'lightest.bike' 1.7kg 1000w mid drive

[amberwolf]

Aren't "trials" cranks made this way? (with threads for a standard freewheel)?

https://www.google.com/search?newwindow=1&tbm=isch&q=JIS+threaded+trials+cranks

Or am I missing a requirement somewhere?

Like these really short ones at 470g/pair

jitsie Square Taper Crankset 140mm JIS

This is a forged Jitsie crankset made of high quality 6061-T6 aluminium. Cause of its length of just 1450mm, ideal for use on kid bikes (Monty 205 Kamel for example).

trial-world.com

 

[neptronix]

470g for the pair is easy when the crank is140mm long, hehe.
Interesting that these are actually pretty common.

 

[neptronix]

Thanks, I’ll look into more crank options.

Have you tried installing the bottom bracket yet?

Nope..
The bike i got has some whackadoodle cheap BB that i don't have a tool to take off with, and i've been too busy to go to the bike shop to get it extracted

 

[neptronix]

Awesome that you were able to achieve an even Q factor! and the pedals don't seem too wide either!

 

[neptronix]

I can't visualize it.. relative to the bike do you mean it's going up/down?

Would the ISIS cranks be better?

 

[raylo32]

Damn, that's too bad. But this motor always seemed a bit like an amateur hour design from the start.

Response from Bikee:

“We're sorry, could you make a countersunk on the side you think is most useful?”

The takeaway here is that you are kind of on your own if you run into a design flaw. You are going to have fabricate your way out of it yourself.

But, do I want to? I don’t know. I think I will be much better served by a CYC Photon. I’m not sure if I will proceed with the Lightest Kit build.

 

[neptronix]

Yeah, that's a boo-boo...

If you have those nuts/bolts all the way on ( are we missing spacers? ), it looks like that side was meant to be countersunk based on the bolt length.

Would shaving a millimeter off a bolt with a hand file cure the chainring interference issue?

 

[neptronix]

Very glad i have a 68mm BB at this moment

How much clearance do you have between the nut and the chainring? 0mm?
I think the minimum that would be safe is to have a 2mm clearance because the chain ring won't be flexing in that area.

You could shave off about 1-2mm from that nut. or go down 2 teeth on the chainring and you should have proper clearance.

There's also 1-3mm bottom bracket spacers out there. You don't mind width, so maybe it would get you an extra few millimeters of spacing you need?

..or some mixture of both approaches to avoid needing to countersink.

 

[neptronix]

Yeah the lack of guard is concerning, i feel like it should be a minimum for the kit. Not compatible with baggy pants, lol.

But you have a medium mount, no? i'm thinking with the short mount, the chain will be way closer to the center of the pedal and then have little to no potential for interference.

The double chainring thing is one reason why i like the lightest. It's very bike part compatible. I figured they didn't get it right on the first try, but at least i have wiggle room since the construction is simple. I think it is still possible to run that configuration given the correct spacers etc on the chainring. It could correct a bunch of these funky chain alignment issues on some bikes with weird downtubes - IE @chuyskywalker 's problem, and also probably be easier on the chain ( i would think you get better wrapping around the small sprocket )

 

[neptronix]

Hmm i tend to like big chainrings and suspect that i could wind up in the same shoes and needing a mid size mount.. curious to see what the answer is on that.

Due to the good bike parts compatibility it may be possible to mix and match with other mid drive's parts without too much trouble.. i notice many other mid drives also have square bracket or isis parts.

 

[rivers]

Hi, Interesting discussion regarding assembly issues with the Bikee kit.

I am building a road bike with the medium mount and a 42T chainring. Among other problems I did have to reverse the countersinking on the mounting plates.

 

[Golo]

I have been looking around for different solutions for the bottombracket and cranks.
And this freewheel for the Rocky Mountain Powerplay might work. It is based on the Raceface cinch Bottom brackets and cranks.

If it turns out i really like this motor and if get problems with the Bikeebike bottom bracket i might want to try this.

 

[rivers]

Did you report this to Bikee?

No, I did not report. I just reversed the countersinking because it was obviously necessary.

Yes, had to put flats on the washers using a bench grinder.

 

[neptronix]

nervagon, will you sell me your medium mount?

 

[raylo32]

I'll give you $5. Plus shipping.

I might end up just selling the whole kit, and the medium mount is all I have right now. If/when I figure out a replacement for the medium mount, I’ll check in with you.

 

[neptronix]

What a pain in the ass.

I also prefer a larger chainring, i also have 26" wheels, so i NEED a larger chaingring, and you were ahead of me in hitting this wall.

I see that i have a 42T chainring and what looks like a short mount here ( correct me if i'm wrong ), and maybe part of a mid plate for whatever reason..



It looks like the machining is indeed reversed on the mid plate.

I wouldn't mind swapping you for a short mount and having a less conspicuous look. I'm in Utah so nobody gives a [expletive]. I understand doing so creates other problems.

 

[Chalo]

Southern Cali is becoming a shit-show on the ebike regulation front. Ebikes getting blanket bans in beach communities, blanket bans on state park trails and properties, and soon apartment and home owners associations. 2024 is the year that K-Factor becomes a big effing deal.

Couple small diameter hub motors, stylish (or frumpy) bag containing the giblets and battery, vintage bike... sail under the radar like you ain't there. Sine controllers if you gotta be silent to avoid waking the trolls.

I think RC based, Lightning Rods or this lightest.bike stuff is cool for hobbyists, but between being a PITA, very high maintenance, and attracting unwelcome attention when it's available, it's just not a great day to day option for some folks.

 

[neptronix]

Your large wheels are a huge downside for a hub.
I would only run a Magic pie or Grin RH212, although such motors are taller and less stealth

A GMAC mostly hidden behind panniers with a very narrow diameter front ~350w, but driven at 500w, would probably be adequate, but you have to consider that geared motors can break during heavy/fast offroad use due to the gears taking impacts.

CYC photon is probably #1 or #2 most stealthy mid drive.

The toseven DM02 500w tho.. but the right pedal goes outwards almost an inch more than the left pedal. It's also twice the weight of the lightest.

 

[amberwolf]

A GMAC mostly hidden behind panniers with a very narrow diameter front ~350w, but driven at 500w, would probably be adequate, but you have to consider that geared motors can break during heavy/fast offroad use due to the gears taking impacts.

And the GMAC is *not* a quiet motor, if stealth is a goal.

 

[neptronix]

.. true.. i was thinking more visually stealth than noise wise.

Less visually stealth but can be super quiet with a sine motor is a DD.
But harder to hide due to their tallness.

Some pannier bags can get quite tall:



In the case of this bag, I would sew a couple inch black flap on one side of the pannier so the black motor can kind of blend in to the black frame.

Another interesting route to hide a hub would be hardshell panniers.



..except using a much more narrow 'can'




If you're willing to convert to a bikepacker look then you could pull off a leafbike 1.5kw or RH212, either would provide decent power / thermal resilience during hill climbing.

 

[neptronix]

Yeah i looked into the photon and it looks like it overheats pretty quick for most people even though it appears to have nice heatsinking.
Hot and humid conditions are the worst conditions for a motor ever, you can almost cut the amount of heat a motor can shed in half in that condition.

The lightest is said to have a very efficient stator... if they are honest about the efficiency then for thermal reasons it may be the ideal motor for you. Me, i always like the most efficient option because usually it can be hot rodded significantly.. and the lightness is cool..

 

[neptronix]

Yeah, with geared hub motors, the more internal reductions, the more weak they are.

 

[neptronix]

I have never seen pictures of the internals nor could coax any specs out of them on the stator or magnets to make an educated guess on what the real power is.

They claim around 90% efficiency. If true, it should contain 0.27mm or 0.2mm laminations in the stator. Astro motors which have razor thin laminations can achieve up to ~95% efficiency, so it is technically possible to have a 90% efficient mid drive.

I wouldn't be willing to void my warranty by popping it open until i can confirm the motor is running.

 

[Chalo]

I have a spare baserunner and cycle analyst, so I would to find a small hub motor that can roll a 29er up a 10% grade without melting,

I said two motors. Two 29er motors are the same as one 14.5er motor, torque wise.

 

[neptronix]

If you are willing to drop to a 27.5 rear, losing 0.75 inches of ground clearance as a result, you could get better results out of a hub motor. 26" would obviously be too much of a size drop.

The MAC would be more efficient during hill climbing than this motor. However, this motor is within a pound of the GMAC and you can put statorade in it to make it survive the hill.

Motor Simulator - Tools



This motor would also be a little more efficient than the GMAC on flat ground, and this could make up for it's subpar climbing efficiency over the course of a ride unless your hills are a very large % of the ride.