DIY Carbon full suss- attempt

For a few years i’ve been playing with designing and building my own full suss. Mainly because those i liked were too expensive and the ones i could afford just didn’t have the right geometry.

To start with the swing arm.

First part was designing and getting everything to work right, this took nearly a year of faffing, with some building work distractions.

Eventually ended up with a design,

Now how to build? was half way through planning on doing a split mold for a foam core, the got distracted an bought a 3d printer.

It was ok but couldn’t get the frame square and when you looked at it the framed moved 0.5mm so a new one was made. note the use zip ties!

This led to many many hour of cad fiddleage and printer frustration till everything worked ended up with.

Just slots together to build…

fitting in building jig parts when i could finally got a jig together.

Once aligned up and glued on the jig with some hybrid tape to hold it secure ended up with.

Have missed loads out, must have been 18 months to get to this stage, more to come when i get a minute

Brilliant, would love to see how the rest of the project goes.

Good work. One of my riding buddies makes his own carbon frames.
Here’s his website. http://carbonwasp.com/info.html

YES self build lunacy – love it! I particularly like the ‘cost’ justification given the hours it must have take so far. I would love to do something like this. looking forward to seeing the rest!

Fantastic, can’t wait for the next instalment.
How do you go about calculating strength required/forces involved ???

I’m not sure whether to be more impressed with the swing arm or the 3D printer!

Cheers everyone, yes by now could have bought a new carbon frame but that’s not really the the reason for it, have learnt a fair bit which was a goal plus the size won’t be a compromise. Unless I’ve got it wrong and it’s someone else’s fault.

No real scientific method of strength testing. Pla is surprisingly strong, dispute everyone saying abs is better. A test print with one layer of carbon was kind of tested, I struggled to bend it, so used at least 4 layers.

Have put 80-100kg just on the just upper mounting points and with the axel in place it is incredibly stiff. Not light though.

I read a post somewhere that said on your first build you’ll always use more fiber than needed.

Brilliant! Have you saw the guy Berk on weight weenies? Started with a few carbon odds and sods and now is selling uber high end kit, really good (and long) thread on his progress.

I’m sat at home trying to catch up on work – I need more pics!!!

Moar please!!!!!!

Good stuff.
Al extrusions make a good jig.
When I built mine the two hardest parts was working out fix the metal bits to the carbon, and how to make sure everything was aligned.
Having a jig that you can hold everything in the correct places is vital. You can’t cold set carbon.

Oh yes good work sir!!! more please 🙂

Great work – fixtures etc always eat into the time it takes for a first build, so to finally have some parts made must feel great.

Any images of the proposed front triangle / full frame?

Very sensible not to start adding up costs and comparing them to what could have been bought 🙂

*drums fingers*

Sooo sticking to the rear triangle.

It took a day (well afternoon) to make the vacuum bag it had to be shape so that it didn’t compress the stays.

First few layers of reinforcement

Second lot on

Extra reinforcement for the join between the stays.

Looking at it the structure is fairly sound for compression, i’m more concerned with twisting & sideways forces, which is why these joins got extra layer and the stays got long extra layer runs along the lateral sides.

Had a panic attack when i got the wheel in and thought the disc wouldn’t fit.
Mock up (phew!).

An idea of Tyre clearance.

Just spent two hours sanding while printing out parts of the top tube.
I’ll get more pics later.

Oh was worried about metal bits myself so only metal parts of swing arm are the upper contact points, bearing housings are carbon and mech hanger is bolt through type.

Giff assembly attempt

Ok. I’m definitely impressed now. (..and feeling a touch talentless)

Nice work. Looking forward to seeing it progress.

Cor. Good stuff. 🙂

I have so much to do and because of this bloody thread I’m trying to learn freecad 😳

Not bothering with brakes? 🙂

Seriously cool that, dude

Makes my attempt look amateurish, definitely following with interest

Not bothering with brakes?

Am seriously thinking of incorperating a spoon when the time comes even if its hidden, just need find the thread.

Oliver, was you thread that kept me pushing in the endless days moving pivot points.

Should be a nice looking bike – very impressive.

Oliver – how is the bike holding up? And more importantly what is next?….

So what frame have you taken your inspiration from?

this is brilliant

So what frame have you taken your inspiration from?

Hmmm.. probably think of a long travel xxl sultan, covert, prime and enduro 29 using counter rotating pivots, that can also fit a bottel in.

I’ve taken geometry inspiration rather than asthetic, the look evolved over time. Mainly because i can do swoopy tubes now. I’ll sit down one day and post how i got to the final design.

Fantastic…this is what made Britain Great….man in shed invents moon on a stick…keep it up and keep us updated.

Top work OP!

Keep considering (and not undertaking) a similar project.

Did you jump straight into fabing up a bouncer or try any other smaller scale projects first?

Why the kevlar/carbon rather than carbon (uni or otherwise)?

Edit! Amazing job by the way. I never made anything bigger than carbon RC gliders.

Way back in the early 2000’s I found the link below, and I was inspired to have a go myself, so all power to the OP. Everyone else, it’s not hard. Have a go.

Damon Rinard’s Carbon Frame

richmars- yes read that and just about any home carbon laying thread/ blog site i could find.

eddie- looking in to it kevlar is stronger and lighter than carbon but not as stiff, using kevlar should give some resistance to sudden snapping (that’s my theory), plus hybrid cloth is a bit cheaper. Having said that it is more difficult to cut and i’ve had to grind some scissors to an angle that will easily cut the cloth plus you cant really sand it.

Cookea- jumped straight in, I’ve practiced on a couple of head tubes. I’ll cover that in detail when i move to the front triangle.

Like i’ve said think of it as expensive paper mache.

So getting the swing arm nearly finished.

First layer of carbon on, this was two sessions to cover everything.

To give some support and help the carbon tape form i used some uni directional tape where the seat stays meet the chain stays and on the joining tube from the pivot.

Final layer then

Cloth all cut out ready

As i lay the fiber up i use release cloth wrapped around the tubes to make sure it forms around the tubes and try to minimize wrinkles.

Once covered in release cloth it’s then covered in breather cloth to soak up any resin.

This is then put in a vacuum bag to compress the layers and remove and excess resin.

To layup the swing arm this way takes about 4-6 hrs not including curing time. I normally leave it connected to the vacuum for a few hours then next to a radiator for two days. Probably takes 3-4 days to fully cure the resin

Bigdean,
Looking good.
Always a trade off between inside out and outside in.
Making a mould means the visible surface is smoother, but making a mould is a pain. Wrapping a former is easier but the outer surface isn’t as well controlled. But you know that!

Looks brilliant as a project!!!

So a bit of progress today but very slow..

Today’s task was to get the head tube and another pivot made along with sticking the top tube and down tube together.

The head tube mandrel was on of the first things i made, a decent chunk of stainless off ebay with a quick redesign ended up with this.

Preping and polishing on the high tech aldi special polishing machine.

To fill the gaps between the parts Plasticine and removed the excess,

The was the treated to some flash tape and pva release agent.

The pivot mandrel is just aluminum again polished and coated with release agent.

All layed up and in the vacuum bag.

Just waiting for the epoxy to go off now.

So the top and down tubes these have been printed off over the past few weekends.

All the parts of the down tube (minus bb area) cleaned and trimmed ready.

The top tube parts all ready to go.

These have literally had a few dabs of epoxy to hold them together, bit of sellotaping to get everything square and left to dry.

That was just about 6 hours in the garage today, don’t feel got much done for so much time in the garage.

epic!

what have you made before?

When are you taking orders? Seriously impressive, top Bollocks.

This is an inspiring thread. Well done, can’t wait to see it built.