Wirefly: Freeride/Commuter Project

So I am diving headfirst into this after being inspired by skeetab, bhzwindtalker's BHT based project bikes and an Oset bike that I got to take a quick ride on the other day. The plan is a pedalless that I can freeride and commute to work on. It's going to utilize the BHT motor, Kelly Controller, MC wheels and tires, Dual crown front suspension, swingarm rear suspension. Right now I am working on the design of the bike and have a bunch of parts inbound. I currently have enough space for 20 4s packs in the frame. Not sure if I am going to run at 60 or 72 volts but I hope to work that out as I start testing the bike. I am looking for about 35mph or so and lots of torque. Still a lot to figure out but I am waiting for a few parts to come in to verify things. I am on the fence about running Lipo or building a 18650 pack. I am thinking I will be happy with around 100-120 amps but still unsure what 18650's are capable of and how the pack would need to be built to accomodate that. Here is where I am at so far. Any feed back that anyone can provide would be great. I am new to all this.

Looks really interesting Standfast. I will be following this build.
Looks like we are seeing a new class of vehicle emerging.. a crossover .. a "Pedalless Bicycle" or Ultralight electric motorcycle using mostly bicycle components.

Now BZH & Skeetab have got their BHT powered bikes running it looks like that motor will become the (or at least one of the) standard motor(s) for this type of bike.

I haven't ridden an OSET 20, but my grandson recently got an OSET 16 to move up to when he outgrows the electric bike I built him for Christmas. I like the mechanical simplicity of the single reduction, single speed, motor on swingarm system, and the performance of the OSETs in junior competition trials validates the design for that purpose at least.

I will be ordering a BHT motor and Kelly controller in the next few days for my pedalless build.

Exciting times!

Dave

Drum said:

Looks really interesting Standfast. I will be following this build.
Looks like we are seeing a new class of vehicle emerging.. a crossover .. a "Pedalless Bicycle" or Ultralight electric motorcycle using mostly bicycle components.

Now BZH & Skeetab have got their BHT powered bikes running it looks like that motor will become the (or at least one of the) standard motor(s) for this type of bike.

I haven't ridden an OSET 20, but my grandson recently got an OSET 16 to move up to when he outgrows the electric bike I built him for Christmas. I like the mechanical simplicity of the single reduction, single speed, motor on swingarm system, and the performance of the OSETs in junior competition trials validates the design for that purpose at least.

I will be ordering a BHT motor and Kelly controller in the next few days for my pedalless build.

Exciting times!

Dave

Click to expand...

"Pedalless Bicycle"
''mostly bicycle components''
For me it looks like a light wight motorcross with steering parts from a DH bicycle and 'maybe' a DH bicycle rear shock.

stanfast
The new 25R or little better but more expensive VTC5 would be nice but they get pretty hot and sag much @ higher than 8A.
If u take 200 from them than 6KW pulse output power is ok.

zener said:

"Pedalless Bicycle"
''mostly bicycle components''
For me it looks like a light wight motorcross with steering parts from a DH bicycle and 'maybe' a DH bicycle rear shock.

stanfast
The new 25R or little better but more expensive VTC5 would be nice but they get pretty hot and sag much @ there rated max ampere. If you calculate with half of that rating for pulse discharge you are on the safe side.
If u take 200 from them than 8KW output power is safe.

Click to expand...

Yeah, far from a bicycle for sure. Superlight electric moto is more like it. Once you take the pedals away it really doesn't match the definition at all. Stick a moto seat on there and it doesn't even look like a bicycle anymore. Truth is, I find bicycle seats unfortable (especially on impact landings) and I really don't see a point in having pedals on a bike with this kind of power except for the legal reasons. Pedals seem to add a layer of complexity along with weight and it seems that most just use them to get started or when climbing big hills. I don't intend to do massive hill climbs and I think this motor should have enough grunt to make starting a non issue. I don't really care about the legal aspect. I am more likely to register it as a moped for street use than try to convince people that it's still a bike. Where I live, it really doesn't matter all that much. That said, maybe I picked the wrong subforum, but similar builds with the same motor are here so I figured what the hell!? haha


I have been reading up here on the 25R and the VTC5 trying to figure out if they would work. I *think* 6kw might be enough power to achieve what I am after. Are you saying it takes 200each 25R cells to accomodate 8kw spikes? So maybe 150each for 6kw? Is there a BMS out there that could support that or is one really even necessary with those cells?

Drum,

I look forward to seeing what you come up with. The OSET 20 is a pretty fun little bike. I was really suprised by the startup torque. Just a bit to small and seatless for me to want to ride it to work everyday.

Pedals have beside legal reason the additional advantage that you can pedal (slow) your bike in case of battery or motor or controller defect to home.
Or if you need more range u can peddel the efficency for it.
But i have to admit that i also would like to crap them for wight and complexity safings.

I have a 25R cell here i currently cycle to see cycle life.
If i put 12A on this cell with about 33% SOC left it sags to 3,03V from 3,64V.(this cell already have 70 test cycles)
On 10A it was 3,1V and temperature gone from 21*C to 29*C for 1 minute @ 12A
These cells are rated to discharge to 2,5V unlike lipo.
So active cooling or similar would be good in summer heat.
5A charging is no problem but have cycle life impact.
BMS is not necessary i guess but monitoring cells on charge would be good.
And sometimes a balance charge i guess.

I post cycle results in the 25r he2 vtc5 thread when finished.

Thanks Zener, I will keep an eye on that thread to see how it progresses. I think what I will do initially is just use a smaller lipo pack like 10ah to get an idea of consumption and minimum amps I would need to satisfy my interest, then figure it out from there.

Here is my previous design which I may revert to. Main difference being the motor position is angled down lowering swingarm pivot point and lowering CG. I am also considering designing an all sheet metal frame similar to the Stealth bikes to see if I can come up with something that will work.

So I am working on a sheet metal frame concept as an alternative. This is where I am at with it. The cavity can hold 20s 20ah, trying to keep the center of mass as low as possible, and as simple as possible.

Anybody know how thick the 4130 sheet metal is on a stealth frame?

This is a freaking nice design.
So simple and clean.
Is the seat ready buyable and just to weld or screw on ?
Have you planed to insert some structural stabilisers in the box? Than the wall sheet metal thickness could be reduced.

Checking clearance at full bump. Basing the clearance on the front on the axle to crown measurement of a Marz 888 which is 581 minimum minus the 200mm of travel.

I don't intend to have struts. I want the pack to come out quick and easy. I think I will draw it out using actual sheet metal components and refine the design to get an idea of the frame weight.

i think the samsung 25r is fine with 10A, if this is peak usage. Say 36W per cell. For 6kW peak you need ~160 cells. Like 20s8p or 13s12p.

I would not want the BHT at 60V in WYE, at 6kW this is a heater..will get very hot very fast... Better go for 74V in WYE or 48V in Delta. Delta conversion tutorial i postet in the BHT motor thread. Works fine with this motor.

Sheet frame wont get any cheaper nor lighter than the tube frame from my experience.

Thats good info. Thanks CB.

Well I ordered enough 4s hardcase lipo to do 20s so I forsee some testing both options ahead. The parts are starting to come in so that is helping with design confirmation. The wheels were silver but I took them to work today and powdercoated them black.

In regards to the frame being sheet metal, the cost is not too much of a factor since I can make it all myself whether it is tubing or sheet metal.

I thought the upper portion of the frame could use a little more bridging and it would make a nice place to put the controller potentially. This also helped move the seating position a little bit further back. I also stuffed it with the 20s 20ah worth of lipo packs to see how it fit.

Any input on what kind of range 20ah might provide in trail conditions?

Got the wheels together today. Made some nipple washers on the cnc turret punch yesterday afternoon. Worked out well.

So I am on the fence about building a tubular frame or a sheet metal frame. Advantage with the sheet metal frame is I can fit a lot more battery in a clean fashion. Weight of frames are close enough to not be a deciding factor. The sheet metal version can hold 30ah of 4s hardcase. The tubular version can hold about 20ah of 4s hardcase. With the tubular version I can build a removeable box that houses the batteries and charge off the bike. With the sheet metal version the batteries would likely be best staying on the bike during charge. Any thoughts?

Here is a shot of the sheet metal frame.

Got most of the sheet metal frame built on Saturday. Punched out the parts, bent them on the press brake and welded them up. Went together smoothly and was fun, I haven't welded in about 4-5 months so that was fun to get some under hood time. Still have to build the swing arm and machine the head tube. Hopefully I will have enough time after work to get some of that done this week.











Fork and batteries came in too! Startin to get somewhere finally!

Wow, that's awesome progress for one day!
I know it helps having the high-end tools, and obviously the skills and experience to use them properly, but even so that's impressive.
Keep up the good work!
Dave

Having the design figured out ahead of time saves a lot of time fiddling. Unfortunately the seat mounting will be the part that will require tinkering to get the mounts correct because the seat mounts are too complex to measure accurately so just building to fit is how I will have to deal with that one. I will have to document it though so it is sorted for the next one because now my wife wants me to build one for her.

Swing arm tacked up.Caliper mount is sorted. More parts came in. Little more progress made. Ordered the rear shock today along with the sprockets. Getting closer!

Is that the OSET 20" hub? could you share some specs? thanks!

Adam

Bike build is looking gorgeous so far man! keep up the great work!

Any pics or info on how the motor is going to mount? im curious

P.s I was hoping you were going tubular

Nice work I'm loving the way this beast is coming together. I really like the way you built your frame and really nice welding skills. Cant wait to see her up and running! -Donny H.

bzhwindtalker said:

Is that the OSET 20" hub? could you share some specs? thanks!

Adam

Click to expand...

Yeah it is. EP-OSET-HB32H Alloy, anodized red, 12G (spoke dia.) x 32H(spoke QTY) x 3/8"(axle) x 139mm(drop out width) x 180mm(total axle length)
http://osetbikes.com/gb/20-0-parts-2/wheels-and-tyres-2/

I got it from my local Oset dealer who happened to have it in stock. There is the standard 6x44mm disc flange on both sides. The sprocket side flange is about twice as thick as the disc side. Oset sells the sprocket adapter that is on there as well and it adapts to standard kart sprockets. The hub is about $75 US and the sprocket adapter is around $35 US. I used a 18"x1.85" Accel MC wheel on back and a 19"x1.85" Accel MC wheel on front. I used a DMR 20mm thru front hub. Spoke size I ordered from Holmes was 12ga x 210mm for the back and 12ga x 217mm for the front and they fit perfect with concical spoke washers.

skeetab,

Motor will be mounted like this.


I was real close to building a tubular frame but I wanted the option to add a lot of battery for commuting to work and this was gave me more space and a cleaner look. Especially once the side covers are on. I have built a lot of tubular race car chassis and suspension components before and this was something different to try. Truth be told I have built A-arms and trailing arms for desert race cars like this before already too. Most of it came down to battery. I am pretty sure I can get this thing street legal here pretty easily so a good bit of battery will be necessary to make it practical to use. Right now I am limited to you and bhz's experiences to gauge how much battery to use. I built the frame big enough to hold 30ah 20s of hard case Lipo but I am going to start with 20ah 20s. I am hoping that will be enough to get me 40-50 miles of street use and 30 miles of trail use. I can take either the roads home or the trail that runs along side the Rio Grande river to my house. I wanted the option to take either round trip without having to charge at work because I don't want to buy or lug around another charger setup. My total round trip is about about 20 miles on dirt or 16 miles on road but would like the extra juice to play or run errands.

One of my next hurdles will be sorting out how I charge this thing without taking the covers off. One way was using 5 paralleled sub packs and 20s BMS hooked up for charging only fed by a bulk charger of the correct voltage along with 3 cellogs to peak at each cell before I charge. Or maybe I can use one of these somehow. http://www.progressiverc.com/icharger-4010duo.html It can do 20s but being my pack is built using 4s hardcase I can't just break the whole pack in half and plug it into each of the 10s ports very easily because the pack doesn't split evenly into 2. Any ideas? I want the cells monitored during charging since I get the impression that bulk charging is a bit risky.

Hey SF,

Amazing job so far.. you definitely have some buildin skilz 8) I'd recommend the Adaptto controller / BMS
for your build here. Check out the thread under "Market- new stuff for sale", if unfamiliar with the kit.
It's a real nice complete and powerful set-up that pairs especially well with the 4S hard packs your employing.
The Adaptto's come in 2 flavors Mini and Max. I think you would be fine with the mini (what I'm planning on using
with my alternative big block) but a Max could really make it fly... for a while anyway :lol: The set-up handles all
of the monitoring and only requires a simple power supply of varying (relatively low) voltages to work.
Heck keep the pack at 20AH and carry the simple charger (better yet buy 2... one for work) and keep that rig lighter.
The peace of mind of halftime charging can be priceless.

The guys at Adaptto and product availability can be spotty but be persistent... if you get invoiced, it's legit.
I think the units are worth the wait and a serious step above most options. Thinking if you act now, the build may
not have to wait... but then again you're awefully fast at this assembly game
Looking real Pro.. keep up the good work!

Kevin