Saturday, May 20, 2017

Java Freccia Carbon Mini Velo: Part 2 - Weight of Frameset Components

After taking a close look at the Java Freccia carbon mini velo frame and fork in the previous post, let us now see exactly how lightweight this frameset is.

By building the bike up from a bare frame, it makes it easy to measure all the weights exactly. The main objective of this project is to build a mini velo that is as lightweight as possible.

From some research, I have the weight comparison of some popular and more well known mini velo framesets.

Wheelsport Fantasy (aluminium frame, carbon fork): About 2.3kg
Tyrell FX (aluminum frame, carbon fork, folding): About 3.1kg
Tyrell CSI (aluminium/carbon frame, carbon fork): About 2.15kg
Tyrell PK1 (titanium frame, carbon fork): About 2.45kg

As you can see, the lightest frameset, which is the Tyrell CSI, still weighs about 2.15 kg as it is mostly aluminium with a carbon rear triangle and fork.

The Java Freccia frameset will beat all these frameset weights by a large margin, if the claimed weight on the website is to be believed.

Java Freccia claimed frameset weight: 850 grams for frame, 360 grams for fork, giving a frameset weight of only 1210 grams (1.21 kg)!

I know that these claimed weights are often overly optimistic, and are usually too good to be true. Even then, the difference with the other frame weights are so big that there will definitely be weight savings even if the actual weight is not as light as claimed.

Frame: Claimed weight is 850 grams, actual weight is 1060 grams. Quite far off, but still lightweight.

Fork: Claimed weight is 360 grams, actual weight is 412 grams. Smaller difference than the frame.

Claimed frameset weight: 1210 grams
Actual frameset weight: 1472 grams

Although the actual weight is higher, just as I expected, it is still considered a very lightweight frameset, as it is more than 800 grams lighter than the Wheelsport Fantasy mini velo frameset!

This is a significant weight saving as the frameset weight has been reduced by more than one third.

How about the weight of the other frame components, such as the headset, carbon spacer, carbon seatpost and etc?

Headset bearings, compression ring and cover. 58 grams. No headset cups required as it is integrated into the frame for weight savings.

Specifications of the headset bearings, in case anyone is interested to know.

More carbon goodies. Carbon top cap by Controltech, 27 grams.

Carbon spacer weight, 63 grams before cutting. 120mm long.

As this frame uses an aero shaped seatpost, the aero seatpost is also included. This also means that I cannot use the modified FSA SL-K seatpost which only weighs 206 grams.

Aero carbon seatpost that comes with the Java Freccia frameset

Aluminium plate that clamps the saddle rails onto the carbon seatpost. Quite a common design nowadays.

It even has a special rough coating on the seatpost to prevent seatpost slippage. Similar to that found on the clamping areas of carbon handlebars.

There is an aluminium insert that extends about 10cm upwards from the base of the seatpost, presumably to strengthen the seatpost without adding too much weight.

This seatpost is also quite lightweight! Only 213 grams, only slightly heavier than the modified FSA SL-K seatpost which weighs 206 grams.

Seatpost clamp design, which has two wedges at the side that pushes a third wedge against the seatpost to clamp it in place.

Seatpost clamp mechanism weighs 27 grams

It also comes with a rubber cover to prevent water entering the frame through the seatpost area

Complete assembly of the seatpost, seatpost clamp and rubber cover onto the frame. This seatpost clamp design gives a very clean look to the frame, with nothing sticking out.

As described in the previous post, the frame and fork has special mountings to accept aero type V brakes. However, since I am using standard road caliper brakes, these mountings are not required. As such, it is a good idea to block off these holes by inserting a bolt.

Aero type V brakes seen mounted at the rear of the front fork

To save a tiny little bit of weight, I decided to use nylon bolts instead of steel bolts to seal off these holes.

Nylon bolts, not for any load bearing usage. Perhaps only suitable for decorative purposes.

4 M6 mylon bolts only weigh 2 grams

Nylon bolt sealing off the holes on the fork

Same for the holes on the rear triangle of the frame

In summary, this carbon frameset saves over 800 grams over the Wheelsport mini velo frameset, which will result in a super lightweight mini velo.

The next post will show the frame geometry comparison between this new Java frame, the Wheelsport frame and also the Merida Scultura frame.

Sunday, May 14, 2017

Java Freccia Carbon Mini Velo: Part 1 - Frame & Fork

Another mini velo? While browsing Taobao, I came across this mini velo frameset that looks rather interesting. This is a carbon fiber mini velo frameset, which is quite rare as mini velo frames are mostly made of aluminium or steel. The main advantage of this carbon mini velo frameset is the weight, which is much lower than the aluminium Wheelsport Fantasy frameset that I have. The weight will be examined in a subsequent post.

My plan is to get this new carbon mini velo frameset, and transfer all the components from the Wheelsport mini velo over to it. Let's take a look at this frameset and see why I decided to get it!

Java Freccia carbon fiber mini velo frame

No welding on the joints, as they are all molded by carbon fiber sheets

Integrated headset design to save weight. No need to press fit any headset cups, just drop the sealed bearings in.

Down tube tapers from a bladed shape at the head tube to a squarish shape at the bottom bracket for stiffness

Nice glossy finish on the frame!

Seat stays are joined to the seat tube BMC-style.

Aero shaped seat post, with hidden seat clamp wedge for a clean look

Riveted front derailleur mounting, for brazed on type FD

Press fit bottom bracket, in order to save weight. Hope it does not cause any problems...

Only part of the cabling that runs external to the frame. Two holes for RD cable and FD cable.

Special tubed portion that guides the FD inner cable from the cable guide at the bottom...

...and out from the rear of the seat tube. If designed correctly, the inner cable will not rub on the edges of the tube. This also means that water will not enter the frame through this hole as it does not lead into the frame.

Rear triangle of the frame

Aluminium rear derailleur hanger. Note the exit point on the chain stay for the RD cable.

Flared rear triangle design, 130mm OLD. Can use either road caliper brakes or the special aero V brakes.

Java Freccia carbon front fork

Even the long steerer tube is made of carbon for weight savings

Angled mount for the bottom headset bearings already molded into the carbon steerer tube. No need to press in a crown race.

100mm OLD, for 451 sized wheels

Can use either road caliper brakes or the special aero V brakes

Usually, it can be risky to buy a carbon frame from an unknown source. However, since this is a Java branded carbon frame, I am not too worried as Java is already quite an established brand in the folding bike and mini velo market. Moreover, this Java Freccia bike model is also being sold locally, which means that this is unlikely to be a frame with dubious quality.

After studying the frame and fork in greater detail, I found that the quality and design is quite good. The surface finishing is nice and glossy, with well defined edges and smooth surfaces. There are also little touches here and there which shows that some thought has gone into frame design. Generally, the build quality is quite decent, which is what I expected from Java.

In the next few posts, I will write in greater detail about building up this carbon mini velo, and what are the differences between this and the Wheelsport mini velo.

Wednesday, May 10, 2017

Avanti Inc 3: Continental Grand Prix 4 Season Tires

After changing the rear wheel on the Avanti Inc 3, I realised that I have upgraded both the front and rear wheel on that bike. As such, both the front and rear rims have a higher profile compared to the stock wheelset. The Schwalbe Marathon Supreme tires that I have had for a few years does not seem to match so well to the high profile rims, as the tires has a reflective strip all around.

Also, after changing to drop bars and road crankset, the bike is now a more sporty bike that wants to go faster. As such, I decided to change the tires on the bike to something narrower and hopefully faster.

Having heard of many positive reviews about Continental tires, I decided to try it out instead of sticking to my usual Schwalbe brand. As an all weather commuting bike, I have to ensure that the tires have sufficient grip in wet weather, while also having some level of puncture protection. Therefore, the more race oriented Continental GP4000 is not so suitable even though it is fast.

While browsing through the wide range of tires that Continental has, I came across this Grand Prix 4 Season Tires that seem to provide what I need. Let's take a look!

Continental Grand Prix 4 Season Tires, folding version

28mm wide, for a good balance between comfort, grip and speed. The previous Schwalbe Marathon Supreme is 32mm wide.

The tire circumference is helpfully provided for programming the cycle computer. Max pressure is 115 PSI, which is high for a commuting tire.

Robust race tire due to the layers of puncture protection available.

There is a tread wear indicator on the tire, but I can't find it.

New tires!

Slick in the middle for low rolling resistance, grippy design at the sides for cornering grip

Made in Germany! I didn't realise it came with brown sidewalls though...

284 grams for 1 tire, which is about 90 grams lighter than the previous Schwalbe Marathon Supreme

After changing the tire on the rear wheel, I compared it to the front wheel to see the difference in width. However, there seems to be very little difference in width...

Rear wheel with new 28C Continental tire, front wheel with 32C Schwalbe tire.

Visually, there is almost no difference in width...

Front wheel with Schwalbe Marathon Supreme tires is 30.66mm in width

Rear wheel with Continental Grand Prix 4 Season tires is 30.04mm in width

Front wheel with Continental Grand Prix 4 Season tires is 29.02mm in width

Comparing the front wheels, the Continental tires are about 1.6mm narrower in width as compared to the Schwalbe tires. This is much smaller than the 4mm that the sizes (28C vs 32C) indicates. Seems that the Schwalbe tires were narrower than specified, while the Continental tires are wider than specified, causing this condition.

I was rather disappointed as this meant that this tire change only yielded a small difference in width, when I was expecting more. If I had knew this was the case, I would have gone for the 25C Continental tires (which might turn out to be 26mm in width).

Fresh logo on the Continental tires, as installed on the rear wheel

From far, the brown tire sidewalls are not so visible. Without the reflective strips on the tires, the rim profile looks deeper.

This upgrade turned out to be rather inconsequential as the tire width was not changed much. At least it looks quite good on the bike. After testing it out for a few months, I find that the ride quality is good and feels faster than the Schwalbe tires. However, it may be due to the change in riding posture (from flat handlebar to drop bar) that yielded the increase in speed.