Thanks so much! Confirms my suspicions that it is not in my discretionary frame building budget 
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Second shipment of 55 parts came from Rapiddirect. Incredible prices again, along with precise tolerances and the fitment of everything is per-fect.
I’ll make a trip today to our partners workshop who we have collaborated with for the duration of the project. Front triangle production starts soon. Hopefully we have some full frames ready to test in the next 30 days.
And of course I wouldn’t make a post without some shiny parts, enjoy!
The mainpivot axle and rear triangle bridges are 316L for longevity and strength. One could also use aluminum, titanium etc. but I chose to test this material this time as I’m not really worried about weight that much in prototyping.
We also came up with a fixture that centers the main pivot point and aligns the shock mount parallel to it. This way we don’t have to have external fixturing and jig pieces that inevitabily require more design practice and custom fixture plates to house all of this. Maybe for serial production it would be ideal to have a custom fixture set to ensure repeability, but prototyping needs to be fast and iterative.
Subscribe, like and hit the bell button (like a proper influencer would say)
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I decided to give these new high volume air shocks a try and sourced a vivid in 230x65mm size:
I really appreciate the fact that I can dial the sag fast in a new bike with air. I’m also prone to losing bodyweight in the summer, so I appreciate that I don’t have to swap out coils since I ride multiple bikes around the year. If someone has experience or setup tips for higher volume shocks, let me know.
There were some troubles fitting the pinion welding jig to our bb structure for assembly, but that is being sorted with some custom tooling. Everything else for now seemed to be feasible in real life as it was designed. This means that the welding/soldering of frames can start as soon as we get some schedules to match.
More pics soon.
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Frames are now being manufactured! Already so excited for the summer as I got to test out a pinion gearbox. I am really impressed with the tech and the transfer of weight from the wheel to the BB. It makes so much sense in every way, I don’t think I’m ever going back to a casette unless I choose to swap E-bikes before gearbox Eebs are relevant.
I also bought an action camera, the DJI osmo action 4 to film some footage about these bikes.
I’ll perhaps film some short clips today and practice editing. I’ve used capcut before but I heard it’s impossible to use nowadays with the watermarks etc. I downloaded davinci resolve.
Frame color still undecided. Leaning on white. Let me know which one would look cool if you have ideas.
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Thanks to Jukka from 4130.fi for his awesome fabrication skills and participation in the project. The first of the prototypes is ready and we are planning to assemble it tomorrow!
Pics soon 
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A little teaser. I’ll post some pics of the manufacturing process before the full reveal of the bike.
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Lets post manufacturing pics later
The first prototype is ready and i did manage to drive it around the block just to feel everything out.
First impressions are: The rear shock reacts to tuning really sensitively. It’s the first bike where tuning actually makes a noticeable difference for me.
As the suspension is linear, you can really feel where the rear wheel is at all times. With more progressive bikes you know the rear suspension is there but don’t really notice it that much as you sit deeper in the travel you get more firm response and dampening as you push your legs against the bike.
Rearward axle path is maybe noticeable? I think the way you can route the chain with the idler makes designing the bottom bracket area a lot easier. It would really be fun to test a normal single pivot and compare it to this.
The ~80% antisquat is noticeable, but not for disadvantage. When i come to think of it, you barely lose any efficiency and you have that 20% of cushion for those small rocks beneath you. Over 100% antisquat makes the pedaling super solid but you could also use the locking mech on the shock if you care to split hairs. Solid kinematics! If i could choose to pick 20% more antisquat i would have to really think of it.
Overall the geometry and high stack feels so natural. The chainstay grows to 460 at sag and high stack tends to set your center of gravty a bit back but i feel really centered on the bike with the lenghtening high pivot construction.
The chain is like from a motocross bike. Probably lasts forever. Pinion gearbox feels incredible. Taking the rear wheel off is so easy id say the process of servicing is really elegant.
Steel is indeed real. I had the belief that manufacturing a steel frame is a tolerance killing heat bending shit show. Really no issues in this one. Everything went on bullet straight without any filing or unnecessary hammering.
The rear is really light and the front is bottom heavy. I measured the bike at 17.8kg. Thats incredibly light if you consider taking off alot of unsprung weight and transfering it into the bb area. It makes so much sense to me, I would go the way to say that i’m never going back to derailleur mtb’s ever again. Ill probably have to purchase a mgu bike next, i’m so convinced about the technology. Shift grip doesn’t feel bad at all, but i am real curious about smart shift.
What else is there to say. I’m going to try to break it before i paint it so we can reinforce it if necessary. There is some flex on the frame. Previous frame was stiff. I like stiff, but i heard flex is not bad especially for a rookie like me.
The rear shock is impressive. I would recommend it to others!
Again huge thanks to Jukka at 4130.fi for taking the lead on manufacturing and supplying parts with unmatched hospitality.
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Few test runs at the local jump park and the bike is holding up great. The linear suspension platform feels great and more sensitive than anything ive tried before. The bike uses the whole travel, thats for sure. Perhaps 10-15% more progression would be ideal between sensitivity and real hard hits and thats then at minimum a 4bar setup. Id be keen on building a bike that has 10-25% progression area, so i could test out what is the best compromise between everything.
The vivid handles things nicely and responds real nicely to tuning, like i mentioned before.
I installed some magura mt5 calipers since my riding has evolved over the xc calipers i had earlier. Shigura setup now with the deore pushers.
Couple of youngsters tested the bike out and complimented how good the geometry is. I love the high stack and ordered an ergotec high stack stem to see how far i can push it before it starts to be disadvantageous. I am simply copying all the geometry i can from motocross. They have done everything almost the same from day one and it keeps making more sense the more i adopt things. Mtb just evolves closer to mx every year and everyone claims to have invented something new, expect its been made 50 years ago.
Im thinking of powdercoating the bike yellow and i made one render with AI. Heres some pics. Please let me know what you think and see you on the trails
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Regarding paint job, I did some renders among other things:
I’ve been modeling a high stack cnc stem and sent it for Rapiddirects Quotation. The preliminary pricing looks ok for a batch of 5 stems. This one has 20mm reach and 60mm stack from the bottom of the stem. This would equal around +40mm stack compared to a “normal” stem.
Fun to have these floating around a virtual background, it gives a nice sense of what the final product could be.
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Hi Tommy,
I really liked the white version of that main frame. White is a great color for decals!
That stem looks cool. I think 20mm reach is a good spot to start with. The Ergotec is also cool but at 40mm reach a little to long to make a big difference over a normal stem with high rise bars. Is that steerer clamping asymetric?
-Thom
Hello!
The steering clamp is asymmetric for little aesthetic difference. The main idea here is to raise the stack, not so much to worry about the reach. 20mm reach was easy enough to model, and I had one version with 0mm reach.
White was my first intuition for the frame color. Need to think this one through..
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I welded a stem with 4mm reach (8mm with 1" clamp and excentric cups) and 65mm rise about 3 years ago. Since then it´s on my freeride bike meanwhile with a 70mm/12° Ergotec bar. It feels totally natural with a long rear-center.
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I promised to post some pictures of the manufacturing process so here are some for those who are interested in such processes..
Satisfying work.
I haven’t yet decided on the color of the frame. I’d like to have a signature color scheme where people can immediately recognize it as the Kova brands color.
White is still heavily something I’m considering as not too many bikes use it and it looks clean when kept nice and also you can measure wear from it. Also fading more paint is quite easy if ever necessary.
We have also started mapping out some development ideas to have even more refined frames. Main areas to improve are the pinion mount area in terms of adding stiffnes and ease of manufacturing/assembly and secondly reducing mass from the rear. The single pivot platform is really nice for enduro and traction, and could be tweaked from 4% progression to 10% to achieve some versatility (for dh use). I’ts quite a fine balance between versatility, performance and costs in framebuilding that I’ve noticed.
Lot’s of more interesting things coming and I shall keep posting.
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Ergotec high stack stem installed and tested.
My thoughts on the benefits:
- I had to lower the pressure from the front to balance out the suspension since this stem moves your balance point backward. Lowering the pressure made the front act just a tiny bit more linear and sensitive (this is a bonus in air shocks)
- My shoulder and back didn’t hurt and it was like driving a scooter; relaxed and comfy
- Since my body was more straight, my eyes pointed naturally more forward towards the trail. I have a tendency to stare at the front wheel when I don’t focus
- Feels like it’s impossible to go over the bar and I don’t need to use my chest and hands to keep me away from the bar at any dynamic riding moment
- Easier to follow the principle of ”heavy legs, light arms” as your CoG is almost always on top of the bottom bracket
- Lifting the front is somehow easier as you already have less weight on the front and can just lean back a bit. Reduces the amount of pulling you need to do.
And also my thoughts on the negatives:
- Feels like the rear suspension is doing a lot more work than the front, which makes the front and rear feel out of sync. I think it can be resolved by softening the front even further
- The bike could now be longer in reach as the effective reach is shorter with the higher stem. The bike feels about 5-10mm shorter now and to balance it, the bike would need more reach to begin with.
- Last negative is that I have to sell my old stems as I don’t think I’m going back to lower stack
I haven’t pulled the trigger on procuring those custom cnc stems as the Ergotec is 50€ and custom costs a lot more. Maybe I’ll run the ergotec until I know for certain what works.
Until next time.
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I hope Ergotec will make a shorter version of that stem. Their produts are great. Two rides ago I changed my Ergotec 70mm riser bars to their 100mm version on my short length-high rise DIY stem and it’s great. I can lift the front so much easier and still have plenty of grip at the front due to my 475mm chain stays. I also lowered the pressure in my forks by 10PSI.
Great to see you also experimenting with geo and cockpit setup.
-Thom
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