Hi Paul,

Nice to have another engineer take a shot at improving the A-bike!

I started out with the 6" version, but have upgraded to an 8" A-bike, which rides considerably easier, but the steering is still too stiff for my comfort.
I agree that this is the most needed improvement.

I haven't been using the A-bike recently, but hope to do so when the weather improves.
My main mods so far were the saddle, and the grips (see other posts).

If you're in Amsterdam you're welcome to try the 8" version.

job

Another bike that you can look at is the Pacific Carry Me http://www.foldingcyclist.com/Pacific-Cycles-CarryMe-DS-folding-bike.html. It uses the same tire as the A-Bike City (8" tire size) and the frame set-up is a bit more like regular bike as far seat/ bottom bracket location. I am not how the frame compares in strength when compared A-Bike. It makes for a good case study from an design study to see how well each holds up under daily use. :)

I agree on the listed design improvements. The steering system is the most likely to fixed the easiest. I think that the many pivot points is one of the weak areas that will be difficult overcome. The drive train as it stands now uses a freewheel for the crank arm support area. Given the small wheels being used I can not think of another way around of getting the drive train to work given the enclosed design set-up. You would have to totally redesign bike to make some of the ideas listed work out. There are other designs around that needed to be looked to see how well hey stand up to normal use. I would not personly increase the gear ratio on the bike. Given the short wheel base and small wheels, the set-up works good now.

I own a copy version of the A-bike design and find a bit of fine tuning once in a while is needed to keep up the a safe riding standard. Also consider fact the the bike is intended for shore trips only. If longer rides are needed, a bike designed to do these should be looked at instead.

Hi all,

Last week I decided I needed a folding bike. Found out about the [i][b]A-bike[/b][/i] and got a second hand original one (6" wheels [i]plus[/i] model) the same day. After getting it home and examining it I was pretty disappointed. Overall, the bike is weakly constructed in all areas and will not stand up to years or even months of serious use.
Normally I would leave it at that. But I very much like the bike concept - folding is just brilliant. And I am an engineer and I have years of knowledge about bike tech.

So, I think I will set out to improve on a number of aspects.
The two main areas I will focus on are [b]1) stiff steering [/b]and [b]2) overall frame stability[/b].
[b]Ad 1[/b]: Upgrade the steering to ball bearings (preferred) or better bushings (close tolerance/ improved material);
[b]Ad 2[/b]: Upgrade all pivots and other areas causing play.
In a later stage I will be looking at [b]3) transmission ratio and efficiency[/b].

I am thinking about selling these upgrades to other A-bikers so as to make the project feasible (e.g. design & production of CNC machined parts).
The goal will be to build an [i][b]A-bike[/b][/i] that is super reliable and sturdy and will give a better, lighter, more nimble ride. As little as possible weight is to be added.

I would like to get input from other users on my plans and of course on any other areas that you think need improvement. Add to this topic or PM me.

Happy riding,
Paul
(p.s. I live in The Netherlands)