Which Folder ;)

[MazB]

I'm looking at getting a new bike this time a folder, at present I'm using the UM55. I've got it down to 2 models:

1. Wisper 806fe

2. Izip Mezza

Don't really know too much about the Izip except at some point it was a cheep, cheerfull and heavy alternative. But seems as though Izip have come up market with this one costing over a grand!

Wisper of cors is a great name but cannot find too many reviews, posts or comments on the 806 but it looks a very nice machine and I will be able to test ride this.

Any comments on either would be appreciated or if you think I should look at others just throw them at me (not literally !)

Maz

 

[jerrysimon]

What about a Brompton with a nano kit ?

Probably around the same price.

Regards

Jerry

 

[flecc]

Each has an advantage and a disadvantage.

Small wheel folders generally suffer from a low top gear since it's difficult for the combination of chainwheel, rear sprocket and small wheel to end up with anything different. The outcome can be that one is spinning the pedals very fast at 15 mph to keep up with the motor.

The Wisper 806 uniquely has twin chainwheels of the kind found on full size derailleur bikes, so the large one gives a suitably high top gear while the smaller chainring ensures that's not at the cost of an inadequate low gear range. It does however have a front hub motor which is a slight disadvantage on a folder where there's very little weight on the front wheel, so there can be a loss of traction uphill on loose surfaces, wet leaves etc.

The Izip is the opposite, it's gearing is the normal setup so doesn't have the benefit of a high top gear, but it has a rear hub motor which suits the small wheel folder bike better and there's no risk of loss of traction.

As ever though, I'd advise making the effort and travelling if necessary to try both before buying, since personal preferences are so important.
.

 

[daniel.weck]

Small wheel folders generally suffer from a low top gear ... The outcome can be that one is spinning the pedals very fast at 15 mph to keep up with the motor.

on my 6-speed Brompton (SRAM gear hub + 2x rear derailleur), my legs only started to feel overwhelmed once I reached 50km/h, which is *way* after the motor had been shut down at the legal 25km/h speed limit Even on my 3-speed Merc (Brompton clone with Sturmey Archer gear hub), I could easily ride past the legal e-bike speed limit without running-out of pedal cadence.

 

[flecc]

Yes, but Brompton had to invent that derailleur bodge to overcome the cadence problem, proving my case. That's also why there's some optional much larger chainrings for the Brompton, and Dahon feel obliged to have both SRAM Dual Drive and Rohloff versions available to permit moderate cadences at reasonable speeds. It's also why my 20" wheel Q-bike has a 60 tooth chainwheel to give a reasonable top gear for most circumstances.

Also cadence is a matter of preference, I'm happy with high cadences as you evidently are, but the majority of e-bike riders definitely don't as witness the many posts bemoaning the cadence problem on small wheel folders in this forum.

And the cadence on that Merc Brompton with 16" wheels and a 3 speed Sturmey has to be high by any standards if it's chainwheel is clearing the ground!
.

 

[daniel.weck]

And the cadence on that Merc Brompton with 16" wheels and a 3 speed Sturmey has to be high by any standards if it's chainwheel is clearing the ground!
.

LOL, I don't know the gear/inches or meter-development figures, but I wouldn't even contemplate doing 50km/h with this 3-speed Merc !

The newer 2009 Brompton 6 speed comes with a wider range gear hub (BWR Brompton Wide Range), which has been much debated over at the BromptonTalk@yahoo.com mailing-list. With my 2006 6-speed Brommie, I find myself wanting more chainring teeth at the front for going downhill, but with the Bafang assistance I am now happy with the lowest gear for high-cadence hill-climbing (in Pedal Assist Sensor / pedelec mode, without torque sensor).

I don't have very strong legs, so I do prefer a higher cadence indeed

 

[flecc]

I don't know your sprockets on the Brompton of course, but your top gear is probably between 69" and 75". That's low by any standards, typical top gears on full size upright bikes being around 86" to 92". Getting those on small wheel bikes is very difficult, Wisper on the 20" wheel 806 getting a 91" with a second 50 tooth chainring with a cadence of 55 at 15 mph.

I've got a 60 tooth chainring and 13 tooth top gear rear sprocket on 20" wheels giving a top gear of 92" and a cadence of 114 at 50 kph, so you can see your cadence at that speed on 16" wheels and probably less sprocket advantage must be well beyond reasonable for most cyclists, even sporting types.
.

 

[jerrysimon]

Brompton Gearing

Gears Ratios/ Range/ Optional higher gearing/ Optional lower gearing
1-speed/ 5.93m /n/a / NO/ -7% & -18%
2-speed/ 4.45m - 5.93m/ 133% / NO/ -7% & -18%
3-speed/ 3.79m - 6.76m/ 178% / +8%/ -12% & -18%
6-speed/ 2.63m – 7.94m/ 302% / +8%/ -12%
(BRW)

Link (better formatted)

Jerry

 

[daniel.weck]

I don't know your sprockets on the Brompton of course, but your top gear is probably between 69" and 75". That's low by any standards, typical top gears on full size upright bikes being around 86" to 92".

84 actually

Some alternative chainring and sprocket sizes:

 

[daniel.weck]

On my stock Brompton M6R+, 40km/h in the highest gear is achievable at 100rpm (50T chainring, 13T rear sprocket, 3-speed SRAM gear hub, 170mm crank, 16" 1-3/8 349mm wheel). At 120rpm, 48km/h is achievable (that's how fast I had to pedal in my downhill test, and it felt pretty uncomfortable indeed )

Sheldon Brown's Bicycle Gear Calculator

EDIT: with 84 Gear Inches / 6.7 meters-development, some simple arithmetics mean that 50km/h gives the following cadence:
50km/h = 50,000 m / 60 mn => (50,000 m / 6.7m) / 60 mn [rpm] ==> 124.3rpm

 

[flecc]

On my stock Brompton M6R+, 40km/h in the highest gear is achievable at 100rpm (50T chainring, 13T rear sprocket, 3-speed SRAM gear hub, 170mm crank, 16" 1-3/8 349mm wheel). At 120rpm, 48km/h is achievable (that's how fast I had to pedal in my downhill test, and it felt pretty uncomfortable indeed )

Sheldon Brown's Bicycle Gear Calculator

Exactly as I thought Daniel, you had to have a large chainring like that 50 tooth, and as you say, that cadence at 48 kph is far from comfortable, my 109 at that speed being a bit OTT for me.

Al these cadences are way beyond what many forum members complain about on small wheel bikes, many complaining about the cadences on standard geared Panasonic motored full size wheel bikes, hence my original post above.
.

 

[inno-cycle]

I'm looking at getting a new bike this time a folder, at present I'm using the UM55. I've got it down to 2 models:

1. Wisper 806fe

2. Izip Mezza

Don't really know too much about the Izip except at some point it was a cheep, cheerfull and heavy alternative. But seems as though Izip have come up market with this one costing over a grand!

Wisper of cors is a great name but cannot find too many reviews, posts or comments on the 806 but it looks a very nice machine and I will be able to test ride this.

Any comments on either would be appreciated or if you think I should look at others just throw them at me (not literally !)

Maz

Hello,

I've not tried the Izip, but I've used an 806fe quite a bit and have had lots of customers trying it too. My overview would be:

Positives:

- The disadvantage of the front hub motor is far outweighed by the gearing. You will always be able to find a suitable gear. I have found that this is particularly important when on a flat road or a slight descent as on every electric folder that I've tried, your legs end up spinning round without assisting the bike whatsoever. York is realtively flat, but I'm sure the same goes for the other end of the scale when you get to bigger hills.

- The build quality is superb, the frame is finished really nicely and all of the components seem to be a really good spec, right down to the handlebar grips used. We have other folders in the shop and the quality really stands out.

- The cadence pedal sensor is excellent. When you push hard it really goes. Equally when you are going easy on it, the motor doesn't do masses - this is ideal for when you are in busy stop-start traffic.

- The battery (underneath the rear pannier) is very discreet and means that coupled with the front hub motor the weight is very evenly distributed, making it feel light.

- The advertised range of 30 miles is very much achievable. A customer recently took the bike and did a varied course and it still had charge left after completing 25 miles.

- Having seen a lot of electric folders, I think the price is very competitive for the quality of bike.

Negatives:

- A number of customer have commented on it not having a throttle. I don't know how old your UM is so this might something you are used to.

- It could do with an on/off switch on the handlebars, to turn the assistance off, you have to turn the battery off. Although I'm sure this can be easily resolved.

- If you are going to be using it on really rought terrain (which I don't think it was particularly designed for), the front hub rigid fork combination could prove an issue.

- It has a higher step-over frame than some of its competitors.

I hope this is helpful. I don't know where you are based - but if you can get to York, you are more than welcome to borrow one for a day and see how you get on.

Cheers,

Martin

 

[MazB]

Hi,

thanks for the replys, Martin great descrip of the Wisper and and I have to agree it is a nice looking bike.
I am used to a throttle and rear wheel motor, so these two differences are an issue.
I'm in Bristol and Atmosphere bikes have both in stock so I will be trying them out and any others as they have a good range of electric bikes.

My issue with the IZIP is the cost and not many reviews floating about, or even many mentions on the forum about performance which we would normally get with such a pricey bike.

BTW ....you lot lost me on the candence but I enjoyed reading it

Maz

 

[inno-cycle]

Hello,

I'm not the most technical - I have someone who make sure that is taken care of!

The Wisper site describes it as a cadence sensor, but basically if you make it easy to pedal it doesn't assist you much. If you put it in a higher gear it give you masses of assitance. It's a bit odd - but you'll see what I mean when you try it, it takes a bit of getting used to!

The adjustable handlebars on the Izip will be very handy.

Have a cracking time trying them out.

Cheers,

Martin

 

[Alex728]

BTW ....you lot lost me on the candence but I enjoyed reading it

cadence - speed at which you turn the pedals. Some bikes sense this and use it also to vary power from the motor (as opposed to just sensing that you are turning the pedals).

on a normal push bike 60-85 rpm is a good cadence for a commuter. those who are fond of lycra/sweat and in some cases dubious chemicals can reach 90-120 rpm.

 

[flecc]

BTW ....you lot lost me on the candence but I enjoyed reading it

Maz

. Cadence is just the number of pedal turns per minute Maz, so a 60 cadence is one rotation a second, a 120 cadence of the sort Daniel tortures himself with is two rotations per second.

Sport riders like the lycra wearing drop handlebar crowd regard a 90 cadence as around optimum and you'll mostly see them pedalling at near to that. Utility riders like those going to the shops will often be seen pedalling slowly at around 35 to 45 cadence, less than one turn per second, and there's lots on inbetweeners like the mountain bike crowd.

Body weight and size comes into it, the big built usually preferring slower cadences, the lean and lithe preferring higher ones.

N.B. Post crossed with Alex.
.

 

[daniel.weck]

a 120 cadence of the sort Daniel tortures himself with is two rotations per second.

LOL

only for a short distance, just to show-off my GPS data logging 'skills'

See here:

http://www.pedelecs.co.uk/forum/electric-bicycles/4825-diy-stage-8-continuous-improvements-2.html#post61464

 

[helHH]

Hi MazB,

I'm looking at exactly the same choice And I've tested both bikes.
Here's the post with my experiences and a spec comparison.

I agree completely with Martin's post re the wisper. It rides like a dream without power, but it doesn't have an off/on switch at the handlebars or different levels of pedal assist. The izip has all that plus a throttle and a stronger motor, but is a little heavier and not quite so beautifully geared, plus there's a little motor drag if ridden with the power off.

I've tested them both on a very steep hill and the wisper definitely needs more muscle input than the izip. For me, that would be fine, but if you're looking for a high level of assistance then the izip is obviously more powerful.

I've found it hard to make a decision mainly because of the price of the Izip if I want to buy locally (online it's in the 50cycles sale, which almost evens out the price difference, not sure it's still available, of course...).

In the meantime I've been looking at alternatives from smaller manufacturers to see if I can find something that ticks ALL my boxes, but it's difficult to get out there to try them etc. I've half a mind to just go down to the shop and test them once again, then make up my mind on the gut feeling...

Be interested to know what you settle on in the end!

Cheers

Hel