United Trifold: Assembly Begins

In my case, I am basically building a United Trifold from scratch, since I decided to upgrade nearly every part of the bike. From the bare frameset, I added the crankset, wheelset, seat post and handlebar, plus a totally new single speed drivetrain.

By doing so, I learnt a lot about this bike, both good and bad points. And this is just the start of the bike modification, there is lots more to come! It's definitely not the most cost effective way to build a bike, but it is fun. Besides, I bought this bike not because I really need it (I have many other bikes), but because I was curious to find out more about this type of trifold bikes. I used to have a Brompton M6R, but the upgrades were mainly cosmetic and functional, and not a total teardown like this one.

With my dream wheelset and basic drivetrain installed.

New carbon handlebar and Ergon grips installed, on the new Fnhon handlepost.

Single speed setup, with just one rear sprocket, and a new chain tensioner.

52T Stone narrow-wide chain ring on the non-series RS510 crankset.

Installing cables on a folding bike is always tricky, as you need to ensure that the cable slack is enough to enable folding and steering, and yet not leave too much slack as it can get in the way during folding. Sometimes it takes a lot of measurements, plus trial and error to make it work optimally.

Measuring the weight of the two brake inner cables before installation. There is no shifter cable for this single speed setup.

After cutting the excess cable off, here is the weight removed. This gives a total inner cable weight of 35 grams that is on the bike.

I added this SM-CB90 Brake Cable Adjuster to the brake outer casings, to release more cable when I need to open up the brake calipers more, during wheel removal.

I love the new 3D forged handlepost, with no welding at the joints. Also check out the new Litepro headset.

Here is how the handlebar looks with the brake cables connected! Super clean with no shifter cables.

It was tricky to find a suitable place for the inline SM-CB90 brake cable adjuster, as it needs to avoid areas with sharp bends, and also avoid being near the frame to avoid knocking sounds during riding or leaving scratches on it.

Litepro A62 seat post, with a new lightweight carbon saddle.

Here is the original Tektro caliper brakes, conditioned to work smoothly, and with new Ultegra brake pads.

Also using the stock Tektro brake calipers at the rear. Smooth cable routing is one of the factors for good braking performance.

Love the look of the wheelset, with the unique paired spoke pattern. Looks just as good as the Kinetix Pro wheelset on the Dahon MuEX.

Rear drivetrain completed! Drivetrain efficiency is at good as it gets, with a near-perfect chain line and no internal hub drag.

The ideal chain length is when the two pulleys are in line with the hub axle. (or is it the chain tensioner pivot?)

Single speed drivetrain, with one 14T sprocket on the standard freehub body.

The bike is almost ready for a test ride! There is a huge weight saving from the stock setup, it will be revealed in the next post.

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.

Focus Paralane: Shimano WH-RS770 Wheelset and GP5000 Tires

The new Focus Paralane all-weather road bike will need a new pair of wheels. My previous all-weather road bike was the Fabike C3, but that wheelset with Alfine 11 Di2 internal hub is not suitable for this new bike. Although the DT Swiss front wheel can be used, I would rather get a pair of front and rear wheels that matches.

What I needed is a proper road wheelset, with 12 mm E-thru axles and disc brake hubs. This was what I had, the Reynolds Assault wheelset. However, I had already sold it, which I regretted a lot. At that time, I did not plan to use it on any other bike, since I already had the new Zenith Elite wheelset from Ascent Bikes. Therefore, I decided to sell the Reynolds wheelset to free up some space at home.

If I did not sell that Reynolds wheelset, it would have been perfect for this Focus Paralane, as a used carbon wheelset for all-weather duties.

Therefore, I had to get a new pair of disc brake compatible, 12 mm E-thru wheels. I did not want to fork out over $1000 for a pair of carbon wheels, for all-weather riding. Therefore, I went for the more budget option, which is a pair of aluminium wheelset.

This Shimano RS770 wheelset is a peculiar wheelset, as the rim is made of a hybrid of carbon and aluminium. More details below.

Looks totally like a low profile lightweight carbon wheelset. I like the stealthy look of it.

It has a wavy rim shape, similar to Princeton CarbonWorks wheelset. Probably a coincidence...

The rim is actually made of aluminium, but reinforced with a layer of carbon on top. Probably only Shimano is mass producing this type of rims.

Why does Shimano use carbon reinforced aluminium rims? This actually dates back to some years ago, when carbon wheelsets for rim brakes were getting popular. At that time, road bikes were predominantly on rim brakes, therefore the braking surface is still on the rim.

Some other manufacturers have a full carbon rim, which means that the braking surface is made of carbon. This tends to have poorer brake performance and heat dissipation properties compared to conventional aluminium rims.

Shimano wanted to make carbon rims, but still retain the superior braking performance of aluminium rims. Therefore, this hybrid construction was created, so that the braking surface is still aluminium, but the rim profile can be made thinner in aluminium, and cladded with carbon fibre for strength and also appearance. Check out the Dura-Ace WH-7900 C24 wheelset to see what I mean.

Somehow, this construction has endured even to this day, on the mid-range disc brake wheelset, as shown here by WH-RS770. It is Ultegra grade, but not labelled under the Ultegra series. There is no advantage to having the aluminium braking surface on the rim, since disc brakes are used.

Black spokes and spoke nipples are used, to match the black rims.

Although the braking surface seems to be present on the rim, it is not to be used.

The wheel comes with tubeless rim tape already installed.

However, the end of the rim tape was not pressed down properly, and tends to detach. If an inner tube is used, it is not a problem. However, if a tubeless setup is used, sealant will get underneath the tape and may leak.

External rim width is 22 mm, which is old school. Nowadays external rim widths are easily 28 mm or more.

Internal rim width is old school as well, at just 17 mm. Most new road bike wheels now have a wider internal rim width of at least 19 mm, or 21 mm.

Rim height at the shallowest areas are 28 mm.

If measured at the taller areas, the rim height is 30 mm.

The hubs look nice with a shiny anodised silver finish, with black areas as well. Still using traditional cup and cone bearings, but for 12 mm E-thru axles.

Centerlock disc brake mounting, which makes installing or removing rotors so much easier compared to using 6 bolt type.

WH-RS770 is the model number of this wheelset. Bladed straight pull spokes are used.

Rear wheel has a steel freehub body, to prevent gouging caused by the steel sprockets. Adds some weight over an aluminium freehub body, but lasts much longer.

Weight of front wheel is 743 grams, heavier than the Zenith Elite but lighter than the Reynolds Assault.

Rear wheel is pretty heavy at 923 grams, due to the steel freehub body and cup-and-cone bearings.

This gives a total wheelset weight of 1666 grams, which is slightly more than the Reynolds Assault (1637 grams) and heavier than the Zenith Elite (1504 grams). Not too bad for an aluminium wheelset!

Using the same Continental GP5000 tires on this wheelset as well, for maximum speed.

GP5000 tires on the RS770 wheelset. However, a silver band can be seen at the interface between the rim and the tire.

This silver band is from the exposed aluminium at the top edge of the rim, which is not covered by the carbon fibre layer.

This silver line does not look good, as it spoils the integrated look of the wheelset and tire. Does not affect function, but it lowers the aesthetic value of this wheelset. Will do something about it later.

Actual tire width is about 27 mm, when mounted on this wheel with 17 mm internal rim width. In comparison, actual tire width is 28.5 mm when mounted on internal rim width of 21 mm.

Added the Dura-Ace RT900 rotors as well. Now it looks fast!

Comparing the RS770 wheelset with the Zenith Elite wheelset, both with 28 mm GP5000 tires. Rim height is obviously different. The silver line on the RS770 wheelset stands out too much, unfortunately.

For pure academic purposes, I installed the previous Continenal Grand Prix 4 Season tires on this new rim as well.

Using Continental Grand Prix 4 Season 28 mm tires on different internal rim widths:

20 mm rim --> 31.8 mm actual tire width

18 mm rim --> 30.8 mm actual tire width

17 mm rim --> 30.8 mm actual tire width

As you can see, the previous generation of Continental tires are generally oversized, even when mounted on narrow rims. The new generation (GP5000) is more true to size.

Later on, after the wheelset is installed on the full bike, I will be able to evaluate the ride quality of this RS770 wheelset with GP5000 tires.