Target

Compilation of my riding in 2021. That was a year of experiments: tubeless mod, full disc 24" bike, a 26"/24" mullet setup. Getting used to stay in balance on the front wheel when doing anything.

My bad, I forgot to mention that's the bar clamp. Clean uses 16 mm bolts for both bar and steerer clamps (for simplicity of assembling, I guess). While it's working just fine for the steerer clamp, it doesn't look ideal for the bar clamp. The bar clamp bolts are a bit too long. On a normal bar clamp, the bolts being too long isn't a big issue. But on a Clean Pro stem, these bolts stick out dangerously towards the chest, causing risks of unpleasant feelings on front wheel moves, or even of cutting you with sharp edges of the threads. Except of the bolts, the design of the bar clamp overall is very chest friendly. Of course, I measured everything multiple times with different bars before I ordered those expensive bolts. And you're right, one shouldn't come to any conclusion after measuring just the stem without the bar installed.

Finally, the most important thing is here! Black titanium M6 bolts for the stem and black aluminium bolt for the top cap. Now the stem looks much cleaner than with the stock silver bolts. Plus, I used shorter bolts for the clamp, so they don't stick out like the original bolts do. Plus, it always feels good to shave a few grams.

The look of the Extention fork is controversial, especially those offset dropouts. I just told myself that it's a matter of getting used to. I remember times (mid 00's) when a trials bike without a seat looked too radical and even ugly for me. Yeah, that's definitely possible, but I just couldn't think of ruining the inner thread with a star nut. Plus, I wanted to keep an option of internal routing open.

I'm using Fiveten Trailcross LT, and absolutely love them. They feel stiff, but not too stiff, the toes are more or less protected, the stealth rubber grip is just fantastic, and they breath so much better than any other trials shoes!

Tough fork choice Initially, I bought the WAW carbon disc 26" through-axle fork, and everything was fine until I installed it into the frame and measured the wheelbase. It turned out that the wheelbase with the WAW fork is 1085 mm. That's 10 mm more than with my current Rockman Carbon 24" fork! That was totally unexpected and unpleasant. Apparently, I haven't taken into account that the WAW fork is a bit higher (405 mm) and has slightly larger offset (35 mm) than the fork I'm currently using. I'd be OK with 1075 mm WB which is long but acceptable, but 1085 mm WB is just too damn long. While looking for alternatives, I found a 24" disc carbon fork made by Extention with the 20 mm offset and 415 mm height. This seemed interesting, because according to calculations, this fork would make the WB about 1071 mm. Plus, this fork looked beefier (and was heavier), had thicker steerer tube walls than Crewkerz, had 15 mm through axle, and was designed for 180 mm rotors (while Crewkerz made their fork for 160 mm rotors for some reasons). So I imagined the front end with this fork would be as rigid and stiff as it can be. The only issue with Extention is that they have a steerer tube threaded inside, and a special star nut/top cap designed for internal routing. This design isn't compatible with traditional sloped stem top caps (or stems with integrated top cap like my Clean Pro), so I'll need to make an adapter for a traditional M6 top cap bolt.

Keep in mind that you can always remove anodizing, or paint over, or even re-anodize to black. The best option is re-anodizing if you can find someone who can do that for you. I'm not a big fan of those red accents everywhere too, so I've tried each of the options.

For me, the most crucial thing for riding is geometry. And other things like stiffness, weight or frame material don't affect riding that much. So if you're into short bikes, and don't like how the long bikes feel, I'd say that S-M Crewkerz is your only option since all existing carbon bikes (Maestro, Xox, Clean) are long. Regarding the stiffness, Crewkerz feels much stiffer than the Echo MK6. And it's a good thing, because the bike feels more controllable. As far as I know, Crewkerz is one of the most bombproof aluminium frames on the market. A lot of people are using them, but I've heard about only 3 or 4 broken frames.

Interesting, never heard of reach adjust headsets before! I think that increased reach should be just fine in my case since I'm planning to compensate it with a shorter stem. But if my setup doesn't work as I expect, it'd be interesting to play around with a reach adjust headset.

You mean rotate a normal fork backwards? Or was it some kind of a special fork designed for Jeff? Interesting, never seen him riding something that looks like a backwards facing fork. If we're talking about installing a normal fork backwards, the wheelbase would be extremely short, too short (about 1015 with my frame).

For the moves on the rear wheel, that's true, position of the front axle doesn't really matter. But for the front wheel moves, front axle position does matter. By changing stem and handlebar, it's easy to adjust "bb to handlebar" distance. So if you find your bike too long, you can install a shorter stem, and that would be enough for pedal ups to rear and other rear wheel moves. But that wouldn't work, for example, for switches from the front to rear, or for gaps to front. For switches, the distance between the wheel axles matters. And you can't adjust that by changing a stem. So for me an ideal wheelbase is about 1050-1060. And with the given frame, I'm trying to adjust front wheel position to make wheelbase shorter. And after that, the "bb to handlebar" distance can be easily adjusted using a proper stem/handlebar combo.

Here's something very unusual for a trials bike - an angled headset. I like the Gu 24" frame, but it's a bit too long with a wheel base 1075 mm. So I have been looking for options to make the wheelbase a bit shorter. By installing this angled headset, you can adjust headset angle of your frame by +1.6° or -1.6°. The idea is to change the headset angle from 73° to 74.6°, thus making the wheelbase shorter. The result (measured on a real frame and fork): the wheelbase becomes shorter by 8 mm. It's not an easy task to find an angled kit compatible with an integrated headset. I've managed to find only one option made by the company "9point8", produced in Canada. It turned out that bearing seats on the Gu frame are not exactly standard, but the Slack-R kit for Specialized bikes fits just fine.

There's no fun in building a bike too fast! So I'm going to enjoy the process a little bit more: creating drawings of some custom parts in brakes, headset, hubs, getting them machined, removing unnecessary parts of the frame, creating decals, making tubeless inserts, removing some anodizing, waiting for titanium bolts from China to arrive...

It's not that easy to get a 24" pure trials frame these days, especially one with a disc brake mount. I have been looking for a new Gu frame, but it seems that in the latest batch they ditched a disc brake mount. So I managed to find a slightly used one in a great condition!

I'm curious which quick link have you snapped? Is it KMC one or something different?

Some new toys have arrived: Jitsie bashring. I've used Trialtech Sport Lite, but being the lightest on the market (11 g), it bends too easily. So I went with a slightly heavier option. Echo Spanish titanium bottom bracket. I've been using one for the last five years without any issues, so I bought a new one just to be on the safe side. Carbon headset spacers with a matte finish. For the previous builds, I've used some very lightweight CNC carbon spacers with 1 mm thick wall. And as it turned out, the can snap from trials riding. So these new ones are not CNCed and much thicker.

Finished painting matte black the Neon Single Wall rims. These lightweight rims work surprisingly well for me. I've been using the previous pair of Neon rims for 5 years until the front one got bent and the rear one cracked. Pretty reasonable life time for such a low weight and low price, so I bought a new pair. They seem to be out of production, I managed to find some last items in stock. The front one was available only in golden, hence the repainting.

As far as I know, 9 mm through axle is not their own proprietary standard, but a rare and outdated one. I think you can find Hope hubs that will fit into Crewkerz through axle fork. Nevertheless, I don't understand why they've chosen 9 mm standard and not the much more popular 15 mm with a stiff and lightweight hollow axle. Cannot think how 9 mm would be better than 15 mm.

Not sure, just the one with the "Degreaser" label on it from the local store. I don't think that's super important, anything with degreasing properties would work really.

Degreased the KMC Z1eHX chain. I prefer to use wax based lubes (such as Squirt Chain Lube) for my chains. It's so good to have a chain that is always clean, doesn't attract dirt and doesn't leave greasy chain marks if you accidentally touch it with your fingers or clothes. In order to apply a wax lube, you need to completely remove the factory grease first. I put a new chain in a bottle with degreaser, shake it vigorously and let it stay there for a few hours.

New full black Clean Pro 24° stem just arrived! I went with a very short stem by today's standards - 125 mm. But I think with the Gu 24" frame and high rise bar that would be fine. I've used more traditional 150*30 stem before with the Clean 107 mm handlebar rotated forward, and it was too low and too far forward, felt strange even for front wheel moves. Then I tried different bars and stems, and came up with the solution that feels amazing - 127*27 stem with high rise Clean 107 bar rotated a bit more upwards than usual. The idea is that with 73° head angle frame you need shorter stem than with traditional 72° frame. And having a frame with a short 108 mm head tube, you have to compensate it somehow, for example by rotating the bar slightly upwards, and with adding some spacers. There is a very significant difference between old Clean Pro 27.8° stem and this new one - new one is 78 (!) g lighter. Hopefully this new one still feels stiff.

I'm planning to build my dream bike, in which things I like about trials bikes are combining: 24" wheels, high bb, comp geo and Hope disc brakes. I used to build bikes as light as possible, but this one will be a bit different. I'll try to build this bike with the main accent on stiffness, but still saving weight where possible. The first parts are already here! Titanium pedal cages made by Racing Line for my Trialtech Jack Carthy pedals. I've bent and broken the original 2-mm alu cages really quickly. These titanium cages should be much more durable, but we'll see. Rockman cranks. I love silver cranks because unlike black ones, they still look cool after a few scratches. Always liked the look of the Rockman CNC cranks, and finally got my hands on these. I've been using 300-g ultra-light Born cranks for 5 years. They were quite flexible, but held really well until the left one snapped. These 413-g cranks should be stiffer yet not too heavy. Trialtech lever blades for Hope Trial Zone. I really love the shape of the blade on Trialtech rim levers that I used before. It seems like they are the only blades on the market that are designed specifically for 1-finger usage. And they are also pretty stiff. So hopefully this will be a significant upgrade for my Hope levers.

I guess it's time for a little update. The tubeless experiment went surprisingly well! I didn't have any issues at all with the tubeless setup. No burping, no suddenly lost pressure, no snake bites. I've broken 2 frames and a fork since December, so I guess you can't say that I was too careful with the bike. I wasn't happy about presta valves cut from the tubes. It was tricky to install them properly on the rim. They area between the valve and the rim was the weakest place in the setup, and tended to leak air if the valve installed not ideally and its nut not tighten up really hard. So I bought and installed tubeless aluminium schrader valves. They hold in the rim valve hole much better, and the setup feels really reliable now. They needed some modification though since they originally designed for using with high double-wall rims. Some rubber and plastic washers have made it work on the single wall rim.

In my opinion, trials rims are pretty stiff comparing to lightweight XC and gravel rims seen on many builds with Berd spokes (not only on carbon rims btw). And reviewers of these XC/gravel/enduro wheels say some good things about wheel stiffness. My concern is mostly tangential stiffness, that is not so important for MTB, but really important for trials if disc brakes are used. Anyway, it would be really interesting if someone built a trials wheel with these spokes.

Very interesting product, but I'm not sure if it works appropriately for trials with disc brakes. The manufacturer claim these spokes absorb vibrations. Could it mean they'd feel more flexy than steel spokes when you jump on a rear wheel with a locked brake?