Motorized Bike Project.
 

So, without going into a ton of detail, I have the itch for a new project to tinker with, but with being in classes to finish a degree and working on sorting out my finances and eliminating debt, I decided to build a motorized bicycle instead.

It has no practical application in my life really, just something to tinker with that is cheap. Who knows, maybe I will use it to go to work from time to time once I work out the bugs.

Funny enough, I have started backwards with my build and actually bought the engine first. What can I say, I'm weird. I even chose a questionable engine to use, known as the Phantom 85. Basically a factory built version of a YD100 with a Stihl MS460 cylinder and piston - well, chinese copies of them at least.

These engines are known to be quite powerful, and quite unreliable too. I told you I was weird.

They have fixed the biggest issue with the motors, which was their decision to use a loose fit graphite injected bronze wrist pin bushing. They would wear out extremely fast and cause the piston to turn and slap around in the cylinder and catch the rings on the ports and all sorts of other catastrophies.

The newest version they are selling now use a 12mm wrist pin and roller bearing. They achieved this by using the "110cc" connecting rod with the YD100 crankshaft and lower case.

The current issue is that the pistons are experiencing ring land and skirt failures. It may be a 1 in 100 type of issue, but it is still happening.

My plan for the motor is to in theory make it worse. How? Eliminate the reed valve and install an aftermarket piston with caber rings with no piston windows. I haven't decided yet on a domed 460 piston or milling down the top of a 380 piston to set a tighter squish gap. They are basically the same, but the wrist pin height on the 380 piston is 1mm lower. The squish gap on the Phantom motors is actually over 1mm, which is enormous. I will decide for sure once I can measure my own gap. The pistons are cheap enough anyway I may just order both to experiment.

What can I say, I am crazy.

My thinking behind this is due to the fact that this engine makes so much low down torque it has actually wrecked a couple of rod bearings on a couple of other bikes. That Low Speed High Load force on bearings is no joke.

Instead, I plan to clean up the transfers and intake port, widen the exhaust port (and possibly raise the port roof to add 2 degrees, but I will need to check timing). Also clean up the piston ports for the transfers and open them up a little. This is all advice from a person that builds competition chain saw engines. After talking with him for a bit, he said that he has never felt the need to window a piston on any engine he has built, and I take his word for it.

I also plan to split the cases so I can properly balance and true the crankshaft. Why not? Like I said, cheap tinker project. I like the idea of trying to take away just a bit of it's low down power in exchange for a higher top end and more RPM. Plus, I can always go back and window said piston later if I change my mind.

I am still deciding on what type of bike/frame to use for it. I am torn between spending the money on a high quality entry level gravel/hybrid bike OR one of the fuel tank frame Felt Fakers like the Zeda Dawn V2 https://www.bicycle-engines.com/zeda...as-frame-bike/

My big consideration is comfort. I am not actually trying to build a race bike. I want to have a sprocket set that can achieve maybe 30-35mph max and climb hills without much help from me. Some people have said the Felt Fakers can be made comfortable for taller riders, and I do like the style and built in fuel tank. The only thing I do not like is that it comes as a single speed. I may look into adding a 3 or 5 speed freewheel to the back.

Well. At least you'll be able to say you're not Just Another Guy With a Flying Horse Kit.


Real interested to see how this pans out. But me, I think I'll stick with my 'lectric one. It goes almost as fast and it's never blown me up even once...

I considered electric as well, but I just love a good planet killing combustion engine. I may still do an electric bike next, but at the moment all the parts are expensive or hard to get, at least the good parts that are worth buying.

These phantom motors are way more powerful than the typical kits out there. Not even kidding, WAAAAY more powerful. That is actually part of the reason they are a bit unreliable out of the box. I've watched more than one guy who had their bike up to 40mph+ with zero engine upgrades, just the right sprocket size to do it and the carb tuning dialed in properly. There is no off the shelf aftermarket for them, at least not in terms of proper exhaust pipes other than what it comes with, which is actually pretty big compared to the typical 2 stroke kit exhaust. The piping is massive. With just an expansion chamber from other bikes modified to fit I have seen two achieve over 50mph. Speeds I never personally want to achieve on a bicycle.

Speaking of which, I'm sure I don't need to tell you that whatever you select for a frame you'll really want something that doesn't rely on rim-pinchers for brakes...

Oh, no. Disc brakes for me for sure. I have never liked rim calipers

Would Chuck Norris need brakes? Oh heyill no!

I really enjoyed messing with my motorized bicycle, Megadan.
It always needed something but it always ran when I needed it.
I have done some 50 mile round trip commutes on it.

Always fiddling with the clutch. Always making brackets to attach lights and stuff.

I ran lights designed for a bicycle generator off my ignition wire because both were 6v.

I finally sold it when all the roads around my place had prohibitively high speed limits.

Yeah, it has no real practical purpose in my life. It is quite literally just a fun project to give me something relatively inexpensive to do.

I lived in AZ when I built mine, so I could use bike lanes if I didn't exceed 20mph.
-When I first moved to TX, I lived in a huge community. Most roads had speed limits around 35 mph. They were perfect.
-Now I live by high speed arterial roads. The only way I would use them is with an e-bike, riding only on the sidewalk and paths.

From my experience (I've owned the phantom 85 and all of the little 2 strokes.)
for 2 years my main mode of transportation was a motorized bike. It's what I was riding when I got the call about my dad, motivating me to rush over to the next county on hilly backroads.

All of those engines are from the same factory. The phantom 85 I bought was horrible. The head, piston and crankshaft replacement to go from the 66cc to the 85cc creates a ton of problems that ruin any longevity of the bike.

REPLACE ALL BOLTS for mounting the engine and for the intake and exhaust with good ones bought locally. as much as these vibrate I've seen the exhaust and intake bolts shear right off. I've heard of the rear sprocket bolts doing the same, but haven't experienced that myself. You know the typical chinesium quality doesn't pair well with a high vibration 2 stroke.

All of the quality from any of the sellers is hit or miss. The biggest way to get the best performance from my opinion is shorten the intake, get a high compression head. Polish your ports (lots of deburring from the casting on the jug) Windowed piston and reed valve attachment.

Being a china bike rider you know all to well about jetting the carb (hard to find jets for the stock carbs, best finding an aftermarket that fits)

As far as exhaust upgrade go, they're hit or miss. It's all about the rpm range you're running at. The stock one does well if you know how to enlarge the opening just a smidge. The ones referred to as "banana pipes" are just snake oil and sound a bit louder, but aren't truly tuned to give any performance.

All of these kits are way too overpriced vs buying the cheapo kit and finding the aftermarket parts to slap on yourself.


If you want I can link everything that was on my bike that's still in use today since 2018
(the new owner has only had to replace the chain and air filter)



And just like any other china bike
LOTS OF LOC TITE is a must.



Base motor kit

I recommend this High compression head, as the other design are lacking in cooling. You will notice a difference compared to the stock one

Windowed Piston. DO NOT get this upgrade if you don't get the reed valve, or you will lose a lot of performance

Reed Valve (wont get much out of this without having a windowed piston



And the final part, bike wheels with the mounts for brake rotors tend to fit the rear sprocket just fine. This is a must if you want any longevity as pushing the engine harder than stock can rip right through your spokes. Hell even a stock engine can do it if you get one thing out of alignment.

Oh, believe me I am well aware of all of this information. I don't go into anything without doing epic levels of research. I do thank you for taking the time to say all of that though as it may help others.

Believe me, I planned on doing a LOT to this engine, and replacing most of the hardware, anyway.

As far as the Phantom 85 reliability, it's actually improved some now that they stopped using those stupid bushings. They now use the same connecting rod as the new "110cc" YD100 engines, which use a 12mm needle bearing. In fact, it uses the same needle bearing as the MS460 chainsaw the jug and piston are based off of.

The only real reliability issue they have now is the pistons are breaking apart, and part of that is due to the casing quality, the other part is due to the ring gaps being a bit on the tight side as far as I can tell. One ring was ok at .012" but the other was on the tight side at .006mm. Ideally for the bore size I wouldn't want a gap smaller than .011" when considering they run fairly hot.

I actually purchased a high quality MS460 piston with caber rings for it and gapped them myself. I take no chances. I am also splitting the case and replacing all of the bearings. The crank bearings were damaged during assembly. The crank itself also needs to be trued badly as I can see the runout visibly and it causes binding with the bevel gear. Since I am going to have it apart I am going to balance the crankshaft and try to get my balance factor to 65-70%.

As far as the rear sprocket mount. My idea was actually as you described with the rear hub. Of all the options, that seems the best one in my opinion. I can then run a set of spacers and a 200mm rear disc for clearance.

Ready for comical levels of bad, even by Chinabike standards this thing is so bad it makes our bikes look like a Rolls Royce.

So, let's start with the 3 dimensionally warped exhaust flange. They got this sucker so hot, even if I wanted to try and straighten it, I don't think it would hold a seal without grinding half of the flange away. Then it would be super thin. Thankfully, they did open a warranty claim for it so I should get a new one.

https://i.ibb.co/pW9Ytxf/flange-2.jpg

https://i.ibb.co/FhvLfL6/flange.jpg

THEN! To skip forward, I noticed the engine would get tight and loose as I turned it over. The crank is so out of true the bevel gear (small drive grear on the crank) is visibly moving in an eccentric manner. I had planned to pull the crank and true it anyway because I always planned to balance it. Not only that, but everything has a gritty feel to it like it was rolled in sand. Even the crank and lower rod bearing sound SUPER gritty.

Imagine my surprise when I split the case and THIS fell out. (picture is linked, larger image for better detail if clicked ) This isn't even all of it lol. Everything is coated in aluminum flakes too. I have some work ahead of me :wtf:

https://i.ibb.co/wN7y021/phantom85caseshavings.jpg

So, yeah.... New breaings going in for sure.

So, second part of my now build/rebuild is not using the stock piston. In the week I have been on just a Facebook group for this engine, 3 piston failures. All of the breaking apart at the ring lands and crown. A couple on the skirt.

I am not yet decided on what route I want to take with the piston yet. One thing I do know, I am NOT using the stock piston. The casting quality and ring quality aside, the piston wall clearance is grand canyon levels of huge.

My first option is an MS460 piston, which is .12mm taller in crown height over the stock piston, so I still have a ton of room with the squish gap before it becomes an issue. It also uses the same exact type of rings at 1.2mm, and the one I ordered is a pop up piston and it came with Caber brand rings. One slight upgrade, besides a small bump in compression, would be the fact that the piston ports for the transfers are a good amount larger than the Phantom ports.

This is the stock vs. MS046 piston transfer ports. If I had to guess, they are about 30-35% larger.

https://i.ibb.co/mXJRYFT/phantom-stockv046.jpg

The second is an MS380 piston. This piston could work, and in terms of performance has the greatest potential. It's 1.2 mm taller in crown than the stock piston. As it stands, this means my squish gap is negative. On the plus side, this does mean that I could mill the top of the piston down and precisely set my squish gap to whatever I want. If there was any real drawback to it over the 046 piston, it would be the thicker 1.5mm rings. It's not a big difference, but extra drag does mean lost power.

On the plus side, the piston transfer ports are flipping enormous in comparison to the other two pistons. I would hazard a geuess of close to 60-70% larger when compared to the original Phantom piston. This means at higher RPM there is greater potential airflow, which makes up for the thicker rings a bit.

https://i.ibb.co/ySMPzMC/038piston.jpg

The other issue is that it uses a 13mm width needle bearing over the 15mm of the 460 and stock piston. On the plus side there are needle bearings that work, and the rod end at the wrist pin is a hair over 11mm wide, so there is plenty of room to work with.

https://i.ibb.co/9qMnJpC/038piston3.jpg https://i.ibb.co/ncLSQ6x/038piston2.jpg

I am still up in the air about windowing whatever piston I choose or not. A part of me thinks this engine could be a little softer in the low end power and make up for it with higher RPM power. A non-windowed 038 piston with some careful port work could change this motor into something a bit more reliable without sacrificing the upper RPM power. We shall see.

To wrap up the piston side of things, after waiting a rather long time for the bearing to get here I can now confirm all I need to do is mill the top of the 038 piston to set the squish gap to exactly what I need and window the piston. The 038 bearing is exactly the perfect size for the rod end. It does loose a little bit of bearing surface area as the rollers are a tiny bit smaller than the wider 046 bearing, but I don't thing this will be an issue.

https://i.ibb.co/KNRkLjk/038-wrist-pin-bearing-3.jpg

https://i.ibb.co/fX7qnmC/038-wrist-pin-bearing-2.jpg

https://i.ibb.co/SrdcJNH/038-wrist-pin-bearing.jpg

I am about to wrap up the bottom end today or tomorrow. First I took my housings, removed the bearings, and cleaned them in the parts washer at work. I then replaced both clutch shaft bearings and both crank bearings with FAG high speed rated (14k rpm) 6202 C3 spec bearings.

Since I had the crankshaft out I decided to do the balance drilling. I set my balance factor on the factory piston and achieved a 68% balance factor.

https://i.ibb.co/XYJYBCw/crankbalance.jpg

https://i.ibb.co/v3vby0Y/crankbalance2.jpg

The last step in this process is that I need to true the crankshaft. I have the dial gauge and stand needed to do the job, but I lack the stand to do it. There are stands out there one could buy, but they are quite expensive and I would have to wait a coulpe of weeks for it to arrive. Instead, I decided to make my own using some scrap bits from work.

It isn't pretty, but it's level and will do the job just fine. Cost. Free.
https://i.ibb.co/k4jddwx/cranktruingstand.jpg

I got my bottom end back together and was able to check the squish gaps with the pistons I have on hand. I measured the chamber CC as best as I could and came up with a 6 cc chamber. Not exact since it is a fixed head cylinder, but fairly close.

Surprisingly, with both base gaskets in place the MS380 piston actually clears. It has a fairly tight squish gap of .6mm and would give a compression ratio of nearly 12:1, which is a tad high lol. The bigger issue is it blocks the transfer ports and closes off the exhaust port, so it definitely needs to be milled down to work.

The stock piston with both base gaskets has a 1.72mm squish gap and has an incredibly low compression ratio, 8.9-9:1. Possibly a design choice to keep heat down and allow it to run on cheap gas. With one base gasket it drops the squish gap closer to something more acceptable of 1.12mm, and bumps the compression up to 10:1 With no base gasket it's right on the edge of squish gap tolerance at .52mm, but like the 038 piston the compression is near 12:1

Unsurprisingly, the MS460 piston ends up with the best overall figures. With 2 base gaskets its still nothing special with 1.6mm squish and 9.1:1 compression, but with one it has a squish gap of exactly 1mm and a compression ratio of 10.45:1. A pop up piston with 2 base gaskets lands somewhere in the middle with a 9.6:1 compression ratio while also maintaining the port timing of the 2 gaskets.

I am going to run a flat top 460 piston with 1 base gasket as I view it as the best combination overall. and then likely port the exhaust side to restore some of the lost timing and increase duration.

Dangit Dan! Stop it! I don't need any more projects. :lmao: Building these motorized bikes are so much fun. I got too many irons in the fire. I promise I'm not going to do another motorized bike. Not right away anyway. :hehe:

LOL. Jerry, this is keeping me from having too many irons in the fire. I keep wanting to buy another motorcycle, but it's the last thing I need. This gives me something to fill the time and scratch the itch.


The funny thing is, this engine is considered one of the most powerful out of the box engines and here I am trying to improve it.

You and I know there's no such thing as being the most powerful already. :lmao:

Or that anything made in China isn't going to need some help to actually make it good or reliable.

So I decided on running a standard 460 piston with one base gasket. With that in mind I splurged and bought the highest quality piston I could and got a Meteor brand piston.

The quality difference compared to the others is tangible and visible. It's also .02mm taller than the Hyway pop up piston, which means my squish gap should be .96mm, and a compression ratio of 10.5:1. I am quite happy with that.

I took my rather pricey piston and then proceeded to ruin it and put two windows in it lol. Not too bad considering the old beat up lathe I had to work with.

https://i.ibb.co/d48qm6M/20220430-162602.jpg

Now I just need to finish cleaning up the ports and get if running.

Better than what I did back in the day with a dremel.

I kind of want to start a 2 stroke motorized bike racing league now.

They have a racing league in California, but it is dominated by bigger four stroke mills.

They do have 2 stroke races, though I know little about them. I do know that there are guys out there doing hybrids with cylinders from Minarelli scooters pushing stupid amounts of power though. 10-15hp from a 70cc engine. :wtf:

Then you have the speed demons who are just obsessed with going 60+mph on a bicycle. Heck, there is even a gentlemen who builds custom wheelsets just for motorized bikes with 11mm thick spokes, sealed roller bearing hubs with extra thick axles, and really beefy double walled rims.

The last time I looked into doing this for the fun of it, none of this stuff was even a thought. It blows my mind lol

Heck, even this phantom engine I bought has to make about 5-6hp and is very torquey. Watched a video of a guy that took a stock phantom, had an expansion chamber modified to fit it installed, put a 32 tooth sprocket on his bike and hit 52mph.

anything over 40 on a bike feels, well "fun".

Saying from experience when I got mine to top out at 55 with just the right gearing (took a full mile to hit that speed).

Then the drain screw vibrated out and I lost my gas.

I am more concerned with pulling power than top speed. With a 40 tooth rear my max speed at 9000rpm will be around 40 to 45. That puts my cruising speed around 20 to 35, which is all I desire.

Well you have the high compression setup. If you want more pulling power I'd lengthen the intake a bit, remove the baffle from the exhaust (if using the standard chinese 2 stroke one) and open it very slightly using a step bit.

and by slightly, I'd make it just 4-5mm larger than it's current opening diameter



Shorter intake and more open exhaust is higher rpm but less pulling power and vise versa.

The intake expansion chambers (boost bottles) have felt like snake oil to me. I haven't seen any improvement from them, just a change in sound that some perceive to be an improvement.


If you're feeling brave you can run nitro to the intake. I will say it is fun, as long as you don't have to turn and there are no potholes.

They do work, but only for a short stent and it's risky

The Phantom 85 standard exhaust is actually already a lot bigger than the normal.china doll engines. 28mm inside diameter with a straight 19mm exit pipe. The exhaust port matches the pipe and is pretty darn big. The intake side has very aggressive port timing and a steep slope just like the saw it is based off of. With a Reed and windowed piston combined with the exhaust and really good exhaust timing and blowdown right out of the box this engine is pretty torquey as it is. All I have done is bump the compression a bit and port matched the intake to the Reed block. I will actually play with more aggressive stuff later.

Boost bottles aren't worth the time. I have no desire to run nitro or nitrous or any other silly stuff. Premium unleaded is fine by me.

Made a video somewhat covering the bike and build.

https://www.youtube.com/watch?v=t6zs0fmf1vI&t=14s

My slightly bigger disc brakes came in today. 160mm vs 203mm discs.

https://i.ibb.co/d70LWq5/280043885-1...14047318-n.jpg

Not to worry, the front is getting the exact same brakes. The main reason for the huge rotors is for sprocket, chain, and caliper clearance. The chain on the 40 tooth is going to create a potential contact point with the calipers, but it will hopefully be just close enough.

https://i.ibb.co/CBymrZ5/279950451-1...34835582-n.jpg

I am still going to have to space the rotor out, but with the new style of dual pull calipers I have, that has to be done anyway since the new caliper positions the pads further out than the original unit. Thankfully, I have a lot of room to work with on the brake side, so I actually think this will work out rather well.

https://i.ibb.co/LSq8Khf/279913206-1...47166523-n.jpg

You can also see in that last picture how far the caliper sticks in toward the hub. The new calipers I bought are a dual pull style instead of the single that the original units are, and as I mentioned previous the pad centerline is moved outward as well, but on top of that, they also stick inward less than the original units too.

https://i.ibb.co/BLCXK6N/279856331-1...62079229-n.jpg


So, my plan to to setup the bike and just start with the rear wheel and work my way forward. I plan to pull the rear wheel anyway to actually check the wheel bearings and make sure they have proper lubrication, it will be a good time to work on the rest of the setup. I just don't trust whomever assembled it.

The "OCC" sized sprocket hub adapter is sized perfectly for this bikes rear hub. My plan to hopefully prevent issues with slipping is to to key the surface of both the adapter and hub with a little sanding and then utilize some Loctite 638 retaining compound which has a shear strength over 4000psi and is also decently high temp and oil resistant. Thankfully this adapter is also machined properly and a nice snug fit with the hub, which will really help.

If you are thinking that the retaining compound won't be enough, I have watched that stuff hold a bearing race in place when the breaing locked on up an enormous 480V motor and ended up spinning the shaft on the inner race and wrecking it. It's some impressively strong stuff.

One nice thing about buying a cheap bike like this is my entire lack of guilt in buying cheap ebay parts to upgrade it. The parts on the bike are just as cheap and shitty :hehe:

I finally started to assemble my bike now that pretty much most of my parts have come in. I am still waiting on my dang handlebars but after 11 days of waiting they should be delivered tomorrow. That means I can get my controls and everything else sorted out next week.

In the meantime I went ahead and installed the motor so I could check sprocket alignment and get an idea of my hub adapter position. Fits in the frame rather well with decent clearance all around. Carb has enough room to install without having to unbolt anything, and I also think I can make my VM18 carb work with an angled foam filter on this reed block, which would be awesome.

https://i.ibb.co/9Z5qcJq/phantomnazz.jpg

I am currently waiting on some jets to use with this stock carburetor. I do believe they are a Keihin 99101-124 jets. I measured the one that came in the carburetor and the only real difference is it is .3mm longer. Otherwise they should install and function all the same. While the original jet is unmarked I did size it out to a 75, so I went ahead and ordered 78, 80, 82, and and 85. Many phantom owners complain of them being jetted on the lean side, and with the port matching and other work I have done I likely made it a little worse, so I wanted a decent range to work with.

In the meantime, I have another obstacle to overcome. My front tire and the exhaust are trying to be buddies. It's actually not too bad, so I should be able to fix this issue with a little torch and bend action.

https://i.ibb.co/CKrp6dZ/phantomexhaustissue.jpg

My other obstacle is a little more frustrating, but I have to work within the parameters that I am given. It's the fitment of the disc brakes and sprocket/chain setup. Unfortunately, the 40 tooth, which I would love to run, is just a tad too big to clear the caliper. My attempts to space out the rotor created other issues and didn't buy enough room anyway.

https://i.ibb.co/jDsYMcZ/phantomsprockettoobig.jpg

My options here are 2. Both of them simple.

First option is to use a 36 tooth sprocket. This is the normal sprocket setup used on bikes with 26" rear wheels when using a 203mm rotor, so I know it will clear. The downside to this option is that it will gear me even taller, similar to a 32 tooth on a 26" bike. I don't mind if I have to pedal assist the bike a little, but it may prove too much gear. Lots of speed demons on the 26" bikes like using the 32 tooth with the Phantom. With an expansion chamber pipe and stock carb I have watched a guy do 52mph with no other work. Thats a little faster than I desire to go on a bicycle, but inversely, if the motor has the power it should cruise rather well at 30mph lol.

Second Option, if I decide the gearing is just too tall for what I want, is to get rid of the rear disc brake and go with a regular old rim brake out back. I will still have the bigger/better front brakes which is a plus. This would also allow me to pick almost any rear sprocket setup I want.

Got my 36 tooth sprocket in and got it mounted up with the disc after servicing the rear wheel bearings. Kind of glad I checked them too because they were bone dry.

Honestly, it reminded me of the bearings the Hawk came with where they just had a little smear of that clear goop that they pass off as grease. Definitely going to check the front wheel and crank set now.

The other issue I stumbled into while working on the back wheel was I noticed one side of the axle is actually already bent a little bit. I'm just going to roll with it for now and look into some possible upgrade options in the meantime.

So, I am just going to install the rear wheel and check/tighten the spokes for now. If I can get those things done tonight I will get the bars and controls sorted out, then work on the exhaust. Supposed to be a rainy day tomorrow, so it will be perfect for some garage time.

My only other decision to make at this point is what size fuel tank to use. The half gallon tanks are nice because they are small. I bought a 4 liter tank, because why not? It's a bit big, but not obnoxiously so. I do like how it mounts better, with bolt-through tabs instead of the welded on studs like the small tank that are notorious for breaking off.

Hopefully I find this sprocket combo works out well because I really like how simple and clean it all went together. The caliper clears the chain perfectly and everything lines up just right. I took another note from my experience as a Chinarider and replaced pretty much most of the cheddar grade hardware that came with the hub adapter and on the hub itself for the brake rotor. They were already rounded out a little by whomever assembled the bike, so it was a good excuse.
https://i.ibb.co/3y3qFKy/rearwheel.jpg

Lookin good! I would try to mount the engine so that the float bowl on the carb is level. Unfortunately, that will make the conflict between the exhaust and front tire even worse.

Won't mount that way in any case. This is with the mounts aligned, and not unusual for these things to be angled anyway. This is a single jet carburetor without a pilot jet or idle circuit.

I gotta say looking in this thread is a dangerous game lol. It has me considering the idea of building such a bike and as it is i am already considering picking up two Supercycle SC1800s from Canadian tire. One to keep stock with some mild mods and the other specifically for building into a motorized bike. And now that i see sprockets out there that use the disk brake hubs to make them work its got me thinking about it further. I already have a disk brake rear wheel on one of my bikes here that does not have disk brakes. So that would be a perfect donor for that...though on the flipside that bike in itself lends itself well to a motor conversion.

The hardest part is finding the right style of adapter for your bike in terms of alignment, but yeah they do make it easier. I am using a clamp on sprocket adapter secured to the rear hub. I keyed both surfaces and applied Loctite 638.

Took me a moment to understand what you meant there but i see now that there is an adapter that bolts to the hub itself then the sprocket bolts to that to make it a fixed mount instead of the rubber isolated set up of the clamp on hub. Kinda wonder if the electric motor kits out there use the same chain as the gas motor...would make for a clean install on one of those as well.

Well, in my case the adapter clamps to the hub inside of the spokes and 3 bosses stick out through the spokes for the sprocket to bolt to. This is the one I had to buy because my Hub is a goofy diameter, so instead of one of the cheaper ones, I had to shell out about double. Thankfully this is a good high quality unit.
https://www.bikeberry.com/products/b...37807830761638


The other style I was talking about for the disc brake hubs is this. It bolts on where the disc would go and the sprocket bolts to it. Depending on the bike or wheel hub you may or may no be able to run a disc with it. This particular company offers three different rotor offset options depending on wheel and tire setup.
https://mbrebel.com/product/medium-3...tal-thickness/

Im perfectly fine with the idea of using the disk flange as the drive flange and just live with the rim brakes on the rear with a disk brake front end if i were going gas powered like you. From what i have seen the electric kits use the same rubber flange set up so at least that part might be standard between the two. If so i would probably look at just solid mounting the sprocket and leave the brakes alone. As it is i happen to have disk brake type wheels on my Supercycle XTI when its supposed to have non disk wheels like the SC1800 im looking at doing the Ebike with. As it is im thinking i might convert my Triumph dual suspension bike first as the electric power would def help off road with it.

It's actually pretty common to use the disc flange for the drive and run a rim brake out back on a motorized bike. Often done with a dual pull single brake lever to prevent having too much braking power in the rear when combined with a front disc brake.

I have considered an e-bike, but I may hold off for now since they are expensive as heck, both to build or to buy. I am starting a new job soon that makes using the bikes as transport to save money a bit more difficult due to the distance and the routes available to me, so for now they are just a hobby anyway. 12 miles of city riding is a bit more than I want to deal with for a commute on a bicycle of any kind.