LightningRods mid drive kit

[John Bozi]

Nobody mentioned if this is wrong to post frames that are compatable so I will continue unless asked to do it elsewhere... besides people who are interested in buying the kit might get the answers I need too....

I went out bike shopping

I like this bike because it has a straight down tube - and simple bb area the shell 73mm by my rough measurements with external english bb. I think the shell is seperate to the part which hold dh front tensioners.... so it would have been 83 including that.

My question is...... Is the pivot to close to the bb and so would this make a good frame? I know battery space is not great but that can be worked around ....
Its at the end of my budget at $3k

The second option is Giant $2k but has the nasty S bend which I hear the stretch bracket can get around. Its good for more battery space with a bracket.. Its 83mm bb

however its got strange pivot system that looks more uncompatable...

 

[Driveless]

The best part of the Motoped is how the drive chain pivots off the rear swing arm's jackshaft, unlike the Qulbix kit, so the Motoped is similar to a motorcycle drivetrain; does not require a chain tensioner.

I absolutely agree with you. The best part of the Motoped is having the final drive jackshaft inside of the swingarm pivot. It's better than a motorcycle actually because they typically just try to place the countershaft drive sprocket close to the swingarm pivot.

Matt did a great job with the e-Motoped. It looks done to me!

Mike have you thought about building multiple motor kit's with multiple big blocks?

I wonder if you could replace one of your jack shafts of gear reduction with another big block or maybe just stick another motor in the center making it that much taller?
Since you would have two motors the amount of gear reduction used for one might not be necessary.. idk

I do appreciate the engineering that goes into your kit. I think the motor in the center of the 2 jackshafts on the luna is the way to go as opposed to motor on one end 2 jackshafts on the other. Seems to allow more contact of the chain to gear teeth from what I can tell. Less chance for stripping gears.

 

[PRW]

Mike, are you getting my emails? Please let me know (Peter Williams)
Thanks

I wrote Peter to tell him that his mid drive is done. Peter, I have not been getting any e-mail from you.

thanks Mike, PMs received, even though mail is not getting through.

 

[spinningmagnets]

Re: pivot location...

The concentric (having the same centers) pivot on the Stealth is a good thing for pedalers with a hub motor. But...once you engage a motor onto the front of a chain, the entire game changes. Humans put out maybe 200W of pedaling, so any "effect" on the front of the chain can be neglected over other concerns (chain-growth when the rear suspension cycles).

With a concentric pivot/chainring, applying 3000W will try to pull the swingarm up, compressing the shock some (called "squat"). If you imagine a ridiculous pivot location that is very high, applying lots of power from the BB to the rear wheel (on the top run of chain) would pull the rear wheel down (also not good).

For a powerful mid-drive (whether it uses the bikes gears, or is a one-speed), the Qulbix Raptor pivot position is perfect (edit: perfect in my opinion), its halfway between too high and too low, to minimize the overall effect. Plus, the BB is attached to the frame, instead of the swingarm. I also like how the elevated chain stay means you never have to break the chain to remove it from the frame.

Putting a Big Block on a Motoped or Stealth is not a horrible idea (either one would definitely be fun), but...if optimizing a nimble feel for off-road, the Raptor is the best orientation, and has the brightest future.

When pondering a pic of the Raptor rear suspension, visualize a 200-lb rider on it, and the suspension already compressed 1/3rd, and look at the location of the pivot in relation to the top of the chain.

 

[John Bozi]

I do think i'd like just a little more speed (maybe 23-25mph), and also, an 18t would fit the upper roller on my tensioner better. Right now, when the suspension compresses a bunch and the tensioner swings forward, the upper roller I added shifts a bit too close and i'm losing maybe 20% of it's range.

I was wondering if you have found a solution since then that works well.

Ages ago I researched every possible single speed tensioner and most of them have a limit of how many teeth they'd work with.

I also one just explode on me just using the bafang....

What's the maximum teeth, and which tensioner is the most robust, and would any take the thick 1/2 1/8 connex bmx chain which Mike has suggested as being the strongest possible that he knows of...

I have also run with a ton of playing around and had success with running a motor bike tensioner... but have had lots less luck recently trying to get it to work again... I think my chain may be playing up ....

cheers

 

[John Bozi]

Can someone please tell me where the bottom bracket attatches please? I am guessing its not over the shell...

Most bikes these days well mine and the last couple I looked at 2015 dh bikes had external bearings. Where does the bracket put it weight? on the cups of the bb supplied in the kit?

I am finding it quite hard to look for suitable bikes... Is there a compatability guide anywhere?

For example FS pivots not protrude past the bb shell... this what I'm guessing...

Sorry if I sound like a pita, its just time consuming looking at bikes when I dont know what is possible or not. The white bike I post above looks unsuitable according to protruding pivots is that right?

I have read about 20 pages and have seen people trim the kit side of things but it looks undesirable for such high power and going against the original design...

Unfortunately when I went bike shopping I didn't think about the pivot sticking out thing, but this is the closest but blurry pic of the giant..

I think I will have to go up to Giant LBS again and look if it protrudes.

My current bike with bbs02 shows that the pivot is pretty much flush with the bbs02 bracket.

thanks for help.

 

[Driveless]

Re: pivot location...

The concentric (having the same centers) pivot on the Stealth is a good thing for pedalers with a hub motor. But...once you engage a motor onto the front of a chain, the entire game changes. Humans put out maybe 200W of pedaling, so any "effect" on the front of the chain can be neglected over other concerns (chain-growth when the rear suspension cycles).

With a concentric pivot/chainring, applying 3000W will try to pull the swingarm up, compressing the shock some (called "squat"). If you imagine a ridiculous pivot location that is very high, applying lots of power from the BB to the rear wheel (on the top run of chain) would pull the rear wheel down (also not good).

For a powerful mid-drive (whether it uses the bikes gears, or is a one-speed), the Qulbix Raptor pivot position is perfect, its halfway between too high and too low, to minimize the overall effect. Plus, the BB is attached to the frame, instead of the swingarm. I also like how the elevated chain stay means you never have to break the chain to remove it from the frame.

Putting a Big Block on a Motoped or Stealth is not a horrible idea (either one would definitely be fun), but...if optimizing a nimble feel for off-road, the Raptor is the best orientation, and has the brightest future.

When pondering a pic of the Raptor rear suspension, visualize a 200-lb rider on it, and the suspension already compressed 1/3rd, and look at the location of the pivot in relation to the top of the chain.

I'm going to have to call you out and say BS.
It's economically easier to produce a rearswing arm that is not on the same axis as the chainring.
I like the Qulbix, but I'd hardly say it's swingarm is perfect. Having to use a chain tensioner, not perfection.

There's a reason engineering seems to have a trickle down from the motorcycling world to mountain bikes, its already been done and perfected there.

Motoped's 125cc is putting down more power than a 3000w, they must be having horrible squat issues..
And this busa, with 160 hp, must be squatting more than Arnold Schwarzenegger!

 

[Thud]

There's a reason engineering seems to have a trickle down from the motorcycling world to mountain bikes, its already been done and perfected there.

Sorry boss, that is an "over generalized" statement.
All of motorcycling is a mash up of cost driven compromises. Mountain bikes are a mash up of engineering to justify the costs of the final product.

Horst Leitner (a name any Moto crosser & now mountain biker should know) has shown the way to eliminate chain torque in rear suspension systems (clear back in the late 70's), & pedal-bob in bicycle geometry.

The whole issue of chain torque & squat is over thought.
Most chain driven motorcycles suffer form the ill-effects. but very few ever invest cash to solve the problem....that is only a problem in extreme applications of power.
example: Hard acceleration over rip rap bumps...the open class motocrossers from days gone by really improved with an AMP Research torque eliminator.

 

[Driveless]

Chain squat issue being in extreme power examples that our ebikes will likely never see, unless you made "death bike" suspension.

Most suspension bikes are compromises I agree with you there.

Which is why the Luna Cycle platform has the most bang for the buck value of the options available using lightning rods kit.

 

[spinningmagnets]

I'd like to publicly state that I am no suspension expert.

Adding lot of pulling power to the top of the chain doesn't so much pull the swing arm up as it pulls the frame up. The frames (and engines) on the afore mentioned motorcycles are much heavier than these bicycles. The stiffness of the rear shock spring also plays a role, and the shocks used on Raptors are not as stiff as the shocks on motorcycles. In spite of my inexperience in these matters, I recognize there are many factors that influence squat.

I'm not hating on the concentric Motoped pivot/jackshaft. I would love to have one. However, if given a choice, I would prefer the Raptor, even if the price was the same (although, the Raptor is currently cheaper).

 

[Driveless]

Oh believe me I've heavily considered both routes especially after seeing the motoped build and qulbix's current bare bones frame sale.
They both have their strengths and weaknesses.

But not having deep pockets I opted for to forget suspension in the traditional sense, the luna cycle fat tires will have to provide adequate dampeing for bumps for my needs, at least until I can afford a mission e-motorcycle

 

[John Bozi]

Mike can I get these dimensions please? Or do you prefer emails? I imagine I am not the only one who would need this info so see keeping it public might be more beneficial either way I am happy....

 

[r3volved]

I had to grind the edge down slightly for my fit.

 

[KONAKID]

Me too... But its a tight fit on the Kona Stinky rear suspension....but no problem' just a few minutes on the grinder wheel.
Just make sure there is enough "meat' left for strength!

and BTW if it helps the width of the "ring" around the BB before grinding is 10mm and the width of the bracket..if its for a 68mm BB - is 68mm. and the steel plate is 2.7mm thick.

Tim

 

[t0me]

I did a little trimming in exactly the same way on my 2004 kona stinky and 2010 giant anthem.

 

[John Bozi]

Thanks for the clearance pics and measurements guys.

Few more questions.

Reading through past pages there was talk of torque braces..

Does the big block kit require additional "torque whta tever fabrication arm brace" to run at its suggested power levels on a bicycle? If so who has got pictures of them built on?

I am trying to imagine the clearance the bb chainrings will have at the swingarm and the drive train line.

How many teeth is stock that runs to rear sprocket and what is the diameter of the that inner ring? Does it line up mostly centred with the rear cassette? What's the smallest amount of teeth it can be swapped out with? Has anyone done that and which products?

What does it naturally line up with on your kits and which bb are using too?

I am aiming @ lower speed levels than most for more efficient long steep climbing.

cheers

 

[Material Defender]

I'm in the final stages of figuring out whether either of the LR kits will work on my current bike, a 2014 Trek Fuel. It has a 90mm bottom bracket with an internal diameter of 46mm. The attached image is my current design intended for use with Mike's 100mm lower mount. Does this look like it will work? Any suggestions? Yes, I will probably place spacers between the BSA adapter and the lower mount to account for the .6mm gap in the design. Thank you for your help.

 

[John Bozi]

I was pretty set to buy the glory today until I realised that it is designed as single front chainring bike and it's swingarm juts out past the 36t 104 position.

I have no idea if the big outer LR chainring will clear the swing arm. This is getting trickier every turn I take. If I haven't chosen a bike I can't choose the bb width for the kit, If I wait till I have the kit then I can only choose a bike with that bb.......

Am I cursed now to look for bikes designed for more than one chain ring?

 

[t0me]

The chainring maximum size would be an issue for sure. Also from 2010 onwards I think the Giant Anthem and glory has the curved bottom bar of the frame, they suck for a mid-drive without changing the bottom brackets so you can have it a lot further forward, otherwise the motor will point right down and totally stuff your clearance. Would make for a crappy bike offroad.

 

[John Bozi]

The chainring maximum size would be an issue for sure. Also from 2010 onwards I think the Giant Anthem and glory has the curved bottom bar of the frame, they suck for a mid-drive without changing the bottom brackets so you can have it a lot further forward, otherwise the motor will point right down and totally stuff your clearance. Would make for a crappy bike offroad.

Yeah I know LR has the stretch kits to accomodate for the bar and Im fine if the inner chain ring is smaller, its just whether or not the outer one that comes from the motor will clear or not.

If Zack Jordan on LR facebook could confirm there was no clearance issues on his glory (which type and year too) and if I could work out if the design spacing is the same I could go ahead and buy...

EDIT: also note his "torque arm" which basically would destroy any chances of mounting a few batteries in the triangle.

 

[riba2233]

EDIT: also note his "torque arm" which basically would destroy any chances of mounting a few batteries in the triangle.

Why, 18650 batteries are narrow enough, you can fit both them and torque arm.

 

[John Bozi]

Why, 18650 batteries are narrow enough, you can fit both them and torque arm.

I was hoping for a wide battery tray of about 15cm wide in the triangle as I run now. but in cases where there are sharp corners cylindrical cells might have an advantage I hadn't thought about since going to lipo..... I really don't want to change chemistry but still an idea to consider.

My main worry is damaging the pivot holes. Stretching out those holes if they twist abnormally would be hard to fix..

Is there any other solution to mounting a torque arm? what other solutions has anyone tried like bracing the tube elsewhere, like the seat post or something?

Anyway I might even do the fork battery thing...

cheers

 

[Deanwvu]

Here's Mike's Big Dummy drive mostly complete (in this pic I did not have the Terracycle idler I needed to run the 2nd chain):

Non drive side by deanwvu, on Flickr



Here's the final drive after I got the idler:

20150730_180740 by deanwvu, on Flickr


More pics in my build thread (see link in signature)

 

[stonezone]

I do think i'd like just a little more speed (maybe 23-25mph), and also, an 18t would fit the upper roller on my tensioner better. Right now, when the suspension compresses a bunch and the tensioner swings forward, the upper roller I added shifts a bit too close and i'm losing maybe 20% of it's range.

I was wondering if you have found a solution since then that works well.

Ages ago I researched every possible single speed tensioner and most of them have a limit of how many teeth they'd work with.

I also one just explode on me just using the bafang....

What's the maximum teeth, and which tensioner is the most robust, and would any take the thick 1/2 1/8 connex bmx chain which Mike has suggested as being the strongest possible that he knows of...

I have also run with a ton of playing around and had success with running a motor bike tensioner... but have had lots less luck recently trying to get it to work again... I think my chain may be playing up ....

cheers

upgraded to 20s and top speed is pushing 30. perfect for our trails and crazy fast. As for BB sprocket clearance on the glory, I'm not having issues at all with the 44/48 combo and stupid fat 3/16 chain. its close though and caused me some grief during thrown chains, but if everything stays in line there's plenty of room. I have access to my dad's shop for the next 2 weeks (lathe/mill/forge and plenty of scrap) and I'm going to try and throw together my 2 roller tensioner idea. I'll post pics when it's making progress...

I'll be back in the middle of august and should have everything rock solid after much brainstorming.. cant wait, i'll keep you posted.

only other news to report is that it's ween windy and kites are fun...

 

[John Bozi]

Thanks for all the help to everyone

It was a bit of a crazy time looking at bikes and have bought a second hand bike for $1k au (paranoid I haven't discovered cracks yet) that really needs motor help because its dam heavy without!

I decided to reconsider all the latest trends with bigger wheels and bendy tubes to get the lr right up close to the bb with a straight down tube.

First night she sleeps at my place the wife is pretty upset with my attention to her.