United Trifold: Dream Wheelset

The stock United Trifold came with a Nexus Inter-7 hub SG-C3001, which is an internal hub with 7 speeds. This is unique among all the trifold bikes on the market, as most of them are just clones of the Brompton.

By this, I mean that they all use a narrow rear OLD of 112 mm, with a narrow rear hub that can accommodate up to 4 speeds on the short freehub body. Some of them have a Sturmey-Archer rear hub with 3 or 5 speeds as well. However, none of them use a Shimano internal hub, either of the 3, 5, 7, 8 or 11 speeds variety. Only United has these specifications, which is one of the many unique points about the bike.

From what I know, United Trifold is available in a few different models, with the 5 speed (Sturmey-Archer), 7 and 8 speed (Shimano) internal hubs. There may be others that I am not aware of.

Internal hubs actually make a lot of sense on this kind of compact trifold folding bikes, as external derailleur systems complicate the drivetrain and make it hard to fold properly without additional chain management devices.

However, I am not a big fan of internal hubs, as they are heavy (at least 1 kg more than derailleur type) and also have more drag, due to the internal mechanism of the hubs. Internal hubs are ideal if you need a low maintenance bike, such as how I set up my previous all-weather commuting bikes, the Avanti Inc 3 and Fabike C3.

In this case, I plan to simplify the drivetrain, by removing the 7 speed internal hub and replacing it with just a simple single speed drivetrain. No shifters or derailleur will be necessary, which keeps the setup clean and easy, and also saves quite a lot of weight.

With that, a new wheelset is needed. Strictly speaking only a new rear wheel is necessary, to replace the rear internal hub. The front wheel is fine and actually spins quite smoothly. However, I decided to just get a brand new wheelset, so that I have matching front and rear wheels.

I studied the frameset, after removing the stock wheelset from it. I was surprised to see that the rear OLD is 135 mm, even though the hub OLD is just 130 mm. A washer was used to take up some of the 5 mm difference, plus some rear triangle compression by the axle nuts.

In this case, the frame has a front OLD of 74 mm, and a rear OLD of 135 mm. Normally, the OLD is 74/130 mm for rim brake frames, and 100/135 mm for disc brake frames. Wheelsets are also sold in this standard front and rear combinations, unless otherwise specified.

I will get a 74/130 mm wheelset, and use an adapter to increase the rear OLD from 130 mm to 135 mm. This time, I am free to choose whatever wheelset I want, as long as it is 16 inch 349 sized.

Previously, I had gotten my dream wheelset for the Dahon MuEX, which is the Dahon Kinetix Pro wheelset. I love the spoke pattern which gives it a unique look and makes it lightweight as well.

This time, I can get a 16 inch wheelset in this same spoke pattern as well. Not so common, but available from Elosix. All black colour of course.

New 16 inch 349 wheelset, in the Kinetix Pro spoke pattern!

Front wheel is just 394 grams, a bit lighter than the 20 inch 406 version at 408 grams.

Rear wheel is 557 grams, lighter than the 20 inch 406 version at 590 grams.

Overall, this 16 inch wheelset weighs 951 grams with rim tape, which is lightweight. This is almost the same as the Silverock wheelset that I used on the Fnhon Gust, which is 959 grams.

External rim width is about 19 mm

Internal rim width is 13 mm. This is typical of old school rims such as this.

Rim height is 24 mm, which is the medium height variety.

I chose this rim height as it comes with internal spoke nipples, which look really good but are hard to service. I never had to service my wheelsets so I think this will not be an issue.

This is a standard rear hub with a 11 speed freehub body. Overkill for a single speed drivetrain, but this is the easiest way.

I also thought a lot about the choice of tires. I could choose the Schwalbe Kojak or Schwalbe One tires, in folding or non-folding type. Naturally I would choose the folding type of tires, as they are lighter and easier to install.

From what I can find, non-folding types are available in black colour only, while folding types are only available with yellow side walls. I was unsure how the bike would look with a purple frame and yellow tires, which was why I checked out some examples online.

Black colour might make it really boring, which was why I decided to just go loud and use yellow tires on the United Trifold.

Kojak is available in 32 mm width (32-349), while Schwalbe One is available in 35 mm width (35-349). The stock tires are 37-349, so either one will fit within the frame and caliper brakes.

Useful comparison table with the popular tires compared side by side. Source is unknown.

The comparison is between Kojak and One, and according to the comparison table, the One is lighter, has lower rolling resistance, and better grip. The price is higher though as expected.

In this case, the cost is not so important to me, which is why I chose the Schwalbe One. It is also slightly wider at 35 mm, which is good as it does not require such a high tire pressure.

Schwalbe One tires, with folding beads.

These tires are expensive! Still cheaper than from the local bike shops though.

Schwalbe One with yellow side walls.

16 inch, 349 size.

These tires are lightweight, at just 174 grams each!

The stock tires are about 400 grams EACH, which means that I can easily save 400+ grams just by replacing both tires.

New 16 inch inner tubes are needed. SV4 is the size for presta valves.

Inner tubes are 82 grams each

Front wheel with tire installed!

Rear wheel with tire installed. Testing out a single sprocket on the freehub body.

New wheelset for the United Trifold! In an eye-catching yellow tires on the black rims.

I really like the spoke pattern!

The wheelset is now ready, the next challenge is to setup the freehub body so that there is only one sprocket on it. From my understanding, I just need to add spacers on the freehub body, and adjust the sprocket position to get the ideal chain line.