The BEST and FIRST Qulbix Raptor mid-drive build!

[LightningRods]

It depends on who is doing your laser cutting and what the material is. I find that stainless steel cuts the cleanest, with the least slag, followed by mild steel, with aluminum being the worst. I clean up my sprockets with an orbital sander, then hand sand (purely for looks). I bevel the teeth with a bench belt sander.

 

[Grantmac]

What tooth counts are you using for the two stage LHD setup? You can PM me if it's off topic.

 

[LightningRods]

Doesn’t matter to me. On the primary stage I use a 12T #219 driver and a laser cut 75T driven for a reduction of 6.25:1. The second stage driver is either a 20T 1/2”x1/8” or a 40T #219. The rear wheel sprocket can be anything from same count as the driver to 2x for an overall reduction of 12.5:1. With a Big Block that ratio will climb a tree.

 

[DanGT86]

This website will generate a sprocket .dxf file or cnc code for you using your input of roller diameter and pitch.

I have not tested a sprocket generated from it in the real world but it looks like a nice free tool.

http://www.idleamusements.com/?page_id=367

 

[Grantmac]

Doesn’t matter to me. On the primary stage I use a 12T #219 driver and a laser cut 75T driven for a reduction of 6.25:1. The second stage driver is either a 20T 1/2”x1/8” or a 40T #219. The rear wheel sprocket can be anything from same count as the driver to 2x for an overall reduction of 12.5:1. With a Big Block that ratio will climb a tree.

How are you coupling the primary driven to secondary driver?

 

[LightningRods]

I made a hub that spaces the two sprockets apart. Both sprockets and the hub have the same bolt pattern and are solid mounted together.

 

[Grantmac]

And it runs on the bottom bracket shaft inboard of the crank?

 

[LightningRods]

 

[Compoundbike]

Perhaps a stupid question but how does the Sabvoton SVMC150 match with the L-R Swingarm Big Block Drive ?
Im thinking of getting L-R Swingarm Big Block Drive.

 

[LightningRods]

Until recently sine wave controllers did not work with my Big Block motor, including Sabvoton or Adaptto. With Alan Hu's help the motor has been modified to run perfectly with all sine wave controllers. I strongly recommend the ASI BAC2000 with my swing arm drive. In recent testing the Big Block ran to nearly 9,000 rpm with massive low end torque and smooth linear throttle control using the BAC2000.

You are free to use the controller of your choice.

 

[Compoundbike]

Yes i can imagine the BAC2000 is better however im $ limited on this weekend toy. So i will try it with a Sabvoton.
So which parts do i need for the Qulbix ?

165mm billet 6061 wheel hub with 4140 chrome moly axle (dropout is 155 mm)
96t #219 stainless steel wheel sprocket
DID #219 drive chain
Chain tug final drive adjusters.
ACS 16t freewheel cog (right side)
12g Spokes 230 mm for the 19 inch motor wheel

 

[LightningRods]

The main complication is that the 165mm hub is made for the 165mm wide Qulbix dropout, not the 150mm. You can order a 165mm dropout width swingarm from Qulbix. Or work out your own solution for a left side sprocket mount.

The motor and it’s mounting brackets are the main part. The 219 driver sprocket comes with the motor. In addition to the parts you listed you also need a new brake caliper mount to relocate the caliper outward. I don’t sell the spokes.

 

[Compoundbike]

Ok so in this case the Option One Stage Big Block Drive seems better, if i don't want to buy a new Swing from Qulbix right?
But the parts except the Hub remains the same ? My goal is to realize the conversation around 1000$.

 

[LightningRods]

The right hand drive single stage is the easiest install. You can run several different final drive setups. Because the chainwheel runs at high rpm with less reduction you can run 3000-4000 watts through a derailleur without destroying it. We're now pushing the Big Block to 8000 watts and more at up to 8500 rpm. With that much power and revs you don't need multiple speeds and frankly derailleur chain and sprockets can't handle it. You can run 1/2" single speed chain and sprockets or even #219 cart chain. The only drawback to the RHD single stage drive is that you can't pedal with the motor due to the high chainwheel rpm. You can still pedal the bike so it's legal as a pedal driven bike. Top speed pedaling without motor is slow, around 7-8 km/hr.
The reason that most 3000 watt mid drives destroy final drive parts is too much motor reduction combined with overdrive final stage gearing. My RHD has two stages of reduction. Less torque multiplication at the chainwheel, less resistance from high final stage gearing, far less overall driveline stress. Once we give up trying to synchronize a 3000 rpm motor with 100 rpm pedaling, everything becomes much simpler.

 

[Compoundbike]

I understand however im not always sure if i pick every part right. Will this Hub fit http://www.eastgem.net/rear-hub.html with Acs Freewheel and Driven Sprocket to the One stage Big Block drive?
Or do you recommend a another 155 mm hub?

Right hand drive is the Option one stage big block if im not mistaken? Sorry those questions may seem silly to you, but for me its not so easy to plan everything right.

 

[LightningRods]

That threaded hub from Eastgem could work fine. Others have suggested it. I haven't tried it personally. For the rear wheel sprocket I recommend a White Industries HD freewheel rather than the ACS. ACS are good inexpensive freewheels but not nearly as strong as the W-I. You will also need a thread on disc brake mount in order to bolt your brake rotor on to the left side.

Another option is to use a freehub with one of my sprocket adapter plates. You can run either 1/2" or #219 sprockets. The Fouriers single speed conversion is inexpensive and readily available.

 

[Compoundbike]

Lightning Rods isnt answering me on FB, but I heard there are Fires in West Oregon.. also White industries have some Production issues due to the Weather etc. I hope nobody is injured and not affected by those hazards.

 

[LightningRods]

I’m fine. No fires in my area. I haven’t answered you? I’ll go check my messages.

 

[LamereCycles]

Are any qulbix raptor kits left?

 

[LightningRods]

I presently have one available. I’ve had an inquiry on that one but no deposit. I’ll make more.

 

[LamereCycles]

Willing to make deposit today.

 

[LightningRods]

I’ll check in with the other customer and PM you.

 

[pjwalmsley]

I've been falling into the brainstorming rabbit for a 'better' mid drive...

1. Wheels

What is everyone using for wheels with this kit? Lightweight motorcycle or downhill bicycle? Shinko? Schwalbe (wonder if this bike fits 28" wheels for 2.15" Marathon E-Plus)? Other?

2. Comparison

I've heard this motor is comparable to a QS205 but lighter and lower amp consumption for the same power. Thoughts on how the Big Block compares to some of the larger properly wound RC style motors;
https://alienpowersystem.com/shop/brushless-motors/120mm/120100s-sensored-outrunner-brushless-motor-50kv-25000w/
This motor seems like it could provide a more ideal reduction and increase the power to size & weight ratio. That said, it isn't sealed and it comes from the RC world. They have confirmed it can be used in wet weather offline but I still fear putting an open motor that close to the ground/mud (it would be different mounted with a belt on a motoped style frame) or covering the vents. The mount and drive train would need to be DIY.

3. Corrosion

I posted in the Facebook group a while back with my main concern being noise and range. I've back seated the range concern but a new concern was raised. One of the comments was from someone also from Boston. They endorsed the Qulbix 76 but discouraged the LR kit due to rust. Boston is on the water and uses too much nasty road melt which has destroyed my 3 previous bike drive trains despite fair weather riding.

I started looking into 8mm pitch corrosion resistant chains. There isn't much selection for #219 chains. The British 8mm pitch chains allow for a similar reduction. This was the best I found at $210 for 15 feet:
https://www.ebay.com/itm/BS-05B-1-8mm-Pitch-Dunlop-Stainless-Steel-Roller-Chain-5-Metre-Box/193014091329?hash=item2cf0894e41:g:KlcAAOSw9NdXscPq
There were other chains (Tusbaki, HKK, Iwis) that look good but are too costly or difficult to obtain.

Unfortunately, stainless sprockets are a PITA to get as well... I found an un bored front sprocket with 8mm pitch for $80. Squat for the rear, especially in higher tooth counts. I think I could 3d print a TI front sprocket for around $100-$140 and CNC. I could 3d print (Markforged Mark 2) or CNC a rear sprocket at a local makerspace (Artisan's Asylum).

If #219 and 05B are compatible we could use the kit sprocket or an off the shelf or cnc/3d printed sprocket;
http://www.tsracing.com/Extron-Kevlar-Pro-1-Piece-219-Sprocket-P5813.aspx?gclid=EAIaIQobChMIg-md8L3o5gIVBl8NCh0CHQF-EAkYASABEgIrcvD_BwE

@Mike could we machine stainless sprocket(s) for this chain or is that asking too much of you and your machinist for a smaller run? I could probably cut one locally fairly easily. Thoughts on the chain I mentioned?

4. Noise

I've heard that a decent controller (already purchased), larger front sprocket (hampering a proper reduction without an XL sprocket), and plastic guard will help.

I think a dampened sprocket should also be considered. It looks like they make them for motorcycles;
https://sprocketcenter.com/525-chain-kit-ognibene-silent-drive-sprocket-set-with-choice-of-chain-honda-crf1000-africa-twin.html?gclid=EAIaIQobChMIkJXYn8Ho5gIVJOeGCh1MxQ4yEAQYASABEgI0svD_BwE
LMX put together a damped sprocket a while back;
https://www.youtube.com/watch?v=GJTRYV8Qqx4
https://lmxbikes.com/en/drivetrain/203-12t-219-pitch-sprocket.html

Maybe this could be made in stainless and/or we could add 'lobster rubber bands' or proper rubber to pad the impact of the chain? A printed Ti sprocket could go a bit further including dampening on both sides?

Belts have also been discussed. However, I think it's interesting to note what Cake and LMX have been up to;
https://ridecake.com/shop/add-on-parts-kalk-and/belt-drive/
Surprisingly LMX is experimenting with 1.2mm 8mm pitch belts with some success.
https://www.youtube.com/watch?v=8BEZn1xDJyc&t=38s
I found it interesting that I found a tensioner was necessary. Interested in seeing the long term wear - the Gates data sheets discourage tensioners against the belt and older gates drives failed due to the non open CDX style tensioner... They make this belt (carbon 1.2 wide) in CDX style but it's 200mm long which is too much. A 12mm belt isn't too wide... Perhaps it's best to see how quickly it fails...

Mike suggested a belt drive won't work for the Qulbix 76 due to tire clearance... Additionally, what if we added a tensioner on the swing arm keeping the belt a bit lower until we are past the tire? I assume he was envisioning a 40mm belt not 12mm? Anyone have a link to the Typhoon swing arm build?

The belt sprockets could be 3d printed a kevlar sprockets attached to an al/stainless spider, perhaps even with gaps on the sprocket like the cake bike for dirt to slip out. Lightweight metal drive sprockets are easy enough to find and keep cleanish.


I don't own this drive yet and don't mean to bash or nitpick. Just trying to build off and improve upon what others have created.
Perhaps it's best to 'start somewhere' and just get the standard kit then start playing with concepts for improved wear resistance, or if possible, get the kit with a sprocket cut for 05B, some stainless chain, and go from there.

 

[LightningRods]

The best wheel solution for a big block motor being run up near 10 horsepower is a lightweight motorcycle rim and tire. The old big block would push a Qulbix type bike into the 60 mph range. I have a new and vastly improved motor that I’m sure will run at least into the 70s. Bicycle tires just aren’t safe. Most of the people I know are running 18” or 19” rims. I want to run 21” MC rims with 2.75”-3.00” tires on my next build.

I have one of the 25kW RC motors mentioned and have had it bench tested by two different controller vendors. It’s the same size and approximate weight as the big block. It’s resistance and current draw is much higher. It really is a 25kW motor which is about twice the big blocks maximum output. I may use it to build a road race bike for track only use. The ported open case is an issue for off road. It would not be a good motor to swingarm mount for anything other than dry pavement. A 25kW mid drive might sound like it would be fun on a bicycle, but I’d want at least a converted 125cc motorcycle for that much power.

I’m just going to flat out recommend that people not buy my drives for commuting on salted roads. I’ve had a couple of drives sent back for repairs that had been run on salt. It’s horrific. They looked like a WW2 fighter plane that had been in the ocean for 75 years. Kill a hub motor instead.

The big block is not a noisy motor and when installed properly 219 chain is quiet chain. Most of the noise comes from the small driver sprocket. I’ve been completely enclosing the motor drivers with good results. The chain running in open air between sprockets makes no noise, and the large rear driven sprocket makes very little. The driver is running at 8x the rpm of the driven and is putting an extreme bend on the chain. It’s the noise culprit.

I’ve always liked belt drive. It has its limitations. Alignment and tensioning is far more critical than chain. In order for belt to have good power capacity it has to be either wide or a coarse tooth pitch. An 8mm pitch belt will have pulleys 60% larger in diameter than a 5mm pitch belt. An 8mm belt drive needs to be at least two stages in order to provide the 8:1 to 9:1 reduction that the big block needs. Tensioning is definitely an issue. I’ve tensioned most of my belt drives in the past with slide tensioners that vary the center to center distance between the pulleys. This is the best way to do it. Idler tensioners are much easier to design a drive around and have the advantage of never slipping under power as a slide adjuster can. I’m chatting with Recumbence about this very issue and also plan to write to my contact at Gates. The tech bulletins from Gates say not to back bend Carbon belts.

Sine wave controllers have advantages but don’t affect the noise level on the big block much. That seems to apply more to hub motors. If quiet operation is your top priority, a hub is quieter. Compared to other mid drives, mine are quiet. The big benefits I’ve found from sine wave controllers are smoother, more progressive throttle and field weakening.

 

[pjwalmsley]

Thanks for the lengthy response!

So moto rims it is! I'll have to see if I can squeeze in 21" wheels on the Qulbix frame; I have a feeling I'll have to stick with 19".

I overlooked that 8 pitch belt !== 8 pitch chain; that does make things a bit more complex.

Interested in picking up a kit when they are back in stock. I'll PM you.