Better performance in the cold?

[Erik]

I noticed that my Agattu performs better now that it's gotten colder. Could it be some sensor in the motor allowing it to draw more current cold / less current when hot?

 

[Mussels]

My Wisper has got faster as well but that's probably a coincidence as I put a bigger tyre on at the weekend.

 

[Stephen-Gately]

I think it may be that you are peddaling faster, so you spend less time in the cold. In summer I took 45 mins to walk to work, now it's cold I'm there in 30 flat.

 

[the_killjoy]

I must be the odd one out, my Wisper battery definately doesn't like the cold ~ I can defiantely feel the difference in speed and range.

 

[Hooligooner]

Could it be that the colder air is denser allowing more oxygen to be pulled in with every breath, so the rider pedals harder for what they perceive is the same effort?

 

[Mussels]

Could it be that the colder air is denser allowing more oxygen to be pulled in with every breath, so the rider pedals harder for what they perceive is the same effort?

At the moment my muscles are not staying warm enough so they are performing below par so it's not that. In my case it's much more likely to be the raised hub motor gearing by fitting a bigger tyre and nothing to do with personal effort.

 

[Wisper Bikes]

Brass monkeys

Unfortunately as Kill Joy has discovered the batteries certainly do not work as well in cold weather, it must be that tyre mussels. As a mater of interest what have tyres have you fitted?

Sorry that your panniers haven't got to you yet I will send them out today.

All the best David

 

[flecc]

All battery types lose efficiency at low temperatures simply because they are chemical devices and chemical reactions need heat.

Any perceived gains on an e-bike when it's cold can arise in two primary ways. First the effects on the rider mentioned above, and second is that tyre rubber is stiff when cold, which can let it roll better than when it constantly reshapes to road surface variations. The latter absorbs energy but improves grip.
.

 

[Fecn]

There'll also be a very small gain (~2%) from the lower air pressure we get when the weather's cold. Because the air is less dense it's easier to move through.

 

[Mussels]

Unfortunately as Kill Joy has discovered the batteries certainly do not work as well in cold weather, it must be that tyre mussels. As a mater of interest what have tyres have you fitted?

Sorry that your panniers haven't got to you yet I will send them out today.

All the best David

I've put a Schwalbe Big Apple 60-559 on the back, according to Schwalbe the circumference is about 110mm bigger than a 50-559 tyre so that's an extra 10% by my working out. No wonder it's faster then! (I've not really thought about it before now)
Note to Wisper owners: I have 60mm wide mudguards and I'm left with 1mm clearance in places, I don't know if these tyres will fit your bike.

 

[RobNYC]

All battery types lose efficiency at low temperatures simply because they are chemical devices and chemical reactions need heat.
.

Is the decrease in efficiency a pretty linear process from some optimal temperature?

Does the battery degrade differently in the cold air as well?

Is there a temperature at which I shouldn't use my bike? or a temperature in which I should not leave the battery? For example, would it make sense for me to ride my bike on my 4.5 mile commute on some days, but to bring teh battery inside while I am working?

I tried to find some info on the board about cold weather and batteries to no avail.

 

[Tiberius]

There'll also be a very small gain (~2%) from the lower air pressure we get when the weather's cold. Because the air is less dense it's easier to move through.

Hi Fecn,

Not quite right, I'm afraid. The air pressure stays much the same - variation between high and low pressure systems is bigger than the variation summer to winter. Colder air is more dense, so will offer larger air resistance.

Interestingly, aircraft usually work better in the winter than in the summer. Denser air means more oxygen into the engine and more lift from the wings.

What aviators do (or at least do when they are students) is to calculate the "density altitude". This takes into account the pressure, temperature and moisture content and is the equivalent altitude in a standard atmosphere. I was once in a very cold winter in Boston (USA) when the density altitude was 3500' below sea level.

But this is getting off topic. I suspect the reason bikes are apparently faster in winter is simply that cold air going past the rider is a lot more noticeable warm air.

Nick

 

[Mussels]

But this is getting off topic. I suspect the reason bikes are apparently faster in winter is simply that cold air going past the rider is a lot more noticeable warm air.

Nick

Bloody right it was at 6am this morning!