carbon fiber/aluminum frame

alright i will look into it. it should be easy to make the 36er frames with the design we have for the 20" all we have to do is increase the leg size. your talking about a frame like the nimbus nightrider frame correct?

the modded nimbus, that is:

Red Menace FTW!

oh something like that. i will have to see what we can work out. haha

A standard 36" frame would be the thing to start with. It would just be a scaled-up version of a 20" frame–probably using the dimensions and a KH or Coker. It should be stiff and light with the constructions techniques you are using. It would be great to get a prototype into the hands of an experienced 36" rider (not me unfortunately) for evaluation and feedback. You could ask for volunteers to test it–I bet you would be able to find someone willing to make the sacrifice.

The V-frame would be very interesting, but you should being with something simple just to see if it performs well.

Good luck with your project.

I hope this thing can hold up to abuse as well as anything else. You and Cody should really wail on these frames to test em out. If they hold up well definitely put me on the list for a 20 inch longneck. :sunglasses:

Edit:Oh, don’t remember to post detailed pics as soon as you have a complete frame. I’m itching to see one.

if you know cody then u know he will put this frame through hell and back. they should be finishing them up tomorrow. so i will post final weight specs and pics of the frame as soon as i have them.

Cant wait :smiley:

You can drill the bearing holders and drill the crown (not whole through it)

ya we machined out a bunch of un necessary metal in the crown and there is a incert that goes into the carbon that attatches it to the bearing holders that is solid alu. so we are hollowing out those pieces and have more to take off of the bearing holders themselves. the 500 grams also includes almost twice as much carbon fiber as we need becouse they havnt cut it to size yet. so with all of that we are hoping to drop atleast 100 grams.

Unicyclerman, there may be an area you missed in your design (which looks beautiful BTW). I have a frame similar to yours, which was made by Roger Davies in the 90s. But it broke due to twisting forces on the fork legs. Hard pedaling, such as uphill or downhill, puts a tremendous amount of twist into the frame. If your frame is assembled with the carbon simply glued into round holes in the lugs (or vice-versa) it’s possible the adhesive could fail there.

More detail:
In the case of my frame, it wasn’t the first one Roger had made, and it may have been the only one to have this problem. He had gotten the production process very precise, so apparently there was such a tight seal between the parts that it forced most of the adhesive out. But it left a weak spot and hard pedaling broke the join. Fortunately the frame was so light it was easy to stick it in an envelope and mail it back to England. :slight_smile:

His repair was to use some aluminum pins going all the way through where the lugs connect to the carbon tubes. Probably only added a few grams of weight for the four little pins and the frame has been solid ever since.

The picture shows the pins (and the old Thudbuster “Uni-Pivot” seat post!).

oh thanks for the info. what do you use that frame for it looks like your running a muni wheel on it. if your running muni and the carbon holds up to that then mine shouldnt have a huge problem. the way ours fits together there is 0 clearance in that joint so we are probably going to have to press them in. i hope we dont run into the same problem but thats why im starting with these prototypes before i sell any faulty equipment to people. we should be able to get a really strong bond on the adhesive. we have access to a whole clean room and everything so that we know the surfaces of the material will be in the ideal state for it.

Ha, I have one of those too! It never broke or anything, but I have treated it pretty well too. So no brig hops or drops… But it’s amazingly light. Unfortunately it’s too narrow for my new 26" Schlumpf wheelset. But I was thinking that one could make a wider crown and compatible bearing holders for it… Would be cool.

alright it seems there has been a very unfortunate mis understanding between me and the engineers that are making this frame. the weight they gave me before is the weight of the crown and bearing holders without the carbon. the carbon isnt cut to length so we have twice the carbon we need so with that it is at 600 grams. :angry: so disapointing. so when i was hoping for 350 i gues i was really hoping for 450. so now i gues it will be at 500 or below. sorry about that mis information. we will have final specs and pics tomorrow. its hard to work with these guys since they dont ride or know much about it but they are really smart engineers. so its hard to convince them of anything. it also seams that they are going to be more expensive than i thought. i gues i got a little too optimistic on this one.

Come on dude, below 500 grams is still an awesome job. As for those know it all engineers, they don’t really know much if their not willing to learn from others. I should keep that in mind since I plan on being an engineer.:stuck_out_tongue: I totally dibs one of these if they can hold up to hardcore use. Can’t wait.:smiley:

The Roger Davies frames were made with pretty thick-walled tubing. Essentially bombproof unless they get hit by some major side impact. But I think you could let it bounce and roll down a rocky mountainside with no ill-effects to the frame.

According to Roger, the problem on mine was all the adhesive getting pushed out because the seal was so tight (also air couldn’t get out, which helped force the adhesive out). After the “break” the frame wasn’t in two pieces, it just had twisted at the joint. The joint was so tight I couldn’t twist it back, so I had to walk out of the trail.

So with a super-tight joint you could have a similar problem. For more detail try contacting Roger Davies (at UK). Or just take your prototype frame to Moab in March and ride it up and down some of the steep stuff! :slight_smile:

ya it is going to be more heavy than i had otherwise thought but that is becouse they refuse to sacrifice any strength for weight. so it should last a long time.
and john the walls on the tubing we are using are really thick as well so if yours can hold up ours will also. and they thought about the glue thing before i could tell them the problem with yours so they gave it a little space for the adhesive to grab.

so have you gotten a whole rideable prototype finished yet?

it has to be shipped from utah to where i live in california so i will get it when i get back from riding in fresno with joe campbell and cody this weekend. then i dont know if we are going to make it out to AZMW its a bit expensive to make it out there. so sorry to anyone who was looking forward to seeing the end product then

hey everyone. this is unicyclerman’s brother. i’ve been doing the design and construction of our carbon/aluminum frame. we’ve finally finished the first prototype. here are a few pictures of the frame:

the design for the bearing holders has changed slightly to reduce weight, but we decided to run these on the test prototype because they were already finished. feel free to ask me any questions concerning the design or technical specs of the frame. i will be shipping the frame to my brother on monday, so he should be able to start testing by the end of next week.