Motorized Bike Jackshaft. What it does and how it does it *Viewer Request* Hill Climb and Speed Test

Quick run down on how a jack shaft kit works.
This has a 11T drive gear increasing the ratio by 10%
Jackshaft from SickBikeParts.com
BBR Jackshaft: bit.ly/2s1CObx
BBR tuning GT2-A 2.4L frame package: bit.ly/2sF7RcI
Buy motorized bike parts from HERE: bit.ly/2rmdOYb
Built by MotoredLife.com

[@Calthecool]

It definitely does make it faster, both in top speed and acceleration.

[@travonepleasant]

Please is there a place that i can see proof. Because I've been wanting to do this all with the hope it goes faster.

[@Calthecool]

@@travonepleasant If you’ve ever driven a manual car, you should know that lower gears provide more torque, and higher gears provide more top speed. If you have only one gear (if the chain went straight from the engine to the wheel, how most motorized bikes are set up) then the gear ratio has to be low enough that the engine won’t die when you start moving, so the bike will have a limited top speed. However, if you can change gears like the bike in this video, you can start in a low gear that allows you to start moving easily, and when you reach the top speed of that gear you can shift to a higher gear, allowing you to have a higher top speed. I’ve built a bike similar to the one in this video, and in the lowest gear it was easily able to climb 25 degree hills, and in the highest gear it was able to go 35mph.

[@iamthefuckinhamster]

@@Calthecool How many rear wheel sprocket teeth do you have?

[@PossGal]

"Its not really made to make you go faster" *me being a gremlin and gearing it up to do 50+*: wut?

[@MotoredLife]

It it will but not with that old engine. Lol

[@pvt_mtbl9516]

@@MotoredLife that was so funny I forgot to laugh.

[@DrDinkle]

For those confused. This kit will introduce gears which should in turn increase your top speed. This will work only if your engine has the power to push you. In my case with a 44 tooth sprocket my engine reaches its max rpms and can't spin any faster, but my engine has enough power to go faster with a lower tooth like 36 sprocket as the rpms won't max out early. If your motor reaches a speed where it's power is at it's max and due to air resistance, weight, etc(not rpm redline), then you will not go any faster with gears. So you can opt for a lower tooth sprocket to hit a higher top speed but your low end power will be weaker due to lack of torque at low rpms or a high tooth sprocket to have great torque but your engine's rpm red-line will hit earlier resulting in lower top speed. So with gears you will technically be able to simulate and utilize a variety of sprocket types. You can start with torque-ey high tooth sprockets and shift your way up to lower tooth sprockets for longer gears for cruising and top speeds. Hope this clarifies as gears won't always increase speed if you are already limited by external forces and horsepower rather than your rpms being limited from redline. Let me know if I got something wrong thanks!

[@crdirtrider856]

Finally an intelligent and concise comment. Thank you

[@hugopoulin8734]

Thanks man for your explanation

[@bravojr]

You deserve a lot more attention! Well and good, very well said.

[@dfro.9770]

Someone really needs to do a jackshaft installation video. Or even just a breakdown of the build after it's been installed.

[@Thrashaero]

nah, screw jackshaft bullshit. everyone already has one on their bike. it's called the crank axle and bottom bracket. what someone really needs to do is show chainring sprocket and freewheel hub installation for left side of crank. the right is already used by it's own gears, why leave left side naked?. keep them separate, no point in combining them on one side (where the two separate chains and sprockets are all close together. when you can split them for 2 sides with much less parts, weight, price, effort, and increased sturdiness.

[@shimes424]

@@Thrashaero it's probably patented and nowhere to be found

[@marthamryglod291]

I know this reply is late, but I have one and this video is pretty good. The install kit has good instructions. Just buy the HD one. It has a strong bearing and sprag clutch. Also, it does lose some power to the wheel because of the extra rotational drag. The cool thing is that you can crawl through trails in low rpm and low speed without pedaling if you aren't too heavy.

[@DosXquis]

@@Thrashaero i think phatmoto does the concept your talking about on there built in jackshafts on their newer bikes

[@wingbiddlebaum1807]

@@marthamryglod291 can you link me to the hd one.

[@lilde9417]

This is exactly what I've been wanting to do to my bike. Thanks Bro. Now I got something to build from scratch.

[@zacharybarksdale8072]

Do you know if that jackshaft comes in a kit or what other parts he used to make it work with the bikes original shifter system?

[@andrewjb05051998]

@@zacharybarksdale8072 it's called a shifter kit, you can get them from sick bike parts.

[@jonsmith2217]

Lowering engine RPMs increases fuel efficiency and less wear and tear on things.

[@jonnyrox116]

Here's how I keep those motors from sucking air and causing erratic idle, put an O ring in the manifold end of the carb and compress it as you tighten the bolt...no more air leak and you can actually adjust the idle speed.

[@MotoredLife]

+Jon Rothenbusch agreed

[@GenMinion]

So I wasn't the only one hearing the crasy high idle at stop? I've tried the o-ring thing, btu unless it's a VERY thin one, you'e going to have issues. I make mine out of old inner tubes.

[@mikebmx101]

@@GenMinion that innertube idea is genius, gonna grab some when I hit the bmx track 🙏

[@nicholast8217]

Improved mine greatly. Use some sort of gasket between the carb and motor, cut o ring for a garden hose worked on mine

[@masterzz57]

red silicone always works

[@Drumvain]

Awesome build! Love the gears, this is proper. Bike is a beast

[@blackswan0017]

I wonder if you could modify Jack shaft kit with one of those three speed hub hyper bikes that have the rubber belt drive. If you could get the belt drive to operate with the jackshaft kit that might put less strain on the bike chain factor because those belts are pretty heavy duty on top of that you wouldn't put massive stress on your cassette for shifting because it internally shifts inside of the hub. One speed for going up hills to speed for Mid drive cruising 3 speed for overdrive. It's my next build I've been thinking of.

[@ionsorinporojan149]

Hello ! After I've studied the mechanism of the shifter , I built one for my 66 cc motorized bicycle . No big deal , but it helps the engine to work normall as a motorcycle engine ...because now it have gears ... Good video , thanks for sharing !!! 😀😀😀

[@m.kasper7646]

Very well explained and good photography as well, nice job thank you.

[@MotoredLife]

+mark kasper yup no problem

[@codelicious6590]

I really want to try a Jack shaft kit with a Sturmey-Archer 3 or five speed hub and an old heavy steel frame to try and make a speed demon!

[@mikem5475]

You will destroy those internally geared hubs in no time

[@jimmy30671]

it looks like a lot of work I have two bikes i was thinking of putting jack shaft your show was very helpfull thank you that build look good

[@israrhaq73]

I am in love with your bike, awesome

[@XGNGAMER16]

I’ve had my bike a little over 2 months now and I’m going for a gt90 conversion kit along with a jack shaft kit

[@jamess1787]

Jim and Pablo at SBP are awesome! 🙏

[@JPSimen]

Lower your idle speed sir.

[@dannyelston1803]

J. Simental S. ,my name is Danny I bought the 3.4 liter frame but I don't know what size neck I need ?it says 44mm yith a 42 mm and I don't know what to do? If you have any help let me know....thanx

[@cameronpeschel7360]

Those engine kits tend to run rich fuel mixture causing it to idle high, I have one. If he were to lower his idle it would bog down and almost die. This bike sounds great.

[@asappestcontrol1250]

Sounds just like a dirt bike. ,,,👍

[@uknowngamer1017]

@@MaFTB youre right!

[@awdrifter3394]

It's only 80cc, how much fuel is it really going to save by lowering the idle?

[@pipeman451]

Nice work. Have you vids on building thatBike. Nice work fun to watch

[@rulz5513]

dudeeeee that thing is soo beautiful

[@mikeraia2605]

I like the bike and the fact that you can use the gears on your bike, i guess its got its good points and bad points. But thanks for the video, i watch alot of very helpful videos its a fun hobby these bikes.

[@jdubyaadams33]

BADASS! Cool little scooter!

[@dillonking2624]

Sick build!

[@movingwater9111]

Hi do you have instructions on how to instal a jack shaft?

[@rumenkostoff]

How did you make that fuel tank, also on 1st gear does it climb hills and does it start off without pedaling?

[@thomaslabantt6625]

Owned!!!!!!!! That was so sweet

[@joneserupinsmoke9161]

But definitely a good information on video it only adds on to the posable things we can do and come up with

[@rafagarcia3049]

Question is it possible to use a fixie hub (fixed gear sprocket on one side and free wheel sprocket on the other) as a jack shaft

[@napoliansolo7865]

Looks to me like using a jack shaft lets you keep your disk brakes. I've been checking out those frames with the tank built in. They look awesome.

[@billculhane8487]

Napolian Solo b by 5hg4

[@haroldkerwinjr3026]

Thats why im interested.

[@mr.equity1120]

Or you could get a smaller sprocket that doesn’t interfere with the caliper. Personally I use a 36T

[@mikewest9033]

What kinda bike is that? Im loving it with that motor on there. Is the gas tank built onto the bike?

[@asphaltcowboy7868]

I have built two schwin orange county chopper bikes in the past, but both bikes were single speed.. found out afterwards that these bikes come, single, 3 speed, and 5 speed..thinking of doing a multiple gear chopper...but the flaw I see is..do you think the bicycle chain is strong enough for the job? The bicycle chains, I'm sure are less durable compared to the much thicker engine chain? And with so much torque, are the teeth on the bicycle sprockets hold up well without rounding off the teeth over time, causing chain to slip or jump off? Plus how often would one have to grease the jackshaft hub?

[@joeypriolo]

Just bought a jackshaft. This video is very reaffirming! What chain are you running to your freewheel/cassette? Did u use the original mountain bike chain or get one that's more heavy duty?

[@benjamincoletti3267]

Hello love your videos I was wondering if the jackseptic it would fit on My BT 80 electric start. I don't know if it is possible because of the centrifical clutch instead of direct drive in the bulky electric start motor. Appreciate the help

[@ChuckHaney]

So the U-bolts with the shifkit are the only thing holding that motor on? No front motor mount?

[@RajVerma-lb3op]

how long would the bikes chain, sprocket, and shifter last with a jackshaft kit?

[@421rants]

Thank you.........the mystery of the jack shaft......solved. Great video. Thanks..... Subscribed. = )

[@ivan872]

How much space is needed between frame and the tyre? Nice vid

[@davidrussell8918]

I dont really need to go fsster, but I live on a gravel road, and even with a suspension fork, it can be a rough ride, I think that would help me so I could go slower on the gravel. Right now I have to lug the motor to go slow enough, and sometimes, its still not slow enough. I dont want to slip the clutch. Do you guys think this is the way for me to go?

[@backyardrestorations]

Question 1: I’ve just ordered a 66cc stage 4 engine. I have many components for me to make one of these should I make it or buy one? Question 2: Do you have to use the clutch when you change gears with this thing?

[@kalebhermann8097]

Do they make a jackshaft kit for the 4 stroke engine?

[@reyesmaravilla66]

What size are your tires?.. And i can see your air filter is upside down doesn't make any difference...? Nice bike! I just finish one like yours (blue) very basic still...

[@kalleklp7291]

That's a hell of a cool bike..

[@MerlinOpeth]

Sounds great

[@MotoredLife]

Check my new vids!

[@matthewfredrickmfkrz1934]

There's some shwinn 12 speed bicycle with the crank located freewheel it had three sprockets IIRC

[@richardrivera5978]

Great motorized bike nice rims!!!!!!

[@madeinsweden7776]

How does that thin bicycle chain hold up?

[@rangerjones5531]

Noticed your test route passed right by the hospital, coincidence?😁

[@FaireOficial]

Please, as you call this crown that allows the pedal to rotate freely, I wanted to buy only this pedal, but I can not find it anywhere.

[@johnsheetz6639]

Just got my little first gas conversion Facebook marketplace runs like crap but it runs of course I knew it for 120 bucks that's where I come in. It has the jackshaft and I confirmed the kit to be 100cc first impressions the carburetor is garbage. And the plug wire is arcing. Still spitt and sputtered to about 25 30 mph once I did all the 2-stroke tricks to get it started out of breath. Oh yeah and it's stuck in high gear. derailer froze

[@Miklalo]

Nice work i like the setup but have one question does this work on trail bikes like a RoadMaster ? How much space do you need to Install? If this doesn’t work on the bike i have i plan on buying a beach cruiser anyway just wanted to ask you first

[@ATCRyderX]

That thing is #fire, dude. love it. I got here from your vid of the ACCRUE mags. Are those the 5 spoke ones? How are they??

[@MotoredLife]

ATCRyderX© these are on point but I paid for it ya know

[@joshrichards2491]

Yeah I paid 168.00 for mine

[@nautastro1503]

Interesting game indead , with Jack shaft , hills and gears , with 2 stroke engine that can be tuned for low rpm torque or hi rpm . Working hard you can get a lot of performance for money.

[@ppppppaaaaaauuuuuull]

i'm surprised how well that works. Cool ride My experience with a jack shaft was terrible , throwing chains , braking freewheels, braking chains and walked home everytime I rode with the jackshaft . Amazon return after 25 days of trying to make it work. I'm trying something a little different now , a single-speed on the pedal side and a 3-speed on the motor side, 3 sprockets on the back wheel, 40t , 36t and 32t atm. want to eventually go 36t, 32t and 28t sprockets. I live in a fairly flat area. No videos yet but have some interesting pictures on my KZbin community page. Still working on it. Waiting on parts

[@angelsalgado9289]

Sweet ride

[@TimpBizkit]

It would be nice if someone did a neat little gearbox (like in the Bafang electric motor mid-drives) that has the free-wheels incorporated in it and you can simply attach the crank shaft of the engine into it and it would step it down 40 or 50:1 or whatever it needs. It needs two freewheels, one so the pedals can rotate the chainring without turning the engine, and the other so the engine can rotate the chainring without turning the pedals. The Bafang BBS drivetrains already have this for the electric motor. A clutch switch to disengage the engine at a stop, and also a freewheel lock up switch so you can pedal start the engine. A kit like this for a Honda GXH50 or 100/120 along with a choice of chainrings (Lekkie Bling Ring etc) would be very intriguing. I'm in the UK so internal combustion engines on a pedal cycle are a bit of a police magnet unless you can go to the hassle to get them type approved and registered as a motorcycle somehow. It would involve at least adding mirrors and indicators, brake lights and beefy brakes, and wearing a cumbersome helmet.

[@Westhelockpicker]

So you have to pedal the bike until it starts?

[@owenridener5881]

Would like to know more about the 4 stroke 49cc kit

[@joneserupinsmoke9161]

Four strokes are gay bro .there's a lot of bids in here .two strokes way faster

[@wingbiddlebaum1807]

how do i get s sprocket on the ratcheting hub to match the chain that goes to the rear

[@bryduhbikeguy]

That Really is a Beauty!

[@djodjodubois9458]

Es que le pédalié tourne ou arret de tourné que le moteur fonctionne.? Sa je veux savoir

[@nhermogenes]

where can I buy one of these already built?

[@juandenham9891]

Can you let me know how to order it because I have several motorbikes and that looks like something that I would love to use if you can please send me the link to order that part for my bike please

[@aaronward5265]

Nice bike bro

[@johnlamons7482]

You've got that bike working great. How much?

[@johnny7730]

What size chain goes to your rear sprockets?

[@ZRTMWA]

What fork are you using? I have a fork from a Giant brand mountain bike I wanted to use in my Skyhawk frame but the head (top pole piece) of the fork is wayy too small for the Skyhawk frame...I think I need some sort of adapter? Also, would you recommend a 12 gear rear sprocket or is that just too much gear changing?

[@MotoredLife]

the fork size is 1 1/8'' and requires a 1 1/8" semi-integrated headset. you only realy use like 4 gears

[@rccmrccrawlermods4517]

Fun! Gotta make one..

[@80spunkgirl]

So what would you recommend for someone that is ridden a big displacement motorcycle and knows the ins and outs of clutch play and gear shifting

[@johnharrington4757]

Get a motorcycle

[@kingworm859]

Hola amigo buen día, me interezo mucho tu video, algunos detalles para instalar uno en mi bm, veo que le hisiste algunas modificaciones a tu instalación, pasa los tips, o como me puedo comunicar contigo face, whats??

[@BicycleMotorsports]

Whats going on with that front motor mount? The motor isn't positioned as intended with the studs on the front frame mount. It's about 3/8ths of an inch too high on the mount. How is the motor being held on the bike? That mount issue looks like it would be unexpectedly problematic with an already difficult jack shaft install.

[@MotoredLife]

with the jackshaft and BBR frame the engine didn't sit flush so made a bracket to fix to the pedestal mount it is held on by 4 bolts. Never had a problem actually has less vibration than stock. good eye though

[@ishaiahsmith]

What size hose are you using for fuel

[@rickyboby4774]

I put a 80cc flaming horse with jack shaft kit on a Schwann mountain bike with expansion tank, header, pull start, centrifugal clutch, trispark plug,and better gear cassette in rear. It runs great easy to drive up hill and does about 55 mph but death wobbles a little if I hit a big bump

[@paulyuneps7428]

I'll bet it does!

[@bikenerd6752]

Can u do a more in depth look and show tips u learn putting it on I'm having problems with my chain coming off I'm sure outher would like it as well thanks

[@MotoredLife]

i can do a vid on the next one i do. If your chain is coming off the gears are not lined up perfectly

[@Konstantinosmo]

Hello friend. As far as i can see, the chain that goes to the rear wheel's multy-discs, is not the 415 chain. So ther is possibility of breaking this thin chain?

[@MotoredLife]

Yes, if you mis-shift it shreds the chain and the cassette.

[@derekmckenzie8350]

I have a Trek Marlin 6 mountain bike. I'm looking to get a 80cc 2 stroke. How can I install a kit and still have my gears usable with the motor

[@whysthat2877]

Derek Mckenzie use a jack shaft lol u can change the gears on your bike like u do without the motor

[@movingwater9111]

Hey mate how can i get in contact? Im making a bike or two for my friends mountanous farm. As as an engineer id like to do a good a job as you have done

[@ericlakota6512]

Best bike i seen

[@ae3bec]

y'all have some jacked up roads!

[@MotoredLife]

Fuck yeah

[@faithmedina6099]

Jacked up roots have you seen your youtube account photo latley that shit looks £@€ked up

[@anthonypeters44]

That bike is bad ass

[@OsoBarr]

why is your air intake on with opening at top?

[@joneserupinsmoke9161]

soon as I find a strong enough bike to do what I want or need it to handle I will be putting damn near same gear set up as a dirt bike set up on a good solid bike frame

[@theatom7264]

Nice build man. Been thinking of getting a jackshaft kit for my next motorized bike build. I also want that same frame but in gloss black with a custom paint job like pin stripes or flames on the tank & fenders. Sick Bike Parts seems to be the best supplier for these jackshaft kits & they seem much better than dealing with those pain in the ass direct rear drives. With direct drives our options are the horrid rag joint sprocket clamps that come with the kit or the overpriced sprocket adapters & also those annoying idler wheels to.

[@MotoredLife]

A. G. I'm CNC hub adapter with a ZEDA racing engine all day. Jackshafts are fun though.

[@MotoredLife]

Zedamotorsports.com 👍

[@theatom7264]

arthur clark; I ended up getting an HD hub/wheel kit from Bicycle-Engines. The sprocket is now one with the hub instead of bolting through the spokes & the wheel itself uses a good rim & heavy duty spokes. Had to bend my dropouts a little but fit great after. Even was able to convert my rear brake from a coaster to a disk because it came with a disk brake adapter that screws onto the hub over the sprocket. Costed me an extra 100 bucks but well worth it. It's practically bulletproof compared to the kit method & still cheaper & easier than getting a jack shaft kit.

[@toy2bato898]

That gear shift si smooth

[@tylersong4103]

I could use some advice I have a kmb frame similar to yours just got a dio reed motor from zeda and have the jackshaft installed however I can’t seem to get my rear derailleur to make the jump to the mega range gear. Haven’t even had the chance to ride the bike yet due to the issue with the derailleur any advice and tips would greatly be appreciated

[@MotoredLife]

+Tyler Song I actually have a 8 speed shifter 7 speed gear.

[@donnythomas3231]

I had a jackshaft on my old bike I found that if it is not aligned perfectly the bike chain will keep snapping. And using other brand chains always snap. Stick to shimano brand chain last heapz longer than alternative derailleur chains. And carry a spare.

[@bullwhipjohnson8247]

Is this a version of the BBR bike frame? It seems to have a built-in gas tank. I also like that it has disc brakes and a suspension fork. Bearings, Brakes and Wheels are the most important and most overlooked part of these motorized conversions.

[@MotoredLife]

+bullwhip johnson right you have to make a good bike bike before you can make a good motorized bike.

[@bullwhipjohnson8247]

Motored Life Is this bike sold separately and built especially to be motorized?

[@MrHighpressure]

are all the chains the same pitch?

[@murphymcpoyle1735]

how would one build an alpine hill climber exactly?

[@malikfrank4041]

Is it necessary to have a jackshaft?

[@MrPlumber27]

Where did you get that cool frame with the gas tank built in ? Sweet ass bike dude

[@jasonwhite8722]

there on ebay

[@rocketranger21531h]

Question about your setup. I’ve built 2 gas bikes so far but I’m looking into going with one with a jack shaft on my next build but I want to get rims like yours but can’t find them with multiple gears. Did you have to do that yourself or did you find that wheel setup already built? My goal is to build a bike that I plan to ride the entire length of the original Route 66 highway on and being able to keep rpm’s down would be key.

[@MotoredLife]

Just a heads up jackshaft are illegal in all of the US. The wheels came like that. They come in 1-8 speeds

[@rocketranger21531h]

Motored Life where did you get the rims

[@MotoredLife]

From eBay years ago. I have seen several sets break so i think they are no longer for sale.

[@gregtheone975]

Nice bike

[@robertmiller8578]

Also what is your top speed that you achieve with this set up or can achieve?

[@marthamryglod291]

Mine went 40 on the flat all day, 55 downhill, crawl speed around 3-4 mph without pedaling. Stock motor, open exhaust pipe. My 32t straight drive ported, piped, milled head and carbed motor would cruise 45-50 and hit a wall around 58 from wind resistance. But the jackshaft kit is more fun for putting around.

[@robertwebb4075]

Ive boughta zeda 80 triple 40 and a jackshaft kit from bike berry ive had to cut in some places to make the brackets work and now the chain is the issue what chain do i use for the pedal crank to the rear cassette

[@MotoredLife]

Just a regular bike chain. You need the anti jump chain guard. Whats happening?

[@robertwebb4075]

@@MotoredLife the chain its self does not fit on the pedal sprocket

[@Robert-hf5xr]

That's pretty cool

[@anthonyjohnson7700]

Helpful I might need to switch

[@idezilla]

Speed? Can you stop when going at that speed?

[@MotoredLife]

Paul Barton this bike has dual disc brakes

[@mikemazurek180]

How do I get a push button shifter?

[@heavystarch100]

Awesome! But looks like a pain in the ass to install! I would like to see the wear on the derailleur cogs if they're plastic! Definitely would use aluminum ones. This is so practical.👍👍

[@alfreeman69]

How much would a bike build like that cost

[@asphaltcowboy7868]

Do they make a 415 bicycle cassette?