Bike seat review

[cwah]

Hey guys,

I finally got my hand on the bike seat. I decided to try to on one of my bikes. Currently it would be my Dahon jetstream:

Here are the pictures:

 

[cwah]

 

[cwah]

The bike seat cost shipped 200USD. With about 35euro customs, it cost me a total of about 150GBP.

A bit expensive... but this seat has room for a good battery pack.

I calculated that I can have 9 cell on width and 13 cells length. So if I do an 18s configuration I can have a total of 18s * 6 row = 108 cells, or a pack of 66V13.5AH with my Sony US18650V3 cell for about 4.8kg.

Good, stealthy and waterproof pack that would indeed be.

Will keep you all informed

 

[Clockwise]

Is it a seat or a pannier rack or both rolled into one, I'm having trouble picturing is on a bike.

 

[cwah]

Picture on a bike:

 

[patpatbut]

Hi Cwah,

Cant wait to see that in action. Hope it all goes well!

Pat

 

[cwah]

Yeah, I'm hoping to make it work.

I'm thinking to bolt the seat on the rear fork area to still have rear suspension working:

What do you think of this configuration?

 

[Deleted member 4366]

You'd be better chucking that arrangement,and using two strips of steel about 12mm wide and at least 2mm thick. Run them directly from the bracket on the seat to the outside of the fixing bolt on the suspension.You'll need a longer bolt for the suspension and a spacer (washers) in the middle of the bracket at the so you can bolt it up tight. You might find then that with someone sitting on it, the whole fixing arrangement will work like a parallelogram, and the seat will move forward when you apply the brakes, s0 you'll need two addition strips to triangulate it from the bottom of the suspension to maybe the front bottom corner of the frame.

It might be better to use hard aluminium tube rather than steel strip. Bash the ends flat and drill fixing holes like I do for my racks. See here:
http://www.pedelecs.co.uk/forum/electric-bicycles/14308-how-make-rack-battery.html

 

[cwah]

Yes makes sense dave. I chatted with the seller and he insisted to try it first with the initial setting. It may be loose enough to allow suspension to work.

I'll try that first then

I also started to put batteries inside the seat

These battery holder are not bad to assemble DIY pack. Apparently the spacing is made to allow heat radiation... let see how they handle vibrations.

 

[trex]

How many cells do you have in the box, cwah?
the support posts seem to be logically designed.

 

[cwah]

On the picture 50 cells. So at 8.1wh/ cell it's a 405wh pack.

My final pack should have about 100 cells. So a 800wh pack in this box

 

[eHomer]

It's a very neat looking arrangement but I'd prefer to get the centre of gravity down, either side of the wheel, rather than all above it.

My first lithium battery bike kit came with a neat alluminium cased 36v 10ah pack which locked into a purpose designed rack on that bike.

As good batteries still seem to be the most expensive part of electric bike construction, I decided to standardise on that pack for all my bikes, so I bought a spare, giving me 20ah at 36v.

When I put one of Dave's MXUS cassette kits into my Trance full suspension bike I pondered for quite a while over mounting the battery(s).

I decided in the finish to go for the least obtrusive looking and lowest centre of gravity, so I found a pair of quite small pannier bags and a lightweight rack that could be adapted to the rear suspension frame.

The batteries are mounted vertically, one in each bag, with an interior velcro strap to stop them flopping about.

It gives me (as I understand it), 360wh X2, so 720wh, and there's still room in he bags for tools, cape, tube etc..

I tried both batteries on top of the rack initially, but it made it very top heavy, especially when left on it's stand.

 

[mike killay]

I am not too sure that having the weight high over the rear wheel is all that much of a problem.
Motorcyclists carry pillion passengers and also in Holland etc., it is quite common to see people sitting sideways on the rear carrier.

 

[eHomer]

I am not too sure that having the weight high over the rear wheel is all that much of a problem.
Motorcyclists carry pillion passengers and also in Holland etc., it is quite common to see people sitting sideways on the rear carrier.

True, but then again there's a big unladen weight difference between push bikes and motor bikes, say 20kg against 150kg average.


Not sure I'd like to ride very far with someone sitting side saddle on my push bike rear carrier, though I agree you do see it being done !


50 years ago I road a trade bike for an off license that had a large frame extension front carrier over a 20" wheel, that was very "lively" with a crate of schweppes in it

 

[patpatbut]

It's a very neat looking arrangement but I'd prefer to get the centre of gravity down, either side of the wheel, rather than all above it.

My first lithium battery bike kit came with a neat alluminium cased 36v 10ah pack which locked into a purpose designed rack on that bike.

As good batteries still seem to be the most expensive part of electric bike construction, I decided to standardise on that pack for all my bikes, so I bought a spare, giving me 20ah at 36v.

When I put one of Dave's MXUS cassette kits into my Trance full suspension bike I pondered for quite a while over mounting the battery(s).

I decided in the finish to go for the least obtrusive looking and lowest centre of gravity, so I found a pair of quite small pannier bags and a lightweight rack that could be adapted to the rear suspension frame.

The batteries are mounted vertically, one in each bag, with an interior velcro strap to stop them flopping about.

It gives me (as I understand it), 360wh X2, so 720wh, and there's still room in he bags for tools, cape, tube etc..

I tried both batteries on top of the rack initially, but it made it very top heavy, especially when left on it's stand.
View attachment 7583View attachment 7584

Hi eHomer

Nice build with double up the juice.

However, I am so suspicious about putting the heavy batteries on the panniers

As they are heavy, they might went through the pannier bag after the jump.

My heavy New York kryptonite lock 3kg went through the left side of the pannier after the bump (luckily it was not the battery)

I am so tempted to put the battery on the left side of the Topeak DXP truck bag but not sure will it survive...

Pat

 

[eHomer]

Hi eHomer

Nice build with double up the juice.

However, I am so suspicious about putting the heavy batteries on the panniers

As they are heavy, they might went through the pannier bag after the jump.

My heavy New York kryptonite lock 3kg went through the left side of the pannier after the bump (luckily it was not the battery)

I am so tempted to put the battery on the left side of the Topeak DXP truck bag but not sure will it survive...

Pat

I can understand the concern about not wanting to lose a £200 battery pack through a split pannier bag !

I'm a real worrier about that sort of thing, so I took a number of steps to make sure it can't happen.

Although small, the pannier bags are made from quite thick material and have a solid back, which is fixed to the rack with rigid hooks as well as straps. There's a lower clamp as well, so that can't slop about either, when the bike is leaned.

I then lined the bottom of the inside with a 10mm thick dense foam pad, to avoid any point loading or abrasion from the flat end of the alluminium battery case.

Lastly, the thing that makes it all nice and rigid is the velco strap shown in my photo. that holds the battery quite firmly inside the pannier upright against the rigid back panel. Without that, they did indeed flop about, and would have soon worn a hole in the bottom of the bag.

 

[jackhandy]

It's always tricky to know how to mount the battery/ies on a bouncer:

Either have a considerable lump added to the unsprung back-wheel weight, or on the seatpost, like my frog.

Ideally it would go in the triangle, but there's not room for a torch battery in mine. I tried the spare Ezee flatpack battery strapped to the side of the triangle & that was good for c of g, but inelegant, to say the least

Or course, the problem is compounded by the 2nd battery you guys have.

 

[trex]

strapped under the downtube?

 

[cwah]

I tried to install the bike seat on the bosch sinus B3 and it was a miserable failure:

The axle were to short in order to be tightened properly. I decided to remove the torque arm in order to do that but then I had chain issue....

Make sure your axle is long enough to allow foot peg (very thick of maybe 5-10mm metal) to be fixed on it

 

[patpatbut]

I thought you are trying to put this on your Dahon. Have you tried it yet?

Pat