# First full suspension...and it's made out of sticks.



## kosayno (Sep 7, 2006)

This one is three years late but I finally got it done. I had promised my sister-in-law I would build her a bamboo hardtail back in March 2011 but busy life just got in the way. At the time she was riding a full suspension but recently went back to hardtail when her fs failed. After having to endure her *****ing and moaning about the rough ride of the ht on almost every ride, her boyfriend and I decided we needed to get this one started...and in time for Christmas. He would supply the parts for the frame that I would build.

Being my first full suspension I just wanted to keep it simple by doing a elevated chain stay single pivot design. The hard part with was sourcing the dropouts. Couldn't find what I was looking for, I decided to make my own out of carbon fiber.

I used 4mm thick cf plates and sandwiched them together to make 8mm plates then cut them out with a jigsaw for the dropouts and the rocker arms.

The tabs for the dropouts and rocker arms were not not quite perfect but I had to make do because cf plates are not cheap.








For the pivot I used a head headtube with a Cane Creek headset.















Front triangle tacked up on the jig.








Wrapped the joint with cf and a little rough sanding. Headset installed to the pivot.















Rear triangle tacked up and istalled for alignment check. All ready for carbon fiber lugs around the joints.















Lugs done and sanded smooth.




































All ready for build.











































Final measurements: HT-69 deg, ST 74 deg, BB drop-70mm, CS length-17.5". 4.3" rear travel, 120mm fork. Frame weight- 8.1 lbs. Final weight was a hefty 31.8 lbs. Time of completion- a frustrating 3 months but lots of lessons learned. Needless to say I didn't get it done anywhere near Christmas.

No trail time yet but riding around the neighborhood and park the bike feels responsive and handles well. No noticeable flex from the rear yet. All said and done I feel pretty happy about the way the bike turned out.


----------



## Drew Diller (Jan 4, 2010)

Well -- you know what my reaction is gonna be.

F'n SWEET!!

Nice job man.


----------



## Flip D (Sep 16, 2005)

Sweet bike and very nice fork choice. I have few questions. 

Carbon wrapping the lugs and joints, are those CF sheets or tow thread? What epoxy did you use?

Are the aluminum tubes bonded? If so what did you use?

I've been thinking about doing a similar technique with a HT for about 2 years now and always like to see what other people are doing.


----------



## Eric Malcolm (Dec 18, 2011)

LIKE!!!!

Great to see these alternative builds. I really enjoy the colour variation that CF and the Bamboo gives.

Well Done.

Eric


----------



## todwil (Feb 1, 2007)

NICE bike!! Are your hands tired from all the weaving and sanding


----------



## TrailMaker (Sep 16, 2007)

Pretty dang cool!

Looks almost... normal! You could paint it and no one would even know! Now that you have your process all worked out, you can use some lightweight materials for your next build, to get the weight down.


----------



## kosayno (Sep 7, 2006)

Flip D said:


> Sweet bike and very nice fork choice. I have few questions.
> 
> Carbon wrapping the lugs and joints, are those CF sheets or tow thread? What epoxy did you use?
> 
> ...


I put a layer of 3k plain weave kevlar cloth over the joints before putting a few layers of 3k plain weave carbon cloth and then wrapped everything with 24k carbon tow. For epoxy I used West System 105 resin with 209 hardener.



todwil said:


> NICE bike!! Are your hands tired from all the weaving and sanding


 It's definitely a workout for the hands.


----------



## Funrover (Oct 4, 2006)

That is just awesome!! I love it, the name is great. Wonderful job!!


----------



## TrailMaker (Sep 16, 2007)

TrailMaker said:


> ... you can use some lightweight materials for your next build, to get the weight down.


Hey;

That may have seemed flippant, but it was really intended to be a sort of round-about question. The eye sees nothing that would necessarily account for it, so in your post build analysis, how do you think the weight got that high? It doesn't make any sense at all, given the spec.


----------



## LyNx (Oct 26, 2004)

That looks really sweet, must say, looks absolutely fantastic :thumbsup: 

As to you could paint it and no one would know it's bamboo and CF, but then what would be the point :skep: 

As to the weight, I figure a HT and headset used for the pivot would add about a 1/2 pound to the weight and then you probably over did the carbon wrap and a few other things, this being your first FS and not wanting anything to break. Can't blame you for the pivot, that should last a long time 

Me personally wants to know why so much BB drop? To me that's insane for the trails I ride, I'd have to be constantly just timing pedal strokes, not pedaling, just can't imagine a 11.7" unsagged BB height, with sag that down below 11.3".


----------



## kosayno (Sep 7, 2006)

TrailMaker said:


> Hey;
> 
> That may have seemed flippant, but it was really intended to be a sort of round-about question. The eye sees nothing that would necessarily account for it, so in your post build analysis, how do you think the weight got that high? It doesn't make any sense at all, given the spec.


I was kinda surprised myself that it weighed so much. Early in the build I was convinced the final weight was not going to exceed 7 lbs. I'm seeing many ways they bike ended up weighing so much. A little here and a little there added up quick ie the ht and headset for the pivots, all steel hardware(just look at the size of the hadware required for the rocker arm and shock bolts), over did the carbon fiber and too much epoxy in the bamboo tubes.


----------



## kosayno (Sep 7, 2006)

LyNx said:


> That looks really sweet, must say, looks absolutely fantastic :thumbsup:
> 
> As to you could paint it and no one would know it's bamboo and CF, but then what would be the point :skep:
> 
> ...


I think bamboo is beautiful and definitely don't want it to be mistaken for something else. However, I did try to use a black stain to darken it up but still show the beautiful grain of bamboo but it just did not want to soak up more stain than just a very light coat.

A lot of the trails we ride a rocky, steep, and have long climbs. Yes that bb is low, but I've ridden lower bb and I don't see it as a big deal over big rocks as long as you know how to time you pedal strokes. If you also didn't notice that it has such a steep st angle yet the ht angle is really slack. I built the bike for the conditions I explained about our trails here in Colorado. Slack ht and low bb for control and balance, steep st for those long extended climbs. At least that's how it should work in theory, will see how it really handles in practice once we get on the trails.


----------



## BungedUP (Aug 18, 2003)

That is a very clever use of available tools and materials to make a bike. I am impressed and inspired! 

Anything in particular that you learned that others could benefit from when doing something like this? Ways to minimize mess, process of wrapping/gluing, etc.?


----------



## kosayno (Sep 7, 2006)

BungedUP said:


> That is a very clever use of available tools and materials to make a bike. I am impressed and inspired!
> 
> Anything in particular that you learned that others could benefit from when doing something like this? Ways to minimize mess, process of wrapping/gluing, etc.?


My advice would be to only making hardtails. On a serious note, just keep everything covered in plastic, especially the bamboo tubes. If you want smooth, clean looking lugs, take it slow and practice lots of patience. Same goes if you want are vacuum bagging.

For wrapping the epoxy/carbon lugs, vacuum bagging is best, but it can also be a headache especially for bb and st junctions. I've just about given up vacuum bagging for these two areas because it's so hard getting a good seal and enough vacuum pressure. The worst is when you just wrapped the lugs with wet epoxy and carbon and you can't a good seal and have to revert back to the ol' electric tape method before the epoxy becomes dries. Vacuum bagging materials are not cheap either.

I've done enough frames now that I've got a good work flow, but it seems like there's always some unexpected issue that comes along and adds significant time for a whole build. If you want to build a bamboo there's lots of resources for ideas if you just google.


----------



## LyNx (Oct 26, 2004)

Where about in CO are you at? I've ridden in Ft. Collins and that area, Crosier Park, Crested Butte, Gunnison and can't think of one place I'd want a BB that low. Know how to time pedal strokes, but there's a point at which is goes from being part of riding to taking over your entire concentration and not being fun. When I was last up there the bike I was riding had a 12.25" BB un-sagged and could have been higher for sure.


----------



## kosayno (Sep 7, 2006)

LyNx said:


> Where about in CO are you at? I've ridden in Ft. Collins and that area, Crosier Park, Crested Butte, Gunnison and can't think of one place I'd want a BB that low. Know how to time pedal strokes, but there's a point at which is goes from being part of riding to taking over your entire concentration and not being fun. When I was last up there the bike I was riding had a 12.25" BB un-sagged and could have been higher for sure.


So then you know what our trails are like. I live in the Denver area but I ride all along the front range and also the western slope. My thinking is opposite of yours however. Places on the fr with big rocks like Dakota Ridge, Hall Ranch, Deer Creek, Golden Gate Canyon, Devil's Backbone for example, never left me wishing I had a higher bb. Then again, I'm told all the time by my bike mechanic friend that I'm always using the wrong bike for certain trails. Personally, I've never had issues but that's just me.


----------



## LyNx (Oct 26, 2004)

Yeah, fun and varied if you're willing to spend a hour or two driving around for it. Rode Hall Ranch, Golden Gate Canyon, 3 sisters, Aldefer, Devils Backbone, Blue Sky, Coyote, Lions Gulch and wouldn't say BB height was an issue, only one I'd say had enough rocky tech to make that a thought was the top of Coyote and Crosier. Curious what bike you're riding, rigid, HT or FS and what BB height was/is it?



kosayno said:


> So then you know what our trails are like. I live in the Denver area but I ride all along the front range and also the western slope. My thinking is opposite of yours however. Places on the fr with big rocks like Dakota Ridge, Hall Ranch, Deer Creek, Golden Gate Canyon, Devil's Backbone for example, never left me wishing I had a higher bb. Then again, I'm told all the time by my bike mechanic friend that I'm always using the wrong bike for certain trails. Personally, I've never had issues but that's just me.


----------



## kosayno (Sep 7, 2006)

LyNx said:


> Yeah, fun and varied if you're willing to spend a hour or two driving around for it. Rode Hall Ranch, Golden Gate Canyon, 3 sisters, Aldefer, Devils Backbone, Blue Sky, Coyote, Lions Gulch and wouldn't say BB height was an issue, only one I'd say had enough rocky tech to make that a thought was the top of Coyote and Crosier. Curious what bike you're riding, rigid, HT or FS and what BB height was/is it?


Currently I'm riding 29er hardtail with a 120mm fork and bb height is 12.25" unsagged. One of the best handling bikes I've owned was a Zion(Jenson housebrand) rigid ss with 425mm a/c. I never measured the bb height on it but I would estimate around 11.5" with those short fork legs. Head angle was 71 deg with a 80mm fork so I probably had it around 73 deg with the rigid setup. I rode that setup at all the trails you mentioned but except Crosier and loved the way it handled.


----------



## LyNx (Oct 26, 2004)

I asked specifically about what type of bike because BB height on a rigid compared to an FS is a whole lot different since the BB height on the rigid never changes, but the FS can and will by prob use as much as 50-60% travel in stuff you'd want to be pedaling through, which drops the BB relative. Yeah, I know those Zions, they were some smoking deals and everyone seemed to like them a lot. Personally I enjoy riding my rigid Monkey a lot as well, just since moving to slacker angles would like to get a longer rigid fork to slack it out a bit, BB height hasn't been a n issue either on that and it's someplace close to 12", but again, that doesn't change.



kosayno said:


> Currently I'm riding 29er hardtail with a 120mm fork and bb height is 12.25" unsagged. One of the best handling bikes I've owned was a Zion(Jenson housebrand) rigid ss with 425mm a/c. I never measured the bb height on it but I would estimate around 11.5" with those short fork legs. Head angle was 71 deg with a 80mm fork so I probably had it around 73 deg with the rigid setup. I rode that setup at all the trails you mentioned but except Crosier and loved the way it handled.


----------



## dbhammercycle (Nov 15, 2011)

Wow, really cool and very well done. Your attention to detail shows in this build. I came across an earlier post of your kid's bamboo bikes and sought out your build thread, but this tops what I was expecting. Awesome, simply awesome.


----------



## jgrano (Dec 5, 2011)

Awesome build man. Love seeing some FS bikes around here.


----------



## bmxconvert (May 17, 2006)

How did you go about choosing the placement for the rear pivot? In my experience, having such a high pivot on a single pivot or horst-link bike makes for large amounts of pedal feedback(cranks getting pulled in reverse during high speed compression) unless you have a hub with terribly slow engagement. I also find that such a high pivot causes the bike to feel as though the bottom bracket is rising during pedal strokes. 
Did you run any sort of calculator to determine your shock placement?

I'm assuming that your rear pivot is just a straight 1 1/8" tube with star-nuts pressed in to either end. Do you foresee any issues with the carbon wallowing out since there is no pinch bolt system to tighten it onto the pivot shaft? It looks like there is a 5mm headset spacer on either side of the swingarms carbon plates; does the pivot shaft pierce all the way through the plates and thus requiring the spacers on each end?

I've been in the industry for more 12 years now and after riding tons of all the top end bikes as well as having custom frames made I'm feeling like it's about time I put my years of welding/machining/mechanic experience to use and build my ideal bike. I'm certainly curious how you came to determine that the bike you built came to be or if it was a trial by fire type scenario. You've done some very clean work so I'm assuming there is reasoning behind it.


----------



## Chader09 (Aug 14, 2013)

bmxconvert said:


> How did you go about choosing the placement for the rear pivot? In my experience, having such a high pivot on a single pivot of *horst-link bike*..


Slight correction. There is nothing Horst link related about this design. It is a pure single pivot with a direct drive shock.

A Horst link is a totally different 4-bar link design. The Specialized FSR is the longest running example.


----------



## bmxconvert (May 17, 2006)

Chader, I believe you may have missed my point. I understand what a Horst Link is. I was saying that *both* single pivot *and* Horst Link bikes that have either the only or the main pivot significantly higher than the primarily used chainring (typically the middle ring) display the characteristics I described previously.
I know it's a single pivot (and not even a linkage driven single pivot, there is literally only 1 pivot). I was saying that two of the suspension designs that have been around for many many years now are known for the "lifting" sensation under hard pedaling as well as increased pedal feed-back through chain growth, and knowing that they are relatively well known traits in both I was simply trying to understand if he felt that square-edge bump compliance from the rearward wheel path out-weighed the characteristics or if he had some other reasoning.


----------



## Chader09 (Aug 14, 2013)

No, I got the point of your discussion and it is a good question. High pivots are less than ideal for many types of riding.

But you muddied the waters with your text.
Maybe it was a typo and should have read "single pivot *or *horst-link bike".

The "of" implied that they were connected in some way and was misleading.


----------



## bmxconvert (May 17, 2006)

Ah yes. Sorry. It was a typo. My fingers can't keep up with my brain.


----------

