Hongfu FM079

[wheelbuilder]

I've installed a few of those tubolitos for customers. The valve tube (that the core screws into) is plastic, and deforms easily. They start leaking after a few rides usually. Teflon tape helps, but it's kind of the nature of the product.

[poynt]

I had one that the thread rounded out and I couldn't keep the valve tight. Tubolito sent me a replacement and on the faulty one I epoxied in the vave stem and all is fine now.

[Klaster_1]

Tubolito contacted me and sent a pair of replacement tubes, great service Berk has sent a warranty Lupina too, this time in 3K (because lighter) and oval rails, so kudos to Jure and his team

Meanwhile, I put the new J&L hollow Ti rotor bolts and weighed my 140mm KCNC Razor, which turned out 3g lighter than in spreadsheet - a freebie! And a heavy butyl tube I run in front as spare.

[Klaster_1]

The replacement oval rails Lupina is ~3g heavier than Saevid Alien.

[BmanX]

This is a great build and some good ideas for my 1x build.

[Klaster_1]

Yesterday, I finally got to unpack my bikes after moving to a new city. Inspired by @Godzuki, I replaced the bolt in Darimo Sub4 with hollow J&L Ti bolt, which saved ~0.7g. Anyone knows where to source hollow Ti bolts compatible with T1 clamps? These should have a rounded yoke contact point, not flat.

[joejack951]

That Berk saddle is beautiful! I need to try one. Do you know if he paints his parts? It would need to be white for my bike.

[Klaster_1]

That Berk saddle is beautiful! I need to try one. Do you know if he paints his parts? It would need to be white for my bike.

You can order a white leather saddle, like some WW members, but I have no idea about painted carbon shell, I'd ask Berk about that.

[joejack951]

I will see what he says. Thanks.

[Klaster_1]

Tubolito has warranted both of my failed S-Tubo Road, the new tubes are ~1g lighter and did not lose pressure overnight like last time.

[Klaster_1]

This Saturday I decided to put a fresh ARO-09 rotor on just in case to see if it would rub less, I think something in my setup causes rotor rub, a lazy piston or non-faced mounts. Anyway, I went for a ride next day and on the way back something pinged and flew from under the front wheel. "Probably a pebble", I thought. At the next "downhill" - it's pretty flat in SpB, so after a while - I noticed that left lever goes all the way to the bar! The rear brake was barely enough to stop in time before I hit the traffic. I forgot to tighten the pads pin during adjustments and lost both pads and pin. Now I have to grind down another set of Cooma EX pads down and order another set of TP pins. What streak of bad luck, I already had three parts warranted this year. I need to make a checklist for after the service.

On the subject, anyone knows where to find M5 pad pins in aluminium? All I can find is Shimano M4.

[Klaster_1]

If anyone's interested, here's how -12deg 110mm Hyperstem compares to -12deg 110mm IX2. The Hyperstem was traced from this document, then extended 1cm, all measurements match chart from here. To match bar position, IX2 should be ~5mm lower. In this configuration, IX2 will be ~3mm taller than Hyperstem, so probably no need for a top spacer.

[cheapvega]

Epic build sir.

[Klaster_1]

This took me several months to gather materials and will, but it's finally here: the BTP/the Climb style liquid resin/carbon hood(s). I mostly followed the the series of blog posts at The Climb by @fallen86. The Climb hosting/domain has lapsed, but it's still available in the archive, start from here.

Ingredients:
1. A cut of 3k twill CF cloth from Aliexpress, 10USD.
2. A can of liquid resin a-la Plastidip. Plastidip was impossible to find, only car paint shops have any and they don't sell it in rattle cans, so I had to do with other brand. Transparent color. Cost me about 6USD.
3. A roll of food wrapping film, 1USD.
4. Cutting tools: scissors, sharp box opener knife. Free.
5. Cardboard box to use as a paint box. Free.
6. Shift lever.
7. Gloves.
8. Well ventilated environment.

Day 1:
Obviously, I had to remove and weigh the stock stock hood. Removal was tight, even with help of alcohol spray, but I managed

ST-R9170 stock hood weight, right.

Next step was to wrap the lever with film. Just like regular packaging tape, the film tends to fold and stick to itself, except to an even greater degree. This makes the material very finicky to work with, given a 30cm roll can't be stretched evenly over a lever without additional cuts because of geometry. I had to redo the wrap a couple of times to learn how to work the material. Next time I will try regular adhesive packaging tape because it comes in thinner strips that I suspect would simplify the job and one other major reason I will note below.

After the wrap, I made a pattern cutting. First, wrap a paper napkin around the lever and cut off the excess. @fallen86 went to immediately wrap the CF at this step, but I didn't like how it would gradually come apart after all the bending, and with a disposable, pliable napkin you can experiment with different shapes. After I got a good enough wrap, I traced the napkin on a sheet of paper and mark the sides to make the sense of direction later, you don't want to forget what side goes where with a wet piece of cloth on your hands. The pattern can be adjusted later and used for both sides.

ST-R9170 hood cloth cut pattern.

Now comes the most stressful part for the day: resin application. I did all the painting in a small 30x10x30 cardboard box with a sheet of paper covering the bottom. @fallen86's instructions were too vague for me, so I was very careful not to mess up. I applied a thin layer of resin to film first, this turned out a good idea, but next time I'll apply more resin, possibly two layers because rattle can sprays it rather thin. Then I applied the resin to the inner side of the CF cloth, wrapped the cloth around the lever using the directions on the cut pattern and sprayed the outer side. I was hesitant with resin amount, next time I'd apply more. At this step the cloth becomes surprisingly pliable, but also easy to slide out of position, I had to be careful with the outer film wrap not to dislodge the cloth and was concerned that I'd mess it on the first try. Exhausted, I left the lever to dry for the night.

Day 2:
I was very excited next morning to unwrap the lever and see how it turned out. @fallen86 noted the film came out easily, but this was absolutely not the case for me. I had to employ scissors to open the the wrap, then to ply off very much like sun burnt skin. Outer layers came off relatively fast, but the innermost layer took me up to an hour to remove by small pieces, in the end I couldn't manage to remove it completely. Most of the surface had patches of raw CF strands, which was no good. The topmost section did not have enough cloth and the rear had an excess. Fortunately, as @fallen86 pointed out, the material is indeed easy to patch up. I cut off the excess cloth, soaked it with resin on both sides and patched the top hood. Then applied some more resin to the rest of the surface, wrapped the lever up and left it to dry until the evening. In the evening, I unwrapped the film, which had the same issues coming off. The result didn't look as bad as I expected all!

There were more issues to address, though. The patch I applied earlier had very rough edges with sharp CF strands poking out right around the area of hand contact. Other areas still had raw CF exposed exposed, the first pass was no enough. After applying resin to the problematic areas, I left the lever to dry until next day.

Day 3:
Leaning the lever against the cardboard box was a mistake, the paper stuck to resin, I managed to scrub most of it off, but it left visible marks. The Climb blog has photos of lever drying hanged to hooks - a great idea, I should have went with it from the start. Unfortunately, I didn't have enough materials to improvise a hanger, so I picked a plastic can from garbage and converted it to a drying pedestal instead. While flimsy, it did the job. Throughout the day I patched exposed CF with resin at several hour intervals.

By the end of the day, the surface was good enough, so I decided to remove the hood. First, I cut off excessive CF. Then, with a box sharp box cutter, I marked final cut lines. @fallen86 cut the hood off too, but I decided to place the main incision at a different place. I had several months to think of how to fix the hood in place. Cut along the bottom is shorter than along the side, at least for ST-R9170, which I suspect would yield a firmer fit. Over time, sticky cloth tape really grew on me, I apply it liberally as a substitute for electrical tape, so it was a natural choice to seal the cut. The inner hood surface and the lever were cleaned of the remaining film, then I put the hood back on and cut the rest of excess off. The cut was not clean enough, so I had to remove the hood, trim up the edgers with scissors, fit the hood. Repeat several times and the hood fit the lever nicely.

To cover exposed CF edges along the cuts, I applied several layers of resin and left the hood to dry until the next day.

[Klaster_1]

Day 4:
Pretty much done, only had to trim the edges for better fit with a handlebar.

The cut is held by sticky cloth tape:

Just like @fallen86 described, the hood is slightly more tacky than the stock hood. It doesn't feel unpleasant to the touch. Unfortunately, as you might have noticed, I used a rear ST-R9170 shifter to make the hood, but the the moment I don't have other parts to convert the shifting to Di2 (RD is in transit, still have to order wiring, battery and junctions), so it will be a while until I get a chance to test ride the hood.

I kept the main photo for the end. To be honest, I expected at best something in range of 15g and to throw away the first result as a failure. But 4.23g That's twice as light as @fallen86's hoods (10g per hood) and way lighter than BTP hoods (12.5g per hood).

Takeaways:
1. Until proven by testing otherwise, this is a solid and cheap, albeit labor intensive, way to drop 30g or even more.
2. Liquid resin brands other than Plasti Dip seem to work too.
3. Transparent resin looks OK, but blemishes are noticeable.
4. Food wrapping film did not work too well for me. Next time I'll consider other materials (packaging tape) and vacuum bagging (food storage bag, vacuum cleaner and fast hand to seal it, lol). Some mold release agent would be useful too.
5. Errors are easy to patch up.
6. Rattle can sprays resin thin, don't hesitate to use more in several layers.
7. Molding a hood over a lever that's installed on a bike prove rather challenging. That's why I won't make another hood for my other ST-R9170 that's already installed - I really don't enjoy bleeding brakes. But I will absolutely do it sometime later, maybe after the Di2 conversion has been completed and the first hood tested.
8. Proper molds would have resulted in a more proper (you can't do overhangs when wrapping a lever) and better looking (no food wrap blemishes) hood, and made the job much easier.
9. Food wrap didn't help against CF pitting into collar bolt recess. Next time, I'd use thicker wrap or more layers or packaging tape for similar areas.

I express my honest gratitude to fallen86 for his super useful series of blogs, without your guide I wouldn't be able to come up with something as cool as this by myself