MaxTBehrens Posted October 2, 2015 Author Posted October 2, 2015 Here is another bike which uses the BB as the pivot for the rear suspension, sortof..http://www.pinkbike.com/news/pole-rinne-yla-review-2015.html From the article:" is the heart of the bike, a concentric pivot that rotates on cartridge bearings that also double as the bottom bracket"That was my previous thought for placing the shock in Gen3, but decided against it. I like what it says , but I prefer my simplicity of the 2 BB's. I would very much like to test my Gen3 design for squatting, and how bad it will be. But I'd like to test it on the trails, not a simulation. That doesn't mean the squatting won't be calculated though, it is a viable point.
Paulst12 Posted October 2, 2015 Posted October 2, 2015 nice job! how did you get the down-tube formed, and what material is the flat section just behind the BB? That area would see quite a bit of flex in your design, is it a spring steel of some sort?Its a full titanium frame. The flat plate is titanium spring plate. Total weight was 50grms heavier than an s-works epic frame.
Jay_B Posted October 2, 2015 Posted October 2, 2015 Having ur rear shock placed there eliminates your water bottle attatchment?I recently built a softail. Here is the frame. That is pretty... if i may ask where did you get your titanium tubing and who did the welding for you? I looked into building my own designed bike but had a hard time sourcing the titanium tubing i wanted locally. Also what size tubing have you used there?
Paulst12 Posted October 2, 2015 Posted October 2, 2015 That is pretty... if i may ask where did you get your titanium tubing and who did the welding for you? I looked into building my own designed bike but had a hard time sourcing the titanium tubing i wanted locally. Also what size tubing have you used there?You have to source in China.Pricing is much better. Full TIG Weld done by a specialist.Used 0.9T tubing throughout
hayleyearth Posted October 2, 2015 Posted October 2, 2015 Having ur rear shock placed there eliminates your water bottle attatchment?I recently built a softail. Here is the frame. Last of ones 'concerns' when one is looking into designing/buying a +-150-160mm bike #camelback I am also interested in the question rudi asked RE the flat part behind the BB...dont know if you have your own thread for that build? So maybe 'off topic' for this thread.. Sorry MaxTBeherns! Edit: I took to long to write my post - see your replies after I posted... I'll be following this thread though - interested to know how you will make your decisions regarding the suspension placement/movements (as you mentioned that is your 1st priority/concern now) and then also the finer details regarding the tubes designs and connections of them all (like around the head tube etc). It is cool that people still make time to do such things!
nolipoli Posted October 4, 2015 Posted October 4, 2015 Those Titanium frames with the flat plates are available complete on Alibaba. They typically have around 100mm of travel, which seems to be the limit of the flexible plate, as well as the flex between chain stays and seat stays. WRT to the BB concentric rear pivot, Have a look at a suspension design package called Linkage (www.bikeCAD.com). There is some nice info available there. Also look at the "considering a home build" thread. Plenty of discussion there.
KingTJ Posted October 5, 2015 Posted October 5, 2015 Good luck with the build....i have always wanted to build my own bike, just dont know where to start.. A quick question, do you have any engineering/designing back ground? And where 8s a good place to start?
MaxTBehrens Posted October 5, 2015 Author Posted October 5, 2015 Good luck with the build....i have always wanted to build my own bike, just dont know where to start.. A quick question, do you have any engineering/designing back ground? And where 8s a good place to start?No background whatsoever. I downloaded the student version of inventor pro, which is free, and started with the learning curve of the program itself. Then followed research, and so I started. Any place I would deem as a good place to start. Its strange to get going at first, but once you into it, there's no stopping. Edit: spelling
MaxTBehrens Posted October 5, 2015 Author Posted October 5, 2015 Good Morning Having finished the Generation Three design, the time has come to post it on this here thread. So, addressing the issues I had with my Gen2 model I gave the geometry a final good hard scrub. This all is drawn around a 650b build with 140 at the rear and 160 at the front, but it is designed for 26ers and 29ers, with the 29er limiting your travel to 115 at the rear and 140 up front. As I have said this is drawn around 650b, and I am yet to toy around with the 29er specs, but that is soon to come. So starting the same way as the others, I drew up a sketch, getting a handle on the geometry and placement of things. I slackened the head tube by 0.25deg, and lengthened the chain stays by 15mm. Reach, stack and all the others remained the same, more or less. With the shaping of the tubing I really just played around to get to know the program. Again I have no beef with straight tubes, this is just me having fun. I decided to incorporate the use of two rockers, to give the shock a nice progressive movement. Meaning, theoretically, it'll be gracious on the small bumps but also resist bottoming out. Having seen the movement of the shock, I noted that the top rockers angle is a tad bit too close to parallel with the shock, but I fixed that with minor adjustments of 3mm to both the length of the rocker as well as the seat stay. I know no system is perfect, and compensation has to be made somewhere. Mine is on squatting. Having my head buried in that link a fellow hubber sent me containing loads of information concerning squatting and anti-squat, I saw that the anti-squatting design not only sacrifices a little of its small bump compliance, but also pedal power is absorbed through the suspension then. In both cases it is a little, I agree, but their design favors anti-squatting and mine favors an isolated drive train and small bump compliance. But everyone has a preference, that's why there are LOADS of other designs out there to pick from! I quite like my Generation Three design, and will continue to make improvements on it, fiddling to see if I can fit 29ers perfectly with maybe the help of different dropouts and limiting rear travel via mounting a smaller shock, e.g. 184x44 or 165x38 and fitting different rockers to house the smaller shock. I am having Great fun designing these frames, and I'd like to thank all who follow this thread and deliver commentaries on my design, and giving excellent and valuable information. Oh, and to whom it was a concern, you can now have a water bottle on your frame.
rudi-h Posted October 5, 2015 Posted October 5, 2015 looks good! at what stage do you start doing force / stress analysis? would be interested to know how you'd go about calculating peak loads e.g. casing jumps, landing drop-offs badly or simulating an OTB crash in a rock garden etc. without breaking the frame. I think this is where a lot of IP lies with the established frame builders.
nolipoli Posted October 5, 2015 Posted October 5, 2015 looks good! at what stage do you start doing force / stress analysis? would be interested to know how you'd go about calculating peak loads e.g. casing jumps, landing drop-offs badly or simulating an OTB crash in a rock garden etc. without breaking the frame. I think this is where a lot of IP lies with the established frame builders.I think as a home build the best solution is to send your mates out on it first, equipped with gumguards.
MaxTBehrens Posted October 5, 2015 Author Posted October 5, 2015 looks good! at what stage do you start doing force / stress analysis? would be interested to know how you'd go about calculating peak loads e.g. casing jumps, landing drop-offs badly or simulating an OTB crash in a rock garden etc. without breaking the frame. I think this is where a lot of IP lies with the established frame builders.Thanks! When I have gained the know how. I'm still VERY new to this whole CAD amazingness. I think as a home build the best solution is to send your mates out on it first, equipped with gumguards. That's definitely the way to go! But rather send enemies than friends... and forget the gum gaurds... Lure them in with the hope of receiving a new bike
JKK Posted October 6, 2015 Posted October 6, 2015 Thanks! When I have gained the know how. I'm still VERY new to this whole CAD amazingness. That's definitely the way to go! But rather send enemies than friends... and forget the gum gaurds... Lure them in with the hope of receiving a new bikeAwesome project! If you ever want to do a stress analysis/force calculation, send me a PM. I will be more happy to help and offer advice.
MaxTBehrens Posted October 6, 2015 Author Posted October 6, 2015 Awesome project! If you ever want to do a stress analysis/force calculation, send me a PM. I will be more happy to help and offer advice.Thanks!! I will do so!
rudi-h Posted October 6, 2015 Posted October 6, 2015 Awesome project! If you ever want to do a stress analysis/force calculation, send me a PM. I will be more happy to help and offer advice. Please have this discussion about the stress analysis right here on the hub if you don't mind. I spent a large part of my working life on mechanical and structural design and have much more than just an interest in this topic. Would be great to see what assumptions, load cases and calculation methods comes out of this.
patches Posted October 6, 2015 Posted October 6, 2015 Having ur rear shock placed there eliminates your water bottle attatchment?I recently built a softail. Here is the frame. You have to source in China.Pricing is much better. Full TIG Weld done by a specialist.Used 0.9T tubing throughout Those Titanium frames with the flat plates are available complete on Alibaba. They typically have around 100mm of travel, which seems to be the limit of the flexible plate, as well as the flex between chain stays and seat stays. WRT to the BB concentric rear pivot, Have a look at a suspension design package called Linkage (www.bikeCAD.com). There is some nice info available there. Also look at the "considering a home build" thread. Plenty of discussion there. Paulst12, did you order the tubing as a "semi-knock-down" type kit and just assembly/welding was done here? Cos as Noli said, I see one can get them complete on Alibabahttp://www.alibaba.com/product-detail/New-style-Titanium-Full-Suspension-29_60109555735/showimage.html What would be the advantage of having it assembled here vs just bringing in a complete? Avoiding minimum order quantities? Quality of work?
Recommended Posts
Archived
This topic is now archived and is closed to further replies.