La Bourde

Thanks for the comments guys. I had a look at the other majors properties of rubber, there are quite a few. Years ago I took out of the bin at work a book about tribilogy and rubber. Gess it is time to flip through it to get a better understanding.

I can't find any hardness information somehow. I also measured some transparent V-brake pads from Odyssey, the shore was 81A.

Hi, I recently got some Coustellier brake pads with an used bike. Somehow, I had the impression that the rear pads did not work well as I know them. I supposed there are old or were contaminated with some kind of chemicals. So I just did a small experiment to understand what are the hardness of the rubber of different brake pads. I bought a Shore durometer, to measure the hardness of the rubber. They are several scales of hardness and thus several durometer types exist. For a tire or a brake pad, the shore A scale is used. I took some of my brake pads and took 5x measure for each one. I computed the average then. Here the results: Jitsie black: 81,4 A Crewkerz yellow (not sure), first pad: 87,2 A Crewkerz yellow (not sure),second pad: 88 A Crewkerz orange, first pad: 82,6 A Crewkerz orange, second pad: 83,4 A Coustellier (green), first pad 90,2 A Coustellier (green), second pad 90,8 A White (brand and model unknown, for rims without grind), first pad 91,2 A White (brand and model unknown, for rims without grind), second pad 91,6 A Another green Coustellier (not on the picture): 90A The last Coustellier I measured is from the front brake. The two other ones were on the rear brake. Somehow, I could not measure a relevant difference. Maybe I have to compare to the ones of my other bike, that are newer. Measuring hardness with precision and accuracy is quite ... hard (sorry for the pun). There is a standard (ASTM D2240-15(2021)), that is unfortunately not free (maybe I can have a look at work) The precision seems to be quite good, I measure a +/-1 shore difference. I had to be careful with the placement of the durometer, all the supporting surface had to be in contact with the rubber of the brake pads. I hold the durometer per hand (no operating stand) My biggest issue was that, the value was decreasing the longer the durometer was in contact with the rubber. This is due to the elasticity of the rubber. So I just measure the peak value - I guess this is the more relevant value I can measure. Unfortunately the measure is sensible to the temperature and the durometer has to be calibrated, which is not the case here. Whereas the absolute value might be off (accuracy), a comparison between the hardness of the different pads shall be valid. To me, the Coustellier are very powerful and they seem to last quite long. I found the black Jistie amazing, but unfortunately they wear faster and one of them broke in two.

I use Putoline 2,5w in my HS33 too (got also Shimano disc brakes). It is quite good, better than the original Magura fluid for sure. But I compared recently on a really cold day with the brakes of a friend, that uses the trialtech fluid. The Trialtech fluid seems even better. (I wonder what it is, maybe a silicon based fluid?)

Hello, Hope you recovered well from your sprained ankle. It seems strange to me, that the brake slips. I can't tell you the solution but here the things you can check: - the brake is bled correctly. Sometimes the brake feels inconsistent (and often spongy) due to air in the system - the brake fluid is thin enough. I noticed that when the lever does not comeback fast enough, I let slipped the brake (I cannot really explain why) - maybe the brakepads are too old or they altered faster due to some kind of contamination. I got some Coustellier brakepads with an used bike, that were really hard (only the rear ones!) I now own a durometer, I will measure the shore degree they have. But I am pretty sure, there will be a big difference. - did you check for a tiny leak? I rode only disc brakes for many years. I had to accommodate to the lever feeling of the HS33, that can be really stiff. So one has to ensure, he/she is always applying a constant force on the lever.

TK videos made me want to try trials. Thanks a lot guys!

I think you are right Mark, to me the interest for I9 seems to be a combination of a hype and a good product. But it is also a niche product, and according to my experience a lot of user of niche, expensive products are biased by the price they paid the product. At least the few first months or years. I recall how the Reverb seat post was first hyped and then became a trash product when it became more affordable. In addition, there are so many different parameters (weight of the rider, level, riding style, frame stiffness, frame alignment, clamping force of the axle, wheel stiffness and deformation of the hub body...), it is hard to isolate where the issue comes from (user error, frame problem?) And as you many times said on this forum, the more a part is sold, the more defects (absolute scale) are expected. But I heard many times that hope does not communicate a lot about the defects and often refuse warranty. This does not match with my own experience I made years ago. The support was amazing. I am and was always satisfied with Hope products. That is sad if Hope had a faulty batch and did not communicate further about it. I think at the end it brings more discredit on the brand than it helps. It is quite difficult to know whether a product is reliable or not a few months after it was released. But later when the second hand market is full of a product or a product is quite difficult to find used, I think it is a good hint about the quality (in case the production numbers are comparable). And it seems difficult to find an used hope hub... I guess the goal of the fifth version is to address the few downsides of the current hub (drag, better standards support) and improves even further the reliability.

Can you develop why? Too me he seems to be quite "emotional" and to have a limited know-how in mechanical engineering. He is a prorider and not an engineer (see edit). But at the end, I think he speaks from his own experience and it seems to me fair, although maybe too impulsive. I cannot recall exactly who were the other riders, but I think they were French (John Langlois maybe?) A lot of the pro street trial riders now ride with I9 hubs. Is this switch also related? I have 3 hope Pro IV hubs and no issue at all. But I am neither strong nor heavy nor a good rider. Edit: I did not mean that all pro riders do not have a sufficient mechanical background or that YT would not be capable of giving a good feedback. Someone without mechanical background or understanding can deliver a good feedback, mostly independent of a technical solution and its has to be considered. In addition an engineer or a scientific consider something true until proven otherwise... And assumptions are often wrong...

The Atomz AKT had a really good call in France. Quite light, stiff and strong. But French people might be too patriotic. Crewkerz, who is the reincarnation of Atomz has also a good call, at least for the Cleeps (I saw some cracked Jealousy frames). I think some frames of the Echo/Deng production were quite strong, but heavier.

Some pro riders (e.g. Yohan Triboulat) had reliability problems with, like skips, broken inner ring or hub shell. The drag is high and sometimes the springs get broken.

It has potential to become a good alternative, for sure. And their new brakes seem quite amazing too... Hope it will fix the reliability issue of the pro IV. Pinkbike mentioned a trials version, but did not see a picture of it. Nice to see they will be spares for the next 10 years.

The MBK T1000 geometry was around 1080, 385 and +30, according to some old web pages. To me, the AKT 2 is a little better with its less exposed chain tensioner and its through rear axle.

The Atomz Atk II was available in: short: 1075mm 380mm +35mm 71,5° long: 1085mm 380mm +35mm 71,5° I would like to find a short one. It was a really nice bike. There was two versions, the first one had an external headset and the later one a semi-integrated one. Atomz Quark II was available in 3 sizes: S: 1075mm 380mm +45mm 72° M: 1085mm 380mm +50mm 72° L: 1095mm 380mm +55mm 72° I rode a L one after coming back from street trial and the difference was quite huge. It was really light, quite rigid, easy to dent but somehow it seems to be quite reliable. Then I went for a Crewkerz Cleep2, it feels even more weird first, but now I love this bike so much. I had to change my riding for sure. It is really stiff and works so well on sidehops.

The MBK T1000 is around 1080mm, 385mm and +30mm Evo2 was 1080 mm, 380 mm, +40mm, 71.5° (Geometry from the manufacturer) Koxx XTP long?

Get well soon! Loose also one tooth and broke another one in a crash at the pumptrack But still love to ride it! The bike looks sweet. The bottom bracket seems to be quite high too me (for this kind of bikes), which could be great for some trial moves.

You eventually changed the rear tire? How is the new spot?

I like the look too, especially with a rigid fork, but my wrists don't like the idea of riding a rigid fork again on this kind of bikes. The current sprocket is made of steel and I think it is strong enough, it weights more than 100g. It is no longer true though I had one made of aluminum and it lasts maybe 6 months. I am light and I don't do big moves. But you are right, I have also my concerns regarding the fork. I check regularly for cracks. That is why I wanted to save some weight on the frame ... to put a Manitou Circus in 80mm without weight penalty. But I can't find a white one for a good price currently The stiffness will be higher and the lockout will be more efficient too, the one on the Reba is somehow weak.

This week I decided to sell the Octane01 Spark frame. Unfortunately I noticed a small crack close to the brake mount. So it seems trials was to harsh for this frame. Rest in peace, spark! Hope the Majesty will be stronger...

Amazing effort! I like also that you detail your components choices. Wish you a lot of fun on this bike.

Small updates :-) Some months ago I bought a new headset from Shadow Conspiracy and some plastic pedals from Cinema. I lowered the bar by removing 8mm spacers. I had to change the front tire and went for an old Kenda spare. I eventually found a NS Majesty Park frame. According to the specs, it has the same geometry as the Spark, but should be lighter. I had to double check the weight of each frame: the NS is indeed 400g lighter! I had two sessions on the new frame with exactly the same components and I did not notice any difference in the geometry. I compared both frames, one next to the other and only the seat tube of the NS is longer and the junction with the top tube higher. That is all! Ok the tubing and the quality is overall better on the NS. Riding the Majesty feels so similar ... Manuals, bunny, 180°, pedal up. It is the basically same bike. I mean if there is any difference, it is so small, that the rider condition will impact much more the riding! I was expecting a difference in stiffness, but to my surprise, I have the impression that the Majesty is as stiff as the Spark. The first few meters on a bike, I really notice the difference of weight and weight distribution. I had the impression the rear end was lighter. Somehow it felt snappier, more responsive. A nice improvement. Today I changed the bar for a lighter one, put some new grips and change the stem for a 80mm long one, still with 17°. I removed a 4mm spacer, the bar is slightly higher. Overall I saved more than 550g with this new build. The first few moves in the garage shown me that the stem change goes in the right direction. The bike is easier on the front and there is more room for the body. I felt I had a more central position on the bike.

I have the impression these components are not really develop with crashing people in mind. The shifters are quite exposed, the cranks as Jamesb noticed seem to be quite harsh for the ankles, the derailleur looks like it want to snap the frame already... But I never was a fan of SRAM components.

The Jitsie is a strange piece of bike. It is like a comp bike bike with 24" wheels and a seat. Not sure this is what you are looking for. You can look for something like a giant team trial (version 3, which is more modern), or a Planet X, Koxx Code, or a 26" alloy street/trial: Inspired Hex, Element or Extension Drax if it fits your budget. Maybe a Monty 230 Urban fits too. Have a look at Ali C's vlogs, he rode different kinds of bikes and you will see how he adapts his riding style.

Hello and welcome (back), Modern comp bikes (stocks and mods) are now so extreme, that no one wants to cruise with this kind of bikes. They are really loooong with the weight shifted forward. I own one (a Crewkerz Cleep 2) and I really to "ride" with. But it is completely different type of "riding". It is better for natural, sidehops, front moves. Street/trials bikes suit you better. They are short and their geometry is closer to the Orange Zero's one. I owned one and I love how short and maneuverable they are. It was a dream in manual. The 24" bikes are easier to rotate and for riders who prefers BMX tricks. 26" street trials bikes (Inspired Hex, TMS Silex 26, Extension Drax) are slightly better for trial moves. They roll better on uneven surface and they are longer than the 24". They are quite difficult to find used and the market is so small, that there is sometime no dedicated parts. For example, there is no specific tubeless tires. I built a 26" street trials based on an Octane One Spark frame. It is a street/park frame, but the geometry is close to an Inspired Hex. It is quite close to my old Orange Zero, but heavier. Aluminum frames are much lighter and more responsive. Another possibility is to get a 10-15 years old comp bike. An Echo, Ozonys, Atomz, Koxx (XTP short?) for example. The bottom brackets were lower than now (+30/40mm instead of +65/80mm) and they were shorter. But maybe already too high and too long for your taste. Your style and your budget are the keys. If you really want to ride a lot of natural, go for an old comp bike (or a modern one and try to adapt) if you think than +30mm will be OK. Else try to get a 26" street/trials. If you want to try BMX tricks, go for a 24", but it will be much more difficult on natural surface.

I appreciate to see you ride a modern comp bike! But I appreciate even more, that you ride the same frame as I do! The Cleep 2 has a recent geometry, but the frame is quite heavy compared to the Jealousy. Maybe 400g (0,88 pound) heavier. Would like to see your reaction when you get back on your street/trial

Hope the rider was not injured! Looks really nasty.