Concept A-bike folding seat

Just a short note this time. I did a drawing of a seat that could be used on a A-bike type design. It uses the design feature of a rear mounted seat section that has two pivot points on the side of of the front mounted seat section. There is a cut-out section on the rear section to allow the seat to fold into the bike just as is done now on the current seat. This is just a thought of making this bike a bit more comfortable and user friendly.

Small wheel testing.

Today, I tested out how small wheels work out in the real world. To do this, I used a scooter I had bought years ago and started to use it. Although this is not the A-bike, it showed just how the small wheels responded when in use. The ride quality was very bumpy. These are solid wheels and the A-bike will have air filled tires so there should be a small difference I hope. I figure that to get the bike up to speed and keep it there, a lot more pedaling input will be needed when compared to a full sized bike. The shorted crank arms will mean a faster pedal rate for what put into your pedalling of the bike. The next post will be the first riding impressions of the real bike after a ride on it.

Bought a 8" wheeled A-bike.

Today, I bought a A-bike from a B.C. Canada hobby shop. The price was better then what I have seen on E-bay. I want to see just how well this bike works. It also gives me a chance see how this bike holds up over time.

I looked at the specs for the bike and found out the final drive ratio is 5.66 to 1. The bike has a total of 44.6 gears inches. This is on the low side. I figured this out by taking the gear ratio and multiplying it by the diameter of the 8" wheel. When compared to Strida folding bike http://ridethisbike.com/products/Strida/version-5-o-folding-bike.htm, the Strida design has 56 inches inches. This allows for a bit better speed when pedaling it.

In order to try out how a fixed gear 44.6 gearing inch equipped bike would feel as far as speed goes, I used my ride bike and picked out gear setting that would give this amount of gearing. I used the 42/ 25 gear setting on the bike to get the same amount of gear inches that is on the A-bike and started to pedal without shifting. I looked at my cycling computer and noted the speeds I was getting. I was achieving 19 KPH (11.7 MPH) and the pedaling speed as not too high. Looking up an old cycling chart I have showed me I was doing 80 R.P.M. In order to get up to the claimed 15 MPH (24.3 KPH) a rider would have to get a cycling RPM of 110 to get that speed. That can be done but only for short bursts. A more realistic speed for this bike would be 12 MPH (19.47 KPH) for a cyclist that is used to maintain these speeds. For a cyclist used to only doing about 60 RPM would maintain a speed of only 8.2 MPH (13.3 KPH). In this regard, I am guessing that the design of the bike will meet the needs of a short range commuter. How well it works on real roads is something I am looking forward to trying out.

I am looking forward to getting this little bike to try it out. I think it will be fun use. When compared to riding the road, mountain or a folding bike with 20" wheels, I know that the A-bike will have very different feel to it! When I get the bike, I will post a number of pictures of it. It will also allow me to see how the drive train is set-up and see if a recumbent can be worked of it. The small folding recumbent drawing I have posted would be nice to see built into a working bike.

12" wheeled A-bike set-up drawing

I have been doing a bit of drawing to see what I could come up with as far as 12"wheel version of the A-bike design. This drawing shows what I have come up with. It shows a number of changes as far as the proportions go in the frame. I have no idea as to how much time or money would be needed to start this as a building project. It would be more then the cost of the one you can buy. The projected wheel base is 34 to 36 inches. The projected height of the bike is 36 inches.

This just a drawing. To build this bike, a lot more work will be needed to get the various size of tubing for proper fit of tubes and materials needed for making the folds points work out. Just trying to work this out is fun to do.

One another note, I tried this drawing of recumbent version of the A-bike. It uses the drive train set-up used on the A-bike but is modified with a longer chain that goes on to a mid-drive. This would then allow another transfer on to the final drive wheel. The bike is based on a recumbent I built using 12" wheels. I made a number small detail changes to make it work around the smaller 8" wheels used on the A-bike design. At this point, it is just a idea, not a work in progress. Anyone interested in trying this beyond a drawing concept is welcome to

try it out.

I have been looking up bike designs again after getting away from this for a while. I have seen the A-bike design. It is small and interesting to look at. I lack the money to buy one although I would like to get one to get a feel of how it does feel to use. I just like the idea of a very compact bike to use. It would be nice to create a recumbent bike using the parts used in the folding compact up-right design.

Here is a link to the A-bike. http://www.foldingbikes.co.uk/sinclair_abike.htm.

This link goes to a Chini based exporter of the bike. It has the specs and other info regarding the bike there. http://www.diytrade.com/china/4/leads/3028398/A_bike_folding_bike_foldable_bike_mini_bike.html.
It would be great to see if somehow someone could make a bike like this using standard bike parts using the same basic A-frame design as a base. I now lack some of the things needed to make one but I will post a drawing of a possible A-type bike design that could be home made.

Welcome to my blog. It has been set-up so that people that enjoy building home made bikes of all types can be posted. Whether it be a recumbent or up-right bike design, feel free to post a story here about something you have created!