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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 12/04/2013 :  00:50:29  Show Profile  Reply with Quote
(Edit: click here to jump straight to start of building postings)

My previous fully suspended off-road bent has been very successful bent.



I've ridden it over 5500 km's in just over 12 months. Only bent I'm willing to ride over winter seasons and it's also good enough in local club road legs when equipped with Schwalbe Furious Fred slick tires setup as tubeless.

I've tried my best to beat hell out of it. Originally aluminium stem has been most problematic, it's now steel and holding well. Rear suspension pivoting has welded triangles which both almost cracked when racing, with weld-in patch stripes those are also working well. Rear swingarm got big dent and even bent, so did RD hanger couple of times...

Now is again winter season and good time to plan and then build new revised version. After plenty of tinkering it'll have same wheelspace, same rear suspension details, removable hardshell seat and remote steering.

Here are areas to improve and modify:
  • Rear swingarm is laterally flexing. In high speed twisty courses with bumps has impact on steering predictability

  • Stem needs to be simpler, stiffer to not bend or break when falling

  • Weight. It's now 19 kg in summer racing condition. Putting lightest fork and components might drop that to 18 kg. Home built mild steel frame components weight over 6 kg...

  • Some seat-BB distance adjustability

  • Dual-air 26" fork with 120-130 travel. Better adjustability and shave off weight 0.5+ kg

  • 1x10 gearing with SRAM Type2 RD, 34t narrow-wide 10% oval chainring and 11-41 custom cassette, drop weight from chainring(s), FD and trigger

  • Hydraulic disc brakes (Shimano XTR ?) with 160mm discs, rear mount is IS-2000

  • Likely same Rock Shox Bar-R 190mm rear air shock.


As we're in short of good supply of thin wall CrMo tubing I'm likely building this using carbon. Aluminium inserts for bearings like headset and rear suspension pivoting, rear dropouts and disc brake tabs, maybe threadless BB30.

For fork I like idea to use 1.5" tapered head tube and headset, then do 1.5" steerer adapter with remote steerer tab from 7075 which clamps to 1-1/8" steerer and fits 1.5" lower bearing. This way no need to modify forks as I did to my current Fox Vanilla R.

For stem might work well 1-1/8" carbon tube together with threadless headset, upper bearing topped with clamp, lower is also clamp with tab for remote steerer rod. Bearing preload is set from bottom of stem/steerer. Rod from carbon tube, ends with 7075 threaded inserts glued in place.

I would appreciate any ideas how to homebuild rear swingarm pivoting and seat clamping. Anything which doesn't require milling machines or lathe.

Swingarm needs to be more boxy with single very stiff H-connector and pivoting/bearing needs to add rotational stiffness. If built from carbon swingarm legs need to be stiff and hold well hits in rocks which are very likely.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 09/10/2015 07:59:26

alevand
human power expert

USA
3445 Posts

Posted - 12/04/2013 :  04:21:49  Show Profile  Visit alevand's Homepage  Reply with Quote
I would have problems starting with the pedals that high off the ground. On my mountain bike I have to stand up just to get the first pedal stroke going in some ruff places.

C:
Tony Levand
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 12/04/2013 :  05:21:44  Show Profile  Reply with Quote
quote:
Originally posted by alevand

I would have problems starting with the pedals that high off the ground. On my mountain bike I have to stand up just to get the first pedal stroke going in some ruff places.


You need to be flexible. And intent to stay up and clipped in after starting...

But seriously, after practicing its (v1) behaviour over winter in slippery condition, then racing in summer weathers with MTB slicks really teaches those reflexes. My starting takes 1/4 crank revolution to clip-in other pedal and then torque over inclines or rough spots.

This high BB and fork between ankles is critical to provide independent steering from pedaling. I was going down all the time in tricky spots when racing my MetaPhysic off-road because of twitchy behaviour of SWB and hitting ankles to rough off-road front tire. Also seating position is much similar than in my road bents and thus enables me to use all bents efficiently.

Yes, bent could be LWB as Richard @ BROL is riding in Canada, but in my terrain that's too slow turning in local forests and tracks, and less ground clearance. And longer means heavier.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 12/04/2013 05:23:08
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 12/11/2013 :  10:44:21  Show Profile  Reply with Quote
I've seen first time trapezoid suspension fork:



Video how this Kilo fork performs. Looks to be exceptionally well functioning and does good job keeping wheel grounded.

And another concept for Black Sheep fat bike:



I especially like lightness of this design, use of rear air shock which is easy to adjust and seemingly good functionality. Also Kilo solved pivot bearing problem quite nicely.

And this seems to be suspension fork which is easier to build myself. I'm targeting 120-130 mm travel and as building new frame can accommodate changes to retain my proven geometry.

Anyone ever built fork like this ?

Good ideas to build from carbon ?

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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Speedbiker
human power expert

USA
3835 Posts

Posted - 12/11/2013 :  21:43:33  Show Profile  Reply with Quote
Mika's gonna need a milling machine next...
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purplepeopledesign
recumbent guru

Canada
698 Posts

Posted - 12/12/2013 :  15:25:23  Show Profile  Reply with Quote
That Kilo fork looks like a reverse version of the AMP fork.

:)ensen



Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/05/2014 :  13:06:00  Show Profile  Reply with Quote
Winter is mostly gone, still building awaits starting. Plenty of tinkering still and I'm leaning to modify swing arm pivoting dramatically.

Latest idea is to use WTB LaserDisc Lite rear hub as mid-drive. It's 15mm hollow axle is replaced by longer, industrial bearings with sleeves to mount it below seat, and rear swingarm is then clamped to that axle.



Front hub as example. This moves cassette and RD away from ground and obstacles typically destroying it or sticking to its jockey wheels and cage. Then using 6-bolt fixie cog in place of brake disc to drive chain in left side to custom dual disc hub.

I've been playing with idea to split both front and rear WTB hubs in lathe so that brake disc ends are boded together using industrial epoxy and carbon wrapping, and stock rear hub axle is used with QR for mounting. Front disc side takes 6-bolt cog and 3/32" chain.

This tinkering started after finding extreme downhill MTB by Brooklyn Machine Works which has left side crankset, middle drive axle through rear swingarm pivot and floating brake caliper tab with push linkage to frame to eliminate brake dive.



Floating caliper with pull linkage below swingarm (in right side) might be worth trying, this fixie drive system needs adjustable dropouts anyways.

I'm yet to figure out details for relocating rear air shock and seat mounting. Maybe it's time to do some cardboard prototyping, and disassembling of rear WTB hub of spare wheelset...

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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Speedbiker
human power expert

USA
3835 Posts

Posted - 05/05/2014 :  22:08:59  Show Profile  Reply with Quote
Go for it Mika! Im sure you have make it work.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/06/2014 :  00:09:34  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

Go for it Mika! Im sure you have make it work.



Definitely. WTB hub pair is on its way, Fox 190/50mm air shock is already waiting... gonna order CrMo tubing when decided main construction details.

I believe use of middle-drive makes sense in this kind of hard core MTB bent. Rear wheel gets most of punishment and thus simplifying rear end improves reliability and reduces unsuspended mass.

Also chainline losses might even be lesser after some pounding in muddy terrain or swamps if compared to my current conventional dual idler which is great when clean.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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warren
human power expert

USA
6430 Posts

Posted - 05/06/2014 :  05:56:17  Show Profile  Visit warren's Homepage  Reply with Quote
Careful Mika, that looks complicated and may not be work the extra time invested when you could be riding instead of making brackets.

-Warren.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/06/2014 :  06:45:50  Show Profile  Reply with Quote
quote:
Originally posted by warren

Careful Mika, that looks complicated and may not be work the extra time invested when you could be riding instead of making brackets.


Thanks Warren... that's been exactly my excuse for not progressing this build... riding more instead of getting fatter and frustrated @ garage. And while doing so I think I've approached limits of current build speed and stability wise.

Best to spent some spare time doing cardboard prototyping before wasting time or destroying new hubs for this. When pivoting is solved to have rear hub, air shock, suspension linkage and seat mount then actual building continues.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 05/06/2014 06:48:11
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Speedbiker
human power expert

USA
3835 Posts

Posted - 05/06/2014 :  07:55:51  Show Profile  Reply with Quote
Despite the harsh Finland weather, Mika's fine homebuilt off-road bent has allowed him to already ride hundreds of kilometers already this year. I wouldnt worry about him building and not riding.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/06/2014 :  13:40:45  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

Despite the harsh Finland weather, Mika's fine homebuilt off-road bent has allowed him to already ride hundreds of kilometers already this year. I wouldnt worry about him building and not riding.



Here is my cumulative km's per bent as picture so it's just shy to 3500 km's year to date and 2900 km's on diy-offroader .

I may need little relief and do some building to balance...

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 05/06/2014 13:41:15
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/09/2015 :  00:05:36  Show Profile  Reply with Quote
(Edit: forget suspension components...)

Sorry for really lazy presence in all forums... too busy working & riding my bents. This first bent has almost 20,000 km's mileage to date and over 6600 km's this year to date.

But it's rusting away. Already fractured frame behind rear fork pivot and now fork legs are giving up and bending like banana over suspension linkage mounting point.

Despite wild ideas earlier in this thread nothing stellar is finding its way to new build. I've received quality CrMo tubings since autumn this year and parts gathering started last year. So I'm ready now, both mentally and practically.

Here is planning picture:



Behind is first aging prototype with old 130mm Fox fork and in front of it new dual air fork and 2nd wheelset. Fork steerer has ZS44 headtube with bearings, in parallel with old frame is new round frame tubing for measuring angles planning tube mitering.

Main frame tube will be straight from BB to rear fork pivot. Both headtubes are ZS44 and so is shell for fork pivot which will be built using two ZS44 uppers and 1-1/8" CrMo tube as axle, and so is done remote steering stem. Fork will get driven side clamp and NDS will have splitted bushing between clamp and axle for preloading bearings.

New fork has aluminium tab for remote steering linkage between fork crown and crown race, stem will get another and its bearing preload is adjusted from bottom using star nut. Linkage will get CrMo tube, M8 nuts welded to ends and then joints with locking nuts. No more bent threaded rod...

Rear suspension will be modified but its functionality is retained. First, frame tube continues behind rear fork pivot horizontally under the seat and end just after seat pan. Shock will be mounted behind end of frame tube vertically but fork to frame linkage is much the same as in old, this time lower shock mount is near linkage's middle pivot. All linkage pivots will get inline roller skate bearings.

Seat upper support will be done from two 1-1/8" tubes which have brackets in lower ends to meet end of frame tube, mounting holes for couple of different seat angles. Tubes will get tabs for upper shock mount.

Rear swingarm is much the same but this time built using Paragon dropouts, disc tab and cable & plumbing zip-tie cable stops.

Hardware moving from 1st proto is stellar quality:

  • Rotor REX 2.1 172.5mm crankset with single 34t QX1 oval narrow-wide chainring

  • Campagnolo Record 11s chains (2.5x) with one KMC Campy 11s missing link

  • Homebuilt 14t narrow-wide power idler

  • Shimano M9000 11-40 11-speed cassette, fits nicely to up to 10sp freewheels

  • Shimano ZEE SG Shadow+ short-cage RD with clutch, jockeys are Tacx T4060 with stainless sealed bearings

  • Shimano M9000 trigger shifter

  • Hope hydraulic brakes with X2 calipers, Race Evo front lever and Tech3 rear, both "rear" brakesets with long plumbing from UK

  • Rock Shox Reba Team 26" dual-air fork, set for 115mm travel, has non-tapered 1-1/8" steerer and 9mm QR axle setup

  • Fox Float R 190/50mm rear air shock

  • Wheels have WTB LaserDisc Lite hubs, Hope 160mm stainless brake discs, Light-Bicycle all-carbon wide rims, front is 26" and 30/26mm wide, rear 29er and 35/30mm, and 32pcs 3-cross DT-Swiss Revolution 2.0/1.5 spokes

  • Schwalbe Thunder Burt 26/2.1" front, 29er/2.25" rear, both Snake Skin and tubeless.



Homebuilt carbon&kevlar seat is pretty much destroyed, I need to clone MP's seat again. Likely testing this using MP seat initially. Also need to find out new lighter and less view obscuring handlebar with same sweep as current.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 09/09/2015 00:47:36
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/09/2015 :  14:09:36  Show Profile  Reply with Quote
Some progress. Mitering templates were really useful, got main frame tubings all cut, mitered and all in correct angles.





Will drill 10-12mm holes to ZS44 tubes for entry inside welded tubes for getting frame saver etc rust preventing stuff inside. And cut fork pivot shell when decided its construction details.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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Speedbiker
human power expert

USA
3835 Posts

Posted - 09/09/2015 :  16:34:17  Show Profile  Reply with Quote
Mika, please start a new thread.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/09/2015 :  23:17:30  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

Mika, please start a new thread.



Why ? This is thread about building V2 of the old bent... sure old thread but now activated.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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Speedbiker
human power expert

USA
3835 Posts

Posted - 09/10/2015 :  07:51:01  Show Profile  Reply with Quote
So we can get straight to your newest work. Not everyone uses a computer or laptop and it is easier if your new build is on a new thread.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/10/2015 :  07:53:55  Show Profile  Reply with Quote
I'll keep this short, and update first posting to jump to actual start building postings.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/10/2015 :  23:44:44  Show Profile  Reply with Quote
Main frame is done:





Gussets around fork head tube will be added later with idler mounts & remote steering setup. Next is rear fork, then its suspension pivot linkage.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/13/2015 :  12:02:17  Show Profile  Reply with Quote
Fri-sat-sun progress:





Rear fork is ready. Pivot has 1-1/8" axle, then FSA ZS44 two upper bearings with all parts, then 1-1/4" fork tubes which have been spitted for dual clamps. Bearing loading is done using star nut & top cap in both ends.



Here is fork position for targeted 160mm travel. Rest of the day I'm planning linkage pivot points...

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010

Edited by - mhelander on 09/13/2015 22:41:42
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warren
human power expert

USA
6430 Posts

Posted - 09/13/2015 :  14:47:17  Show Profile  Visit warren's Homepage  Reply with Quote
Hi Mika - I can't see your pictures, all I see is a big minus sign.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/13/2015 :  22:42:40  Show Profile  Reply with Quote
Sorry Warren and all, linked Android Backup folder images and forgot to copy them to my public bent folder... message edited now.

quote:
Originally posted by warren

Hi Mika - I can't see your pictures, all I see is a big minus sign.



Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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Speedbiker
human power expert

USA
3835 Posts

Posted - 09/13/2015 :  23:32:02  Show Profile  Reply with Quote
Looking good!
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/15/2015 :  14:15:03  Show Profile  Reply with Quote
Thanks Thom. Slow progress, too much work and tomorrow's CX event is no go.



Remote steering is done. Remote tab was more laborious to do, first cut 3mm drill bit to it, then was threading new hole when tap snapped in. Running out of aluminium thus did temporary tightening solution as material is needed for rear suspension linkage, which is like that this 1:2 draft:



Tomorrow time to do linkages and hopefully frame & fork mounts for it.

Cheers,
-Mika

Diy bents: Full-suspended off-roader @ 2012, Vendetta clone @ 2012
Commerials: MetaPhysic 700c @ 2011, M5 CrMo Lowracer @ 2010
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warren
human power expert

USA
6430 Posts

Posted - 09/15/2015 :  16:36:20  Show Profile  Visit warren's Homepage  Reply with Quote
Looking good, 3 headsets on one bike!
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