thousandwords

Thought I would inquire about this possibility as well, just to have a rough idea of what type of frame I should be looking for. For a baseline, this is my 26" full suspension frame. My first mountain bike build, and it shows in the mistakes I made. And it was built it for comfort and function- to get me started in mountain biking, with secondary focus on esthetics, hence some perhaps odd choices for certain components. Frame is a medium; I am 5'10" so sitting right at the boundary of medium and large, however, with the 26" wheel the bike is too small for me, I really feel like the proverbial bear riding the circus bike. I don't ride it much these days, because the next mountain bike I build is a 29" wheel large frame hard tail which fits me like a glove. I would suspect this is a bad candidate for a "trial" conversion, given the full suspension frame, I suspect it could be made to be more "trials friendly" but swapping a rigid fork, converting to a single speed sprocket and a smaller chain ring, and swapping for trials specific stem, handlebars and one of those rudimentary "seatposts". But it would still be a rear suspended frame, heavy as hell (it is carbon fiber, but it was overbuilt, so it is pretty heavy for a CX bike). What I am most interested in is geometry though. Not having any actual frame specs, just by gauging by eye- if I was to buy a small framed MTB as suggested, do I need to be looking for something with significantly altered geometry? Thanks!

Thanks Ali and La Bourde! Ali- first of all, wow, what a pleasant surprise to read your comments on this thread...I have watched and will keep on watching youtube trials videos to educate myself, and a good chunk of them are from your channel; I have learned so much from them, and I know I will learn a hundred times more from the ones I have not watched yet. So, just wanted to say many thanks for that, and of course for chipping in with info on my thread! Tartybikes is indeed my No 1 resource for parts. In fact I plan on buying most everything from them. It's a bummer they are out of stock of certain things (snail cam bolts, 20" forks, etc) so for those I will have to source from other online sellers. And I really love that for spokes you give them rim and hub model and they calculate spoke length for you- how nice is that! Fork- I won't complicate my life with straight to tapered adapters, will go for a straight steerer. Gear ratio- 18 front 12 rear it is- thanks for removing any lingering doubt! Boy I am glad I mentioned the hs33 I just purchased- yes the plan was to use a disk brake lever, and I would have learnt the hard way, so I am particularly grateful for that info. After reading it I looked around and will probably get either a Clean or a #Hashtagg H20 lever. They are on the expensive side of the lever spectrum but they both seem to be high quality products. Carbon hub- still on the fence, will probably chuck the idea though. Now the elephant in the room- the weird/alien feeling thing. First off let me just say- this is why, in my opinion, people like me should come to forums like this: there is no way in the world you would get certain angles without the input of experienced people. Technical stuff, even odder aspects of it, you can gather with diligent homework. If I kept digging, little by little I would have learnt about snail cams, correct gear rations, etc. Sure, I would have made some costly mistakes in the process by buying the wrong stuff, but then you go back to the drawing board, dig some more and reconsider. But this "subjective" stuff, the way things feel, is hard is not impossible to stumble upon, as it's not the stuff to be found in compatibility charts or technical specification lists. Which is why I particularly cherish it. Now, I bought that frame for one simple reason. Trials was in the back of my mind for quite a while, and I like to build my own bikes, so I kept looking on ebay for new frames (as a beginner I might not be able to recognize flaws in used trials frames, and given the inherent abuse, I though likelihood is high). A few days ago this UK seller had a new one for sale, and for a good price, especially that, never trying it before, I might come to the rude realization that it's not my thing, once I build the bike and give it a try. In other words- pure happenstance. It just happened it was a 20" frame. I knew absolutely nothing about trials, 20" vs 24" or 26", so to my naive mind it was just the way to go! Not only I do not regret buying it, I pat myself on the back for it, because it truly piqued my interest, and as a result, a mere few days later, I understand so much more about this (and yet still so very little). However, I paid GBP 45 plus shipping (under $100 total). Between my road, gravel, mountain bikes, single speeds, city bikes, I have built myself 8 bikes so far and I am not planning on stopping unitl I feel I do not need another bike. So I am not worried that this Onza frame was bought in vain. But IF it will serve me better to start on a bigger wheel bike (26"), I am more than happy to start with that and revisit the Onza frame later when I am more confident on a trials bike. The ONLY part I have purchased so far for the Onza is the hs33 brake, which can be used on another frame, should I buy another one. I would still not get an expensive 26" frame, just because I really won't know if trials is something I want to get into until I actually try it, but now that I kept looking for parts, to my surprise I noticed that I did not have to rely on ebay for inexpensive frames (I was making the consistent mistake of judging trials by road and mountain bike standards, and good road and mtb frames are expensive as a rule). For instance (just one example), I could buy a brand new 26" speedrace ascent for GBP 235, and it includes factory headset and bottom bracket, so 2 less things to worry about fitting. I would have no qualms doing it if I knew it would make my learning experience more pleasant and the learning curve less steep. So, and this is a question I would greatly appreciate anybody chipping in- should I start on a 20" or a 26"? Should I build the Onza, or get a 26" frame first to learn on and build the Onza later? Like I said, I am equally willing to go either way, but- not having the 20/20 hindsight you all have- I just do not know what actually makes sense. As long as this post got (anybody noticed my handle ha ha), I am really curious about what reactions it will generate- thanks in advance!

Thanks La Bourde! I do not know the headset standard yet, but once frame comes I will find out, as I have headset gauges for different standards. You are probably right it's a straight steerer head tube, I just don't know for sure until I see the frame. That's why I kept the "tapered" option open, just in case head tube asks for one. Once straight steerer in confirmed, fork will be bought- I am heavily leaning towards a disk brake. Glad to hear rims work fine with out grinding, it really is a relief! I saw quite a few videos online about it so I feared it was a must. And no, I won't be riding in the wet at all! Your comment about same lever front and rear now makes sense- I feel the same. Today I just bought online a Magura hs33 brake, comes without the master cylinder/lever precisely for that reason. I am not fond of the plasticky Magura levers, I prefer the metallic Shimano XTR and Formula Cura 4 levers; I found they bleed easier too. Your comment regarding the Magura levers just reinforced my bias and made me particularly glad I chose not to buy a complete brake. Have been trying to educate myself on different components needed for the build, and will start purchasing things soon, but I still have some lingering questions in my mind, some serious, some not so much. Will mention a couple here- one already mentioned on an earlier post, one new. Gearing ratio- just because it was mentioned earlier as being very important: I have no idea what is ideal for that frame, or, or for that matter, for myself. Nor am I aware of a way of figuring that out "scientifically". Subsequently, I will probably shoot in the dark with the typical 18 front, 12 rear and change sprocket later if proving suboptimal. Wheels. I am planning on building the wheels myself (will go for 19" in the rear), and I am tempting on splurging on some more expensive rims (even the most expensive ones are decently priced in the grand scheme of things) like Hashtagg or Clean. At first I was put off by the offset spoke holes (all spoke lengths I had to calculate for my wheel builds had no offset) but I found available online resources for that. Just curious, for those of you that build your own wheels- what online spoke length calculators do you trust? For front hub I am tempted to try a carbon fiber hub (a first for me), if not for the weight savings, then for the cool factor. I am just not convinced it will take even the minimal abuse an absolute beginner like me will put it through. Anybody else using a carbon fiber hub for trials? There are other points of indecision- future posts might include some if still unresolved. Thanks again everybody for any help.

Hi La Bourde, Thanks for all that! Yes, hs33 sound like the sensible way to go and I have already started shopping around for one. I am holding off for now only because I am not sure I have to buy only one for rear or a set for both axles, depending on what I decide for fork. Frame did not some with a fork so I do not have one yet. I want to wait until the frame comes until I purchase any part for the build because I want to make sure I have the correct frame specs first. In the case of a fork, straight headset vs tapered etc. So that means that I have a lot of freedom in terms of how to build. So you gave me an intriguing suggestion- same brake lever for both brakes. out of curiosity- what are the advantages and disadvantages of that set up? I am a little confused as with why if I go that way (one lever for both) I have to run mechanical. I saw an Ali Clarkson hs33 youtube video and they are hydraulic brakes, so with my limited understanding, it would be possible to use a splitter form one single brake lever to actuate both brakes simultaneously. For now, I feel like I would be leaning towards purchasing a disk brake rim (would not mind having two separate levers if that is the easiest set up) for three reasons that I can think of: they are very strong, they are now squeaky (as opposed to rim), and I honestly am not really fond of the idea of grinding rims. I will do it for the rear wheel because I have to use the magura rim, but if I can avoid it in front I would personally cherish that, at least for now lol. While I was looking around I did notice v brakes for sale, they tend to be inexpensive, but I am a believer of using whatever type the frame and/or fork was intended for without any adapter, so I doubt I will decided for them for the rear even if I find adapters. Also, on my mountain bikes I have magura brakes for the most part and I am very impressed with braking power (quality) not the easiest to bleed but that's a different story, and that gives me a lot of confidence towards going for the hs33.

Ok wanted to make a quick followup post just to touch on some stuff mentioned earlier by either you guys or myself. Started watching vids of people recording their builds and stuff started making more sense. 1. Now I know what a front freewheel is. Very cool. I will try to go this way just to try something new if I can source all needed parts (not only the freewheel, but also rear hub or built wheels with fixed rear sprocket as I suspect it's required for a front freewheel). If not will go the "classic" with fixed chain ring in front and rear freehub or freewheel. 2. Yeah those are not "post mounts", in fact it was very stupid of me even suspecting they were, given how far from axle they are, but I got tricked by their appearance, I guess in science it's sometimes called pattern recognition. Now I need to investigate further on mechanical vs hydraulic rim brakes. 3. The snail cams for chain tension- did not understand the reference until I saw it in the vid- again, really cool. I thought that the horizontal dropouts would tension the chain by plain sliding the axle outwards (like in a track bike or fixie), but now that I think of it, standing up and bouncing around on the rear wheel would move things around pretty easy. So now I can see why cam is needed. Needless to say I would not have though of any of the above on my own. So yeah- hard to put in words how much I appreciate all this.

Wow, I knew for a fact I knew nothing about what's ahead on this build but I had no idea I was so out of depth- I was hoping I could transfer most of my knowledge gained form building and riding road and mountain. But after reading the above my eyes open to the reality that trials comes with it own set of particulars and trying to apply non-trial knowledge might not only be non beneficial but downright misleading. And for that I am very grateful to all of you guys, posting here and making me understand that before I learn it the hard way! I guess before I do anything, I will watch a bunch of videos of people talking and showing their particular bike and builds for inspiration and concrete examples of what actually works. And it sounds like one of the very first thing I need to understand better is how the front freewheel works, all the bikes I own and had to build use the typical rear hub mounted freehub/cassette or freewheel, with chain ring in front, so for now I am a little confused. But hey- big part of the pleasure of building my own bikes is the constant effort I have to invest into educating myself about it, so looking forward to figuring that out!

Thanks guys! Chakers198- yeah the Hope Pro4 hubs are available here, I have used one for a recent build, but it was an 11 speed freehub. I could still use something like that with a single speed conversion kit (spacers basically), it worked OK for me single speed bike but for now I know too little about trials builds to know for sure what i want. Once I have the frame I will do a few basic measurements to start fitting parts: rear hub spacing (could be 135 like you said), bottom bracket standard, headset standard, etc. The gear ratios for now are a secondary priority, I first need to slap on a few basic build components- 20" fork, set of 20" wheels, stem (might have to do some educated guessing on size), handlebars, brake calipers (whether rim or disc), bottom bracket one I settle for a specific crank. Once all that is in I will try to figure out size of chain ring, crank arms and sprocket. Now wheels- I have laced every single wheel for my bikes but this time around I am seriously thinking about buying built rims because it looks like trials wheels have a few peculiarities- rims are skeletonized for weight saving purposes, etc. Can still be done, but I feel like with the increased abuse a trials wheel takes, a factory built wheel might be a good idea. I was thinking of using disk brakes for the rear wheel (if I understand the pictures correctly, the frame has a post mount on each seat stay for them. I know some people use adapters to convert those to rim brakes, but especially now as a beginner I am not too keen on starting grinding rims haha. Plus I already have a couple of magura disk brake calipers laying around from my previous mountain bike builds. Once frame arrives, I will test to see if calipers fit those "post mounts"- if they do, I think I might try going disc on the rear. For the sake of keeping some kind of record, I will document my build once I have something concrete to post. Than you again all of you for any input you have, at my stage it's all invaluable.

Hi everybody, Just wanted to introduce myself- I live in Massachusetts, USA and I will give trials a try (pun intended ha ha). Have done some road and dirt riding in the past (still do) but nothing crazy, so I expect a very steep learning curve, especially that I am not that young anymore (just turned 50). Just bought a frame on ebay (from UK seller actually) and once it comes I will start building it (I do have some bike building experience as all my bikes, and I have quite a few, I have built myself from scratch). Just bought the frame so I do not have a well formed idea on components- these days doing some research online. I am sure I will have tons of questions once I start the build, and hope I won't be too annoying trying to find on this forum answers to way too many basic questions. I will probably start a build thread once I have a plan in mind. If you guys feel like chipping in with suggestions on how you'd have built it if it was your project, it would be immensely appreciated. Here' s the frame https://www.ebay.com/itm/234606314097 As for skills, will start slow, with stuff like track stand (which as of yesterday I started trying to figure out on one of my mountain bikes), wheelie, bunny hop. While it might sound that the goal would be to transfer those skills into dirt riding to become a better rider, that is only partly true- I just feel like trials is something i might tremendously enjoy for itself! I hope time will prove me right!