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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/06/2013 :  00:32:25  Show Profile  Reply with Quote
Thom's exaggerating again :) and I'm stubborn (and poor) enough to not ride this with proper knobby winter spike tires like Schwalbe Ice Spiker Pro.

Anyways this has been very good winter bent.

Tony, I'll think about lexan shield but am afraid that it'll get beaten away when racing offroad.

Also forgot that this bent has now my first ever Campagnolo chains, namely Record C9. It's been said by national offroaders to be exceptionally well working and lasting. We'll see about that, likely next spring.

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 - 05/27/2013 :  01:04:32  Show Profile  Reply with Quote
Just little has changed since last comments.

When snow melted and some offroading was done in rocky downhills, remote steering stud started to became loose in fork shoulder. After tinkering how to fix it, I rotated stud and test mounted it with plenty of torque as threads seem to last well. Seems to work so reapplied it with thread locking compound.

Then finally started to scale my bents me onboard in ride fit, this bent has 38 % front 62 % rear. By calculating with 15 % tire sag I got 0.9 bar front 1.6 bar rear pressures for my Racing Ralph 2.25" tires. That's exceptionally low frontal pressure but this still rolls well and has awesome grip and comfort offroad.

Bent was ready for 6 hour off-road race which it was designed and built for...

Cheers,
-Mika

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

Edited by - mhelander on 05/27/2013 01:06:00
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Speedbiker
human power expert

USA
3835 Posts

Posted - 05/27/2013 :  07:56:47  Show Profile  Reply with Quote
How did the race go?
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/31/2013 :  05:10:52  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

How did the race go?



I've created ride report about this event.

As what comes to this bent, I almost broke rear suspension pivot in 6h event :



Here is how Rob English built it for Craig:



As there's other interesting offroad events next week I'm likely patching this failed triangle together if my TIG still works well enough.

For next summer I'm seriously considering to build new triangles. Using same aluminium tubing for bearing races but this time wrapped with carbon and one layer of nomex. And using carbon and hard foam when building whole triangle stronger and lighter than these current ones.

I'm quite short of carbon, nomex and epoxy. While mail-ordering it I'll likely get some nice pre-made carbon tubes for building new rear swingarm, stem and handlebar. Could shave some weight while increasing stiffness.

Also looking for used all-air fork, preferably those sloppy ones with 28mm legs, 120mm or more travel, 9mm QR axle and sub-1.5 kg weight. Not interesting to hard core MTB folks nowadays.

Primarily to get better adjustability for softer suspension and it doesn't harm to drop some weight along the way.

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 - 05/31/2013 :  07:45:23  Show Profile  Reply with Quote
Mika, why don't you machine the bearing races out of a sturdy chunk of aluminum bar stock, rather than tubing reinforced with composite(that I don't think will work)?
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 05/31/2013 :  09:31:04  Show Profile  Reply with Quote
Thom,

That would and had been my 1st choise if could use any proper machining equipment. 20 years ago no problem, now those are rare around here...

Thus I've used only hand tools when building by creations...

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
6462 Posts

Posted - 06/02/2013 :  07:02:36  Show Profile  Visit warren's Homepage  Reply with Quote
Good luck with the new CF bits Mika. Make yourself some nice 7.5mm CF plate to cut up and use for your suspension parts. If you make your bearing mounts heavy duty enough it should be fine and same you a lot of weight.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 06/05/2013 :  22:50:13  Show Profile  Reply with Quote
Thanks Warren, that's what I do when have composite stuff purchased and time to spare.

Meanwhile using hammer and partially fixed TIG-handle fixed current broken pivot. Then using thread locking compound and plenty of time without shock and seat to adjust all in pivoting for free movement without any binding or non-designed movement.

Now it works as expected and lasted well 40 minute and 11 km riding hard in XC race, including transfer to race area and back. Beating was little too much for my wheelset, loose spoke squeaking @ rear, otherwise everything went well. And I need to experiment with shock rebound adjusting as now I got plenty of course mistake caused suspension oscillation which kept me extra busy.

Cheers,
-Mika

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

Edited by - mhelander on 06/05/2013 22:53:52
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warren
human power expert

USA
6462 Posts

Posted - 06/06/2013 :  05:48:07  Show Profile  Visit warren's Homepage  Reply with Quote
Hi Mika,

Yes, there is nothing like a good air shock. I had a lot of handling issues with non dampened spring style rear shocks, but the air shocks with adjustable rebound work well to keep the rear wheel on the ground over bumpsa and around the bumpy corners.

-Warren.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 06/17/2013 :  02:07:43  Show Profile  Reply with Quote
Warren, you're so right. I finally spent some time adjusting my fork and rear air shock rebounds and now it rides so much better.

Couple of videos:

I was faster in full course despite riding in moderate pace, making couple of mistakes and one longer off-course, than any racing laps. Seems practicing and fine-tuning this bent is paying off.

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 - 06/17/2013 :  07:33:40  Show Profile  Reply with Quote
Great, now I have to build another bike!
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warren
human power expert

USA
6462 Posts

Posted - 06/17/2013 :  13:29:08  Show Profile  Visit warren's Homepage  Reply with Quote
Wow, that was incredibly rocky. Have you tried running your videos through the youtube image stabilization filter?
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 06/17/2013 :  22:18:05  Show Profile  Reply with Quote
quote:
Originally posted by warren

Wow, that was incredibly rocky. Have you tried running your videos through the youtube image stabilization filter?



Rocky it is, but quite smooth to ride as seen in my steering effort and minimal braking needs.

Yes I tried YouTube filter. It made blurry video even worse and removed rocky accent I wanted to retain in that short downhill clip.

I'm heading today to XC course and record that if weathers co-operate. Same camera and likely cloudy weather. But I'll try both YouTube and and some other non-clould stabilization filtering as clip will be way shorter, 6-7 minutes.

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 - 08/14/2013 :  23:45:34  Show Profile  Reply with Quote
Little update for this bent.

Did some tire testing procedures, to see are Schwalbe Furious Fred 50-559 & -622 tires better for me and courses I've raced than Racing Ralph Evo 2.25". Did 30 km around lake legs, 1st with wheelset having RR's in ghetto tubeless, 2nd in FF's with tubes and little later 3rd with 1st wheelset but FF's in true tubeless (Stans tape, sealant and tubeless valves).

All laps in about same average HR. Weather was gusty winds, calming rain, and 1st & 3rd were matching, 2nd was maybe little easier. Laps 1 and 2 went inside 60 seconds time, but 3rd was about five minutes faster. Also riding bike path underways and following inclines FF's are keeping momentum like road tires, RR's were killing speed way much more.

As this test had most of it in tarmac, I headed to my two past racing courses. For both I rode matching lap times as my best with RR's in actual races.

Because weight distributes 38% front 62% rear, ideal calculated pressure is 1.15 bar front, 2.17 bar rear. Having DT-Swiss XR-400 rim @ front was ok with ghetto tubeless Racing Ralph tires @ 0.9 bar, but I dropped pressures twice with Furious Fred.

Then realized that 1st wheelset built for this bent were using WTB LaserDisc rims which have sort of bumps to keep tires beaded better. I rebuilt WTB rims with WTB LaserDisc Lite hubs and put FF's on top. Seems to stay beaded way much better.

I have to say I feel sorry about not doing these tire testings way earlier. I could stay with top guns in both of those races with FF's. And have steam to spare for going even faster...

Before WTB rims I participated to 120 km MTB event and broke stem, again. It was built from aluminium stem, cut, welded mild aluminium tubing as extension in between. Later replaced first part with saddle post which was total failure. It fractured during that event and after 10+ km of serious off-road action snapped loose. I had to DNF from 1st pit area.

Next day welded together new stem setup from steel original. Now it doesn't fracture, it may bend but steel is steel.

Current weight with way much lighter tire setup and all other optimization was scaled 19.0 kg.

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 - 08/15/2013 :  13:59:05  Show Profile  Reply with Quote
Winter comes early in Finland. Mika is ready.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 08/15/2013 :  14:20:38  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

Winter comes early in Finland. Mika is ready.



Yes, I'm ready... Ice Spiker Pro tires are waiting...

But hopefully we have some summer time riding weathers left for couple of racing events. It's getting colder and rainier but no biggie, yet.

Cheers,
-Mika

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

Brazil
16 Posts

Posted - 09/07/2013 :  19:13:18  Show Profile  Reply with Quote
This one is ready for all off-road and is fully suspended, 26 x 26
LWB called Truck D4.

Carry up to 30 Kgr and until now has 6200km ridden, very nice
bike made by Zohrer, now is not produced anymore.

www.zohrer.com.br



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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 09/23/2013 :  02:06:08  Show Profile  Reply with Quote
Nice LWB Duram.

My offroader is ridden now over 4400 km according to Strava where I started to enter my rides since Jan 2012. That's more than I've ridden lowracer (just under 4400 km), MetaPhysic (just under 4000 km) and diy-Vendetta (just under 2000 km).

I've said to anyone asking that if I can keep only one bent it'll be this for sure.

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 - 09/23/2013 :  07:59:19  Show Profile  Reply with Quote
Notice how despite living in a cold climate, with multiple bikes Mika's kilometers really add up. Instead of ordering spiked tires I am organizing my indoor trainer area. And this is Ohio, not Finland!
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 10/08/2013 :  06:32:59  Show Profile  Reply with Quote
I've put Ice Spiker Pro tires on my wheelset which had Furious Fred slicks. Those are just too unpredictable to ride on muddy gravel roads and wet grass. Let's see how well those roll when setup as tubeless. 361 spikes @ front and 402 @ rear almost require use of ear plugs when on tarmac.

I've also broken my X.7 RD in final Wednesday cyclo-cross race. After very successful start, from position 8-9, chain jumped between cog and spokes. When getting chain back to cog noticed that RD jockey wheel was against cogs so B-bolt limiter tab was obviously broken away.

I've got my RD between spokes couple of weeks ago and used brute force to get it back and bent hanger properly to make rest of that leg. Apparently B-bolt tab got fracture then and it unfortunately gave up in the race.

As I absolutely hate to DNF from races, coasted back to starting area and used plenty of zip-ties to get RD back to intended position, and finished the race losing about three laps while fixing.



And broken part is that shim's bottom tab:



(sorry for blurry pictures, better ones are here and here)

Fortunately I have X.9 10sp RD in lowracer so stole broken shim to fix X.7 while waiting new RD which will be X.9 Type2. As those are only available for 10sp systems and mine is 9sp, I'll try to add radius to wire guide for matching 9sp wire pull ratio.

I've got my inspiration from daVinchi Design (see heading "Custom Rear Derailleur") :



RD above is modified for different trigger shifter and below is unmodified 9sp, both X.9 new design RD's. daVinchi uses quite rough method where rivets holding wire guide are drilled out and new guide is mounted using bolts and nut.



Above is this new applauded Type2 RD with jockey cage clutch. As 10sp RD's have smaller wire guide I'm going to shape hard foam for proper dimensions and when proven functional wrap it over using epoxy+carbon, and mount using zip-ties.

If successful, I have very rare SRAM-only clutch RD in my 9sp system. Likely beneficial with so long chainline, DH level rear suspension which with non-clutch RD has removed most of the paint from rear swingarm.

Cheers,
-Mika

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

Edited by - mhelander on 10/08/2013 06:36:25
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Speedbiker
human power expert

USA
3835 Posts

Posted - 10/08/2013 :  06:57:20  Show Profile  Reply with Quote
Amazing work, Mika.
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 10/08/2013 :  13:27:57  Show Profile  Reply with Quote
quote:
Originally posted by Speedbiker

Amazing work, Mika.



You mean my zip-tie magic? It was just few minutes to figuring out how and where route those so that RD moves as expected.

Modifying Type2 isn't done yet.

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 - 11/18/2013 :  03:27:36  Show Profile  Reply with Quote
quote:
Originally posted by mhelander

I've put Ice Spiker Pro tires on my wheelset which had Furious Fred slicks. Those are just too unpredictable to ride on muddy gravel roads and wet grass. Let's see how well those roll when setup as tubeless. 361 spikes @ front and 402 @ rear almost require use of ear plugs when on tarmac.


Yes, ISP's work quite well even in single-track. But those are slipping like crazy on snow-less rocky terrain and in one (52 km) leg I lost 5 studs from front and 40 (!) from rear tires.

So my other wheelset got Conti TopContact II Winter friction tires, 50-557 front and 37-622 rear. Working somehow in fine gravel and off-road, still rolling worse than Furious Freds in tarmac.

I'm waiting snow to stay on ground...

quote:
Originally posted by mhelander



Above is this new applauded Type2 RD with jockey cage clutch. As 10sp RD's have smaller wire guide I'm going to shape hard foam for proper dimensions and when proven functional wrap it over using epoxy+carbon, and mount using zip-ties.

If successful, I have very rare SRAM-only clutch RD in my 9sp system. Likely beneficial with so long chainline, DH level rear suspension which with non-clutch RD has removed most of the paint from rear swingarm.


Here we go:





Made that piece from epoxy slab hardened in cup. Attached to original cable guide using hot glue and steel wire, zip-tie keeps cable in new guide groove.

That bottom part did drop early so now I have another cup of hardened epoxy, mixed with splitted scrap carbon strings so it'll be tougher than this one.

Here is this bent in its current form, taken when had my 1st leg on snow this fall:



This leg was to test modified RD and it worked very well. Almost no chain slapping at all when pedaling over very rough terrain. No chain drops. Shifting both front and rear same time is little affected.

Equipped with WTB Bronson Race knobby tires good for snow and wet conditions, but impossibly slippery on wet hard snow or ice. Went down once in 30 kph speeds that day...

That leg initiated breakage of my homebuilt seat. It's my fault, I've done flimsy upper seat support to just keep seat in its place, relying on seat ribs and their rigidity. First other rib fractured, then later other also fractured which dropped seat some 2-3in and put seat to almost as reclined as in my road bents.





Had only one carbon cloth and carbon+nomex cloth in ribs, that wasn't enough to resist my merciless offroad riding and forces put to it by my upper torso. Didn't help that seat is mounted well from front of bottom pan, like in M5 lowracer, and supported well from lumbar curve area. Big bending forces to opposite direction than seat's been designed for.

Now fractures are repaired using patch of dual-uni cloth, then another carbon and carbon+nomex cloths over longer area of the ribs to make seat sturdy enough to work with that flimsy upper support. Used peel ply with absorbing cloths and proper compression, way better than when built that seat originally.

Didn't add much to seat weight (sub 100g), way less than building stronger support for it.

First test rides proved that seat's more solid than ever before. Especially when comparing its rigidity to MetaPhysic's seat I used while fixing this.

Cheers,
-Mika

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

Edited by - mhelander on 11/18/2013 03:39:46
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 11/18/2013 :  06:41:53  Show Profile  Reply with Quote
I've got pretty excited about thread Advice wishbone A-arm + leaf front suspension and use of composite leaf string for suspendind and damping...

Spent some time figuring out rationale behind Corvette's leaf suspension and use of such leaf in this off-road bent. It seems this might work and could really simplify rear suspension details.

Here is my rear swingarm:



And its position in main frame:



Now think about putting single flat composite leaf below frame tube, front mount just behind remote steerer and rear mount under swingarm H-tube. Then adjustable middle holder between leaf and frame tube.

That would be very simple, stiffness at least partially adjustable and maybe some damping could be introduced by placing rubber dampers between frame mounts. Total movement of the swingarm's H-tube is about 5-7 cm which composite leaf is to handle.

Also placing leaf below frame tubing would simplify seat mount altogether and maybe seat could be placed little lower too. At least constructing adjustable seat mounts would be much simpler with this.

This pegs building another steel prototype frame and composite leaf from cheap epoxy and twill glass fiber...

Cheers,
-Mika

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

Edited by - mhelander on 11/18/2013 06:44:10
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mhelander
recumbent enthusiast

Finland
384 Posts

Posted - 02/26/2014 :  04:05:53  Show Profile  Reply with Quote
Tinkering about building next revision of this bent has been ongoing for ages... I've got far enough than planning on mail-ordering quality CrMo tubing for building two new framesets, large and small sizes, to be used by me and my daughter.

Main frame beam will likely be 1-3/4" round in 0.049" wall. Rear fork from 1-1/4" and 0.049". Remote steerer for 1-1/8" threadless headset and 1-1/8" 0.049" CrMo stem.

Then proper CrMo BB lug, hopefully tapered 1-1/8" to 1.5" suspension fork steerer and nice disc & RD dropouts from somewhere.

Hollow tube through industrial sealed bearings for rear swingarm, tube preload and clamping still open. Shock linkage triangles with two frame mounting position with bearings in frame side.

New idea is to plan frame geometry so that remote steerer can be used for rigid 29er or road (carbon) fork with tiller setup, and seat more reclined. Much like my MetaPhysic, to be used for road and touring riding. TroyTec kind of "full suspension" via middle frame pivoted rear suspension and about 60mm travel. Or with 100+ mm suspension fork and remote steering for real off-road use.

Upper rear shock mount, power idler and 2-4" adjustable seat mounting is still open. Likely will require stiffened composite seat as now but seat mount will have fixed power idler mount and is adjusted in relation to BB together.

Next to do little bit of drawing and dimensioning, ordering stuff etc...

Cheers,
-Mika

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