Handmountainbike Jeetrike - Umbauthread und Erfahrungsthread

[.MK.]

@lega2finia , sehe mir gerade noch Dein Foto genauer an. Mir war bisher nicht klar, daß die beiden Hebel ja mechanisch verbunden sind. Da funktioniert es dann ja wirklich nicht, wenn man verschiedene Hebel nimmt... Und dann ist es natürlich kein asymmetrisches Bremsen, wenn man eine Bremse nach rechts und eine nach links führt. Sorry.

Was bleibt ist natürlich immer noch die fehlende Bremse hinten...

=> Am Ende muß halt jeder die für seine Bedürfnisse passende Lösung finden...

 

[lega2finia]

MK, ich stimme dir auf den Bremsen zu! Die Feststellung, dass die Julie mehr Volumen hatte und die vorderen Bremskolben besser drücken konnte, ist ausgezeichnet!
Aber ich glaube, wenn wir die beiden Hebel wie das Tetra-System (mein Foto) aneinander befestigen müssen, müssen die Hebel genau gleich sein, den gleichen Hub haben und perfekt parallel sein. Von derselben Marke und demselben Modell ist es also sicherer. Ich bestreite nicht, im Gegenteil!
Chicken12, sehr gute Idee, die Bremsen mit dem Ellbogen zu betätigen! Es ist wahr, dass ich durch Drücken des Arms nicht stark bin und außerdem der Körper sich den Hebeln nähert und wir noch mehr Kraft verlieren. Hast du die Hebel umgelegt? kannst du ein Foto machen?
Ich arbeite an einer Rücktrittbremse -coaster brake- ich werde die Teile Ende der Woche haben, um sie zusammenzubauen. Ich hoffe es wird gut funktionieren ...

edit : Ja, das ist es MK, du hast das zusätzliche "Tetra-Problem" verstanden! Aber diese Ebay-Anzeige ist interessant, ich werde schauen ...

 

[chicken12]

Hallo Chicken12,
Ich freue mich sehr, einen anderen Jeetrike-Besitzer zu finden, mit dem ich sprechen und Ideen austauschen kann!
Beim Bremsen bereitet das ursprüngliche Tetra-System Kopfschmerzen. Es funktioniert nicht, weil es nicht nur schlecht designt, sondern auch schlecht gemacht ist (ich hoffe, Jaroslav wird das nicht lesen ... aber es ist die Wahrheit!)
Wenn Sie den Shimano XT-Hebel für die Rückseite behalten und eine Magura Julie für die Vorderseite aufsetzen, besteht kaum eine Chance, dass er funktioniert. Die Hebel müssen genau den gleichen Hub haben, sonst haben Sie immer eine Bremse, die vor der anderen funktioniert.
Es ist auch notwendig, den Bogen, der die beiden Bremsen verbindet, zu entfernen und durch ein besser gestaltetes Teil zu ersetzen ... Wenn die Bremsen nicht parallel sind, geht es auch nicht (Foto)
Ich für meinen Teil entfernte die hintere Bremse und verband jeden Hebel mit einer einzelnen vorderen Bremse. Zumindest funktionieren beide Vorderradbremsen. Aber ich muss es besser machen, ich habe nicht genug Kraft in meinem Arm und es ist immer noch nicht genug.
Für die Batterie habe ich in China einen 17A gekauft, der mir mit viel Unterstützung rund 42/45 km gibt. Das ist wichtig. Mit dem ursprünglichen 12A überschreite ich 30 / 32Km nicht, was wirtschaftlich ist. Ich bin oft zusammengebrochen! Außerdem habe ich die Konsole gegen eine präzisere ausgetauscht, die die Spannung angibt. Ich weiß, dass die Batterie bei 41 V abschaltet, also versuche ich zuerst einzusteigen!
Ich werde jetzt die 17A unter den Sitz legen, und ich werde die 12A zusätzlich für lange Reisen nehmen.

Mein Bremsteil ist nicht großartig, aber zumindest die Hebel sind parallel. Jeder rote Schlauch geht an eine Vorderradbremse, es gibt keine Hinterradbremse mehr.

@lega2finia welchen 17ah akku hast du verbaut?

 

[lega2finia]

Chicken12, ich habe einen Fehler gemacht, meine Batterie ist nur 14A, das habe ich gerade gesehen, als ich die Bestellung gefunden habe, die ich aufgegeben habe. Hier ist der Link : https://de.aliexpress.com/item/33015845742.html?spm=a2g0s.9042311.0.0.1f626c37JgeXtQ

 

[Handbike-Andi]

Hallo zusammen
Seit einiger Zeit lese ich mit.
Für mich tun sich da einige bekannte Themen auf.
Bremsen für Tetraplegiker ist ein grosses, gleichfalls bekanntes Thema. Im Innovationszentrum für assistive Technologien IAT der Schweizer Paraplegiker Stiftung läuft zu diesem Thema ein Projekt "Torpedo-Frein".

Vorerst mal die Frage, warum ihr nicht z.B. die Tektro Auriga Twin (HD-T525 bzw. HD-E525) nutzt? Die wird 2021 mit einem neuen Bremshebel kommen mit deutlich verbesserter Blockierfunktion (HD-E745).
Ein Andere Alternative findet ihr hier https://mysmartbrake.com/ eine kabellose Bremse. Dabei kann der Bremshebel in alle erdenklichen Lagen gebracht werden. Das Betätigen der Bremse kann so eingestellt werden, dass es sehr wenig Kraft braucht. Man könnte sogar alle drei Bremsen betätigen, so eingestellt, dass die hintere Bremse schwächer bremst. Natürlich braucht dieses System einen mechanischen "Notanker".

Rücktrittbremsen sind sehr kritisch. Man muss zuerst die Kurbel in die richtige Position bringen um bremsen zu können. "Fällt" man dann mit voller Wucht mit dem Rumpf in die Bremse, lassen sich viele Systeme nicht mehr, oder nur mit grossem Kraftaufwand lösen.
Das Handbike kann mit der Rücktrittbremse nicht mehr rückwerts geschoben werden, ausser man verfügt über ein System, dass sich deaktivieren lässt - Aber Vorsicht es muss sich nachher wieder aktivieren.

 

[lega2finia]

Hallo Handbike-Handi
Vielen Dank, dass Sie Ihre Ideen zu diesem Thema eingebracht haben. Bremsen war für mich schon immer ein Problem und ich bin aufmerksam auf alle Lösungen.
Der Tektro Auriga Doppelhebel ist zu beachten. Dies ist normalerweise das, was Sport-On auf alle seine Modelle passen sollte… und Kunden sollten es nicht tun müssen, nachdem sie Shimano bezahlt haben!
Ich hatte den Tekro auf meinem vorherigen Handbike (Hase Lepus), aber die Griffgelenke hielten nicht lange und ich konnte ihn nicht reparieren ... Ich hoffe, er hat sich verbessert (?)
Sehr interessant ist auch die SmartBrake-Lösung. Ich weiß nicht. Ich konnte den Preis nicht sehen, aber ich denke, er muss sehr hoch sein? Natürlich muss es wirklich gut funktionieren, wie zum Beispiel der Shimano Di-12 für die Geschwindigkeiten… aber ich denke, dass es 4000 € kostet… die 12000 des Handbikes zu ergänzen… Ist es vernünftig, so viel Geld zu investieren in einem Fahrrad?
Ich versuche, erschwingliche Lösungen zu entwickeln, indem ich vorhandene Produkte maximal nutze. Außerdem finde ich es am bequemsten und sichersten, die Hände auf den Pedalen zu halten, um zu bremsen. Bei Unebenheiten in jedem Gelände haben Sie Ihren Ellbogen nicht immer in der Nähe der Bremse, aber Ihre Hände sind immer auf den Pedalen! (normalerweise)
Ich denke, ich kann nächste Woche Bilder von meinem (deaktivierbaren) System einfügen. Danach hoffe ich, dass Sie mir alle helfen, es zu verbessern!

 

[lega2finia]

@ Chicken12,
Auf der aliExpress-Website finden Sie "Jumbo" -Batterien mit bis zu 21A. Aber ich weiß nicht, ob sie unter den Sitz kommen können.

 

[.MK.]

@Handbike-Andi , danke für den Tipp - hatte noch nicht davon gehört. Wieder ein Puzzle-Stein.

@lega2finia , Preise gibt's auf der Webseite nach Anmeldung. Sieht ja so aus, als wäre das DIE Lösung für Eure Bremsprobleme.

 

[lega2finia]

Guten Morgen alle,
Das Containment wird die Installation meiner Bremse ernsthaft verlangsamen, aber da ich den Hauptteil habe, werde ich versuchen, Ihnen zu erklären, wie es funktionieren wird (wenn es übrigens funktioniert!).
Zunächst besteht das Prinzip darin, auf der linken Seite des Bafang-Motors die quadratische Leistung des freien Pedals zu verwenden. Es dreht sich daher in die gleiche Richtung wie meine Arme, tritt in die Pedale oder tritt zurück. Die meisten Elektromotoren haben einen integrierten Freilauf, dies ist beim Bafang nicht der Fall, wo er sich auf der anderen Seite im Kettenblatt befindet (Kettenblatt daher entfernt Sport-On die Kurbel)

Die Bremshebel (das Gerät wirkt mit Kabeln auf die Bremshebel) werden an Lenkerrohren angebracht, die durch BMX-Vorbauten verlaufen. Das Rahmenrohr hat einen Durchmesser von 32 mm, sodass wir diese Stiele leicht befestigen können (hier gibt es nur einen).

Zum Schluss das Gerät selbst: Es ist ein Aluminiumhebel, der an den daran befestigten und an die Bremsen angeschlossenen Kabeln zieht und damit bremst. Es wird von einem BMX-Freilauf angetrieben, der an der Achse der Bafang-Kurbel montiert ist (hier ist es eine Fahrradachse).
Der Freilauf arbeitet rückwärts: Wenn Sie normal treten, dreht er sich und der Hebel bewegt sich nicht.
Wenn Sie rückwärts treten, blockiert das Freilauf und treibt den Hebel dank des kleinen "Fingers" (der einen Ring hat) an.

Auf der anderen Seite sehen wir, wie sich der "Finger" verhält: Er rastet einfach in die Zähne des Ritzels ein. Ich hatte vor, den Ring durch ein Kabel zu ersetzen, das mit einem Verriegelungshebel verbunden war. Wenn Sie nicht "zurücktreten" möchten, aktivieren Sie den Hebel, der den "Finger" entriegelt. Sie können ein Backup erstellen, das Handbike schieben, um es aufzubewahren ... Natürlich dürfen Sie danach nicht vergessen, das System wieder in Betrieb zu nehmen !!

 

[.MK.]

@lega2finia , könntest Du vielleicht die Bilder direkt in den Post einfügen? Das ist für die Leser einfacher (geht entweder über das Foto-Symbol unten oder auch direkt über die Zwischenablage mit CTRL-C und CTRL-V). Kannst auch den Post oben nochmal editieren und die Fotos ergänzen .

Und noch eine Bitte: Ich glaube, Du sprichst Französisch, richtig? Und Du übersetzt die Inhalte mit Google Translate? Manchmal ist das schwer zu verstehen, weil die automatischen Übersetzungen manchmal nicht gut funktionieren. Kannst Du eventuell zusätzlich auch noch direkt in Englisch schreiben, ohne automatische Übersetzung? Vielleicht geht das dann besser?

Danke!

 

[lega2finia]

@lega2finia , könntest Du vielleicht die Bilder direkt in den Post einfügen? Das ist für die Leser einfacher (geht entweder über das Foto-Symbol unten oder auch direkt über die Zwischenablage mit CTRL-C und CTRL-V). Kannst auch den Post oben nochmal editieren und die Fotos ergänzen .

Und noch eine Bitte: Ich glaube, Du sprichst Französisch, richtig? Und Du übersetzt die Inhalte mit Google Translate? Manchmal ist das schwer zu verstehen, weil die automatischen Übersetzungen manchmal nicht gut funktionieren. Kannst Du eventuell zusätzlich auch noch direkt in Englisch schreiben, ohne automatische Übersetzung? Vielleicht geht das dann besser?

Danke!

@MK: OK, I'll write in English now. It's also easier for me, as I don't know German at all, and my English is better. Is there anything you want to have a translation in my previous post?
And yes, I'll try to post my picts in my message. What is exactly the issue ?

 

[lega2finia]

Ein Andere Alternative findet ihr hier https://mysmartbrake.com/ eine kabellose Bremse.

(I hope you understand English too ??)
I've created an account to have the prices of all this stuff.
The important part, this kind ot actuator, or electric pump, costs 700€. The lever or thumb trigger is 200€.
It's pricey, but not as I was expected (!) I mean, sometimes the prices are just so ridiculous… First issue is you need probably as central units as you have wheels to brake. In our case, for the 2 front at least. The second issue is that without ANY fingers movement, you still have to imagine how you can move these damn levers.
If my coaster brake is a mess, I'll think about that.

 

[.MK.]

At least from my side I am totally fine with Englisch. If anybody raises complaints, we still can switch back to German...

Now the images are not invisible any more .

This is a brilliant idea !

So the cog wheel attaches to the squared shaft and has an included freewheel, right?

Did you estimate already the forces applied and the travel of the cabel? Does this match approx to the force and travel of your lever? Did you find a good compromise between sensitivity / force needed to brake and travel / turning angle on your handles? But probably this can be fine adjusted later on still, right?

And why is the lever so much longer than the finger? Is the brake wire attached a the end of the lever?

The lever hangs down if not engaged, this is the "rest position", right?

So the wire / cable just connects from the lever to the original hand brake lever, correct? And then you have your regular hydraulic brakes?

And, last questions, do you manufacture your stuff yourself? Do you have a company doing this for you?

If it works I would propose to send a link to Jarek, I also shared my ideas with him. Just in the interest of the community of other users. And I still feels he deserves any support, even though sometimes feedback is not that appreciated...

 

[lega2finia]

@MK : You've got it !
The cog is actually a BMX single speed 16 tooth freewheel. It's the most stupidly inexpensive bike part. Less than 5€ for this one. It is threaded inside to bolt it on the hub. In this case, we used an inexpensive crank arm, cut it near the head, and machined it cylindrically. The freewheel is strong dry pressed on, and that's all.
My approach to the forces is mostly through CAD (Cardboard Aided Design) … There's nope! My first idea was having the lever approx. the same length of the Shimano my bike was fitted with. This way the force between both levers was the same, but you're pushing on the cranks that are 170mm. So there's obviously a huge power here. I ended with a longer lever, to make sure and to have an adjustment possibility. The brake cables are going to be bolted in the hole at the end, but it's always possible to make another hole to fit the leverage.
If you have, like me, a "Mountain Drive" Schlumf, there a nice and unexpected cherry on the cupcake: when the MountainDrive is in low gear, it gives you a great amount of braking power due to the reduction ratio ! Thus, your push on the cranks can be significantly lighter. Cool stuff.
All these parts are manufactured by a guy in my neighborhood. As a quad, there's nothing I can do myself, except giving him my Sketchup 3D drawings with measures. And after that, I must find another friend to put them on the bike… and another one to make them fit or match. It's a long process.
I think now you can understand better why I'm a bit upset with Jaroslav. When they send me the bike, it was full of "shit" everywhere. It took me (and my friends) a very long time -and it's not finished- to put it in order. I told Jaro about that, and it was also to inform him there were some issues in the manufacture. I was expecting he apologize for sending me a shitty bike, but … I've seen nothing !
That's why I'm not sure I want to share this brake with him, if it works. I'm OK to give the idea to other guys, but I don't want Sport-on to make money putting it on quad's bike. For your information, I've already given him the "quad bezel" they put now for the Rohloff's gearing (inexpensive turning handle, made of sliding doors bumpers)
I showed him how to make one for my bike, and now it's their common quad's equipment… And they didn't ask if it was OK, neither they said "thank you". Not a big thing anyway, but could be appreciated.

 

[.MK.]

Der Rücken am Handbike ist fertig . Wegen Skoliose ausgewölbt, übernommen vom Rollstuhl und vom Sanitätshaus in Carbon gefertigt. Weitere Details weiter oben. Nach hinten klappbar, um mehr Platz zum Übersetzen zu haben, ebenfalls siehe oben für Details. Hier einige Fotos. Bei Fragen einfach fragen!

abgeklappt zum Übersetzen:

Morgen kommt noch der Halter für Fahne und Rücklicht dran, dann sind wir für's erste mal fertig...

 

[.MK.]

Raise the flag ! Also, die Sicherheitsflagge mußte ja auch noch ran. Samt dem LED-Tagfahrlicht (manchmal fährt man halt auch dunkle schmale Sträßle im Wald, und das Handbike hat ein niedriges Profil - da scheint es sinnvoll, was zu machen um etwas mehr aufzufallen. Ein Unfall ist mehr als genug...

Daher hier noch ein paar Fotos vom Halter, der die Flage und das Rücklicht hält. Und vom fertigen Handbike.

Vorerst heißt es damit: Projekt glücklich beendet . Bis zum nächsten Projektupgrade...

 

[lega2finia]

This Carbon back looks very nice and comfortable MK ! And this belt too.
And your machined parts are still nice ! … Maybe overkill for a flag and a light but who knows uh ? If you want an upgrade to a HUGE flag and a BIG light it will be just enough !

 

[lega2finia]

On my side (this term is appropriate) I was also feeling a lack of trunk support. My Jay back wasn't curved enough. Fortunately, I've found on eBay what I was searching for a long time : Lateral chest support for wheelchair users. And they are swing-away, so they don't interfere while transferring. By the way , MK, your idea of "tilting back" giving room for transfer is clever. I've lent my bike to a friend this summer (he is a quad too) and he felt the transfer very tricky ! Did you share with Jaro ?

My chest supports :

 

[lega2finia]

We are also getting close with my "coaster retro brake system"
I've been able to use it on Sunday for the very first time and …It WORKS !
At this moment, only my rear brake is connected with and … it's not the best one. The disk is only 180mm, the OEM brake pads look very hard and need a lot of pressure, so if there's a "panic stop" to do… don't expect too much !
But my goal is to have the front brakes on this system. With two wheels on the ground, two big 200mm disks and two twin-pistons calipers, … I think it must brake !
Despite all, I have some modifications to do :

• the 1,7mm Diam. cables are too thin and feel elastic. I've ordered motorbike's 2,5mm Diam.
• the cables route must be optimized.
• the pull plunger (my "clutch") could be beefier. I've ordered two bigger ones.
• the pull-plunger lever is too small and difficult to use. I've ordered a bike "parking brake" lever
• the leverage ratio isn't appropriate. The lever is too long and doesn't give me great pressure on the brake lever. I've already moved the cable's end halfway on the lever : of course, the travel of the pedals is longer but the power is far better. And I think with the two front calipers, I may need twice the pressure isn't it ? If yes, it could be an issue here, unless I redesign another lever with a different position of the pull-plunger to make more room. We'll see…

 

[.MK.]

@lega2finia , yes I shared images of the tilt mechnism and even the link to this forum here with Jarek.

Regarding the flag holder: Some things are done because they are needed (probably most things in the thread here), and some things are just done because they can be done! Sometimes they are just made to make somebody or the maker himself happy...

A few sentences to your brake efficiency:

• I still remember the basic principle, but based on the images attached the paths of the wires and connections stays a mystery to me. So to be able to provide better advise could you probably provide a rough sketch what connects to where how (hydraulic / cable)? And probably refer to photo images with numbers to be able to align both. Especially, since both images added seem to reflect different states of the project...
• What exactly do you mean by pull-plunger lever / pull plunger?
• You can believe me, that a double piston brake will provide only a little more power than a one piston pair brake if at all. Don't expect much improvement through this. This is more a question of robustness against heat, brake pad size, better alignment of the pads. And probably again a question of just and only having it becaus it is possible. I say this as a happy user of Shimano Zee 4 pistion breaks on 2 bikes, the best brakes I ever had
• Brake force depends on disk size, pad material and overall pad force. Overall pad force does not depend on the surface area of the pads or number of pistons, but on the hydraulic ratio between hand lever movement and brake pad movement.
• Cable tension makes them feel elastic? I hardly can believe this... From where to where do they go? What's their purpose? Where does the system start to be hydraulic? Was the idea to go by cables to the connected brakes in your post #44 above?
• Probably this is the question of having too much friction by cable bends? Probably some component in the chain might flex / bend when applying the brakes? Cable housings might flex or not be fully engaged into the end caps or holders? I would definitevely not assume that the cables itselv are the problem and that replacing the cables will improve anything.
• Lever ratio: Did you try to do the math? I would expect max force by two fingers at brake lever to be about 25kg (like lifting a heavy back pack with two fingers). So typical force in use should be around 5 - 15kg. Yes, forces are N not kg. So continuing with N. Typical travel on brake lever should be around 3cm until reaching the point of engagement. Next question is what force you can apply by applying the pedals backwards at your favorite brake location of the pedals. Now you can convert this into a torque, go along the gears until you end with the torque at the motor outlet. Now going back to lever force. If you end with less than 150 - 200N, you will know why the brake is weak. If this is the issue, then the only thing helping would be to change ratio to increase the brake travel until engagement.
• One last advise: Forget about cables, go fully hydraulic. Especially if you need to efficiently use the few forces available, you can not afford to loose them to friction. Go to a hydraulic lever that can provide enough volume (Julie, like mentioned above). Mount it down close to the motor lever. Directly connect it without cable with appropriate lever ratio. That's the best you can do.
• Very last advise: You will not need double hand force for two front brakes. Same force in hand lever is fine, but double flow volume at output of hand lever (right type of lever needed, Julie again). This results in half pressure in the pipes. So each break get's the volume needed to reach the engagement point and to break, but each one only breaks with half brake force only (due to half pressure). But, since you have 2 brakes, overall you have the same brake force again and everything is all right. The magic of hydraulics!

 

[lega2finia]

MK, thank you for your physical approach to my problem. Your help is considerably appreciated !!
I'm going to take some better picts of my rig to be crystal clear. Unfortunately I 've not enough skills to calculate the torque in the system, nor the pressure on the brake pads. I know what a leverage ratio is and what to do to increase it, … but that's all ! Most of the time I progress making trials and mistakes, and upgrading all I can upgrade. But here it's very frustrating (because it doesn't work), time-consuming and costs a lot. I've lost 6 months trying to understand why this bike wasn't braking correctly. OK the fault wasn't mine but Jaroslav stupid quad's adaptation. But after that I swapped the brake calipers, the brake levers and the brake hoses … without any results. Now I'm building my own system, with many difficulties, so if you can help me, you're welcome ! I've already made a retrobrake on my previous bike (a Lepus from HaseBikes) but it was too bulky and ugly to fit the Jeetrike. The idea was similar, using the chain this time, a freewheel with a cam applying the brake lever. Here's the beast.

 

[lega2finia]

OK MK, I've tried to make better picts with some explanations about what is what/what it does. It can be obvious sometime for you, but for someone else… who knows ?
So what is bothering me :

• the cam length. It was too long (from the center to the brake cable end) and the difference between the crank length wasn't big enough, the leverage ratio was poor. Now after moving the cable attachment closer to the center, it works better. But can I improve it more ? I have to match with the crank travel and also with the Shimano brake lever travel…
• the brake cable length, his cable housing, the cable ends… all these parts give me this "sponge" feeling (and, of course, you're right : I'm not able to stretch the cable. It's only a feeling)
• the pull plunger lever : when the device is loaded, the pull plunger is hard to move. Please note that I have to maneuver it only when the bike has to go in reverse.
• the brake attachment on the Shimano lever : I have to drill a hole closer to the end of the lever for better leverage…but it will also increase the needed cable travel…

 

[.MK.]

@lega2finia , I am willing to try to help out as good as I can from the distance. I need some time, probably over the weekend to think into the concept and pictures. Then I should be able to do the math to figure out the lever length to get similar brake force like a usual hand application will provide without doing many more trials without success.

Was just taking a look to our Jeetrike. Did you notice the chain tensioner mounted just below the pedal chain ring on the front side? Are you aware that when pedaling backwards the tensioner moves and gives the chain room? THIS might be the reason for the whole thing to feel wobbly and weak?!!!

Overcoming this might be a pretty difficult issue, because you need the tensioner to be able to give room to adjust the chain length when steering. Probably using a stronger spring in the tensioner, being strong enough not to noticably give room when pedaling backwards but still giving room to steer?

Aside this - I need some answers to a few questions to allow doing the math. Assume, you are the "green guy" .

• At which pedal location do you want to brake? 1 / 3 will not work, you can not apply much force there. So 4 by pulling back to you or 2 by pushing ahead? Or both?
• Which pulling force can you apply (in case of position 4)? This should be roughly comparable to the combined weight you can lift when sitting in the wheel chair with the left arm and with the right arm. (Do you have a body strap preventing your upper body from moving towards the pedals in this case?).
• Which push force can you apply (position 2)? This should be roughly comparable to the weight you can push away when pushing down combined with both arms (can you lift yourself out of the seat, then this is at least your upper body weight)? Or can you just use a scale to measure the push force you can apply with right arm and left arm?
• To measure the forces please try to apply same ellbow angles as you would take to brake.
• How many tooths do the upper (pedal) and lower (motor input) gears have (the two gears put together by the chain running up)?
• To double check: Which angle (degrees) / distance (cm) do you currently have to pedal back until the brake engages noticably?

• Is the yellow path the path of the brake cable or where does this go along???
• Why do we see the red outer cable hose in the blue section? I would have expected the cable hose to end at the upper end of the blue line and only the inner cable to extend to the lower end of the blue line.
• Currently only the rear brake is applied by the lever in the pictures. And lever to brake is hydraulic?
• Both front brakes are still attached to Jarkes double handles like visible in the images above?

 

[lega2finia]

Hi, MK, here are the answers. But please don't take too much of your time !

@lega2finia ,
Did you notice the chain tensioner mounted just below the pedal chain ring on the front side?
YES, I've adjusted the chain tension by removing a few links. The tensioner is still there, and do his job avoiding chain jumps. I've let a small slack on the chain and all this stuff looks OK, so far. You are right, chain tension create a small delay while braking, but not very noticeable at this stade.

• At which pedal location do you want to brake? 1 / 3 will not work, you can not apply much force there. So 4 by pulling back to you or 2 by pushing ahead? Or both?
  - I need not only to brake, but to steer ! and more, to brake while steering… I use mostly something between 4 1/2 to 2
• Which pulling force can you apply (in case of position 4)?
  - It's my best position… I can pull to 350N (Yessss !)
  Do you have a body strap preventing your upper body from moving towards the pedals in this case?
  - YES. It's more for lateral support, but the job is done.
• Which push force can you apply (position 2)?
  - It's my weakest position, as it need strong triceps, …and I have none. You can expect 20/30N, nothing more I guess. It can be a little more if my arm are straigth, so a little after position 2
• How many tooths do the upper (pedal) and lower (motor input) gears have ?
  - If I remember well, it is 38 on the upper, and I don't have my crew disponible to count the lower… But it should be the same, because as far as I can see, the pedal and the cam have the same rpm. Or if it isn't the same, it's very very close. I'm pretty sure 1:1 is the ratio. And of course if I use the MountainDrive reduction, the motor turns a lot lower than the pedal.
• To double check: Which angle (degrees) / distance (cm) do you currently have to pedal back until the brake engages noticably?
  - it takes less than 1/4 of rotation, maybe around 1/8 to engage strongly he device. Which is nice and give a good progressivity.

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• Is the yellow path the path of the brake cable ?
  - YES
• Why do we see the red outer cable hose in the blue section?
  - it is just a small piece of hose I've slipped on the free cable. The goal is avoiding the cam to rotate counter-clockwise (in bumps or other reasons) by stiffening the cable. I'm not sure it is useful.
• Currently only the rear brake is applied by the lever in the pictures. And lever to brake is hydraulic?
  - YES. Stock mount Shimano Deore XT, same as yours.
• Both front brakes are still attached to Jarkes double handles like visible in the images above?
  - YES. The rear brake ist used for testing the device. But the goal is to have, if it works, the two front levers on the retro-brake (that' why I have installed two brakets) and to move the rear brake on the elbow mount.

The ULTIMATE solution should be, of course, to get rid of the cables and go full hydraulic. It was also my idea, and what I did on my previous retro brake : the cam was pushing directly on the brake lever. But in the Jeetrike's case it was difficult to do the same, and I was happy with the "flexibility" of the wires. But the goal was having them as short and straight as possible.
Now regarding the actual mount, I can see the brake levers and the cam can be very close, and maybe, maybe, I can imagine a straight link with an Uniball at each extremity, linking the cam and the brake lever. It could be doable. But for that I'll have to go back to the original Jaro's recipe (one lever/two calipers), so I would have to find an used Julie Magura brake lever, or any other brand that could make the deal (?)
I've also seen, if improving braking power is needed, that Hope was making XXL brake discs (220mm). They are pricey (≠50€ each), they need their own brackets (pricey too, of course !) but at least i can afford it. Obviously I've already spent a ridiculous amount of time/money and I don't have brakes. So when I look at the "Smart Brakes", I think if you can install them and they work instantly… they're worth the money ! I have the trike for one year now, and due to the lack of braking, there's lot of trails, and even roads, where I don't want to go because they are too sloped… This frustration has a cost too !

 

[.MK.]

@lega2finia , I would be more than happy to help you as far as possible to get onto your bike, taking all the steep paths trails that are wide enough.

We were helped by many people as well, and the only thing to get somewhere is together.

We solved all issues on our Jeetrike. This gives me high confidence that we can solve your problems as well, or at least significantly improve the system.

Don't worry about my time. The company I work for requests to reduce overtime until end of the year, so I have longer weekends and only 6 days left before I start into Christmas vacation .

Forget about the Hope brakes - 10% bigger diameter ist only 10% more brake power. This will be barely noticable regarding power. Most advantage is the better heat dissipation under extreme downhill conditions, because 10% larger surface is 10% more heat taken away, resulting in significantly less temperature.

If you answer all the questions one by one, I should be able to better understand the conditions and abilities and to be able to think about a solution.

Even in case of the mechanical / hydraulic solution will not be too promising, we can think further: Just as a pretty forward thinking first idea, not thought to the end: Take a brake lever with a spring, easy to operate, install a angle measuring device (potentiometer), and use a microcontroller board to control a servo, that operates the brakes (something like this her: Servo).

Obviously this brings up questions regarding safety, reliability, mechanical fallback etc. Nobody can take responsibility but you. But this might be a second path to follow, if the first path does not work.

So feel free to share all the answers needed to proceed. But you do not need to, if you do not want to...