Bike Check: Isak Leivsson's Homemade High Pivot DH Bike has 510mm Chainstays

Mar 10, 2021
by Daniel Sapp  


Isak Leivsson has a few experimental bike designs to his name. We saw his homemade DH bike that he raced last season under him at a number of races and originally a tester for Pole's out-there DH bike, he's quite familiar with geometries that push the boundaries of conventional thought.

His latest steel DH bike is an evolution of his other ideas which are mostly based on geometry. It's the third iteration of homemade bikes for Isak. The first bike was basically a geometry mule with a standard four-bar setup. The second iteration had a high pivot and really progressive leverage rate, as well as a different linkage design. He only rode that bike in a smaller race as the extremely progressive rate didn't turn out to be what he wanted and the linkage design inherently contributed to a lot of lateral flex which couldn't be accounted for without making the bike too heavy.

The third bike, pictured here, is a continuance of the other two, according to Isak. It encompasses his attempts at fixing whatever didn't work in the previous two. Having ridden the bike for three months, he's happy with it and the only thing he would currently consider changing is possibly building a lighter version with butted tubing but, it's not a huge concern at the moment.


The big changes from V1 to V2 were that the bike grew and took on 29" wheels. From V2 experiments, Isak went back to a single pivot design for V3 but he kept the high pivot. The leverage rate was also made more reasonable.


The reach of the bike is 470mm with a 644mm stack. The head angle is 63-degrees and the BB height is 350mm. Chainstays are a massive 510mm and the bike runs on 29" wheels front and rear. Altogether, the bike weighs in at 19kg or, a touch under 42lbs.


Most of the hardware for the bike came from the local hardware store but Isak made the main pivot bolts himself. He feels it's a large part of the process to accommodate for the things he has accessible to him. Fortunately, there are a few good suppliers like Bicycle Fabrication Supply, where he got the headtube, BB, dropouts, and other miscellaneous parts. When it comes to frame building, there aren't as many people who make full-suspension homemade bikes, so the hardware and parts for that purpose he often has to make for himself.



Designing and building the bike didn't take all that long with a few days of design and then a couple of weeks to build. Isak said that since it was a continuation of what he already liked, it was mostly just moving pivot points around in linkage to get it where he wanted. He says there are always more custom jigs and things to make than anticipated so it does take a little while. Without being able to dedicate full-time work to it, the project was spread out over a couple of months and he didn't build it until his Christmas break.


What does the bike like to do best? Speed. What doesn't it do best? Manuals and playfulness. Isak says that those 510mm chainstays don't play.

As far as other set-up goes, he's running a 0mm stem and taller bars to make his riding position more upright and central on the bike. Also, he initially assumed he would need to make a chainguide for the idler, but so far he's not had any issues with the chain falling off.




The first version of Isak's bike. Things have progressed quite a bit since this iteration.





101 Comments

  • 104 1
 That is seriously cool. I hope the culture of hand-made frames keeps up, and the steel welder crowd keep embracing full suspension bikes, so parts are easier to come by. If you want to weld up your own gravel bike you can buy everything you need off the shelf. Now I want to take a frame builder class!
  • 30 1
 Only thing he needs to make this bike perfectly 2002 is a set of chromoly polished Profile Racing cranks, chainring & titanium axle.

Bad arse!!!
  • 16 1
 Check out Marino Bikes from Peru, he make full sus custom frames for an afordable price.
  • 4 0
 @thelittle: $250 to start for custom HT is seriously inexpensive. Nice!
  • 6 0
 @sngltrkmnd: just don't look at the wait times, and communication isn't a strong point..
  • 7 0
 @lyalltheweebeastie: welcome to handmade stuff!!!
  • 2 0
 @thelittle: are those prices for real?
  • 25 0
 I got one of those leftover Sick bikes from Marino and it's been great - well built etc. Agree the communication is a little difficult but I've been married 2x so nothing I haven't lived through before.
  • 3 0
 @thelittle: Yes, I've been following Marino for a while. Seems pretty cool, but its not home made. I want more people creating their own bikes, increasing the demand for DIY tools, tooling, and parts. I also decided to go titanium over steel: www.pinkbike.com/photo/20259784
  • 3 0
 @gtill9000: Ha! that comment made me laugh/cough on a sip of beer, haha!
  • 1 0
 Here's one.
thebicycleacademy.org

Tom Richey are wisit this place and show some move :-)

www.youtube.com/watch?v=Oz0RmLkZuvI
  • 1 0
 Neither is frame alignment @lyalltheweebeastie:
  • 1 0
 Can anyone guide me to a good website to buy headtubes, bottom brackets and pipe for building up a MTB?
  • 25 1
 This is what a proto should look like -- function over form, quick to make and evaluate. And easy to swap out linkage pieces to try different setups. Well done!
  • 22 1
 Maybe that's what production bikes should be like too. Easy to make, easy to assemble, easy to fix, easily adjustable geo. The industrial look can be polarizing, but I love the sturdy and simple look of it.
  • 3 0
 @kcy4130: I would argue that most production bikes actually are fairly easy to assemble, fix, and adjust (if the frame includes such adjustment).
  • 6 0
 @kcy4130: I really like the focus on adjustable geo right now from Specialized, Rocky Mtn, Canyon, YT, Guerrilla Gravity, and others. I love that I can adjust the GG Megatrail's reach pre-ride and switch between trail/gravity mode with 1 bolt. I'd love for GG to produce a full line of angle-change headset cups. The bike industry needs more tweakable bikes and to offer future-proof platforms.
Designing future-proof platforms is hard though - an engineer can't predict what standards and geo will be next. (but we all know the future is the Donut)
With a GG I'm much more likely to upgrade every couple years by buying a new set of stays and swap some parts to go with them than I am a whole bike.
  • 9 1
 @sino428: Internal cable routing disagrees.
  • 2 0
 @c-radicallis: Fair point.
  • 4 0
 @sino428: Yeah, c-rad is right about internal cable routing. But there's far more than that, brands put a lot of effort into aesthetics. Sometimes to the detriment of practicality. Cool looking bikes sell. They also sometimes prioritize light weight over function and repairability. Which some customers want I suppose. I mean most bikes aren't impractical garbage, I just wish more brands focused a little more on function than form. But I'm a mechanical engineer, so perhaps the functional, utilitarian looks appeal more to me than most.
  • 2 1
 @c-radicallis: Guided cable routing is the most convenient, unless you get brakes with the hoses pre-cut to the exact length you need.
  • 2 0
 @kcy4130: just get a banshee. they work , look good and are easy to work on. No bs there
  • 17 0
 PLEASE INVITE HIM ON THE PODCAST
  • 15 0
 Vid of Issac shredding Windrock on this bike:
m.youtube.com/watch?v=yNAuRCzc_cg
  • 11 0
 510mm chainstays! Now that's a man ahead of the curve. I bet this thing RIPS flat turns
  • 6 0
 Manny landing tho
  • 4 1
 Have you ridden a 510 chainstay bike? It's not that simple. Just because going from 435 to 450mm chainstays improves things, doesn't mean longer is always better. But I think it's awesome that he's trying this, you don't know what the sweet spot is till you've gone past it, right?
  • 9 0
 Seeing a bike with 510 mm chainstays that people think are cool gave me flashbacks to 18 years ago, when people argued with me for insisting that 420 mm chainstays were too short for World Cup DH racing.

m.pinkbike.com/news/Finals-Results-Val-di-Sole-World-Cup-2013.html
  • 3 0
 *13 years ago, not 18 lol. Gwin was probably racing bmx or motocross 18 years ago.
  • 1 0
 @kcy4130: the front center is really long on that bike, so obviously the chainstays need to grow too to keep the balance good.
This bike might be similarly balanced to a more normal bike with a 450 chainstay
  • 5 0
 @NicoOfner: The front center is long? Not really, 470mm reach w/ 63 deg HTA, that might even be a little short for a guy his height compared to most modern dh bikes.
  • 2 0
 It's important to bear in mind that Isak is really tall.
  • 7 0
 @Protour: I think "people argued with me" is a bit of a one sided euphemism. Given that some time has past now @Protour, can we not agree that regardless of the message you had, some of the ways you went about promoting that led to some justified infamy and dislike? That Demo just seemed to make you so damn mad haha.
  • 1 0
 @kcy4130: Yeah you got a point, but I also don't believe official geometry numbers anymore. For example my Commencal Supreme 29/27 is 1cm shorter in reach/front center than it should be. Only has got a 1310mm wheelbase instead of 1320mm. Cainstay and headangle are correct.

So it's always hard to compare. His bike might be actually measured correctly. For sure doesn't look small when he's riding.
  • 1 0
 @kcy4130: and I think the chainstay fits the bike pretty well.
When I was a little smaller I had a NS Fuzz, which had a 440mm reach and a 447mm chainstay.....the cornering was really good
  • 4 1
 @snl1200: It didn't make me mad, it just had terrible geometry and I called it out. In other articles people agreed with me..

m.pinkbike.com/news/aaron-gwins-troy-brosnan-specialized-demo-prototype.html

then later that season Specialized agreed with me and changed the Demo...

m.pinkbike.com/news/Aaron-Gwin-Prototype-Demo-Race-Bike-Andorra-World-Cup.html

Then the same thing happened all over again with their stupid eccentric low pivot design on the Demo years later.

m.pinkbike.com/u/mikekazimer/blog/first-ride-2020-specialized-demo-29.html

All good fun, but I don't miss debating @Wakidesigns because whereas I was stubborn, he was stubborn and clueless.
  • 4 0
 @Protour: hello protour good to see you.
  • 1 0
 @Protour: For sure- it sounds like you had some fair points. I think as a bystander though I remember seeing your name on every post related to anything a Specialized rider or Specialized bike did and thinking "Oh boy. Here we go again..." and I actually agreed with you on some of your thoughts on it. That was just my recollection and I know you likely didn't actually comment on every post but when you did you came in hot! I'm glad modern geometry has you feeling a bit vindicated on that one.
  • 5 0
 @Protour:

The biggest realization for me that bike industry has a complete lack of engineering knowledge is when Santa Cruz said that they had trouble making a 29er DH bike for Greg Minnar and it took them a long time to figure it out.
  • 1 0
 @Protour: I've been riding my gambler in short CS setting for years, this summer I've finally tried how does the long setting (+10mm CS) feel and my first thought after a couple of turns was: "Why on earth haven't I done that before!!!!" Bike simpy felt more balanced and I knew immediately I'm not going back! Btw, good to see you back!
  • 2 0
 Protour is back everyone. 2021 is indeed better than 2020.
  • 1 0
 @kcy4130: they work for some people.Gee and Fabien Barell used to have custom super long back ends on their bikes.

Still this is 510 on a high pivot so its more like 520-525 on regular bikes so its crazy
  • 2 0
 @NicoOfner: thats just commencal geo. Their numbers were always wrong. Even 10+ years ago
  • 1 0
 @snl1200: people on pb like group think tho. I supported him on cs but I also remember being laughed at for being one of the early wide bars guys and then say wide is good but not 780-800 for a regular dude, especially with growing reach
  • 1 0
 @phops: you mean the company who came up with "s shaped wheelpath" and that idiotic leverage ratios their bikes had for ages had bad engineers? Wink
  • 1 0
 @spaced: don't know. My 2019 Supreme was correct, 2021 completely wrong.
  • 3 0
 @NicoOfner: Commençal have a serious problem with their geo charts (or with their QC requirements... just sayin') for a long time... On my Transition, Privateer, Giant, I had at maximum 2 or 3mm of difference (what is the uncertainity of the measure...), when on the two Commençal I had absolutely nothing was what was writtent on their charts.
  • 1 0
 @spaced: Haha- for sure! The Groupthink is a huge thing mixed with "anonymous outrage culture" where you both have polarized opinions and a forum that supports "outrage" and intensified emotional responses. We either have to hate something or love it and those are what churn the click machine!
  • 12 0
 Don't get any funny ideas pinkbike
  • 10 0
 now that diserves a Monster T up front to balance things...
  • 1 0
 to make it heavy for no reason
  • 8 0
 Those top pulleys everyone loves this year need a chainguide. BMW lessons from 2001, trust me.
  • 5 1
 Yeap, see balfa bb7.. the first and best high single pivot to date.
  • 4 0
 That was before clutch derailleurs and narrow-wide chainrings. They did say in the article that he thought he'd need a guide up there but hasn't had any issues yet, so he hasn't bothered to add one.
  • 1 0
 @srjacobs: I was part of the BMW r&d testing that made the guide required for getting rowdy. The clutch and narrow teeth should help but it always fails at the worst moment from my experience.
  • 6 0
 what projects have you been doing this pandemic?

me: attempted to bake cookies

isak: build a bike from scratch

what a show off ... j/k
  • 5 1
 I actually like the shorter chainstays because it makes a bike feel more playful and makes getting around corners easier. A longer chainstay communicates to me more stability but you compromise with nimbleness. Thoughts?
  • 6 2
 To me a balanced bike turns easier regardless of wheelbase.
  • 3 2
 Equal length reach and chain stays corner far and above better than a bike with short chain stays unless you are going incredibly slow.
  • 2 0
 short chainstays = more playful, no doubt ! BUT it doesn't corner better than longer chainstays. For me short chainstays was the best, then I had long(er) chainstays (440mm instead 425mm) for the same reach and... and it's sooo better for cornering !
  • 2 0
 So cool! Love that he has made three versions so far. I’d love to try any of them and applaud him for thinking outside the box and then actually making it! Can’t wait to see what version 4 ends up like
  • 5 0
 i bet it´s out of stock too!!!
  • 3 0
 The bike is cool, but what I really want to see are the jigs he rigged up to build this. @danielsapp Do you have any pictures of the jigs Isak built to construct the frame?
  • 2 0
 If only Brooklyn Machine Works had worked with Ti instead of steel we would have been here 10-15 years ago. Seriously cool project though.
  • 2 0
 The new one doesn't have that cut/welded kink in the downtube... Looks amazing btw.
  • 1 0
 Kind of looks like the back wheel wants to overtake the front one!
www.vitalmtb.com/videos/features/ISAK-LEIVSSON-Vital-RAW-on-his-Handmade-DH-BIKE,38717/sspomer,2
  • 1 0
 Isak's bike is one "Long,Little Dogie". Git along. Yee Hah.....
Seriously, though. I hope that linkage hardware holds up....I LIKE the "local hardware store" sourcing.
  • 3 0
 Now he has a mx bike
  • 2 0
 I like how the fork stanchions are thiccker than the frame tubes
  • 2 1
 Man, next level DIY. Bad-azz. Isn't he like 6'2 though? How does he ride a 470 reach with 0mm stem? Must be cramped!
  • 10 1
 thats what the tall stack height and riser bars are for. I like this return to fitting styles from 2009. DH bikes don't need longer reaches, they need taller stack heights.
  • 4 0
 I guess it has something to do with the long chainstays. Put a longer stem, and probably the front end would get too much weight on it, with the rear wheel too unloaded to track properly.
  • 2 0
 Any close-ups of the 0mm stem? Looks great overall.
  • 2 0
 Interestingly due to the handlebar sweep the hands position is quite far behind the rotation axis. I wonder how that rides. It reminds me of a wheelbarrow Big Grin
  • 3 0
 @IluvRIDING: or a dirt bike
  • 1 0
 Those chainstays are good for really high speed. I wonder what terrain he's riding.
  • 1 0
 he is riding steep fast terrain. windrock kicks ass
  • 1 0
 absolutely love these types of builds. It would be so satisfying to do and ride it!
  • 1 0
 His first prototype looks a bit like an old Kona Stab dee-lux. Which is to say very cool indeed.
  • 1 0
 Keep it up Isak! This bike is sick, and I'm stoked to see where and what becomes of it! Cheers from Canada, Eh! \m/
  • 2 0
 Pretty cool!
Is it named "the hand job "?
  • 2 0
 This looks mental, raw and like a science experiment - I want one!!!
  • 2 1
 Chainstays at bottom out must be 600mm
  • 1 0
 based on the axle path plot, cs length is +15mm at 30% sag, max is +23mm at 150mm of travel
  • 5 0
 @kbh: so just really really long, not really really really really long
  • 1 0
 @kbh: that’s just horizontal movement though, right? Factor in that the axle has also risen vertically and the effective distance from BB to axle, or CS length, would be massive, no?

The amount of change in length isn’t much different than other DH bikes, just that the starting point is much longer.
  • 2 0
 @mtallman2: you are right, the vertical part adds to it, from my estimate at full travel its roughly 560mm

I think the high pivots make CS's lengthen a quite a bit more than low pivot locations.
  • 1 0
 But how about those rotors?!
  • 1 0
 Bike looks fast and dangerous just sitting there. Very cool.
  • 1 0
 Always wanted a high pivot SUNDAY.
  • 1 0
 Next v4 shorter stays n time for THE MULLET
  • 1 0
 Isn't this man like 7 feet tall. There is no way a mullet would have a benefit for him. Unless your talking about putting a 32 inch front wheel on it.
  • 1 0
 @lowgear: thank you. My comment was meant to be hyperbolic. I still stand by the not needing a mullet part.
  • 1 0
 This bike has no rear-center. It's all rear.
  • 1 0
 This bike makes the wheels look so 26.
  • 1 0
 510mm stay on yer bike!
  • 1 0
 Rått!!
  • 4 7
 Looks like a Session.
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