Thursday, November 18, 2021

Giant TCR Advanced Disc 2 Pro Compact

Recently my friend decided to upgrade his road bike, as his old one did not really fit him well. He found the aggressive riding posture too low and uncomfortable for him, as the Merida Reacto is an aero race bike.

Since then, 5 years on, the road bike market has changed considerably. The biggest difference would be the change from rim brakes to disc brakes, which improves braking performance greatly. In the year 2021, a disc brake road bike is highly recommended over rim brake bikes, as rim brake road bikes are outdated. If you like rim brake bikes, sure, there are still some available. However, disc brake road bikes just performs better.

The tricky thing is, in the year 2021, new bikes are out of stock nearly everywhere, due to the sudden popularity of cycling. It is nearly impossible to walk into a bike store and have exactly what you want in stock.

We went to check out a few bike shops, to see the available options. First stop was at Hup Leong (Merida and Cannondale), which was where I got my first road bike, the Merida Scultura 5000 some years ago. However when we reached there, the store was practically empty. We could not even place a pre-order if we wanted, as they cannot confirm a delivery date for new bikes.

Next stop is at Treknology (Trek), where we saw the Trek Emonda SL5, with Shimano 105 disc brake groupset. There was stock available, but the price was quite high for 105 spec. Also, it was not lightweight at all, which was what I expected of an Emonda.

At Specialized, the only bikes available were those super high end models, such as the top end S-Works Aethos, which has a completely bonkers price tag of S$22,000.

Finally, we ended up at Tay Junction at Ubi, to look for Giant bikes. To my surprise, the bike shop was quite well stocked! There were actually many bikes available, in all sizes and models. We were told that the new stock just came in last week, which was why there were many bikes.

After much deliberation, he finally decided to get the Giant TCR Advanced Disc 2 with Pro Compact geometry. The shop had the right size for him, while the specifications are pretty good. Most importantly, the price is still reasonable, although there was a price increase of about $300 over the previous years model. Overall I think this is a good balance of performance, price and weight.

I did some additional tune up of the new road bike, as there were some problems with the front shifting that the shop could not fix. It is also a great opportunity for me to check out the bike and share some pictures of it.

Here is the new bike! Giant TCR Advanced Disc 2.

Another view from the non-drive side. Front and rear 12 mm thru axles, of course.

Bike model is TCR, which stands for Total Compact Road.

Stock bike weight is 8.6 kg without pedals, which is OK for this price range. The Emonda SL5 weighs more than this and still costs $1,000 more!

This bike has an awesome paint job! The metallic glitter makes it look really good in the sun.

The glitter reminds me of the Cervelo Aspero which has an awesome paint job as well.

More pictures of the paint job

The carbon fork has a matching paint job as well.

Seat stays are slightly dropped from the top tube, and blends in nicely around the seat tube.

UCI certified frame, in M/L size.

Made in Taiwan by Giant themselves, which makes bikes for many other bike companies as well.

Stock saddle looks good, with a nice cutout and comfortable padding.

Gentle curve on the saddle, and an aero seat post. Not so ideal if you want to change to aftermarket seat posts.

Integrated seat post clamp, hidden by a rubber cover.

Shimano 105 R7000 2x11 speed mechanical drivetrain!

Semi-compact crankset with 52/36T, which I think is too big. A compact 50/34T may be better.


Crankarm length is 172.5 mm, which is matched to the frame size. I personally use shorter 165 mm crank arms.

Shimano 105 front derailleur, FD-R7000.

This front derailleur uses the toggle link mechanism, which eliminates the long arm front derailleur of the previous 5800 generation. Also, it has a built in cable tension adjuster, which is really useful because there is no need to have an inline cable adjuster on the outer casing.

However, the setup method is quite different, which I am not familiar with. I have only been adjusting Di2 front derailleurs, not this new generation of mechanical front derailleur. Therefore I had to follow the instructions listed in the Dealer's Manual, step by step.

Shimano 105 RD-R7000 rear derailleur. Note the short outer casing length which has been carefully determined for optimum cable routing.

Shimano 105 cassette, CS-R7000 in 11-30T combination.

It does not use a Shimano chain, but uses a KMC X11 EL (extra light). I think this is a higher grade chain than the Shimano 105 HG601 chain, which is surprising.

Standard drop bar with a compact drop shape. Width is 42 cm for M/L frame size.

Shimano 105 hydraulic disc brake shifters, ST-R7020. The tall hoods are due to the hydraulic mechanism inside.

Generic stem of 110 mm length, on top of a huge stack of spacers.

Front brake hose runs into the front fork, while the rear brake hose runs into the down tube from the side.

The rear and front shifter cables run into the top of the down tube through these cable ports.

These shifter cables run along the cable guide, located at the bottom of the bottom bracket.

Shimano 105 brake calipers, BR-R7000 Flat Mount. Set at the 160 mm diameter rotor size for the front.

Giant's in-house rotors, with 6 bolt mounting. Looks cheap, to be honest. Let's hope it works well.

Flat mount disc brakes for the rear as well.

Rear rotor is smaller at 140 mm in diameter, and thus an adapter is not needed for the rear brake caliper.

Stock wheels come with aluminium rims, which means they are probably rather heavy, like the stock wheels on my Merida Scultura 5000.

Rim internal width is 22 mm, which is surprisingly wide.

The bike actually comes with a tubeless setup, with sealant inside! It offers a good ride, and can seal up small punctures automatically. I haven't used tubeless on my road tires before.

Smooth tread in the middle for smooth rolling, with a bit of treads at the sides for cornering grip.

Although the tire size is 25C as listed at the side wall, the actual tire width is more than 29 mm, probably due to the wide rim width. This is actually good news, as this is a good balance between speed and comfort.

Still good tire clearance at the front fork even with 29 mm wide tires.

Rear seat stay area has a healthy tire clearance as well.

The tightest tire clearance is almost always at the chain stay area, as shown here.

There is a 5 mm gap to the frame on either side of the tire.

Based on this estimation, we can probably fit a tire width of 32 mm into this frame safely, and still have about 3.5 mm of clearance on either side. For dry gravel rides this is enough, it is more than the tire clearance that I had on my Canyon Endurace. The tricky part is getting the actual tire width of 32 mm, in combination with the 22 mm wide rim. It's pretty much trial and error as to what tire width to buy, as a claimed 32 mm width may not turn out to be 32 mm in actual tire width.

Anyway, here is the introduction to this Giant TCR Advanced Disc 2 road bike. Based on initial feedback from my friend after a few rides, this new bike rides really well, and feels more comfortable as well as faster than the previous road bike.

United Trifold: Frame and Hub Issues

While building the United Trifold in the previous posts, I keep writing about how the frame is not straight. For example, the rear triangle itself is a bit twisted, as the left and right side chain stays are not parallel. The axis of the bottom bracket and the axis of the rear axle are also not parallel, which I found when installing the crankset and aligning the chain line.

Those are not so obvious, and can probably be spotted only because removed the components from the frame. That said, I can't feel any issue when riding the bike, despite having these misalignments.

Other than those, there are also other areas where there are frame misalignments, as you can see below.

Handlepost is not parallel to seat post.

These two "posts" should be parallel, which is a basic requirement.

Unfortunately, this difference is quite obvious, and can be felt when riding. This is similar to the problem that I faced when building the Fnhon DB11 folding bike.

It seems that the problem is from the United Trifold frame, not the handlepost, as the tilting is still present after I swapped to the new Fnhon handlepost. The head tube is not parallel to the seat tube, which is another problem with the manufacturing of the frame. There is also no proper QC which will detect all these issues.

Front fork is also not straight. Wheel is tilted and offset to one side.

There is also an issue with the front fork, where the front wheel is not nicely centered within the dropouts. It seems that the fork legs are not aligned, causing the wheel to tilt to one side. However, this problem cannot be felt when cycling.

I am not sure if I got a lemon frame, or are the QC of all the United Trifold frame like that. You can check your own to see how it is.

When I modified the drivetrain to become a single speed drivetrain, it is with a normal freehub rear wheel. For normal riding there is no issue, but when I am pedaling up slopes, and I stand up to pedal, there is sometimes a loud cracking sound coming from the rear hub area. This only happens when I apply high torque to the pedals.

There are a few possibilities for this to happen, which I checked thoroughly.

1) Chain slips over the sprocket teeth, due to insufficient engagement. This is not the case, as the sprocket teeth are tall and prevent the chain from skipping.

2) Sprocket splines skips over the freehub body splines. Upon checking, this also did not happen. There would be very obvious marks on the aluminium freehub body if it did happen.

3) Pawl slips from the ratchet, at the pawl and ratchet mechanism inside the freehub body. I opened up the rear hub to see if I could spot anything.

Freehub body removed from the rear hub. This structure is somewhat similar to the Wheelsport rear wheel.

There are 3 pawls instead of 6, which means more chance of skipping. However, I did not spot any damage at the tip of the pawls.

Also no damage on the ratchet, all the teeth look perfectly fine.

In the end I could not find the source of the cracking during high load, but I was also glad that no damage was done. If there are slopes I just have to make sure that I do not apply too much torque.

If I had paid a premium price for the United Trifold, I would be really unhappy with the frame problems that I found. However, since I got the bike at a good deal, I can accept the defects. I wonder if the Brompton clones such as the 3Sixty or the Pikes have similar problems or not.

Thursday, November 11, 2021

United Trifold: Assembly Completed

The modification of the United Trifold is finally completed! It is more of a total overhaul than just a modification, as practically all the components were upgraded, except for the frameset. You can read all about the new components in the previous posts, found on this main page for the United Trifold.

My objective for this new setup was to reduce the weight of the bike as much as I can (within certain cost and practicality limits), while improving the drivetrain efficiency. Looking good is an added bonus as well!

With that objective, the heavy 7 speed internal hub has to go, both to reduce the weight and to improve the drivetrain efficiency. The rest of the modifications are mainly for weight reduction and appearance improvement.

Let's look at the result of this total overhaul, which might possibly be the most heavily modified United Trifold. I'm pretty sure most people are not as crazy as me to put in so much time, effort and money to upgrade this bike.

Overall look at the new bike! The purple frame and yellow tires are definitely eye-catching and not boring at all.

Folds down quite compactly, but not quite Brompton style.

Chain tensioner manages the excess chain length when folded, making it a very important but often overlooked component.

Not as compact as a Brompton, as the saddle and handlebar sticks out too much.

The handlepost and front fork folds to the opposite side compared to the Brompton.

Overall folded width is decent, if you ignore the width from the non-folding pedal.

If a folding pedal is used, the overall folded width would be reduced significantly.

Joint of the handlepost sticks out quite high as well.

As mentioned earlier, the fork and handlepost folds to the left side, instead of covering the drivetrain like on the Brompton.

The rear wheel is suspended very high up from the ground, which makes the folded package relatively tall. Something that can definitely be improved upon.

Finally, here is a detailed component breakdown of the United Trifold. With this detailed weight analysis, you can know how much weight difference there will be when you change a component.

Weight is just 8.9 kg without pedals, and 9.3 kg with pedals!

In contrast to the stock United Trifold, this bike is much lighter in weight. The stock United Trifold 7S weighs 12.6 kg with pedals, while this single speed version weighs just 9.3 kg. That is a difference of 3.3 kg or 26% lower, which is a massive reduction. There is not much room for further weight reduction, considering that I am already on a single speed drivetrain with no cassette or shifter.

You could cut a bit more weight from the bike, by using super light brake levers, grips, crankset and seat post, that would save an additional 300 grams or so. But this frame itself is still rather heavy, despite the aluminium frame. The fork itself is also super heavy.

Being a single speed drivetrain, there are limitations as to where I can reasonably ride it. Steep slopes are out for me, while relatively fast rides on the road is also not possible as I can't pedal fast enough. This bike is built to be a leisure bike for casual riding along the pavement and park connectors.

Testing the bike out at the Green Corridor, which is a great place to cycle when it is not too crowded.

Yes no crowds, which is awesome.

This bike goes well with the Early Rider Seeker 14 that my kid rides, as the single speed is perfect for leisure rides.

I am pleased to find that the gearing of 59.4 gear inches (Front 52T, rear 14T, 16 inch wheelset) is ideal for most conditions. It is light enough to move off from a standstill, and enough to sustain a speed of 20-25 km/h at a comfortable cadence. Longer or steeper upslopes require more leg power to overcome, while going downhill just means letting the bike freewheel along as there is no point pedaling.

I enjoy the fact that I don't need to think about gear shifting, as there is only one gear. I only need to concentrate on the ride, and vary my leg power to follow the terrain. There is a kind of simplicity to this kind of bike riding, where the focus is on the journey and scenery, and not the technology on the bike.

It would not be a bike that I would want to ride everywhere or everyday, due to the gear limitations, but there are certain rides where this bike would be preferred.