Bike Lore Posted October 22, 2014 Posted October 22, 2014 For some bazaar reason I got bitten by a bug to design and build my own bike. I have access to some impressive engineering tools and do some graphic design as a hobby. So getting to the conceptual point is pretty easy. It is the detailed design that is presenting a problem. Hence this post. Yes and I will be making it from Titanium, just because I can. That is if I get the stiffness at the right places. At this point I am fairly sure I will be able to limit the tail whip issues that is common with a springy material such as titanium. Here is a conceptual design. You might recognize the basic layout. I admit I am not redesigning the wheel here. After some photoshoping this is what I hope to end with This is the important part. The Geometry is based on my body size. That is the benefit of designing the bike frame. :-D BUT now I have hit a void of information. I am struggling to get the technical detail of key interfaces The head tube size and taper details. The BB thread and details The Seat post stem tolerances The rear de-trailer mounting and QR details and disk brakes mounting position. I am in two minds at this stage about running 11x1 or 10x2. If I do run 10x2 I need the details for mounting the derailer. Pivit bearing details. That and amongst other things. I am hoping someone can direct me to an design guide with technical details about common part. I started contacting the manufacturers of the parts I am intended on using but it is difficult to get to someone that can provide the right information. It also does not help sitting in Africa. They seem to not believe me that I am going to build this. And if I don't get this info they are most likely right. The big issue with Ti is that you can't easily change things after it has been made. So I need to get everything right the first time.
Bike Lore Posted October 22, 2014 Author Posted October 22, 2014 And if you where wondering. It is designed for 650B wheels. I am not a 29" fan and 26" parts are getting harder to get
popcorn_skollie Posted October 22, 2014 Posted October 22, 2014 this may sound like a stupid question, but what are the benefits of using titanium over other materials?
The MTBer Posted October 22, 2014 Posted October 22, 2014 As far as I know titanium is the strongest. It is Aluminum then Carbon then Titanium. I might be wrong here.
BogusOne Posted October 22, 2014 Posted October 22, 2014 With a 700mm effective top tube ( ) what length stem will you be using?
quintonb Posted October 22, 2014 Posted October 22, 2014 Looks impressive, cant wait to see the end product.Titanium's weight to strength ratio is the best.Thinner wall sections can be used yet still retaining the same desired strength.
Steven Knoetze (sk27) Posted October 22, 2014 Posted October 22, 2014 With a 700mm effective top tube ( ) what length stem will you be using? That is long, maybe a 35mm stem, pointing backwards..........
Titanium Rocket Posted October 22, 2014 Posted October 22, 2014 Hannes, this looks like a really ambitious project. My understanding is that making oval profiles and bending Titanium is expensive and not that simple, especially for a once-off build like you’re proposing. I have had 3 Titanium bikes in the last 12 years, two old Airbornes and currently their derivative, a Van Nicholas. Even after 15+ years of Titanium bike building experience, Van Nicholas use pretty simple designs and tube profiles, see: http://vannicholas.com/Mountain/6/allbikes.aspx Same can be said for Moots and Lynskey. That said, how will you actually make a once off version of the top and down tubes in your drawings? I assume cost must be of zero consideration to you, but do you have the equipment and technology to do such a thing? I'm no engineer, and I'm not being sceptical ... just curious!
James Mulholland Posted October 22, 2014 Posted October 22, 2014 Looks impressive, cant wait to see the end product.Titanium's weight to strength ratio is the best.Thinner wall sections can be used yet still retaining the same desired strength. But at a cost of rigidity. I think titanium has its uses and could even be designed to allow for slight flex, say on certain points of a hardtail to dampen the ride much like a softail would without the loss of direct power. I think for an AM bike a carbon frame would still be the ideal. But I would love to design a titanium SS.
quintonb Posted October 22, 2014 Posted October 22, 2014 But at a cost of rigidity. I think titanium has its uses and could even be designed to allow for slight flex, say on certain points of a hardtail to dampen the ride much like a softail would without the loss of direct power. I think for an AM bike a carbon frame would still be the ideal. But I would love to design a titanium SS.Yeah I would have to agree with you. I would say Titanium is the next best thing to steel in terms of "Feel". I have little experience with Dual SUS frames and titanium so not really qualified to comment. I have machined titanium quite a bit and it really does machine very nicely. I would imagine that welding it would be similar, but you would have to make sure your joints are mitred very well to maintain the integrity of the material.....
Bike Lore Posted October 22, 2014 Author Posted October 22, 2014 Hannes, this looks like a really ambitious project. My understanding is that making oval profiles and bending Titanium is expensive and not that simple, especially for a once-off build like you’re proposing. I have had 3 Titanium bikes in the last 12 years, two old Airbornes and currently their derivative, a Van Nicholas. Even after 15+ years of Titanium bike building experience, Van Nicholas use pretty simple designs and tube profiles, see: http://vannicholas.com/Mountain/6/allbikes.aspx Same can be said for Moots and Lynskey. That said, how will you actually make a once off version of the top and down tubes in your drawings? I assume cost must be of zero consideration to you, but do you have the equipment and technology to do such a thing? I'm no engineer, and I'm not being sceptical ... just curious!One has to start with a dream and then dumb it down to what is possible in reality. I am only at the starting phase and this might end with me just buying a frame from litespeed, Moots or Lynskey. But to give you an idea I might have access to "growing" the parts that I can't forged or machine. You will find this interesting to read and this. I don't foresee that it will needed though. TI can be forged in to any shape but that requires immersing it in the correct atmosphere at the right temperature and applying the correct forces. Not that easy to do with out very specialized equipment. Something that most custom builders do not have access too. Why TI? light weight, super strength and fatigue life, a magical ride.... The only draw back is the specific stiffnesses that is low. In other words it is very very springy. Not ideal for a Full sus. But I think a frame that takes this in to consideration could be remarkable.
James Mulholland Posted October 22, 2014 Posted October 22, 2014 One has to start with a dream and then dumb it down to what is possible in reality. 100%
clement Posted October 22, 2014 Posted October 22, 2014 Hannes, I am also in the very early stages of doing a bike design for myself and have a fair bit of bicycle mechanic, engineering and manufacturing experience (and is also Stellenbosch based) so feel free to come and have a chat to me, I should be able to assist with most of the questions you listed above. Have a look at http://empire-cycles.com/article.php?xArt=31&jssCart=f32a4998a1179befd6bb7c94172cde83 for a bike frame built using titanium additive manufacturing, I assume it will be very similar to the process offered by the CSIR Titanium Centre of Competence.
Josh0 Posted October 27, 2014 Posted October 27, 2014 We have an EOS M280 laser sinter station, that we use to "grow" titanium parts for medical and aerospace industry. http://www.eos.info/systems_solutions/metal/systems_equipment/eosint_m280 I can vouch that we have the best titanium printing station in the country. OP you are welcome to contact me if you would like to get quotes for printing some parts for the build. Best of luck!
Dirkitech Posted October 27, 2014 Posted October 27, 2014 titanium 3d printing? "follow follow follow"
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