Friday, July 10, 2020

Bike Friday HaD: Rear Handlebar Installation

Carrying on from the first part of this modification, which was to remove the wraparound bars from the Bike Friday Haul-A-Day cargo bike, now I need to add a rear handlebar to the bike.

Since there is no more wraparound bar, a rear handlebar needs to be added so that the rear passenger has something to hold on to while riding. Usually this is done by attaching a long stem to the seat post, then attaching a handlebar to that stem. Shown below is a stock picture from the Bike Friday website.

A stem is attached to the seatpost, so that a rear handlebar can be installed.

For this purpose, the Haul-A-Day uses a special seatpost size, which is 28.6 mm in diameter. This is exactly the clamp diameter of the steerer tube, that allows a normal stem to be fixed to the seat post. It is the reason why I had to get a special 28.6 mm diameter seat post from Thomson.

However, based on the distance between the seat post and the rear rack, I would need a really long stem, so that the rear handlebar is not too close to the seat post. If not, the rear rider would be right up against the butt of the front rider.

If you need to adjust the seat post height for different front riders, then the rear handlebar will also be moved up and down together. This is not ideal for the rear rider.

After I removed the wraparound bars, I found that the remaining clamp seems to be able to accept a handlebar. What is the diameter of this clamp?

Clamp at the front of the rear rack, with the wraparound bars removed.

After some measurements and testing with a handlebar, I found that the clamp diameter is suitable for a 25.4 mm handlebar! This is a standard diameter that is perfect for installing a rear handlebar. Besides, the position also seems to be ideal for the rear rider, since it is at the same position as the previous wraparound bars.

One downside is that it is less rigid than a stem that is mounted to the seat post. There is some flex with this mounting point, but I think it is acceptable, as it is only for holding on and there is no steering or braking forces on this rear handlebar.

It would not be ideal to install a standard width handlebar that is around 600 mm wide, as it is too wide for the rear rider, and also makes the bike quite wide. Although the front handlebar is 600 mm wide, it is controlled by the front rider and so it is OK. A rear width of 600 mm might make it tricky to get past through narrow spaces.

If you have a spare handlebar, it is easy to cut off the ends to make the handlebars narrower. However, I did not have a spare 25.4 mm handlebar lying around. Therefore, I had to buy a new handlebar.

I found that Toseek makes narrower handlebars for kids bikes, which is only 480 mm in width. This seems to be ideal for this purpose, and also saves me the trouble of cutting a full size handlebar. Although it is a carbon handlebar, it is not expensive, and Toseek is a brand that I have used before a few times, such as on this Haul-A-Day itself, and also on the Fnhon DB11 folding bike.

Toseek carbon handlebar, 480 mm in width.

It has a 5 degree backsweep, and a 25.4 mm centre clamp diameter.

As it is narrower than normal handlebars, it weighs just 76 grams, which is amazingly lightweight.

After getting the handlebar, I need to get new grips as well. It is better to get thinner grips as the grip diameter is smaller, which is more suitable for kids' hands. There are many many handlebar grips available on the market, so it is just a matter of choosing the colour and design that you like.

I came across this brand called Fifty-Fifty, which seems to make really nice grips as seen from the pictures. I decided to give it a try as the quality seems really good.

Look at the amazing colours!

Fifty-fifty lock-on handlebar grips, in grey colour.

Close up look at the grip material. Looks to be pretty nice and well molded.

The pair of grips weigh 111 grams, noted here for future reference.

Installation was super easy, it is just a matter of assembling the handlebar in the clamps, and sliding on the grips.

Handlebar and grips installed!

Handlebar width including the grips is slightly more than 480 mm.

The two-piece clamp has a diameter that matches the diameter of the 25.4 mm handlebar. Secures well with 2 bolts. You can basically install any handlebar you like, as long as it has a 25.4 mm centre clamp diameter.

The rear handlebar is at the same position as the previous wraparound bars. If I had used a stem that attaches to the seat post, a really long stem would be necessary to achieve the same position.

Together with the rear support, installed previously, the rear setup is complete!

Transformed the rear seat into a space that is more suitable for older kids. The colour of the rear grips matches the front Ergon GS3 grips!

This new setup probably weighs more than the previous setup with the wraparound bars, as the additional footrests weigh more than the wraparound bars that was removed. Not that I am still tabulating the weight of this bike, as it is already heavy at 20 kg. Another few hundred grams is not going to make a difference.

I was also able to attach a 14" kids bike onto the cargo bike, since there is now a footrest to help support the bike. Here is how it is done.

The kids bike is tied to the side of the rear rack, and secured further with bungee cords.

By this method, the width is not increased by too much, while the length is still manageable.

The cargo bike now functions as a range extender, as I can bring my kid out to cycle at places that are further away, without tiring him out by having to cycle all the way there and back.

2 comments:

  1. I am always impressed by your ingenuity. I initially found your site because I have a Dahon and was seeking info on alterations, but I continue to be intrigued with your content.

    ReplyDelete
  2. Hi do you have a link to the Toseek carbon handlebar, 480 mm in width?
    I've tried searching for this exact model (for weight-weening purposes) but could not find it, instead seeing other heavier variants with colour.

    ReplyDelete

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