ericbenjaminjr

I'd really like a prototype in 7075 aluminum. Would the laser cutting do the bevels as well?

I have a pair of trialtech sport cranks and just discovered the pedal thread on the right drive side crank is offset. Each crank has at least 9mm material around the threads but this one has only 7mm at its weakest point. I'm wondering if this is something I shouldn't ride or if it is within tolerances. I wont rant about my favorite manufacturer because I have the feeling the shop I got it from purposely orders B stock and sells it at full price. Because it wouldn't be the first time I've gotten anomalis products from them..

The only thing I can pass on is a DFX file. Or other universal 3D format. I can't generate CNC code with my software...

That would be amazing!

Thanks everyone for all the input. I've had a chance to do some measurements of my own now that I got a set of new cranks. From that I wouldn't go over 3.5mm maybe 4mm if need be. I don't understand why there are so many 5mm rings out there. I mean almost half the rings in some shops are 5mm. I wouldn't want to leave so little thread left over now that I've seen with my own eyes. So next I'll be porting all the designs to solid edge and doing some virtual stress tests. Any suggestions on how I could economically go about getting CNC one offs done would be much appreciated.

Got the full and quarter rings done

I've done a bit more research and asked around a bit. It seems 5mm is ok but not optimal for all setups. So I'm going to wait and try out my original JafBikes ring until I bend it and analyze the damage. In the meantime I worked on one of my own designs. I couldn't help myself but to be inspired by the Jaf ring though. I took a guess on completing the circle of the ring hoping it would provide some stiffness. This is my first draft. I call it the knucklering.

Indeed! I'm also looking into double wall rims but theres not much to compare there. I have an excel chart comparing weight and prices. Ironically, the trialtech single and double walls are just 77g difference. The bonz are 177g lighter than trialtech double wall. So far doubles are winning. I've heard allot of good things about the trialtech single walls. I forgot to mention rockman rims which I hear are just as good? So far what ever I do will be better lighter than my super heavy echo TRs with 2mm spokes and brass nipples.

I'm looking to build up a set of new wheels and wanted to ask around about your best experiences with single walls. I've already decided on trialtech sport lite hubs. The rear has a nice wide flange for good stiffness. As of now I'm contemplating bonz or trialtech trims. I know they're not going to be as strong as double walls but whats the best I can do with singles?

Thanks for the info guys. I'll check into it a bit more.

I did quite a bit of research and found 5mm has become a pretty common standard.

I finally got some time to finish up the remake. I decided on keeping the design as close as possible with the few minor changes. I made the diameter 91.1mm to prevent the chain being hit between the cutouts around the outer rim. The large cutouts are a bit larger and all the same shape. I did a bit of research and I'm thinking making the entire ring 5mm thick will be enough to prevent bending. I'm just wondering how much lighter it would be with 7075 alu or if at all due to the thickness. I also got my Jaf ring from TartyBikes. Its 3mm thick and just by looking at it I know I'll bend it sooner or later. So I'll be moving on to some of my own designs now.

I understand. I guess you're right. I've never run a bash ring that wasnt tapered. I've been reading up on the properties of 7075 aluminum and it seems to be the perfect choice for this bash ring. It has the lightness of aluminum and hardness of steel. I'm no physics expert but I imagined the JAF ring as a straight bar with all its waves and cutouts and imagined twisting it would be fairly easy. Thats how I came up with closing the inner ring, thinking it would stiffen up the structure as a whole. I need to research how I could get one off prototypes done cheaply. Maybe I would take this a bit further... That bike is bad ass BTW @Trials Bummer!!!

Yeah it tapers to the inside towards the freewheel. The crank side is flat. I'm thinking of 7075 aluminum. So far this is all theory. Fun and games with the option to get serious if I come up with something really good.

Well bending isn't good. Never had a bash ring bend on me. Not really something I'd like to start accepting as normal. I made a few changes to prevent bending, and a few minor design changes as well. This is of course no long a steel design. 1. Made it taper to 5mm thicker. 2. Removed some holes. 3. Left the ring around the crank intact. You still wont see it when the crank is on. Did I break it?

LOL, the plutonium version was out of stock.. I added a generic crank and freewheel to the template so I can better see what the end result would look like. Also started drawing up a few ideas of my own on paper. Actually came up with a few. But I'm still very interested in whats wrong with the JAF ring. I really love the design and maybe I can improve on it..

Does it bend? Or whats the deal with it?

Damn, thats not good news. I ordered a half ring today

Well thats just damn refreshing...

Yeah you're right, the original has two sections without any holes at all. But like I said, this was only a workflow test. I needed a subject right away. This workflow is for an 8 section design. Jaff was a great subject because of the complexity. I'll be making a few more workflows before I start to get creative myself..

I was just working on a workflow for creating bash rings. I just ordered one from JAF Bikes. I'm so in love with this thing, just wish I could get it in anodized black 7075 aluminum. I decided to use his design to test my workflow. What do you think?

Couldn't find any specs on it. Just one more thing, whats the stem geo?

Hmm, I was afraid I'd be the only one. Had a good ride today, really good in fact. Everything was on point, like a machine. May have just been some electromagnetic interference LOL.

I'll be running a trialtech sport lite. Is that an urban?

I've been riding trials since 2004 and this has never happened to me before. I was pedal hopping a wall at a spot I regularly ride and I suddenly lost all coordination. All the subtle nuances like timing, calculating distance and pedal position just got all jumbled in my head. The first time in my life I've ever hit the brakes and aborted my approach. I laughed and did it again, and again and again. You know how it feels when you blackout and cant remember someones name? Thats how it felt, like I forgot how to do it! Its a routine move. The wall gets higher from left to right and I regularly practice there to get more height. I know all about how some rides just suck but this was different. I left the spot and hopped another straight wall about a half hour later and everything was back to normal. Anything like this ever happen to anyone before?