[27.5 UPDATE] Prototype Enduro EN01

[troyo]

Update @ post #17


Hi guys! You may be not familiar with my work so check out my handmade frame first:
DH01

Season is over, DH01 came out really awesome, time for an Enduro bike!

Spec:
26" wheels
6.3" travel (160 mm), high single pivot with 0.6" (15 mm) reward travel
Idler (not shown)
66* HA
73* STA
16.53" CS (420 mm)
13" BBH (330 mm)
46.65" WB in Large size (1185 mm)
18.11" Reach (460 mm)
44mm HT
142 x 12 mm axle, 73mm standard BB
Low Direct mount front der. (Sram S3 type/Shimano low DM)
Post mount 74mm DM rear caliper 180mm (not shown)
ISCG 05
7,5 lb~ without shock
Super strong True Temper Supertherm/OX Platinum steel tubing
7075 T651 linkage
BB main pivot 24 mm axle
8,5x2,5" shock (216x63mm)
accepts every seatpost size with a reducer.

Very supple begining of the stroke, progressive feel through the travel. Idler for nice anti-squat and lower pedal feedback.


Wanna built couple of frames for testing (Enduro and some DH but not DH01), and hopefully start a small company in the end of this year. Those are some rough models so some parts are missing, sorry for that. Any thoughts, sugestions or ideas? I will be really grateful for Your feedback!

 

[Ivan]

Do you think the swingarm(s) will be stiff enough?

 

[billymtb]

This will have mad torsional and lateral flex in the rear end. But pretty impressed how you come up with a design from nothing.

 

[MARKL]

Looks good, great effort. I think it will need some triangulation in the rear end. For the Enduro bike why not go 27.5?

 

[No Skid Marks]

Great looking design, but yeah will be too flexy and I would go 27" wheels too. I'd probably up the BB height a touch too. On the money with the short stays but. 27" will need a whole rethink though. Aluminum swing arm could b made stiffer but still to flexy and would fatigue. Or carbon if you have the skills, but again, solving a problem that doesn't need to exist.
Have a look at the I-track designs/concept, pretty cool way to dial in anti squat.
whatever you do, I look forward to seeing it made.

 

[troyo]

Do you think the swingarm(s) will be stiff enough?

This will have mad torsional and lateral flex in the rear end. But pretty impressed how you come up with a design from nothing.

Thank You for Your feedback! You have to remember that any steel is around 3x more stiff than even 7xxx grade aluminium. Those plates in CS are 5mm thick so an aluminium equivalent would be made from 15mm thick plate. Do not forget about 24mm main pivot axle and 12mm wheel axle. Haven't done FEA work to the rear triangle yet, but it if any flex/twisting will occur it will be on the tubing. Those are 22mm x 1,25mm tubes (really really stiff stuff), if FEA will show some problems i will try to do it with 2x 19x0.9 tubing (on drive side). It will be quite hard because of an idler placement/chainline issues.

Looks good, great effort. I think it will need some triangulation in the rear end. For the Enduro bike why not go 27.5?

Thanks Markl! 1st thing is, that I have never ridden 650b bike so it would be hard for me to design one. 2nd thing is that using my knowlage and experience from DH01 project I really doubt that 27,5" wheel will improve that much (not saying it won't). EN01 is designed in very similar manner (suspension-wise, except Virtual vs Single pivot concept and some modifications for an air sprung shock) to the DH01 which blows anything I have ridden so far out of the water (demos , 88, summums, scalps and many more). 3rd thing is that 27,5" in my country is not very popular yet and I'm trying to make an affordable frame, so at least 1st prototypes will me 26". For sure I will make some 27,5" frame in the future.

 

[Calvin27]

Don't worry about the rear end. Stick a 148+ thru axle at the rear and your bike will magically become 1000% stiffer!

Seriously though, you sir, have some mad skills! Both the welding (assuming you made it yourself) and design. I've thought about making my own bike from scratch but a dual suspension is another story altogether! Some of my comments:

- Love the BB pivot! That is so smart!
- Loving the flat section bits near the shock. I would suggest some analysis to determine if it's strong enough. Visually I say no, but meh it's steel so should be fine.
- Maybe consider bending a bit to the top tube and making the seat post support shorter (you will still need to reinforce it though). I get you're doing straight tubes but that's an easy 200g+ if you're weight weening.

Great work mate - keep it up, maybe one day you'll make the next maestro suspension!

 

[Burrito_Boy]

If you build that rear end with the aero profiled/elliptical extrusion 4130 it would be an easy way to boost stiffness without much hassle.

 

[moorey]

thing is that 27,5" in my country is not very popular

I like the sound of your country. Can I move to your county.

 

[No Skid Marks]

[HR][/HR]With the high pivot it is a bike tat would least benefit from 27" rear wheel, you could always run 27" front for the benefits at the front. Oval tubing sounds like a good idea for totional stiffness but what about lateral side to side flex? What about the weight too of suck stiff tubing? It's I sprung weight remember.
why not just minimize our DH01 design? It's so ideal.

 

[troyo]

Great looking design, but yeah will be too flexy and I would go 27" wheels too. I'd probably up the BB height a touch too. On the money with the short stays but. 27" will need a whole rethink though. Aluminum swing arm could b made stiffer but still to flexy and would fatigue. Or carbon if you have the skills, but again, solving a problem that doesn't need to exist.
Have a look at the I-track designs/concept, pretty cool way to dial in anti squat.
whatever you do, I look forward to seeing it made.

Thank You very much! BB is low because of anti squat values.

Don't worry about the rear end. Stick a 148+ thru axle at the rear and your bike will magically become 1000% stiffer!

Seriously though, you sir, have some mad skills! Both the welding (assuming you made it yourself) and design. I've thought about making my own bike from scratch but a dual suspension is another story altogether! Some of my comments:

- Love the BB pivot! That is so smart!
- Loving the flat section bits near the shock. I would suggest some analysis to determine if it's strong enough. Visually I say no, but meh it's steel so should be fine.
- Maybe consider bending a bit to the top tube and making the seat post support shorter (you will still need to reinforce it though). I get you're doing straight tubes but that's an easy 200g+ if you're weight weening.

Great work mate - keep it up, maybe one day you'll make the next maestro suspension!

Thanks man! 148+ FTW Unfortunately I can't bend those tubes. Those are ~1500 MPa, "thin" walled tubes that would probably crack without using some torch to heat them up before bending. Even that those are "heat loving" air hardening tubes, less heat = stronger frame so...

If you build that rear end with the aero profiled/elliptical extrusion 4130 it would be an easy way to boost stiffness without much hassle.

True Temper Supertherm tubing comes in limited sizes, that is why this frame looks like it looks. For that reason I'm thinking of using some mix of Supertherm tubes and 4130 normalized tubing. I would need to heat treat the whole frame after welding then, so for prototypes I will stick to TT Supertherm tubing only. For production models I will probably go in that direction! Some rectangular 38x19mm profiles would be great but they are very hard to get with really thin walls and as it is an enduro frame weight is a big factor.

 

[troyo]

I like the sound of your country. Can I move to your county.

Trust me, You don't want to do that.

[HR][/HR]With the high pivot it is a bike tat would least benefit from 27" rear wheel, you could always run 27" front for the benefits at the front. Oval tubing sounds like a good idea for totional stiffness but what about lateral side to side flex? What about the weight too of suck stiff tubing? It's I sprung weight remember.
why not just minimize our DH01 design? It's so ideal.

27,5 & 26 combo sounds awesome! DH01 was really PITA to make. Wanted to make something much simpler, easier to maintain consistency/tolerances and cheaper (tooling, tubing, labor, alignment and so on). I leave it for the future.

 

[Andrei]

Awesome stuff. reminds me of Corsair Marque and Swarf Curve. Keep it low and slack and 26" foshaw!!!

http://www.vitalmtb.com/community/swarfcycles,26874/setup,23172

 

[troyo]

Awesome stuff. reminds me of Corsair Marque and Swarf Curve. Keep it low and slack and 26" foshaw!!!

http://www.vitalmtb.com/community/swarfcycles,26874/setup,23172

Befor DH01 i was riding Corsair Maelstrom! Nice bike, made some steel axles for it as alu ones were not strong enough. Swarf stuff is awesome (pricey tho...)! After some consultations I've decided to make some room for 27,5" wheel and more seatpost adjustment. What do You guys think about the same geo numbers and bigger wheels? What would You change?

 

[Andrei]

Befor DH01 i was riding Corsair Maelstrom! Nice bike, made some steel axles for it as alu ones were not strong enough. Swarf stuff is awesome (pricey tho...)! After some consultations I've decided to make some room for 27,5" wheel and more seatpost adjustment. What do You guys think about the same geo numbers and bigger wheels? What would You change?

If you can keep the geo with 27.5" it will be very sweet. Which country are you in btw?

 

[troyo]

If you can keep the geo with 27.5" it will be very sweet. Which country are you in btw?

What do You Guys think about changing ST angle to 74 deg.? Someone suggested that, because of long reach. It would shorten ETT lenght therefore make climbing position more comfortable. I'm from Poland

 

[troyo]

Update:

CS extended to 16.7" (425 mm) for 27.5" wheels, WB to 46.85" (1190 mm)

BB height raised to 13.2" (335 mm) with 2.3 x 27.5 wheels (340 mm with 2,4" Maxxis tires)

ST angle changed to 74 deg.

Seatpost dia. 31.6 mm

Have to add front derailleur mount to the front triangle and idler mount to the drive side aluminum plate, shock mount to the front triangle + change tubing thickness a little bit, tweak the swingarm a little. What do You think guys?

 

[moorey]

Rear end looks s whole lot stiffer now. Nice.
One Q, why the change to 31.6 post? Didn't you get the memo about 30.9 being the GOLD standard?

 

[troyo]

Rear end looks s whole lot stiffer now. Nice.
One Q, why the change to 31.6 post? Didn't you get the memo about 30.9 being the GOLD standard?

It's much easier to get tubing in that size. You can always shim down to 30.9mm post, and You are not screwed if You already have 31.6 dropper post. I can go with 34.9 clamp and 30.9 post, but it will add a lot of weight for no particular reason.

 

[brutasauras]

Rear end looks s whole lot stiffer now. Nice.
One Q, why the change to 31.6 post? Didn't you get the memo about 30.9 being the GOLD standard?

Probably because you can get a butted tube in cromo for that size, although by the look of the length you might have to use a straight gauge 34.9mm x 1.6mm or you will be welding the thin part of the tube.