I would love to build a full carbon, carbon wheelset, frame, cranks, seat 29" fat uni… does this even exist?
There have been full carbon 20" trial frames and bigger carbon frames made of cut-to-length carbon tubes with clamped aluminium bearing holders and bridge. But I’ve never heared of a full carbon 29er frame.
If you want the lightest setup possible, you should consider using textile fiber spokes: https://translate.google.com/translate?sl=de&tl=en&js=y&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.innovations-report.de%2Fhtml%2Fberichte%2Fmaschinenbau%2Ftextil-fuers-fahrrad.html&edit-text=&act=url
Roger Davies made some frames this way in the 90’s:
Then, around 2009 EB unicycles made some. Maybe you can ask them if they could still produce one for you:
On the other Hand, I fear this design aproach with straight tubes would not work with a fat setup.
If you want a carbon seatpost and the Qu-Ax carbon seatpost is to weak for you, you can use the Moocow Saddle Adapter and a normal carbon tube.
I’d love to see a carbon Muni frame, but I honnestly think the market wouldn’t be big enough. Carbon frames are not as resistant as aluminum, as in, if you smash it on a rock, it’s done. When you can smash an aluminum frame on a rock quite a few times before it’s unridable.
I always wanted to make one myself, but it wont be a thing I’d be selling. I trust my welding waaaaayyyyy more than my skills with carbon haha.
Don’t they use carbon for DH bikes now? Surely it’s strong enough to stand up to MUni?
I’d love to try a carbon 36er, with carbon rim
Carbon is strong enough… until it hits a rock. My brother had his cross frame ruined because he got a stick get caught in the drivetran. Ruined a $3000 frame in a spot that couldn’t be repaired.
A 36er would be the perfect option for carbon. I wouldn’t ride a muni built with anything less than steel though. : P
Besides normal carbon tubes you have bidirectional weaved tubes, which better resist sideways impact.
As normal tubes we’re OK’ish for bikes, bidirectional could save a few grams, and so would a allow a 78 times better unicycle.
Top of the bill would be a frame using the concept of Cervélo (which originates in Holland also).
But just like they discovered; stiff frames will break though flexible tubes will allow bending.
So, entirely back to the root: for what reason you “would love to build a full carbon” etc. …?
I was in touch with a company who only makes custom carbon tubes against fair pricing.
However I didn’t use my sadledapter yet - as I don’t have any tools fitting in the anorexic space for the nut.
Curious to know, how big was the stick and where in his drivetrain?
I rode and raced a Trek OCLV carbon mountain bike for years, and I can’t begin to count how many trees it bounced off, how many hills it went down without me, how many crashes it took into rock gardens. The only problems I ever had were with the aluminum bits that they glued onto the carbon.
On the other hand I broke steel, aluminum, and titanium bike frames.
Nothing’s indestructible! But I personally wouldn’t have any reservations riding a carbon framed muni.
I’ve also ridden a carbon MTB for years - have got badly bruised toes from rocks which have bounced off the downtube. I certainly can’t see why a carbon muni would be a problem - it’s not even like the frame does tend to get much impact damage when crashing, usually it’s the saddle hitting first, and unlike a bike, generally when a muni crashes it hasn’t got the weight of the rider behind it.
Strength of the tubing is not a problem if you go that direction.
You do need to be careful when clamping. You need to place a plug it. The plug needs to be an upside down egg cup shape and going to a feather edge. This is so you don’t get any stress raisers. I ground a special tool when I produced the plugs on my carbon fibre unicycles.
Problems come when looking at geometry. The tubing is produced over a mandrel and everyone seams to have the same sizes… and they are not what you want!
You also need to do some research on what specification you want the tubing, you need to know which layers and which direction want it laid up to give you the right stiffness and rotational resistance. You can have 2 tubes that look identical but one will flex (fishing rod) and another will be super stiff (handlebars). My expert friend (he was the head of ICI composite research division) once designed a mountain bike frame that was flexible vertically, but stiff laterally… best cross country bike I have ever ridden!
When doing the layout of the design if you are not very careful you will find that there is just not enough room between the crank and spokes. You need a Tardis!