# Build Thread: Another FS Frame



## adarn (Aug 11, 2009)

Hey MTBR,

So I am posting this in hopes that it will encourage me to have this frame done by the end of the summer. Also I figure this is kinda different and some people might enjoy coming along for the ride.

Anyhow, I built a single pivot frame out of steel almost 2 years ago and it was pretty sketchy. It was fun and I put wayyy more miles on it than I expected it to last, but last it did not. Also, it rode like a single pivot.

So time for a new FS. Here's what I want:
-Slack, playful, aggressive... fun and stuff
-145mm rear travel, 150 front
-Aluminum frame
-Fancy linkage (I went with VPP)
-six hundred and fifty b's of wheel

Uhm yep, that's about it.

So to start I used "Linkage" and got the dimensions I wanted:








And Bike CAD'd up the front geo








And the hard part... working on the actual thing...







I think I am going to switch to a bent DT for crown clearance...

So the plan is to Get the whole thing modeled up, machine the pivots and everything (I conveniently work in a CNC shop) and then Weld! And then wait 6 months for the Al to normalize....

But yeah. Should be a fun project. I actually have most of the materials on hand and if the skiing keeps being as bad as it is in Bozeman I might be getting it done sooner than I thought!


----------



## shirk (Mar 24, 2004)

Nice. Looking forward to watching this.


----------



## Golem builder (Jul 31, 2009)

You can buy linkages from the santa cruz website you know. It can make things easier.


----------



## adarn (Aug 11, 2009)

Golem builder said:


> You can buy linkages from the santa cruz website you know. It can make things easier.


Tempting!


----------



## Drew Diller (Jan 4, 2010)

adarn said:


> And the hard part... working on the actual thing...


Haha, true.

Nice to know you work in a CNC shop. I have my own CNC now, but it has some limitations for sure.

Subscribed!


----------



## Golem builder (Jul 31, 2009)

If I build a DS someday I'll take that route. Proven system and honestly easier to build than a 4 bar.


----------



## adarn (Aug 11, 2009)

*yeahhhh...*

Sooooo I decide to be all gung ho about making everything from scratch and what should fall into my lap but this....








Because this will cut the project time by about 85% I guess I'm going to make a 4" travel 29er. Oh well. Should be fun and hold me over until I get excited enough actually make one from sctatch

I think I'm going to do a steel front triangle... SklarbonFiber style.


----------



## ktm520 (Apr 21, 2004)

Sell out! No seriously, it should be good practice to start with a manufactured rear end the first time around. You can still do a lot with 4" coupled with a 5" fork and a slack/long front end.



adarn said:


> Anyhow, I built a single pivot frame out of steel almost 2 years ago and it was pretty sketchy. It was fun and I put wayyy more miles on it than I expected it to last, but last it did not. Also, it rode like a single pivot.


I vaguely remember that single pivot you made. Do you recall what kind of leverage/anti-squat curve you used? Was the shock tune correct? They get bashed on alot, but if designed right they can work really well. In fact the next bike I build for myself is going to be a 5"ish single pivot. I would prefer a dual link, but that's not something I even remotely want to tackle right now.


----------



## adarn (Aug 11, 2009)

Haha, I am!
Yeah, 4" is pretty good and I will be able to just take all of the parts off of my current bike which is a 29" hardtail with a 120 fork. Maybe I'll upgrade to a 130 fork in the future, I'll probably design it around that.

Honestly I'm not doing this just for the fun of building it - I'm doing it because I want a FS bike. A lot of guys build with ventana rear ends and are happy to call those bikes their own. This is wayyyy better and a lot cooler IMO.

Should be fun!


----------



## ktm520 (Apr 21, 2004)

adarn said:


> Honestly I'm not doing this just for the fun of building it - I'm doing it because I want a FS bike. A lot of guys build with ventana rear ends and are happy to call those bikes their own. This is wayyyy better and a lot cooler IMO.
> 
> Should be fun!


I'm with you there. I want fs to ride that I designed/built. If I'm happy with it, goodbye to production frames all together for me. I like rigid hardtails, but hardtails with a squishy fork, no thanks. I've got to have at least a 5" fs bike around to ride. I'd rather build a monopivot than a linkage driven single (Vetanna, faux bar, whatever you want to call it), mostly because it's all my design, and secondly because there isn't much advantage to the faux bar over a mono.

I'm really digging all this fs talk.


----------



## shirk (Mar 24, 2004)

ktm520 said:


> I'm with you there. I want fs to ride that I designed/built. If I'm happy with it, goodbye to production frames all together for me. I like rigid hardtails, but hardtails with a squishy fork, no thanks. I've got to have at least a 5" fs bike around to ride. I'd rather build a monopivot than a linkage driven single (Vetanna, faux bar, whatever you want to call it), mostly because it's all my design, and secondly because there isn't much advantage to the faux bar over a mono.
> 
> I'm really digging all this fs talk.


Do it.

I am working on the drawings for my #2 FS.

The leverage ratio on mine feels really good on trails. My shock is slightly under damped but it doesn't feel wallowy or bottom out easy.

Tricky part on my next design is to still use my 44mm headset for main pivot and move from an elevated chainstay to drop chainstay below the chain. With the 44mm you need to be able to remove the rear swingarm completely to unseat the split compression rings. The not a tone of room for the pinch clamps and other tubes to all join at the axle and still look clean.


----------



## ktm520 (Apr 21, 2004)

Oh, I am. Already started on the design. It will be awhile before I begin fab though.


----------



## adarn (Aug 11, 2009)

ktm520 said:


> I'm with you there. I want fs to ride that I designed/built. If I'm happy with it, goodbye to production frames all together for me. I like rigid hardtails, but hardtails with a squishy fork, no thanks.


Yeah, I'm kind of the same way. Working my way towards the dream stable... Should have a rigid 29+ SS, this guy and then I think I'll build a long travel 27.5 hardtail just to see what the hype is about. Rigid bikes are a lot of fun, but not the kind of fun that a FS is.

Oh and I forgot to answer your question. That single pivot was mostly a straight ripoff of the Heckler... I think I have the curves somewhere....


----------



## Evil4bc (Apr 13, 2004)

adarn said:


> Sooooo I decide to be all gung ho about making everything from scratch and what should fall into my lap but this....
> View attachment 965101


Looks like the good starting form to model a jig from .


----------



## lloyddobler72 (Feb 19, 2015)

Anyone know where I might be able to find a seatstay for a 1998 Specialized Ground Control FSR Comp?


----------



## andrewkissam (Jan 3, 2014)

Just subscribed to this thread. As an engineering student I find this very interesting. Keep us updated!


----------



## adarn (Aug 11, 2009)

Not the update you were hoping for... I got distracted and built myself another bike first... Whoops.

29+ by SklarBikes, on Flickr

But I DID manage to get the shock ordered, I have all the parts ready (on my current bike), and I've figured out how I'm going to mount the pivot and shock.

I'm still in school, and spring break is over on Monday, so I bet I won't get this done until summer. I'll probably get some pivoty stuff machined before then. So that's next... Until then...


----------



## andrewkissam (Jan 3, 2014)

If you don't mind me asking, where do you go to school and what are you majoring in? (that is unless you're a graduate student)


----------



## TrailMaker (Sep 16, 2007)

Nice looking +;

Why the thumbs down title rating, by the way?


----------



## adarn (Aug 11, 2009)

TrailMaker said:


> Nice looking +;
> 
> Why the thumbs down title rating, by the way?


Hey Thanks. I'm not sure why that is there. It just showed up when I posted this. Figured MTBR has something against me...


----------



## adarn (Aug 11, 2009)

andrewkissam said:


> If you don't mind me asking, where do you go to school and what are you majoring in? (that is unless you're a graduate student)


I go to Montana State for MET... one.. more.. semester......


----------



## adarn (Aug 11, 2009)

*finally working on it again*

getting psyched!


----------



## ktm520 (Apr 21, 2004)

You sneaky son of a ....

Nice!

Starting my dually this weekend


----------



## Golem builder (Jul 31, 2009)

sweet!


----------



## todwil (Feb 1, 2007)

Very cool project!!!


----------



## LyNx (Oct 26, 2004)

Nice, I want to see the finished pics of this 29+, looks absolutely sweet, you were right to go with this first before the FS. Wish I had the skills to build my own rigid, as I'm looking for a 29+ now to replace my rigid Monkey, most likely will end up with a Krampus OPs.



adarn said:


> Not the update you were hoping for... I got distracted and built myself another bike first... Whoops.
> 
> 29+ by SklarBikes, on Flickr
> 
> ...


----------



## adarn (Aug 11, 2009)

*Machining parts...*

Making some pivots. My 1938 Southbend is a pretty solid little machine. Hoping to get this thing done tomorrow....

personal project by Adam Sklar, on Flickr


----------



## adarn (Aug 11, 2009)

*Yah!*

Freshly rattle canned...


----------



## ktm520 (Apr 21, 2004)

Tell us more about these big aluminum bushing you used on the upper rocker and fwd shock mount. I can't quite figure out what you did there? Form or function?


----------



## Golem builder (Jul 31, 2009)

Love the tubular shock mount under the TT.


----------



## Feldybikes (Feb 17, 2004)

Need. More. Detail. Pics.

Like NOW!!!


----------



## Chad_M (Jul 11, 2013)

Looks really good.


----------



## adarn (Aug 11, 2009)

Thought it would be cool. And it was easier with the tooling I have.


----------



## adarn (Aug 11, 2009)

*built up*








Gonna go for a test ride.... In Portland. haha.


----------



## Drew Diller (Jan 4, 2010)

I have two hands, here's two thumbs up. Well done.


----------



## ktm520 (Apr 21, 2004)

I love how the lack of a seat tube clamp makes the post look seamless with the tube. Crest rims?? Will those noodles hold up under you?


----------



## rob1035 (Apr 20, 2007)

Very cool! Can't wait to hear how it rides...


----------



## mtndude23 (Apr 18, 2012)

that looks great


----------



## Eric Malcolm (Dec 18, 2011)

Adam

A very impressive piece of work.

I understand that you made this out of Aluminium, so I am impressed with the detailing of the shock mounting as usually most frames that I see made of this material avoid such effort. This is the type of construction I like to do in steel as that is an asset that is usually reserved for steel. So I am impressed.

Eric


----------



## shirk (Mar 24, 2004)

Eric Malcolm said:


> I understand that you made this out of Aluminium


Pretty sure the front triangle is steel.


----------



## todwil (Feb 1, 2007)

:thumbsup::rockon: Adam great job!! Now we need a ride report and more pics......Please


----------



## adarn (Aug 11, 2009)

front triangle is steel.


----------



## adarn (Aug 11, 2009)

ktm520 said:


> I love how the lack of a seat tube clamp makes the post look seamless with the tube. Crest rims?? Will those noodles hold up under you?


you callin me fat?
Haha yeah. This is a total parts bin build. Can't believe these wheels are still kicking. They're from when I was still concerned about weight and I have ridden the hell out of them! the front rim is still stained from when I ran over a skunk! like... 2 years ago...


----------



## adarn (Aug 11, 2009)

Ride report:
Super fun!!!! I made the top tube too long but oh well. I'm going to try out a 35mm stem.

I am crazy impressed with how the VPP climbs.

Also if you want to feel fast, ride single speed hard for 5 months and then get some gears.


----------



## jgrano (Dec 5, 2011)

Damn that that thing is awesome.


----------

