Thursday, June 14, 2018

Crius AEV20 1x11: Frame, Fork and Handlepost

I like to assemble a bike from scratch, as it means that I can specify exactly what components are used, and how everything is selected to work together effectively. However, I can't assemble a bike for a living, because of a few reasons.

1) I take too much time per bike, as I tend to spend quite a lot of time on the small details.
2) Difficult to make a decent profit, as there is no market demand to charge a premium for assembling the bike. For example, charging a 10% margin ($200) on a bike that costs $2,000 seems reasonable to me, but it takes too much time to be worth it. I don't think anyone is willing to pay a higher 20% premium.
3) Opportunity cost of giving up a stable, decent paying full time job with multiple employee benefits is too high.

On the other hand, assembling a bike as a hobby works great for me. I get to do it at my own pace, set my own deadlines, while ensuring that every build is as perfectly done as possible.

Building the Java Freccia mini velo from scratch

Building the Dahon MuEX from scratch

As I already have many bikes, I will not be building bikes for my own use. However, when close friends have a request, I will be glad to do it. Not only do I enjoy assembling bikes (at my own time and pace), it also ensures that every build is a custom setup that is closely tailored to the user's needs and budget.

That is how I ended up building a new folding bike for a friend! I will not be making any profit, as I will just collect enough to ensure that the component costs are covered, inclusive of any shipping charges or miscellaneous costs. Basically just enough to make sure that I don't incur a loss. No labour charges are involved for this kind of build.

Project objective was quite brief in this case. Just create a 20 inch folding bike that is relatively lightweight, easy to use, folds compactly, and finally with a cost of around $2,000. I did offer a choice of colours for certain components, such as wheels and frame, but the decision was to make it all black. No specific choice of components, so I made recommendations based on experience and function. I had the experience of building many Dahon bikes, so I know what works and what does not work.

In summary, I practically had free rein with regards to the component choice, as long as I satisfied the basic functional requirements and budget. Other people are likely to be more specific, but I have not come to that stage yet.

Starting with a 20 inch folding bike frame, everything will be sourced individually and assembled together piece by piece, creating a bike that is definitely unique. By doing so, I can create a bike that is exactly what I want, at a reasonable price, as there are no stock components to be discarded.

A good frame to build on would be either the Dahon MuEX which I used a few years back, or the Crius frame. Since the existing Dahon MuEX frames have been out of production for a few years already, I would prefer to use the newer Crius frame.

To keep it simple and lightweight, a V brake compatible frame will be used, instead of disc brake frames which are also available. This is the Crius AEV20 frameset, which is quite similar to the Dahon Vector line of frames in terms of the appearance.

Matte black for a stealthy look! Uses the older Dahon frame latch design as they are not allowed to use the newer clamp design which is still covered by patents.

Thoughtfully designed 3 cable ports for the RD, FD and rear brake cables.

Split tail design first introduced by Dahon in their Vector series, and later propagated by Tern.

View of the bottom bracket junction area

Most Crius frames come with a FD hanger, which makes it easy to set up a front double system without needing a separate FD adapter. Even the outer casing stopper has been welded onto the seat tube as shown.

Standard rear dropout design with replaceable RD hanger. Looks exactly the same as the Dahon design.

Left side of the rear dropout. Also has a mounting point for the frame magnet system.

It came in a folded configuration, which made the parcel smaller than what I expected it to be.

Frame (inclusive of RD hanger, seat post clamp, plastic seat post shim) weighs 2440 grams. Slightly heavier than the Dahon MuEX frame by about 100 grams.

Stock seat post shim is the plastic version. It is said to prevent scratches on the seat post, but the friction with the seat post is not sufficient even with a high clamping force, allowing the seat post to rotate and slip.

I swapped it out with an aluminium seat post shim, which provides sufficient friction to prevent seat post slippage. Weighs about 13 grams more than the plastic version.

Frameset also includes the front fork.

Standard design with normal welding as seen on aluminium forks.

Fork weighs 476 grams, which is about 40 grams heavier than the Dahon MuEX version.

Steel compression bolt weighs a significant 43 grams.

Handlepost is by Fnhon, and this is the 31.5cm long, 2 bolt version which I have used before.

Standard Litepro headset weighs 70 grams.

As you can see, the frameset (frame + fork + handlepost) already weighs 3.5 kg. Compare this to the Java Freccia mini velo frameset weight of about 1.5 kg, and it is already 2 kg heavier, assuming all other components are the same. This is due to the Java Freccia being a lightweight one piece carbon frame, while the Crius/Dahon/Tern folding bike frame has additional weight from a more robust construction to deal with the folding requirement.

In other words, a lightweight carbon mini velo can weigh about 6 kg, while an aluminium folding bike with an equivalent component spec will be 2 kg heavier at about 8 kg.

The next step is to press in the headset, before I can assemble the fork and the handlepost. While assembling the headset, I found a couple of issues.

Top of head tube is not round, as seen by the missing step at the top corner. Will this cause a problem with the headset installation?

As the head tube was not round, I had great difficulty with pressing in the headset cup properly, even though I was using the proper headset tool. After setting both the headset cups, I found that I could not insert the sealed bearings by hand.

Normally, the sealed bearings can be placed into the headset cups by hand, as there is a very small clearance. However, possibly due to the non-round head tube, the headset cups were also not round after pressing in. This caused some small interference between the headset cups and the sealed bearings.

I had to press in the sealed bearings using the headset tool, very gently and slowly, so as not to damage the bearings. Luckily, after pressing in the sealed bearings, they were still able to rotate smoothly. If the bearings had jammed, I would have to remove everything and start over again.

With the Litepro headset installed! Luckily the headset still works even though there was a slight problem with the head tube.

Once the headset is installed into the frame, it is easy to assemble the front fork and the handlepost. For a more detailed account of that, check out the previous post which writes about it in detail.

Headset, front fork and handlepost installed!

This is just the first part of the build, there are many more parts to go before the whole bike will be completed!

Sunday, June 10, 2018

Shimano Dura-Ace RT900 vs XTR RT99 Centrelock Brake Rotors

Recently I changed the disc brake rotors on the Canyon Endurace, so I had the chance to compare the stock rotors and the new rotors.

The Canyon Endurace CF SLX Disc 8.0 Di2 came stock with Shimano RT99 Ice-Tech rotors, which is the top of the line XTR-grade disc brake rotors. It is not often that a stock bike comes with such good brake rotors. Nevertheless, since I am changing the entire groupset to Dura-Ace R9100/R9170, I wanted to make the groupset complete by also changing to the new Dura-Ace brake rotors.

With this, I can compare the XTR brake rotor with the Dura-Ace brake rotor to see how similar or different they are. More details on the Dura-Ace RT900 brake rotors can be found at this link.

Dura-Ace RT900 brake rotors. Main difference with the RT99 rotors is the new appearance!

Ice-Tech Freeza rotors, which has aluminium cooling fins to help dissipate heat from hard or sustained braking.

The "S" refers to the size of the rotor, which means a diameter of 160mm in this case.  

This is the RT99 rotor, which does not have the large black surface area found on the RT900 rotors. However, this RT99 rotor has the wavy pattern which looks like cooling grilles, but is less aerodynamic than the design of the RT900 rotor.

RT99 160mm rotor weighs 115 grams. It has a more aggressive appearance that is more suited for mountain bikes.

The RT99 rotors come with a black anodised aluminium lockring which weighs just 8 grams.

Dura-Ace RT900 brake rotors weigh slightly more, at 118 grams. The weight difference is due to more material used for the larger black fins.

The lockring looks similar, but in silver colour instead.

Although the weighing scale says 7 grams for the lockring, I think it is just due to normal error due to the low weight. The design looks the same as the black lockring, so the weight should be the same.

From this quick comparison, we can see that the Dura-Ace RT900 rotors weigh just slightly more than the XTR RT99 rotors, mainly due to the larger surface area. The biggest difference is definitely the appearance, where the new RT900 design is radical and maybe even controversial. I am a fan of the new RT900 design, as it is more suited to road bikes as compared to the aggressive design of the RT99 rotors.

Wednesday, June 6, 2018

Shimano Dura-Ace 9000 vs R9100: Crankset

With the new Dura-Ace R9100 crankset, it retains the iconic 4 arm design that was first introduced in Dura-Ace 9000. When the 4 arm design was first introduced in 2013, I did not really like it as I still preferred the 5 arm design. However, over these few years the design has become much more common, even in other brands such as FSA or Campagnolo. I have now gotten used to seeing this design and it now looks fine.

On the Canyon Endurace, I have decided to change the groupset from Ultegra 6870 hydraulic Di2 to the latest Dura-Ace R9170 hydraulic Di2 groupset. With that, all the components will be changed, in order to maintain a full Dura-Ace groupset.

As highlighted in another post, the new Dura-Ace R9100 has some distinctive features that is new. However, it is mostly similar to the previous Dura-Ace 9000 crankset. Let's take a closer look and make a comparison between these two cranksets.

Dura-Ace 9000 crankset, with the silver and black anodized series colour.

New Dura-Ace R9100 crankset is mostly black, fading out to grey at the edges of the chainring.

Dura-Ace 9000 chainring is 50/34T, with a silver outer ring ending in the silver coloured teeth.

New chainring is light grey in colour, ending with the teeth that is also grey in colour. The colour on the teeth will quickly wear off and reveal the silver material colour once it is used.

Inner chainring on 9000 crankset is quite ordinary, and the outer chainring also does not have many shifting ramps even though the shifting performance is good.

Inner chainring on new R9100 crankset looks very similar to the 9000 chainring

Previous generation 9000 right crank arm (170mm) is 306 grams

New R9100 right crankarm (165mm) is slightly lighter at 303 grams. It is much chunkier but also slightly shorter in length.

Comparing the chainrings side by side. Both are 50/34T chainrings.

Slightly different positioning of the shifting ramps and pins

9000 series Hollowglide 50T outer chainring is 102 grams

New R9100 series Hollowglide 50T outer chainring is 100 grams

I wondered if the old chainring can fit onto the new crankarm, but found that it will not fit due to the different 4 arm profile. Rather interesting appearance though.

Old crankarm has sharper edges at the back of the crankarm

New crankarm has chamfering at the back of the crankarm to minimize any sharp edges

9000 series left crankarm (170mm) is 176 grams inclusive of the crank arm fixing bolt

New R9100 series left crankarm weighs 175 grams, almost the same even though it is slightly shorter.

Right side crankarm plus chainrings on the 9000 series weighs 440 grams

New R9100 setup is slightly lighter at 434 grams

Full Dura-Ace 9000 crankset (50/34T, 170mm length) is 615 grams

New Dura-Ace R9100 crankset (50/34T, 165mm length) is 610 grams

The new crankset is very slightly lighter in weight, probably due to the shorter 165mm length. However, the stiffness is reportedly improved on the right side due to the chunky 4 arm design that minimizes any flex. For me, I will not be able to produce that much power to induce any flex, so it probably does not make a difference to me.

In summary, the R9100 crankset is more of an incremental improvement on the already excellent 9000 crankset. With the stiffer right crankarm, the stiffness is improved while the weight is maintained. All other aspects are mostly unchanged as far as I can see. The new all black colour should be able to better match most bike frames, as compared to the 9000 series colour which did not match some bike frames in terms of colour.