Merkybikes M9

[oggie]

Anybody dealt with Brum based MerkyBikes?
Saw a used M9 on marketplace, bafang 620 middrive 160Nm. 1000w seemed good specs for the money. I didn't bite @ £1,700 thought to ask you guys your thoughts on the ebike

 

[lenny]

https://www.pedelecs.co.uk/forum/threads/what-do-you-think-of-my-new-bike.46331/

https://www.merkybikes.co.uk/product-page/e-tough-power-m9

 

[Veganarchy Zetetic]

I have purchased 2 bikes from this company and I would not recommend doing business with them for many reasons.

Both rear brakes were not calibrated properly so every time we used them the motor would not work again until turning the bike on and off.

The plastic cover near the cranks had a crack in the exact same place on both bikes.

The rear shock absorber bushing snapped after a couple of weeks on one of the bikes.

The axles do not fit inside the frame properly on either bike, it is much worse on one of them than the other. The drop out hole for the axles has been damaged or drilled way bigger than it is supposed to be.

The safety anti-rotation washers do not even sit inside the frame so they can not do the job they were designed to do = keep you and the bike safe.

These bikes are NOT SAFE to ride and after contacting and sending photos of the damage to both Naomii and the tech support guy they chose to ignore me entirely!

The used bike you looked at was also sold by Naomii (Owner of Merkybikes) on Facebook marketplace for £1300 with only 300km on the clock...

 

[Veganarchy Zetetic]

 

[Veganarchy Zetetic]

There is also a huge gaping hole where the motor wire enters the controller housing underneath the bike. The front wheel flicks stones, mud, water etc straight into the hole where all the wiring and controller sits. There are probably many more problems with this bike but you get the picture.

 

[sjpt]

And illegal for almost all potential ways of using it.

 

[Veganarchy Zetetic]

Well the hub version I bought does have a 250W mode and can be limited to 15MPH but I think legallity is the least of your problems if you choose to buy a bike from these people tbh.

 

[Az.]

Well the hub version I bought does have a 250W mode and can be limited to 15MPH but I think legallity is the least of your problems if you choose to buy a bike from these people tbh.

Motors don't have 250W mode. They are rated 250W or not.

 

[Veganarchy Zetetic]

Motors don't have 250W mode. They are rated 250W or not.

A motor can only run at the amount of amps and power you give it. If you give it 250W it will run at 250W. If the bike is put on a testing machine, the machine will also see that the power is only 250W. Not that the machines even exist in the UK, or that any of us ever get stopped by the police, or that any of the police even know the ebike laws anyway...

 

[saneagle]

A motor can only run at the amount of amps and power you give it. If you give it 250W it will run at 250W. If the bike is put on a testing machine, the machine will also see that the power is only 250W. Not that the machines even exist in the UK, or that any of us ever get stopped by the police, or that any of the police even know the ebike laws anyway...

That's not how motors work and neither is it how the law works.

The law says that the motor must be rated at no more than 250w. Rating is done by the motor manufacturer and cannot be changed by the way you use it. The rating must be marked on the motor by a label or stamping. You cannot run a 500w motor at even 10w to be legal. A motor rated at 500w is illegal, and that's it.

Regardless of the motor's rating, the power that it gives depends on the circumstances, not how much power you let the battery give it. The power that you give the motor obviously affects how much power you can get out, but it's not the whole story.

Ebike motors have a power curve that depends on RPM. The torque is more or less proportional to the current, so the torque curve is fairly flat, but the power = torque x rpm, so the it increases with rpm up to the point where the back emf starts to limit the current more than the controller does, then both the torque and power ramp down to zero when the back emf is the same as the battery voltage.

The changing power in the different circumstances is the reason, that the law can't tie down the maximum power that the motor makes, so uses the rated power instead. If you give a hub-motor 250w from the battery, you'd get about 100w from it when climbing a hill slowly and about 175w when breezing along at 15 mph, assuming it's a motor designed for the UK ebike market. You need around 400w from the motor to get meaningful help up a hill, i.e. enough to keep you pedalling at around 8mph.

 

[Veganarchy Zetetic]

That's not how motors work and neither is it how the law works.

The law says that the motor must be rated at no more than 250w. Rating is done by the motor manufacturer and cannot be changed by the way you use it. The rating must be marked on the motor by a label or stamping. You cannot run a 500w motor at even 10w to be legal. A motor rated at 500w is illegal, and that's it.

Regardless of the motor's rating, the power that it gives depends on the circumstances, not how much power you let the battery give it. The power that you give the motor obviously affects how much power you can get out, but it's not the whole story.

Ebike motors have a power curve that depends on RPM. The torque is more or less proportional to the current, so the torque curve is fairly flat, but the power = torque x rpm, so the it increases with rpm up to the point where the back emf starts to limit the current more than the controller does, then both the torque and power ramp down to zero when the back emf is the same as the battery voltage.

The changing power in the different circumstances is the reason, that the law can't tie down the maximum power that the motor makes, so uses the rated power instead. If you give a hub-motor 250w from the battery, you'd get about 100w from it when climbing a hill slowly and about 175w when breezing along at 15 mph, assuming it's a motor designed for the UK ebike market. You need around 400w from the motor to get meaningful help up a hill, i.e. enough to keep you pedalling at around 8mph.

UK ebike law has two very specific restrictions related to power:

• Its electric motor must have a maximum power output of 250 watts
• Its electric motor should not be able to propel the bike when it’s travelling more than 15.5mph

Note that the power restriction is based on "output" not "rating". This means that if you buy a hub motor rated to handle up to 1,000W, but you restrict its output to 250W, you are within the guidelines of the law.

 

[thelarkbox]

UK ebike law has two very specific restrictions related to power:

• Its electric motor must have a maximum power output of 250 watts
• Its electric motor should not be able to propel the bike when it’s travelling more than 15.5mph

Note that the power restriction is based on "output" not "rating". This means that if you buy a hub motor rated to handle up to 1,000W, but you restrict its output to 250W, you are within the guidelines of the law.

I think you missed a key word.

• Its electric motor must have a maximum RATED power output of 250 watts

 

[Veganarchy Zetetic]

I think you missed a key word.

• Its electric motor must have a maximum RATED power output of 250 watts

I literally copy and pasted from www.gov.uk/electric-bike-rules

If anything is missing then you best tell the government, not me

 

[saneagle]

UK ebike law has two very specific restrictions related to power:

• Its electric motor must have a maximum power output of 250 watts.

That's incorrect. It's what it says on the government website, but whoever posted it made a mistake.. There are virtually no ebikes in the market that give a maximum power of 250w. 400w is about average for a low powered cheap bike, but most these days are at least 500w. The actual regulation is EN15194, which clearly says "rated" power.

 

[Veganarchy Zetetic]

Then I will use their mistake in court to clear me of any wrong doing when I get caught for following the rules written on the governments website. I have been riding bikes for 30 years. Still waiting to be stopped by the police, should be any minute now.

That's incorrect. It's what it says on the government website, but whoever posted it made a mistake.. There are virtually no ebikes in the market that give a maximum power of 250w. 400w is about average for a low powered cheap bike, but most these days are at least 500w. The actual regulation is EN15194, which clearly says "rated" power.

Then I will use their mistake in court to clear me of any wrong doing when I get caught for following the rules written on the governments website. I have been riding bikes for 30 years. Still waiting to be stopped by the police, should be any minute now.

I will even buy a silly label for a few pence if it helps you all sleep easier at night. Why you are all so obsessed with ridiculous laws I will never understand. You all sound like really fun guys to invite to parties!

 

[saneagle]

Then I will use their mistake in court to clear me of any wrong doing when I get caught for following the rules written on the governments website. I have been riding bikes for 30 years. Still waiting to be stopped by the police, should be any minute now.

Then I will use their mistake in court to clear me of any wrong doing when I get caught for following the rules written on the governments website. I have been riding bikes for 30 years. Still waiting to be stopped by the police, should be any minute now.

I will even buy a silly label for a few pence if it helps you all sleep easier at night. Why you are all so obsessed with ridiculous laws I will never understand. You all sound like really fun guys to invite to parties!

I see that it's my job to make sure that anybody reading these posts understands what the rules are and how they apply to them. They can then make their own informed choice in what they do. I never judge them, nor criticise anybody for breaking rules.

 

[thelarkbox]

Yeah your right they transcribed the rule omitting the key word. tho it may be moot as what metric other than a motors rating can be 250w or less, its voltage?? So perhaps it is correct?
The easy read version shouldn't be a logic puzzle tho.

 

[Veganarchy Zetetic]

I see that it's my job to make sure that anybody reading these posts understands what the rules are and how they apply to them. They can then make their own informed choice in what they do. I never judge them, nor criticise anybody for breaking rules.

That's fine but I did not break any rules. I followed the exact information written on the official government website and I bought a bike that is stated to be legal from the business that sold me the bike. I have purchased dual power bikes a decade ago and the companies are still selling the same bikes now. They have not been shut down by the law for selling illegal bikes. Pretty certain they never will.

I did everything in my power to follow these ridiculous laws. If anyone made any mistake then its the company who sold me the bike and the government for (in your opinion) making mistakes on the website.

Maybe you should all start putting your efforts into taking down the ebike companies and the government for their mistakes instead of nitpicking at people like me for doing everything in their power to follow these asinine laws.

 

[thelarkbox]

That's fine but I did not break any rules. I followed the exact information written on the official government website and I bought a bike that is stated to be legal from the business that sold me the bike. I have purchased dual power bikes a decade ago and the companies are still selling the same bikes now. They have not been shut down by the law for selling illegal bikes. Pretty certain they never will.

I did everything in my power to follow these ridiculous laws. If anyone made any mistake then its the company who sold me the bike and the government for (in your opinion) making mistakes on the website.

Maybe you should all start putting your efforts into taking down the ebike companies and the government for their mistakes instead of nitpicking at people like me for doing everything in their power to follow these asinine laws.

Nit-picking? -et moi?? - ok guilty but not directed at you the messenger @Veganarchy Zetetic just the message and the propagation of confusion.

I did a wee google for the regs pdf but all i found was locked behind a paywall costing 2-400 euros so tough, while im petty enough to enjoy a 'told ya' im not 200 euros plus petty.
Perhaps @flecc will pop by and drop a link ??

Hey if you got a decade plus of service from the bikes in the pics above - you did well my friend

Fighting ads from off shore or if local posted via vpn to appear offshore is like taking revenge porn off the web.
And if trying to change mobility scooter laws to enforce pedestrian right of way on the pavement which could demonstrably save children's lives ( because some have been killed) fails, lobbying to change untested rules wont float far imho..

 

[Peter.Bridge]

I did a wee google for the regs pdf but all i found was locked behind a paywall costing 2-400 euros

I'm great fun at parties