Help! Which Folding Bike For A Newbie

Barnsleyrob

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Jul 20, 2020
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My post on my initial thread seems to be stuck in the system somewhere so I hope you won’t mind if I repost it here.



Well, I’m still narrowing this down but have been to look at the B’Twin at Decathlon and the Enik Snap-In at Towshure. Both are similarly priced but the Enik is 36V vs 24V for the B’Twin and it also has the internal gear set which I prefer to the full Shimano rigging.

The B’Twin felt slightly lighter and had just been unpacked. It felt fairly sturdy whereas the Enik was out on display and I noticed that the seat post rotated very easily so the saddle could be pointing to all 4 corners without much pressure.

Finally the curve ball is the MiiRider One 2020. Well outside my original budget and no opportunity to see it anytime soon but it’s lighter than the others and gets good press reviews. I particularly like the boost function to help me when my ankle stalls ! However, it’s a very new company and only has one product so may not be in it for the long term.

Also, is 24 volts really bad or should I discount it in favour of 36 volts.

links below.



 

PP100

Esteemed Pedelecer
Feb 28, 2020
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All those have relatively small batteries. You can get more for your money we have already suggested others in your original thread.
Seems you have already considered the Rambletta.

 

Barnsleyrob

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Jul 20, 2020
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The Rambletta is too many compromises. Weight, gears, etc.

No other suggestions came forward on my thread and everything was out of stock on the other thread started by another member.
 

Woosh

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May 19, 2012
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The Rambletta is too many compromises. Weight, gears, etc.

No other suggestions came forward on my thread and everything was out of stock on the other thread started by another member.
compromise what way?
weight: 20kgs with suspension
gears: 8-speed 11T-34T rear, 44T front, revoshift shifter
I know I make good VFM bikes but forget the price for a minute.
Find me simply another folder with 44T/11T gearing ratio or 20kgs with suspension and 12AH battery.
 

Nealh

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Aug 7, 2014
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Barnsleyrob

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Jul 20, 2020
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compromise what way?
weight: 20kgs with suspension
gears: 8-speed 11T-34T rear, 44T front, revoshift shifter
I know I make good VFM bikes but forget the price for a minute.
Find me simply another folder with 44T/11T gearing ratio or 20kgs with suspension and 12AH battery.
I’m not criticising your bikes and there’s no doubting the quality based on the support you have on this forum. I’ve also researched the companies behind the various bikes and yours has by far the best pedigree. MiRider has only been going a year and only has a single product as I mentioned so dropping £1300 on them seems a gamble.

The compromises for me are the derailleur - I’d prefer an in hub 3 speed for simplicity and to make it easier to lift in and out of a fairly small boot.

Weight at 20kg is at the top end of what I think I could manage but a lot depends on how it’s distributed. The B’Twin has a brace forward of the saddle that made lifting easier.

Boost mode on the MiRider looks a very useful function particularly given my restrictions.

The Towsure bike was around 18kg and had in hub gears but the Customer reviews of their service are truly atrocious.

Maybe I’m looking for something that isn’t available in my budget or perhaps my shortlist is so atrocious that it doesn’t warrant constructive comment beyond a takeaway menu.
 

Woosh

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the Rambletta has a proper handle that you can see behind the chainring. You can use it to drag the folded bike on its two wheels or lift the folded bike into your car's boot.
Beware of the fanciful claim on low weight.
E-bikes are about 6kgs heavier than the non-electric bike on which it is based. Only very expensive e-folding bikes can be really low weight. The electric Brompton is a bit of a record at just under 14kgs and that is with 8.5AH battery.
The Rambletta comes with 12AH battery, suspension fork and suspension seat post.
For many folding bike, speed is not important but I think it is for the Rambletta. The previous Rambletta has 14T-34T 7-speed freewheel.
The Rambletta has 20" x 2" tyres, 1.6M circumference.
You can just about maintaining 15mph at 83RPM.
By adding an 11T sprocket, I bring the cadence down to a much more comfortable 65 RPM. None of the £1,000 folding e-bikes have that feature.
If weight is your most important criteria, consider a Brompton with a conversion kit but it would blow your budget quite early on.




This is a conversion with my Q70 kit:

 
Last edited:

Barnsleyrob

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Jul 20, 2020
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I agree on the Brompton budget but luckily I have a strong aversion to the styling. It’s not a commuting bike I need but the portability and storage option does matter.

I like the battery location on the Rambletta as it avoids in frame issues and also your company isn’t a fly by night so I’m assuming that when the battery croaks after 5 years or so, there’s an option to replace or re-cell.

Im 5’6” so is the suspension fork version okay for me ? The spec suggests otherwise but I’m warming to it.

Speed isn’t a factor but why does Ah and voltage matter given the restriction to 250W ?
 

Woosh

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Speed isn’t a factor but why does Ah and voltage matter given the restriction to 250W ?
You pay for the battery capacity or Amp Hours.
a 36V 12AH battery has 41% more capacity than a 36V 8.5AH battery.
You use about 10WH per mile if you pedal leisurely.
If you pedal hard, it can be as low as 6WH per mile.
If you ride on throttle, it can be as high as 17WH per mile.
A 36V 12AH has 36 * 12 = 432WH (Watt hours) - good enough for roughly 43 miles with leisurely pedalling.
The 250W is a guarantee that the motor will stay at room temperature at the output level. For flat-ish roads, you need about 200W of energy to maintain 15mph, less your own pedalling input. Basically, if you use the bike sensibly, the motor will work for years.
 
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Barnsleyrob

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Jul 20, 2020
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Many thanks for engaging in a constructive discussion.

The other nice to have is the boost function that would get me over the point where my ankle stalls. It sometimes locks out which puts me on half rotation (left leg) and I don’t want to be strapped to the pedal. The last 1/4 mile home is up hill and it’s sufficient to get most locals breathless - I’m guessing 15 % so the ability to travel up at reasonable (10 mph) speed while just rotating the pedals is a bonus. Unfortunately, there’s no way I can put torque down through my prosthesis, although I frequently don’t remember until it hurts.
 

Woosh

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The boost function button lowers the amount of effort to rotate the cranks but it can't replace a throttle. It is useful for torque sensing system where you have to pedal much harder on hills.
Bikes with cadence sensor like the Rambletta lets you pedal as little or as much as you like. They are much more suited to riders who have lost some strength in their legs and joints.
Basically, when you ride on throttle, your bike becomes a motorbike, you can climb a hill without pedalling. It is banned in Europe but tolerated in the UK as long as you can't twist and go, that is starting on throttle from a standstill.
You have to rotate the cranks about one revolution to activate the motor and the throttle - after that, you can use it anytime you need to. You can use it on the flat or to climb hills when your joints are aching.
If you have no strength in your legs, you can always start in a low gear on the flat to make it easier to rotate the cranks. It only takes a fraction of a second for the motor to kick in then it becomes easy to pedal - or throttle.
 

Woosh

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We get the Rambletta in the second week of October and there is a backlog. I think currently first week in November.
 
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vfr400

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Jun 12, 2011
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Speed isn’t a factor but why does Ah and voltage matter given the restriction to 250W ?
The 250w is not a restriction. Most "250w" electric bikes draw something like 500w to 900w from the battery, with an efficiency of around 70%, so 350w to 630w output power, when giving maximum power. There is no regulation on the power drawn, nor the output power. Instead, it's on the rating of the motor. How they determine the rating is pretty well unregulated.

With all that in mind, you can get very powerful 250w bikes and not so powerful ones. The manufacturers rarely tell you the actual power. Instead they give daft figures for torque, which I would take with a pinch of salt.

There's a direct relation between current and torque. As most electric bikes are 36v, the torque, current and power are all directly related. If they were honest about torque, you would be able to see how bikes compare for power.
 

sjpt

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The 250w is not a restriction. Most "250w" electric bikes draw something like 500w to 900w from the battery, with an efficiency of around 70%, so 350w to 630w output power, when giving maximum power. There is no regulation on the power drawn, nor the output power. Instead, it's on the rating of the motor. How they determine the rating is pretty well unregulated.

With all that in mind, you can get very powerful 250w bikes and not so powerful ones. The manufacturers rarely tell you the actual power. Instead they give daft figures for torque, which I would take with a pinch of salt.

There's a direct relation between current and torque. As most electric bikes are 36v, the torque, current and power are all directly related. If they were honest about torque, you would be able to see how bikes compare for power.
For more details look at https://www.ebikes.ca/tools/simulator.html
They have lots of details about lots of motors; sadly many modern motors missing but it still shows the principles and their impact very clearly.