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Anyone I've spoken to in the real world thinks they are brilliant
We must move in different circles. Most "cyclists" I've spoken to think their great for transport and to help older less well people get out and about. But defeat the whole object of cycling for the healthy. Just another toy for the me, me, me generation.
I would have another one if I was convinced that they were reliable and robust, until then, I won't touch them,
I disagree about just for older folk and the me generation.
They (would) be great for
Getting out riding more often
Going further
Enabling the less fit individual to ride with fitter people and avoid the long waiting at climbs etc
Carrying more gear with you on a ride, like camera equipment
Carrying extra food and making a day of it out in the wilds
Not worried about what other people think about me or ebikes or "cheating", life's to short to worry about what other are thinking. It's not like there's any harm in riding any sort of bike.
If it gets more people riding, out and about, then that's better than sitting on the sofa.
But, there is a real need for them to be better made and reliable, buy with caution at the moment.
(I've told this before). I overtook an ebiker at QE Park, he was pretty nervous on the descents so I waited for an opportunity and passed him by going slightly off-track. He made a surprised noise, so I waited at the end to apologise for surprising him and we had a nice chat. He was an 18st, 67 year old and was telling me how he can now get out on group rides thanks to his 'leccy Scott. Great stuff, I'm sure you'll agree.
A friend of mine is 68 and has been a cyclist most of his life. In recent years he's cycled with a club of which most members are a bit north of 60, they tend to ride mixed terrain routes, not mountain biking but quite lanes, sustrans routes that sort of thing.
Knee replacement surgery which didn't go that well has left him unable to go out on group rides, I suggested an e-bike, he said he'd thought about it but no. For him the satisfaction in cycling was that it was wholly a human powered activity. When he could no longer ride as he liked he would let it go and do something else just as he'd let go playing trombone in the WNO, high level cricket and county level squash.
There'll be no e-mtb in my future when I can't ride under my own steam I won't.
hols - actually as wind resistance stays the same but weight ie force pushing it downhill is greater you do build up speed more quickly downhill - obviously the effect is only significant at speed
Err, not in this universe!
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You will have more momentum with a higher mass though, I notice this when riding with others as I'm a fair bit heavier than most of my riding friends, eg coming out of a fireroad descent I won't lose speed as fast going up the other side. You definitely don't accelerate due to gravity any faster though with a higher mass because physics.
Err, not in this universe!
That only works in a vacuum
exactly - its very obvious when on the tandem this effect and its also noticable on the eBike. The force is greater but the wind resistance is the same so it accelerates downhill quicker because once up to about 10 mph wind resistance is the biggest effect on a bikes speed
exactly - its very obvious when on the tandem this effect and its also noticable on the eBike.
You seem to be confusing different things. If you are applying power (ebike or tandem) and the wind resistance is the same then, yes, you go faster. But that's not the same as simply accelerating due to gravity, where being heavier is no advantage at all. It's usually a disadvantage as heavier usually means heavier wheels and they accelerate more slowly.
What may be confusing things is that the heavier object (which accelerates at the same rate as the lighter one under the influence of gravity) has more momentum for a given speed, so is slowed down less by obstacles, which can result in it going faster down a bumpy slope (although this is often outweighed by the heavier wheels).
is acceleration due to gravity the same when riding down a slope? What i mean is, do two objects of different weight accelerate at the same rate on a slope, like they do in free fall? ignoring wind resistance for this question
yes all a slope does is reduce the effects of gravity. In a vacuum things rooll down the slope at the same rate
Roverpig - I am not confusing anything - you are forgetting the effects of wind resistance Think about terminal velocity ie when wind resistance is the same as gravity. Try actually dropping a piece of paper and a piece of metal.
Whenb we are out on the tandem freewheeling down a road alongside a solo we accelerate away from them. Terminal velocirty is around 60% higher
Thanks tj, i did wonder about that.
Ive noticed myself that im quicker than most people when freewheeling downhill, i am really heavy though.
I'm not sure that wind resistance (assuming it's not blowing a gale) is a big enough factor in "acceleration" to be worth considering. Or at least, it's usually dwarfed by the fact that a heavier wheel accelerates more slowly.
Wind resistance increases with something like the square of the velocity (can't be bothered to look it up 🙂 ) So, when we are talking about acceleration from rest (i.e. the velocity is low) it has less of an effect.
But fair enough, if the wheel is the same and only the static mass is increased then there could be a small increase in the initial rate of acceleration.
When we move on (as we seem to have done) to considering the velocity at the bottom of the slope then, as I said, I think this has more to do with the heavier object having more momentum at a given speed and being slowed less by all the bumps than any small increase there might have been in initial acceleration due to wind resistance/weight.
Is the heavier object applying his brakes, or not?
While I'm not disputing the science that image looks to be dividing Newtons by Kilograms and getting Meters over seconds squared!
edit: scrap that I just realised the true definition of mass! duh
That only works in a vacuum
Unless the ebike has different friction resisting the effects of gravity, then physics still wins in a direct comparison between ebike and normal bike. Whilst the ebike may have increased friction from tyres and slightly more wind resistance from the battery perhaps, I'm not convinced it will have a very significant effect. Perhaps in thick deep mud it would sink in quite a bit more, I'd give you that.
Anyway, the argument that an object with greater mass accelerates at a greater rate with gravity than something with lower mass is either wrong or groundbreaking physics.
I think people are getting confused by momentum.
You're still not accounting for wind resistance.
What speed does a falling sky diver reach?
Does he keep accelerating at 9.81m/s^2 until he hits the ground.
No he reaches terminal velocity when the friction force from falling through the air balances the force of gravity.
A bike rolling down a slope is the same it keeps accelerating until the vector product of gravity is balanced by the rolling resistance of the tyres and air resistance.
Air resistance is proportional to the frontal area of the bike and rider. If you have more mass for a given frontal area you will reach a higher terminal velocity then something with less mass.
An e-bike adds about 10kg of mass to a bike and rider with a negligible increase in frontal area it would definitely be noticeable.
One of the reasons spinters in the TdF can descend so quickly is that they can reach a much higher speed without putting in the same effort. Their heavier frames give them a big advantage in terminal velocity when descending
I'm not sure I've ever reached terminal velocity on an mtb off road where I've not been able to pedal to make me go faster except some massively long fire road perhaps. Also not sure how a higher terminal velocity means it accelerates faster.
because the wind resistance effects take over around 10 mph as the main drag. So not only do you reach a higher terminal velocity but over 10 mph accelerate quicker a well
Maybe not accelerate faster, but it would keep accelerating for longer, this could give the impression (to the lighter rider beside you) that you are accelerating faster.
It accelerates faster - I have done this many times with the tandem where the effects are more obvious. Once up to 10 mph or so the heavier bike pulls away and keeps on accelerating faster
Er tjagain what are your thoughts on bike helmets? They work, right?
Dinnae start that!
😆
The limiting factor for me riding bikes at the moment is time. As a result of not having enough time my fitness isn't great for the odd occasion when I'd like a big day out in the hills with my (much fitter) mates. I'm not sure how an ebike would help me get fitter. I kinda think for me it would be a slippery slope towards never being fit enough to ride a normal mountain bike again, especially as ebikes develop, get lighter with a bigger range, etc. Which makes them a bit pointless imo, i could only see my fitness / health deteriorating.
The logical answer for me and others struggling for time / fitness is probably a road bike.
Love how a thread about ebikes has descended into a discussion about how much gravity assists them.
Bloody g-bikes, get em banned, I saw one doing 30mph without pedalling! It's cheating for fat people as they go even faster than me at 6 stone wet through!
Back to the OP though. If you see one block their path. Tell them they are a fat lazy prick and will get all mtbs banned, everywhere. Unless of course they are 90, or have a doctors note for a severe (in your opinion, not the riders or doctors) disability. Then they are excused. Also point out that, despite what the law says, it has a motor, therefore it is a motorbike.
You know, as you would if anyone else came past you.
The limiting factor for me riding bikes at the moment is time.
Ditto. My thinking is that with an e-bike I could extend my commute to include a load more fun descents, speeding up the climbs and the road bits. And then ride one of my proper bikes when out with my mates. We shall see if I succumb...
@ tomhoward
Is having an ebike any less cheating than YOU taking your bike on a train, or should people stop YOU getting on the train and call you a skinny lazy prick? Unless of course you have a doctors certificate? It seems like what your saying it's ok if You cheat in your way. After all you could always walk or run from the train rather than cheating by going on the bike ?
Each to their own for their own reasons,
Had my say 🙂
This'll the Batesbristol that hates TC's.
Now he hates E bikers.
Sure he could get a job on Trumps staff and stop boring everyone else.
Lester dear, I fear you may have missed the sarcasm In my post. It's an amalgamation of all the things ive been told by the haters on here.
I sometimes take my ebike (turbo levo fsr) on the train, but shhh, they'll go mental if they find out its (not) a motorbike...
Thank you for the skinny compliment though, my 24hr xc marathon training is paying dividends...
I was passed by an 83 year old geezer who was on an Ebike. He was cool, kept me company up a massive hill, told me not to feel too bad that he'd caught me up since he was on an Ebike. We had a great conversation about him being able to get out cycling again because of the Ebike. I'm all for that.