Go kart transmission
- Thread starter Andrew J
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mckutzy
Well-known member
There isn't any bolt on transmission for this...
Closest you going to get to this a motorcycle transmission from a big twin or any other separated transmission motorcycle...
Closest you going to get to this a motorcycle transmission from a big twin or any other separated transmission motorcycle...
JTSpeedDemon
2019 Build Off Winner!
Sorry, but there’s virtually no options for that. For the cost and effort of doing that, you would have been better off buying a motorcycle engine with an integrated gearbox and more power to boot.
I would suggest getting a motorcycle engine if you really want gears, but just know that it will be much more complex to fix, more expensive, and with almost entirely manufacturer specific parts.
If this is your first go kart, I would suggest not getting carried away with wanting all sorts of fancy features and lots of power. You’d be surprised how fast 6.5 HP feels with a single gear when you’re 2 inches off the ground!
I would suggest getting a motorcycle engine if you really want gears, but just know that it will be much more complex to fix, more expensive, and with almost entirely manufacturer specific parts.
If this is your first go kart, I would suggest not getting carried away with wanting all sorts of fancy features and lots of power. You’d be surprised how fast 6.5 HP feels with a single gear when you’re 2 inches off the ground!
if you find one let us know!
Since there is not a single multispeed gearbox that does that.
there was one for a G-series Honda but even that is a unicorn,
Mower gearboxes are not meant to shift under load, much less to run at severe torque AND speed;
so those too are usually pointless
(some tried and claimed to have succeeded at least for a brief period)
Again, if you can dig one up, let us know.. many would love to have such.
'sid
Since there is not a single multispeed gearbox that does that.
there was one for a G-series Honda but even that is a unicorn,
Mower gearboxes are not meant to shift under load, much less to run at severe torque AND speed;
so those too are usually pointless
(some tried and claimed to have succeeded at least for a brief period)
Again, if you can dig one up, let us know.. many would love to have such.
'sid
anickode
Active member
The peerless 700 is the closest thing you'll find, and they require extensive modification to make them handle the RPMs. You still can't really change gears without damaging it though. It's pretty much just pick a speed and go.
Actual shift on the fly transmissions are very complex and thus expensive. You'd be looking at probably a minimum of $1000 if one even existed, and it would likely be the simplest of designs with dog engagement gears.
Actual shift on the fly transmissions are very complex and thus expensive. You'd be looking at probably a minimum of $1000 if one even existed, and it would likely be the simplest of designs with dog engagement gears.
mckutzy
Well-known member
Its kinda sad about this kinda thing... Here in NA its quite difficult to get a transmission for these type of machines. Ive seen junkyards in Asia and India where heap of stuff just piled about...
For example, in India where they still make Royal Enfield motorcycles, older ones have a transmission that is separated from the engine... One can be sought for not that much money at all...
For example, in India where they still make Royal Enfield motorcycles, older ones have a transmission that is separated from the engine... One can be sought for not that much money at all...
many old motorcycles had seperate gearboxes...
I was bidding on one from the late 30s (Victoria) sprocketed clutch on one, shifting lever on the other side and a four speed in between...
got way to expensive for my taste
and it was tiny would've loved to get the measurements and see if that design can be copied.
Anywhoo.. a transmission case is essentially all we'd need
gearpacks for motorcycles can be found rather cheaply, motorcycle dry clutches can be too...
we just don't have anything to mount them comfortably...
Now.. India...
doable, I think we had a few members from India.. another one might show up eventually
'sid
I was bidding on one from the late 30s (Victoria) sprocketed clutch on one, shifting lever on the other side and a four speed in between...
got way to expensive for my taste
and it was tiny would've loved to get the measurements and see if that design can be copied.
Anywhoo.. a transmission case is essentially all we'd need
gearpacks for motorcycles can be found rather cheaply, motorcycle dry clutches can be too...
we just don't have anything to mount them comfortably...
Now.. India...
doable, I think we had a few members from India.. another one might show up eventually
'sid
ol'joe
Member
Are those gear cases cast aluminum or iron, or are they fabricated? One nice thing about castings is that the patterns for them can be built pretty easily or often bought cheaply compared to the tooling required for other jobs.
Plenty of limited production runs are still poured into green sand molds, even today....Joe
I was near the bottom of my coffee cup and thinking about kart transmissions when I recalled the Snapper mower clutch and trannys we used to see all of the time. They were nearly trouble free, simple, would make a 250 pound machine do a wheelie or dang near keep up with traffic on the road, shift at speed, do most of the right stuff. Had a friction wheel that needed replacement once in a while, but those are still available and cheap.
Only downside I can think of would be the complications of building it up from parts and the need to set the engine on the kart crosswise. You can eyeball the setup on the following video... the last parts of the video being the best for understanding....
https://youtu.be/4idnk8zDhDo
enjoy....Joe
Plenty of limited production runs are still poured into green sand molds, even today....Joe
I was near the bottom of my coffee cup and thinking about kart transmissions when I recalled the Snapper mower clutch and trannys we used to see all of the time. They were nearly trouble free, simple, would make a 250 pound machine do a wheelie or dang near keep up with traffic on the road, shift at speed, do most of the right stuff. Had a friction wheel that needed replacement once in a while, but those are still available and cheap.
Only downside I can think of would be the complications of building it up from parts and the need to set the engine on the kart crosswise. You can eyeball the setup on the following video... the last parts of the video being the best for understanding....
https://youtu.be/4idnk8zDhDo
enjoy....Joe
mckutzy
Well-known member
The 700's are a cast aluminum(Zamak,ect)....Gears are steel.
steel gears?? that'd be rather impressive tbh..
the few I've seen have all been sintered metal
'sid
mckutzy
Well-known member
Okay.. ya a sintered steel ferrous metal product... Not an Zamak alloy...
sintered metal is as durable as the fusing alloy,
not as durable as the fused granules...
so calling it steel is technically not a lie, but surely misleading
it's like you have a steel chassis but it's tubes are fused with JB weld..
it's still a steel chassis alright,
but you wouldn't trust it as you would a properly welded frame
'sid
not as durable as the fused granules...
so calling it steel is technically not a lie, but surely misleading
it's like you have a steel chassis but it's tubes are fused with JB weld..
it's still a steel chassis alright,
but you wouldn't trust it as you would a properly welded frame
'sid
There really is no easy way of going about this but besides what has already been stated you can cut down a regular junk motorcycle engine (something that is seized or junk preferably) so that only the trans is left and you can hook the predator up to what is left of the engine and use it as a transmission. You will have to come up with your own lubrication in most cases though for the motorcycle transmission as you may be removing necessary parts. Here is a video of someone doing one of these conversions. https://www.youtube.com/watch?v=wDJmsifTWh8
I too have been looking for a manual trans option for the predator 212 for some time. I know that you could just get any other engine with a trans and a cvt is probably a better option anyway but IMO a manual transmission is unreplacable in terms of driving experience. And there is nothing more satisfying than creating something of your own.
ol'joe
Member
If you will click on the top part of the video on post #9 above and advance it to the 7 minute time slot, that Snapper tranny and clutch is visible enough to make out how the system works. It is similar in action to a mechanical version of a hydrostatic drive, but remarkable simple in it's construction. The Snapper friction wheels are still available as are the liners, so wear parts are replaceable. Hex shafts and bearings likewise, although so are square shafts and square hole bearings. My estimate is you can have an infinitely variable transmission WITH manual clutch and jack shaft for between $200 and $300, but possibly a lot less, of long-lasting industrial quality....Joe
anickode
Active member
Most friction disc transmissions (or any riding mower transmission for that matter) are meant to transmit a small fraction of the engine's horsepower. The bulk of the engine power is there to spin the blades.
Yes, they make them robust enough so they don't grenade if you pull a small utility wagon or whatever, but the friction discs especially are really just meant to scoot the mower along.
Garden tractors are a different story, as a true GT is meant to be able to pull ground engaging implements, but still not intended for high speed operation, and will wear accordingly if used at high speed.
The reality is within the industrial engine powered realm, there really are no true manual, geared, shift on the fly transmissions available.
Yes, they make them robust enough so they don't grenade if you pull a small utility wagon or whatever, but the friction discs especially are really just meant to scoot the mower along.
Garden tractors are a different story, as a true GT is meant to be able to pull ground engaging implements, but still not intended for high speed operation, and will wear accordingly if used at high speed.
The reality is within the industrial engine powered realm, there really are no true manual, geared, shift on the fly transmissions available.
mckutzy
Well-known member
Corporate wise... even having a manual clutch for a fixed gearing was a difficult process... DBR1/3dMS manual clutch, Them boys tried twice in different systems... still was too expensive and still had some issues...
ol'joe
Member
Manual clutch for fixed gearing is no problem at all, as proven by industrial machinery clutched with slack belts. Yeah, most v-belt clutches on karts and scooters fail, but only because the builders use fractional horsepower belts and zinc pulleys.
Go to an industrial supplier of bearings, belts and chains and request a 1/2" wide industrial belt and pulley setup that will clutch 5 horsepower reliably, and surprise yourself when it is still operating and offering wheelies 50 operational hours later.
These are NOT your granddaddy's v belts! I take your statement about friction discs under advisement, never having used one on high speed applications, but slack-belt clutches are a whole 'nuther matter. ...Joe
Go to an industrial supplier of bearings, belts and chains and request a 1/2" wide industrial belt and pulley setup that will clutch 5 horsepower reliably, and surprise yourself when it is still operating and offering wheelies 50 operational hours later.
These are NOT your granddaddy's v belts! I take your statement about friction discs under advisement, never having used one on high speed applications, but slack-belt clutches are a whole 'nuther matter. ...Joe
sadly true.. but there WAS one.. unfortunately it's next to impossible to find out who made it.
so the only chance to get a good glimpse of one is to buy
a realy expensive kids car
(the Lorinser SL 350, the Porsche 911 Junior ...)
and take it apart
to find this:
manual 3+R transmission good for ~5horses to be shifted on the go.
(that one's IIRC a GX120 from a 500SL Mercedes, there's a similar one with a G160 (not GX) in the Porsche junior)
and the Lorinser IIRC had a Briggs flattie (3horse?) with a different gearbox.
some such cars came with a a mower transxle alright,
but few had a true shiftable gearbox.
the ones that had a clutch pedal were all shiftable while driving AFAIK.
'sid
mckutzy
Well-known member
I remember this coming up in one of our "yearly" transmission's conversation, a number of years ago...