15.5 mph maximum?

biffanio

Finding my (electric) wheels
Jan 13, 2012
17
0
Hello all,

I recently purchased an ebike that in the advert claimed to do "15.5 mph is its maximum motor powered speed"

when i first got it, it is impossible to go over 11.1mph on this bike on a totally smooth flat surface when on approximately 60% charge or below on full twist and go throttle.

I sent it back to have this repaired as well as various other faults that developed.

I have just received the bike back and it still only does between 11.5-12.3 mph on the twist and throttle unassisted.

Is this quite common with an ebike as i was under the impression that it would power me unassisted to speeds of 15.5 mph?

Also the speeds notably drop when it hits around 60% charge.

I would like as many opinions as possible please as i do know of another person who is also disappointed with the same make of ebike also with this issue!

Many thanks and best wishes

biffanio
 
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Jimod

Esteemed Pedelecer
Aug 9, 2010
1,042
602
Polmont
It will be difficult to tell without knowing all the facts. What type of bike is it? Does it have different power levels? If so, is it set to the highest power setting?

My bike will do about 15 mph without me assisting it. I say 'about' It depends on the weather, if the wind is against me it can go down to 13 ish and with the wind behind me it can go faster. If there's no wind it sits about 15 mph.
 

flecc

Member
Oct 25, 2006
42,316
17,932
E-bikes vary somewhat, depending on motor peak power, battery capacity and the way the assist speed limit is applied. However, they are electric assist bikes, not electric bikes, so won't necessarily power you unassisted over the whole assist range. Many continuously phase down the power from about two thirds assist speed upwards, the law in fact requiring some phase down.

All this said, yours does sound a bit on the weak side. Two questions, does it assist to 15.5 mph with the battery fully charged, and what make and model is it?

N.B. Crossed with Jim's post.
.
 

biffanio

Finding my (electric) wheels
Jan 13, 2012
17
0
Thanks for the responses guys.

It is a fast4ward peak bike.

It is hitting these speeds daily on a new long piece of smooth tarmac going to work.

The speeds are taken on a non windy day.

when fully charged since repair it will hit 13.1-13.5mph unassisted on a 100% charge mark.

When the charge falls to approx. 60% these maximum speeds drop to 11.5-12.3 mph.

Like i said i know of another peak bike doing the same speeds and also a courtesy bike was exactly the same whilst my was getting fixed.

Thanks

Biffanio
 

Jimod

Esteemed Pedelecer
Aug 9, 2010
1,042
602
Polmont
13.5 isn't too bad, it depends on a lot of factors. Is the road really level or does it have a slight slope? Another factor could be your speedo, is it calibrated exactly to your wheel circumference? If it was out by 1 mph you'd be doing the same speed as most legal e-bikes.

The weight of the rider will also play a part in it. I know that sounds cheeky but it's not meant to. My bike is slightly slower when fully loaded than it is when I'm travelling light. I.E no spare battery or stuff in the panniers.
 
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NRG

Esteemed Pedelecer
Oct 6, 2009
2,594
10
Yes, check the speedo is calibrated correctly first. These motors are voltage controlled so voltage has direct relationship to speed. A fully charged battery should see you go faster than one at 60%, also temperature plays a part, in warm weather the bike will feel perkier than when its cold.

Something to check is the un-load speed of the bike, lift the driving wheel off the ground and check what speed you get on a full charge, it should be 2~3 mph higher than the on-road speed so 15mph you are looking for about 18mph unloaded...
 

geostorm

Esteemed Pedelecer
Mar 7, 2009
297
4
I would say the weight of the rider would make a big difference eg....a rider at 18st... that would be like 2 9st. people on bike ..



Geoff
 

biffanio

Finding my (electric) wheels
Jan 13, 2012
17
0
I am about 10.5 stones so im sure that is no way should make an excessive difference on averages.

Btw on travelling from work tonight the maximum has again dropped to 12.1 mph 1 mile into a 100% charge!

i cannot even reach 15 mph peddeling flat out!

Many thanks

Biffanio
 

eddieo

Banned
Jul 7, 2008
5,070
5
if its not meeting the spec as advertised just send it back for a refund..and read up on the popular reliable bikes that are favoured on here...
 

flecc

Member
Oct 25, 2006
42,316
17,932
I am about 10.5 stones so im sure that is no way should make an excessive difference on averages.

Btw on travelling from work tonight the maximum has again dropped to 12.1 mph 1 mile into a 100% charge!

i cannot even reach 15 mph peddeling flat out!

Many thanks

Biffanio
Then that is very poor Biffanio, with just moderate pedalling added it should very easily do 15 mph on the flat. As others have said, make quite sure your spedo is calibrated correctly, and if it is, ask for a refund on the basis that it doesn't meet specification. If they refuse you would have an easy win in the small claims court. The only standard e-bike that has a 12/13 mph assist speed limit is a particular eZee model which is always declared to have that speed limitation.
 

RoadieRoger

Esteemed Pedelecer
Nov 8, 2010
543
47
My Batribike Folder with 20 in. wheels claims` up to 15 mph` in the brochure . With maximum assist and pedalling like mad you would be hard pushed to maintain this speed for long . If you did you would run the risk of friction burns in unmentionable places or fall off with exhaustion . It might be down to my age .
 

Hero Eco

Pedelecer
Jan 10, 2012
186
1
Gloucestershire
Hi Biffanio

I got your email and we are looking into this, hopefully be back to you tomorrow.

Thanks
Mark
 

biffanio

Finding my (electric) wheels
Jan 13, 2012
17
0
Many thanks for your help guys/gals.

I will let you know how i get on!

Best wishes

Biffanio
 

HD462

Pedelecer
Apr 23, 2012
56
0
Teesside, UK
Hi Biffanio,

Just to add to your info, I've just got a Fast4ward Peak too, done about 25 miles on it up to now. I'm 15 and a half stone, and with no wind, on full charge it does 14.9mph, as the battery got down to 50% or so it dropped to 13.8 to 13.5mph. I tried it in a light headwind, on power only and it did around 12 to 12.5mph. Pedalling, I can easily maintain 17mph, and have done 19. something. It's easy to keep it above 15mph, obviously then the motor would cut out.

I checked the speedo calibration on mine, it tells you how in the instructions, and found mine was out at first. The wheel circumference was set to 208cm, whereas when I measured it, it was actually 201cm. All those speeds quoted were after correcting the speedo.

I'm quite impressed with mine up to now. Even the mickey takers at work were once they had a go, they all said it was good, and that it didn't look like they expected it would (being a mountain bike style, where they'd been expecting a sit up and beg type of thing with a basket on the front). The only thing I am disappointed with is that the computer was advertised as showing speed and trip/odometer, but it shows speed only. Would be nice to know how far you'd travelled. I'm going to add a second computer to mine.

The beauty of lithium ion batteries over older technologies is that they provide high power for longer, then drop off quickly towards the end.

Regards,
Mark.