Is 28mph too fast for a pedelec?

[shawn rosenthal]

I'm in one of the liberal states where 28mph is allowed without license. I do not know if this is something needed and don't know if this is something people want.

I'd be interested to hear your own experience and also your opinion about having others riding at this speed.

 

[D8ve]

Yes I used to hit this speed downhill.
In the EU it's not on but if you want to go for it.

You need serious brakes. Big disk at the front.
Good safety gear. helmet, leathers, treat like a moped as that's what it is!
Tough frame to carry a very large battery. It's going to need +30 watts a mile.
Very high gearing if you are going to pedal?
The power requirement will be high.

If you want to increse efficency to get some range then a recumbent/ velomobile would be an idea.

 

[Artstu]

28 mph on a racing bike is standard fare, so 28 mph on an assisted bike isn't much different.

28 mph without pedalling is a moped though.

 

[the_killjoy]

A 28mph ebike is a much heavier beast than a racing bike, so stronger brakes and a stronger frame are a must (+ the helmet)

 

[SRS]

28 mph assisted speed would be ideal for fast commuting.

If used at this speed where safe to do so then is I see no more risk than any other bike.

We must not forget that 28 mph is the upper limit and not a fixed travel speed.

 

[Topdonkey]

On my bbs02 equipped 750w bike 26mph is the average cruising speed, and downhill it hits mid forties quite easily, but slows to about 14mph on the steeper uphills,I have magura hydraulic disk brakes and since I fitted the kit 3 weeks ago I am suffering terrible brake fade sometimes and have to be careful with my braking on the downhills as you can literally run out of braking power which isn't good.

I'm currently looking for an xl frame sized specialised stumpjumper full suspension as the older ones had a straight down tube rather than the modern curved bit at the bottom that the newer ones have

 

[D8ve]

28 mph assisted speed would be ideal for fast commuting.

If used at this speed where safe to do so then is I see no more risk than any other bike.

We must not forget that 28 mph is the upper limit and not a fixed travel speed.

The 28 should be on flat and up slight hills.
Down hill even faster.
But racing bikes only get 28 on closed roads riding in a peloton
Never uphill.
The acceleration would be deceptive and you can get into trouble easier than an EU limited bike.

At seventeen MPH I broke two bones in my arm and one in the wrist.
28 mph is a LOT more energy. Not double but 2.7 times the energy.
That is life threatening injuries!

 

[jonathan75]

If used at this speed where safe to do so then is I see no more risk than any other bike.

.

That is a perfect logical argument. But *where* is it safe for a cyclist to go silently, semi-visibly, relatively unprotected, at moped speeds, without the natural brakes of bodily fatigue, and physical nervousness about hazard? Safe for him and others?

 

[Deleted member 4366]

It's propably safe gor a light fit rider to ride a light roadbike at 28mph, even with narrow tyres and rim brakes; however, put a 100kg rider, and 10kg of ebike kit on the same bike, and it will be a disaster.

There's so many variables to consider, but basically, if your bike has tyres and brakes suitable for those speeds considering the overall weight, it shouldn't be a problem. Suspension might help too, but that also depends on the weight and other factors.

 

[Fordulike]

A 28mph ebike is a much heavier beast than a racing bike, so stronger brakes and a stronger frame are a must (+ the helmet)

I'm not looking to turn this thread into an arguement, but surely a 15kg normal bike with a 85kg rider would be the same as a 25kg ebike with a 75kg rider.
The bike still has to slow down 100kg's of moving mass and I imagine the manufacturers build their bikes with a total weight limit in mind.

Therefore, I would have thought total weight would be a better consideration when planning a build.
If you are a 130kg chappy, then you may have to consider a more suitable bike, whether it is powered or not.

 

[Fordulike]

Always good to ask pertinent questions though

https://www.micra.org.uk/threads/how-much-weight-can-the-front-passenger-side-take.63940/

 

[Twangman]

The first thing I would say is why do you need to travel at 28mph? If your comuting routes are on main busy rds I can understand the need for speed however I would not trust bike brakes to stop me safley especially if I needed to come to a sudden stop. The fasted I am comfortable on the flat is 25mph. Though I normally cruise around 20mph. I've done 40mph downhill and trust me on a 19kg weight 20" wheel bike plus me at 11 stone it is seriously a squeaky bum moment!

 

[anotherkiwi]

Thank god d8veh said tyres. That is my first worry, along with brakes. Having ridden a racing bike as a young man (in town, no helmet) regularly between 45 and 60 kph it is handling in corners and stopping that are the scary bits. The tyres and brakes back in those days have nothing to do with the ones we have now.

The other day I was at 40+ in town according to the driver of a truck trying to pass me. It doesn't scare me a bit. I have just upgraded my brake pads from Chinese cr@p to Swiss made ones - OMG were we wrong to send all our manufacturing to China! I have great tyres - Michelin City. I am sure that when the bike is converted I will be seeing 40 kph on a regular basis even with assist only up to 25 kph. Lots of hills around here.

If someone opens a car door or steps out from between two vehicules (happened to me) you will not be able to stop in time. If you are on a light weight racing bike the damage will be less than on a 30 kg e-bike that is for sure...

Tony

 

[Gubbins]

If you can maintain 28 mph in town traffic you will end up ovetaking most of the cars an trucks either on the inside or down the middle of the road. Either way it seems dodgy to me. Trundling up the cycle lane faster than the traffic can only lead to left turn accidents.

 

[trex]

...
If you are on a light weight racing bike the damage will be less than on a 30 kg e-bike that is for sure...

Tony

safetyfast's bike weighs 18kgs and cost him £770. By changing his BBS01 with a 48V BBS02, you can get 28mph without pedalling for about £40 more.
The issue is you'll go faster more often because you can, therefore increasing the risk of coming up a cropper.

 

[flecc]

The route back from my local shopping area in a London borough includes a mile of continuous slightly downhill. Depending on the wind conditions, my normal speed over that stretch is 24 to 28 mph on my 20" wheel bike. It was also the same on my 26" wheel bikes. All were UK restricted so at those speeds unpowered and just pedalling.

With plenty of traffic around that's always perfectly safe, even with a few kilos of groceries in the panniers, but of course there are other places and occasions when 28 mph would be too fast for any vehicle.
.

 

[Fordulike]

The issue is you'll go faster more often because you can, therefore increasing the risk of coming up a cropper.

Damn, I had to take a second look at that sentence.
My years in the army, has warped my brain to turning seemingly purer than pure sentences, into double entendre smut fests

It's a squaddie coping strategy thing

 

[anotherkiwi]

If you can maintain 28 mph in town traffic you will end up ovetaking most of the cars an trucks either on the inside or down the middle of the road. Either way it seems dodgy to me. Trundling up the cycle lane faster than the traffic can only lead to left turn accidents.

Not maintain 28mph/45kph reach it. And what is a cycle lane? Come visit the Basque Country, you will love it, no cycle lanes, lots of hills... We ride on the other side of the road so left turns are pretty safe

Tony

 

[flecc]

... We ride on the other side of the road so left turns are pretty safe

Tony

Thinking about this, pedestrians are advised to walk on the right in the UK where there are no pavements, so that they oppose oncoming traffic and can react accordingly.

On the same basis, where roads have painted on cycle lanes, it would be safer for cyclists to do the same, since then the left turn accident could never happen. Only a right turning vehicle from the far side would come from behind and that would have plenty of warning due to the turning across the whole road to get to that opposing cycle lane.

Of course there would be other complexities, but having nothing approaching from behind would be a huge benefit. The outcome would be a very large reduction in cyclist accidents, especially fatal ones, and that could make it worthwhile.
.

 

[mfj197]

Urf, no! If I'm in a car and I see headlights in front on both my left and my right (left from cars coming towards me, right from bicycles in a cycle lane coming directly towards me) I'm not going to know what's what. And all the painted cycle lanes around here have an unnerving habit of disappearing and reappearing, whereupon me as a cyclist would find myself cycling in the wrong direction on a carriageway. If we're on the same piece of tarmac we should be going the same way as the rest of the traffic. We are, after all, all road users. I'd hate to be heading directly towards cars at speed, on the same road.

Michael