Burner Posted November 17, 2015 Author Posted November 17, 2015 Howsit guys. Yah, it's been hectic my side. Hopefully it will be much better in a few weeks....I'm off for almost a month in December, then I can get cracking again. I've also been working weekends so almost no personal time for me. I've been working on home/domestic wind turbines for a while now, and will be launched early next year. We've been testing and researching for a while so it's also exciting for me ATM. Anyways, enough excuses already....I'm hoping to play around with my cnc again soon and get the plugs cut for the frame. I've now got a mini lathe as well, so I'll be able to turn my own bushes. I've made offset bushes for my Spez Enduro and they working well
Burner Posted November 23, 2015 Author Posted November 23, 2015 Finally, I had a quiet weekend and had time to work on the suspension design coz I wasn't very happy with the last version. I think I found what I've been trying to achieve....something that's been tested but not too common but has the features I'm looking for. It's got a floaty (in theory thus far) feel with a one piece rear carbon end for stiffness, a long lower aluminium linkage for stability, around 15mm chain growth and an interesting look to it. Now I can take this to CAD and work out the component details. I'd like to use needle bearings where possible but I'll only know once the model takes shape. I forgot to mention it's 63deg headtube! I'd like to hear any criticism, it will be appreciated
Burner Posted November 23, 2015 Author Posted November 23, 2015 Finally, I had a quiet weekend and had time to work on the suspension design coz I wasn't very happy with the last version. I think I found what I've been trying to achieve....something that's been tested but not too common but has the features I'm looking for. It's got a floaty (in theory thus far) feel with a one piece rear carbon end for stiffness, a long lower aluminium linkage for stability, around 15mm chain growth and an interesting look to it. Now I can take this to CAD and work out the component details. I'd like to use needle bearings where possible but I'll only know once the model takes shape. I forgot to mention it's 63deg headtube! I'd like to hear any criticism, it will be appreciated
nolipoli Posted November 23, 2015 Posted November 23, 2015 That looks very interesting. It looks like you are going to have fun and games to get clearance to the seat tube at full compression though.
Burner Posted November 23, 2015 Author Posted November 23, 2015 Ahhhh, you have a good eye Thats the biggest issue trying to keep very short chain stays. My plan is to set the rear axle about 10mm back in order to clear if I cannot perform any wizardry to make it work as is
nolipoli Posted November 23, 2015 Posted November 23, 2015 You should be able to make a kinked seat tube that will still put your saddle in the same place but create more space at full compression, but then you would also need to fiddle your shock further forward.It's a tough balancing act.
Burner Posted November 24, 2015 Author Posted November 24, 2015 So true, last night I was struggling to get it to work in 2D on CAD....I'll give it some time to sink in. I'm sure I can make a plan with carbon, maybe even something similar to what Spez did on the new Demo
jimmy hardtail Posted November 25, 2015 Posted November 25, 2015 Are you not going to have chain/ crank interference issues with that long lower linkage? That section of rear triangle in green looks like it falls right where the tip of the crank gets close to the chain stay. And if it clears will you get massive chain slap? Im busy working out the basics of my own frame design at the moment, well actually ive been working on it for years, and its all the little details like that that get overlooked.
nolipoli Posted November 25, 2015 Posted November 25, 2015 Hmmm, you make a good point there Jimmy. I would imagine that pushing the near vertical part of the RHS of the triangle backward toward the dropout would solve the chain interference issue. The LHS could stay as is. It shouldn't be too hard to make the pivot clear the crank.
Blokeonabike Posted November 25, 2015 Posted November 25, 2015 Not sure if I'm seeing it right, but I think you'll have trouble with the shock itself and the toptube when compressed?
Burner Posted November 26, 2015 Author Posted November 26, 2015 Are you not going to have chain/ crank interference issues with that long lower linkage? That section of rear triangle in green looks like it falls right where the tip of the crank gets close to the chain stay. And if it clears will you get massive chain slap?Im busy working out the basics of my own frame design at the moment, well actually ive been working on it for years, and its all the little details like that that get overlooked.On the model above I made the mistake of adding a 42t crank It will be similar to the Breezer rear suspension, I also think I can now create a full floating version .....will work it out soon, I'm excited to get that right. I don't think it will get chain slap as the rear most triangle will rotate clockwise, and increases chain length (by 15mm at max 150mm travel), preventing the rear axle to bb from shortening and causing chain slap.....Please explain your scenario...I might be missing something. I'd like to see what you are working on, post some pics Not sure if I'm seeing it right, but I think you'll have trouble with the shock itself and the toptube when compressed?I'm going to either play around manipulating the seat tube or moving the rear axle 10-15 back...as a last resort. On a side note, I'm excited to feel this rear end. It will probably be very stiff having two seat stays reinforcing the rear axle....I must say it's getting exciting
Werner van Aardt Posted November 27, 2015 Posted November 27, 2015 I am also in the process of a build, but I have not posted about it. I designed a trail 29er, 140mm fork 120mm rear travel. But now I am considering a trail 29er hardtail as I am a bit pressed for time because I am going to move around for work a lot in 2016. So what do you hubbers think of a 140mm 29er. Slackish headangle, short stem and super short chainstays. I think it will be an easier build and might be a bit more fun to ride. I don't have time to make moulds and bladder mould the parts of the frame. So I am going to use my cnc router to make polystyrene plugs for the tubes and then lay carbon directly onto that and vacuum bag it. Then I will do a tube to tube construction in a jig.Any comments?
Burner Posted November 27, 2015 Author Posted November 27, 2015 Hi Werner. Welcome to our build discussion. I know a dual suspension bike will be harder to make but I think there's fun and lots to learn when building a dual. How far are you with the design? Maybe you can outsource some of the frame components. I have lots of contacts in the engineering industry that can help make the build easier. Post some more info
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