction. Don't even post anything on the forum. When questioned about how you use your bike, say nothing because the questions might be aimed at trying to avoid paying out on the warranty. There's actual examples of how forum members have posted about what they've done with their bikes, which their dealer or distributor read. Then, when they had a common failure that was nothing to do with their dongle, their warranty was refused.

I don't know the answer to your question, but for an honorable brand like Oxygen, I guess that it would come down to what the fault was.

I think you are being a little disingenuous, just a little. With derestriction, the motor is working harder. That means it will heat up more.. probably not a problem, but the mechanical parts, the reduction gears, the pawls, the washers and the bearings are now getting more revolutions for longer at higher speeds and with more torque and that will cause more wear.
The battery will also heat up a bit more and evaporation of internal fluids will be a bit more, and as you said the battery will be going through more charge discharge cycles so it's lifetime is affected.

 

[Woosh]

Derestricting doesn't affect the motor in any way that would cause it to fail prematurely,

Riding at maximum speed and power all the time is the nearly them same as continuously riding up a steep hill. .

these two posts seem to contradict one another.

 

[JuicyBike]

Thanks everyone. Sorry if I’m being naive, I just want a realistic idea of what to expect. I’ve only had a short test ride of an ebike at Halfords.

Ryan, you really should go and try a few. It is impossible to choose from what other people say about which bike they think is right for you. You need to find out just how comfortable you find a bike is to ride.

Russell's Bike Shed in Sheffield have a scheme in conjunction with their local council to lend electric bikes for longer periods, so riders can test them on commutes. They are thinking of introducing the same scheme to Nottingham, via their Nottingham shop:
Russell's Bicycle Shed
Nottingham Railway Station,
17 Queen's Road,
Nottingham.
NG2 3DW
Tel: 0115 986 2917

Perhaps giving them a ring and asking if they would bring over a bike from Sheffield for you to try would get you a bike for a week. Talk to Russell himself if you can - he's pro-active and very keen to get things going in Nottingham too. Failing that you could pick one up from Sheffield Train Station.

 

[Trevormonty]

Juicybike is right, you are going spend upto 3hrs a day on this bike. The most important feature of any bike is body fit, everything else is secondary.

 

[Deleted member 4366]

Let's try and clarify, as hub motors and crank motors are different. The faster a hub motor goes, the better it is for it because the current decreases with speed, so it gets less heat and load at higher speed and better cooling. The danger to a hub-motor is low speed, where loads are multiplied significantly and cooling is reduced.

The same applies to motor speed with a crank motor except that the speed restriction is on the bike rather than the motor, so with bad gearing, it's possible to have the motor turning at low speed when the bike is going at high speed, which is bad for the motor. As long as you keep the cadence high enough, there's no problem.

In all cases, the battery will take more of a hammering because it will be giving power more of the time. That's not such a problem with a hub-motor because of the reduced current at high speed, but nevertheless, it's could still be providing power when it would otherwise be resting, though it depends on the rider. If he's solely using the motor for power (no significant pedal effort), it would be better for the battery and the motor to go faster. This is assuming that the controller is starting to ramp down the power from 15mph or less, and that depends also on the winding speed of the motor. The ramping down would most likely be above 15mph if you had a high speed motor, though the current is flat until the ramp.

To summarise:
1. It's always better for a motor to run it at high speed than low speed.
2. There's never any more load on the motor when you use a dongle, though a crank motor would most likely be running with high load more of the time.
3. The battery never needs to give any higher power, but it would most likely be giving power for more of the time.
4. How you ride your bike has the biggest effect on the load on the motor.
5. None of this should influence the warranty when people sell bikes to fat guys that pedal slowly and cause the motor to run slowly, which destroys motors, controllers and batteries.

If I were selling bikes, I'd rather sell one to a guy that was going to derestrict it than someone that was going to labour it around at 8mph.

How many dealers said to the guy that brought his 3 month old Chinese bike back to the shop with a blown controller, "sorry, no warranty because you're too fat". or "sorry, no warranty because you're a lazy bar steward that doesn't pedal hard enough"?

 

[georgehenry]

I commute a minimum return trip distance of 20 miles to work and back on a 2015 yamaha crank drive hardtail Haibike using a rack and panniers to carry stuff. I charge my battery before I set off to work and charge it at work before coming home.

I timed my undulating B road 10 mile return from work a few weeks ago carrying a pair of Ortleib panniers weighing together circa 10kg.

No stop watch I just noted the time when the level crossing gates raised to allow my wheels to start turning and checked again when my wheels stopped turning in my driveway.

I managed 29 minutes for the 10 miles and used 35% of my battery.

This is my regular commute so I know the gradients and power levels that work best for me and try to aim for up to a 20 mph average with up to 40% battery consumption on the going home road route, but mostly I just enjoy the ride without ever checking the time.

I use a combination of eco for level slightly down slightly up gradients, standard for steeper uphill bits and off for steeper downhill bits.

I suppose I am trying to make an observation about average speed and battery consumption on a de-restricted bike.

A lot of people say a de-restricted bike will kill your battery/use more battery and I have found that using a lower power level that does not cut out at any given speed allows me to achieve a high average speed (for me!), carry stuff and manage my battery consumption. You have to be prepared to put more effort in yourself but that was one of the main reasons I started commuting to work on the bike in the first place.

My battery is two years and 11 months old, seems to be working as it did from new (Obviously it must be degrading) and I have covered 8232 miles.

To be honest I am not interested in going as fast as possible and spend the majority of my time in eco and only use standard to climb steeper hills at a faster pace.

However the fact that the motor does not cut out means that I don't hit that wall on the road and just find my natural cruising speed around 20mph + or minus a mile an hour or so.

Pushing it hard in eco with perhaps a bit of gradient in my favour I top out with my gearing at a maximum of 25 mph but only ever for short distances.

On the flat in favorable conditions I might hold a maximum of 22 mph plus or minus a mile an hour. Very comparable with a roadie.

I have up geared my bike but also use a reasonable wide ratio cassette to give me a low enough bottom gear for my off road routes and an 8th gear that can hold 20 mph on the road in eco up gentle gradients with me pushing hard and a top gear that goes from 21 mph to 23 on the flat in eco with me pushing and tops out at 26 mph downhil.

The yamaha PW motor is cadence limited with the power diminishing as you spin faster.

With the motor off and me spinning fast in 9th down my steepest short hill I top out at 37mph briefly.

 

[Ryan Yorke]

Sorry for the radio silence, I’ve been away and didn’t have chance to get on here.

- d8veh, thank you. I didn’t feel you avoided the question of Oxygen warranty. I’d rather you be frank and not lead me to believe I would or wouldn’t be covered if you couldn’t say for sure. I guess my question was if I deristricted it and worst came to worse I had to send the bike back, have you heard of any cases of Oxygen realising the bike has been deristricted and re-restricted and refusing warranty? I could imagine if a company wanted to be awkward they could make the case that the bike has been used under conditions it wasn’t intended for and get out of almost any fault that could appear on the bike.

- Danidl, I’m less concerned about things wearing out more quickly that could be easily replaced at a small cost to me - after all, as you point out, the bike will be taking more hammer than it was necessary designed for - I’m more concerned about possible manufacturing faults in say the motor or battery that don’t become apparent immediately, and the company not putting them right on a technicality.

- Woosh, I understand people have disagreements but remember you’re representing a brand here. I really do appreciate your help, but as a consumer that is new to this and hasn’t yet formed opinions on brands it doesn’t paint your company in a great light if you’re trying to pick arguments with other members of the forum. (I genuinely mean this criticism to be constructive)

- Jucybikes and Trevormonty, I agree 100%, I do intend to test all of my ‘potential’ bikes before making a final decision. It’s just to a newcomer it’s an absolute minefeild, there are so many brands available, often exclusive to ebikes. So the reason of this post is to get a list of bikes to test really. Thanks for the heads up on Russell’s Bicycle Shed, I’ll be checking that out! Are there any tips for things to look out for when testing a bike for such a relatively short time for? I imagine any bike feels ok for a 5/10 minute cycle. I guess that’s the benefit of the bike loan.

- georgehenry, thanks for the input. It’s good to know your battery is holding out after so long, and you make a point about using the deristriction to keep your average speed up without going for top speed all the time. I can see there being a bit of a learning curve to getting the best from your bike on your route.

While I was away I got chance to test a Riese and Muller charger, it is an incredible bike. It is an option as I still like the idea of the dual battery and the availability of HS models, but obviously those luxuries come at a considerable cost! My heart says yes but my mind will have to jump through some pretty big hoops to try and justify it! (Including calculating the total cost of running a car for a year - still about £1000 off!)
My other options at the minute include the Raleigh Motus, the Oxygen and one of the many Cube options, but I guess as Juicybikes has pointed out, the only major difference between them is how comfortable they are for me. Before I start testing is there anything else anyone would like to recommend?

 

[JuicyBike]

Are there any tips for things to look out for when testing a bike for such a relatively short time for?

Head for the nearest hill!