Proflex softail Mac 1000w

[veloman]

Less than perfect roads have led me to some more comfort. The donor bike was a 1993 Proflex 853 had for $50 on craigslist. Front shocks are original and a stiff 2" travel. Rear 'suspension' is a combo of a hardware store spring, rubber from test plugs, and an old tube clamped around it all. New elastomers are $50, but I wanted to try my cheap fix. I get about 1.5" rear travel, just enough to take most road irregularities. The huge benefit is that it pedals nearly as good as a hardtail, very little power loss when YOU step on it! I hate losing pedal input power, even if it's on an ebike.

I just got done modding some homemade torque arms from 3/16" steel. Hand cutting them with a hacksaw took a couple hours, and destroy my blade, but I finished! Once I finished them I realized I made some cool looking "R"s.... Rad Rich's torque arms! They are design to just press against the chainstay at the dropout, so no other mounting points should be needed. The beauty of this Proflex is that the chainstay rear linkage is cro-mo! The dropouts are very minimal, so torque arms are a good idea.

Note: my current ride - a steel hardtail has similar torque arms and there didn't seem to be much torsional tension on them when I removed them for the first time tonight (flat tire on the bike trail - pinch flat from hitting a sharp curb corner due to poorly designed/maintained trail). Point is, I don't think the torque arms have been a necessity at 1000w on the Mac geared 6 turn motor.

Tomorrow's project is building a stronger battery case/mount inside that triangle. I think I am going to buy a wall mount mailbox and add some metal mods to secure it. $14 at Home Depot and it's lightweight, an optimal structural strength and well, no box fabrication needed for the most part. My current plastic file holder has been working fine, but it's cracked and not very secure from theft or rain.

The downside to this bike is the cantilever brakes, though they work well for what they are. I think I will soon get a better suspension fork with disk brake mounts.

Electrics:
6 turn Mac geared rear hub
Combination of batteries: 36v 11ah lifepo4, 48v 5ah 20c lipo
12 fet Infineon controller

I think I may run a couple 3s 5 ah lipo packs in series (11v 10ah) with the lifepo4, to give around 900watts at 18 amps. I've been running 21amps and would like to lower them a tad (without sacrificing power) to preserve the lifepo4 battery.

 

[kentlim26]

i am also using headway cells, lifepo4 16cells + lipos of 2cells or 4 cells 5amps pack. to supply the voltage for my huatong controller 60v. i think is very good for the lipos battery protection. if lifepo4 bms cut off , it will eventually cut off by the LVC controller. i can also configure 7.4v lipos 20amps + 16 cells lifepo4, or 16.8v lipos 10amps + 16 cells lipos. Using the lifepo4 Bms to do all the cut off power when power is low.

ken

 

[veloman]

Here it is! Complete and put 10 miles on it tonight.

It's a heck of a lot softer riding than the hardtail, I wish I built this sooner. The handling is a bit squirmy when corning, but it's not really an issue, just a weird feel. The bike sounds quieter too I think. Perhaps the 'suspension' reduces the motor noise traveling up the frame.

The front shock is doing okay, takes the hits well enough for now, but not as cushy as the previous RST fork on the hardtail. I can't swap since this is a threaded headset and much shorter steerer. The brakes do work okay, but lack the serious stopping power needed sometimes. I need to fine tune some stuff, but I really like it.

Most importantly, I want to fix the torque arms which the drive side is not doing anything right now: look at 2nd pic. What's the best way to secure this considering I have very limited hand tools?

I am pretty happy with the new battery case/mount and really like the semi hidden controller placement underneath. I also cut a tiny slot in the controller to fit the programming lead out. Now I can instantly reprogram the amps for when I want to run high power lipo, or to extend range on a lower amp setting. I currently am keeping it at 21amps until I get the torque arms fixed.

Another thing I noticed: my speed feels slower now. I look down and I'm at 27mph and it feels like nothing compared to before. The soft ride really makes you want to go faster.

 

[recumbent]

...snip... I also cut a tiny slot in the controller to fit the programming lead out. Now I can instantly reprogram the amps for when I want to run high power lipo, or to extend range on a lower amp setting...

How do you instantly reprogram the controler?

Is it really that easy?

 

[veloman]

Since the programming lead is now on the outside of the controller, I can hook it up to my usb cable and run the software on it, takes 2 seconds. Of course, setting up the software on your computer is the hard part. I think there is a sticky thread in the ebike section about the software that many use.

 

[neptronix]

BTW, hey.... you have a hole to bolt in where the rack would normally bolt up to.. why not use that bolt hole to keep the torque in check? seems like a perfect way to do it imho. That's how i'll be building my torque plate for this bike ( if i get it )

At your power level, maybe even a bit above, that should secure it well enough for both sides.

I've also seen 3 of these now with a standard MTB rear spring replacing the elastomer.