[Closed] Homemade carbon full suspension frame build updates...

I like the croc skin look!

Not entirely sure what you mean by croc skin look?

but another small update from today (Number 8 ) - [url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/01/full-suspension-frame-part-8-back-few.html ]here[/url]

nice work, if you need any more bits i've got a couple of frames that are heading to the scrap man. mail me if you want them
cheers
paul

ok update number 9 - to me it's finally starting to look like a bike frame - although that could be the epoxy fumes!

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/01/full-suspension-frame-part-9-starting.html ]Here :roll:[/url]

You're mental.

Them epoxy fumes must be amazing 🙂

Love the madness of what your doing.

Max - #36er 😆

(for all those that don't get that - check out max's [url= http://maxengineeringdesign.blogspot.co.uk/ ]projects[/url] and his [url= http://singletrackmag.com/forum/topic/dual-disc-hub-anything-like-this-around ]dual disc hub[/url] plans)

Are you making integrated light mounts?

I assume you're only going to be riding that at night.

Give him chance to finish it before you judge it.

Once its cleaned up, sanded, lacquered etc it might be awesome

Everyone needs a hobby.

Personally, I've been enjoying reading about it for a while now. I'm looking forward to the next update

So update number 10 is here - [url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-part-10-swingarm.html ]CLICKY :D[/url]

Bigjohn - I wasn't planning on making integrated mounts 🙄 and the way I'm building this, the "make it look nice" part comes after I've done a bit of testing - as there is no point polishing/smoothing bits only to have to cut/redo it!

Looks good so far - are you fiberglassing the ali bits before wrapping with carbon?

Damascus, I've seen his homebrew hardtail. BigJohn has the right idea!

monkeyboyjc- yep, a thin wrap of fibreglass around aly bits under the carbon - which should hopefully stop galvanic corrosion (I think that's how you spell it)

Nathan - 😥

ok next update is here - I got quite a lot done today and it's really starting to look like a bike!

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/01/full-suspension-frame-part-11-nearly.html ]----------> Update 11 <---------[/url]

I wish I could make bikes all day 🙁

Also, there is so much foam, forgot if you melt it out or not, do you? Will it add a lot of weight? To save weight I think you should drill random holes in all of the tubes.

I weighed the foam for the front triangle before adding the carbon, it was 170g so I melted it out, but for the swingarm the foam weighed 21g and the chainstays it weighed 12g so I'll leave those in as not worth drilling holes to remove it!

As for my love of drillium, I think it would be to far to extend that to carbon!

Genius Max, what a great idea! Same for your 36er?

Everyone needs speed holes! Produces negative drag according to treks wind tunnel testing.

Finally got another update done - I made a bit of a major measurement mistake, making the chainstay length somewhere in the area of 465mm but now back on track (with more reasonable 430mm chainstays)

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-part-12-measure.html ]>>>>>>>>> PART 12 HERE <<<<<<<<[/url]

What is the approximate weight of the frame?

love it oliverracing,shed engineering is the future !

I'm aiming for a frame and shock weight of sub 2.5kg, 2.2kg is my target, but I know I'll have to redo the swingarm to reach that.

keef - I hope to have this built up singlespeed for ssuk2014 (with a tensions/locked out mech)

Ok - update 13 is now done - looks like the frame will be complete by the end of the week!

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-part-13.html ]--------> UPDATE 13 HERE <---------[/url]

If there was ever a reason for a bloody like button....!

Absolutely tremendous work.

Epic!!

Good work, really enjoying reading this thread.

I have a couple of questions;

How do you know how much carbon fibre to use? Have you done some computer simulations? Or do you have a lot of experience so are confident with making an educated guess?

And how did you decide the suspension pivot locations? Copied from a bike with suspension characteristics you like? or again some sort of computer sims, or ... something else ?

😯

jairaj - glad you're enjoying it! now to answer your questions;

I have researched various homemade bikes to see how many layers that each of them used, also sheldon browns site has a [url= http://www.sheldonbrown.com/rinard/carbon_fiber.htm ]carbon bike project[/url] on there which was useful to look at, as for computer simulations (FEA) I didn't do any and I don't have a huge amount of experience, so I'm just using my best judgement on where I think needs extra strength and where can do without.

For the suspension design I bought [url= http://www.bikechecker.com/ ]Linkage X3 software[/url] (about £15 if I remember rightly), it was well worth it as I have been able to calculate travel, leverage ratios and the overall side profile look of the bike. I have roughly copied a 2009 scott sparks geometry but have used elements of the rocky mount element from around that period too, I have also made a few modifications to suit the parts I have. I also used NX8.5 to do the final details in the design.

there is a little bit more info in the designing in [url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/01/project-2-in-pipelines-full-suspension.html ]part 1[/url] + [url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/01/project-2-part-2-more-designs-by-request.html ]2[/url]

I admire your balls 🙂 ( bike building ones that is ) !

Regarding how much carbon to use, it's easy, you just put way too much on. I don't think Oliver is trying to make the lightest frame available (but correct me if I'm wrong), just a frame that works. That's how I did mine. If you look at a 'real' frame, the wall thickness is maybe 1mm. My theory was make it 2mm and it should be strong enough, and I was right.

richmars - I am aiming for as light a possible but also want it to be strong enough for racing, but I'm aware for the Scott spark the frame and shock weights are about 1850g so I feel 2220-2500g is an ambitious but realistic target. I do plan on remaking the swingarm a bit lighter in the future to knock some weight off it.

How do you melt the foam out? With a heat gun, conducting rods or chemically? Can an idiot do this? I'm an idiot and I'd like to.

Really interesting work there mate, you speak in your blog of a hardtail, do you have a build thread for that too?
What sort of carbon/resin are you using? Is it PrePreg?

thestabilizer - I remove as much as I can but attaching a 400mm metal rod into a drill which removes 90% then a bit of acetone disolves the rest.

Chrishc777 - I have done a bit of a build blog for the hardtail ( can't seem to link but click 2013 on the right side of blog) but sadly I didn't take that many photos, hence why I'm doing so many this time! I use dry cloth with quite a slow set epoxy resin (20-30 hours)

Oliver,
Based on my huge experience of making carbon frames (!) I would say make the first one well over engineered. Ride it hard and see where it breaks. Then improve things on the second. I would say that the hard bit to get right is the metal to carbon interfaces. You need a mechanical joint (a feature in the Al) that the carbon can grip onto, not just the adhesive joint. But it looks good so far!

yep - that's how I've been working, my hardtail has held together well, apart from the bb debonding but that was due to an error when building it. I plan on testing it to destruction (or not) and if parts fail I'll beef up v2 and if not I'll lighten up v2!

For the alu-carbon interface, I am drilling holes in the surface to get a better grip, if this fails I'll use small mechanical fasteners with the join.

What sort of weight fabric is it? and what resin system?

Good work! How smooth do you expect the final finish to be?

chrishc777 - oops - I had edited the previous reply to add that but obviously missed the 15 minute cutoff, the majority of the fabric is about 300gm 1x1 weave - as I was donated a lot of this for a school project and I still have some left over. I also have some 650gm twill weave(also donated for the school project) which I use for making flat sheets and a small amount 165gm twill weave(yep you guessed it - donated too 😀 ) which I use for the smaller parts.

I use the Easy composites EL2 resin system - I have only got the slow hardener left so using that up but would probably buy the fast hardener next time.

Cheezpleez - I hope to get it to a reasonably smooth finish, but it will not be a factory quality finish as that would take days of sanding - just smooth enough to look finished and less of a work in progress.

thestabiliser - Member
How do you melt the foam out? With a heat gun, conducting rods or chemically? Can an idiot do this? I'm an idiot and I'd like to.

That's one of the funniest posts I've read in ages! I also am an idiot, but not enough of one to in any way delude myself that I'm in any way capable of doing what Olive has done. Great work, it looks fantastic. Seriously impressed 😯

Part 14 is now done! - the frame is pretty much finished now with just a few niggles to sort before I can test it! All I need to do is build it up and source a shock pump!

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-part-14-final.html ]-> --> ---> Part 14 <--- <-- <-[/url]

Are you going to actually risk riding it 🙂

I think the price of 'Green Electrical Tape PLC' shares will crash when the market learns your build is done 🙂

easygirl - yep and should be racing it hard!!! I hope to be testing it at afan a Easter weekend!

hairyscary - thanks for reminding me, I need to buy some more

Nice work Oliver - your Carbon builds are a damn sight faster than my brazed steel.

Does steel and carbon work any better than aluminium and carbon or does it just corrode and de-bond rather than electrolytic problems?

As the pivot is so close to the bb shell, you could just weld them together as a sub assembly with a little stub of joining tube before wrapping - the bigger odd shaped metal lump might stop either of them coming loose?

Nice chainrings! If I'd realised beforehand that they were designated for such an epic build I would have happily donated them to you 8) BIke looks great, and I admire you for doing something that is so far beyond my wit and limited wisdom it beggars belief.... as others have indicated previously, 'chapeau'.

mick_r -making the pivot and shell in one was one of the ideas I thought about, but I'm using an aluminium bb shell so welding to it would be tricky.

steel and carbon suffers the same issues as alu and carbon, but can also be combated with a later of fibreglass between the two.

As for the speed I'm working at, it's currently my uni holidays so I'm able to spend most of my time on it and I would like to be able to ride in at afan next weekend!

rexated - thanks, but you gave me a decent deal anyway. 🙂 I definitely think the hardest bit is starting, and working out where to start!

Update 15 is here - The frame is now functionally finished and ready for testing once the rest of the parts have arrived!!!!

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-part-15-its-done.html ]------->>>>>> Part 15 HERE <<<<<<--------[/url]

F****ng bonkers !!!!! Love it mate look forward to updates 😀

Looking at the build the only thing that confuses me is the linkage beneath the top tube. What is the purpose of having this so long?

I would have thought you would have wanted the seat stays and the shock to be more in line to get transfer of the forces in a more direct way.

kind of like this yeti -
[img] [/img]

[edit] not that I know any better, just curious [/edit]

Rusty Mac - By changing the linkage angle and length and the angle of the shock you change the leverage ratio and whether the leverage ratio increases or decreases with travel - looking at the yeti it will decrease making a more linear feel to the shock. I was aiming for an increasing spring rate, so it will feel less linear and not blow through its travel easily and should have better small bump sensitivity.

I do think it looks a little long, but it is only 2mm longer than the one I had designed and was free, half the weight and probably stronger, so I decided to use it. I also think the small triangle size and huge downtube make it look even longer too.

Also - the Rocky Mountain Element uses a similar suspension geometry to my bike, but even more non linear than mine - being a 29er is looks a little more in proportion though.
[img] ?itok=MkVHO22a[/img]

Seriously impressed with your efforts. Can't wait to hear a proper ride report.

Cool, cheers for the info, I know that the element was kind of your inspiration for the build.

Hope it all works out for you, it really is an epic build.

Things to lookout for that may help refine it or for v2, that I am sure you are aware of already. Shock tune and pivot bearings/bushes.

Cheezpleez - I hope to get a first ride report and hopefully some videos of the suspension in action up by mid week and if that goes well a report after 3 days riding at afan! 😯

Rusty Mac - I don't intend on making a V2 bike as such, but more replace/redesign swingarms/sections as needed/wanted - I may also end up making a range of linkages to be able to vary the travel/spring rate. I have also looked at the shock tune for the current shock (rp23) and I guess it wont be optimal for the frame, but I intend to replace it with a properly tuned monarch xx when I have the money, as for the bearings - they are all standard sizes and easily replaceable, I also have about 20 spares of the nylon bushes I have used in the rear pivot so I'm not too fussed if they only last a couple of months!

Hey nice ideas, i am well impressed by it. looking forwards to further updates.

Oli you mad bastard! I definitely want to take her for a cheeky spin when you've given her the "almost definitely won't crack and maim" test. I might even let you have a spin on the Ritchey 😛

Again, just brilliant.

First ride report now done (or more first 2 rides) - all seems to be going well and it rides beautifully

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-first-ride-report.html ]---------> RIDE REPORT HERE <--------[/url]

I don't think this thread had anywhere near enough comments, considering there's a 500 post epic about sod all over there >>

I'm in genuine awe of the whole range of talents you've shown to get this to where it is and the fact you've ridden it now, without it disintegrating is simply a bonus.

Fine looking machine too! Please report back with the post-Afan review, and congrats again fella 😀 .

[img] [/img]

I'm really impressed by this. Would love to be able to do something similar. Please keep the updates coming on how well it performs in the longer term, and what you'd change with hindsight.
Could I suggest a 29er with a bottom bracket gearbox for the next build?

That bike is brilliant.
I want a go.

You've set me off. Why didn't you go down the 29er route? was thinking akin to the element but a bit like a 29er ASR 5. Say 110mm at the back and 120 at the front 69 head angle. Would this be more difficult to fit together than a 26 in terms of getting the tubes to go in the right places, clearances etc?

That's fantastic. It's giving me the urge to try a monocoque/e-stay carbon fatbike. That would be great in carbon.

hs125 - not a fan of gearbox bikes so I guess that rules that out!

matt_outandabout - if you ever see me about, feel free to say hi (and that you're from stw) as if I'm not in a rush you can have a spin!

thestabilizer - main reason for not going down the 29er route was lack of funds, I either built a frame or got new wheels! I have built it ready to be converted to 650b wheels should a cheap set come available. In the future I may buy an Element as my race bike and convert this to 140mm travel trail/enduro bike (already designed). As for that design I don't think packing would be too tricky, but for xc racing I like a really racey feel so think that would be overkill for xc but not enough for hard trail riding.

bedmaker - I do fancy something like those carbon estay scots from the 90s!

Afan weekend report now here - I would say it has been a successful weekend even though I broke the frame...

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-afan-report-and.html ]-----> AFAN CARNAGE REPORT HERE <-----[/url]

From those pics it looks as though you've got an absolute mile of seatpost and a massive seat-bars drop! I'm looking forward to seeing it/seeing if it can support my lardy arse. When you back btw?

Well, you've identified the first weak point - you can only improve on the design now 😀

Did you get any other riders noticing it was a home made bike?!

Nathan - Yep quite a seat-bars drop, but it is accentuated by the low top tube and I like the aggressive riding position! back in Lufbra saturday evening if your up for a ride sunday am?

Bearnecessities - yep - although I'm amazed the only part I didn't make was the first bit to break! And two people noticed it was homemade, but it got called an Ibis by someone!!!! ❓

Nice, it does have a touch of Ibis about it!

Look forward to seeing the carbon linkage 8)

Yea I should be around on sunday although it depends if Mike has a spare seat in his car for the race (I'm racing on the saturday as well so I might be broken)

Oliver,
In a way it's good it's failed, I'm sure you'll fix it and it will be stronger. On the linkage failure, what sort of Al did you use? I got some higher grade stiff (don't remember what number) which you may need. It's fairly thin where it failed. Anyway, gives me an excuse for a picture of one of my links, :

[img] [/img]

If you look at mine, I didn't machine a full hole for the bearing on the inside, which leaves a bit more metal, but you do need a spacer between the bearing and the swinging arm (only about 1mm thick.)

Richard

Oli.... You sir are a legend, the full sus is awesome,
How have I not seen this thread before! I love these self build projects.

Nathan - I'll post something up on the FB page nearer the time.

Richmars - It's the only part I didn't make myself - I nicked it off a broken yeti ASR - so would have assumed it would be strong enough, but I'm re-designing it to make it out of carbon - pics and mini build blog to follow when I've decided how I'm doing it! - I will admit I'm kind of glad it did fail, it had been bugging me slightly that I had made everything, and then used a pre-made linkage!

Oliver,
My design is not unlike that used on a Whyte. I think they do carbon links now, maybe have a look at how they do it.

Oliver I think I rode past you on Friday at Afan. I think it was the climb for Blue Scar, I was on a yellow Transition Bandit.

I didn't realise that was your bike until much later on in the ride, otherwise I would have stopped and had chat with you.

Ok - bike all fixed and carbon linkage done, not got any photos of doing it as phone memory card seems to have gone corrupt, but got a few of the finished article.

[url= http://bike-related-projects-and-antics.blogspot.co.uk/2014/04/full-suspension-frame-new-linkage.html ]>>>>>> HERE <<<<<
[/url]

[b]jairaj[/b] - if it was sometime around 9.30am-midday that is quite likely - I was dragging my family up there so was pootling up along side [s]my family[/s] some walkers 😉

[IMG] [/IMG]