New member // My build

[TDB]

New member to the forum, and first time ever joining a forum! I debated joining for a while because I don't actually have an old mini bike *yet* (well I guess mine will be old someday), I just have a predator swapped Monster Moto. But this forum has helped me out in the past so I figured maybe I could help someone else out with what I learned on my build.

I know that this swap has been done to death but here is my Predator 212 swapped Monster Moto:



The mods that I have done: a "brand-used" non-hemi predator 212, pro taper pillow top grips, hydraulic brake, and a custom clutch guard (I will post a separate thread on that).

Mods that I still need to do: the header (I have one that didn't fit, I've cut it up to fit and it just needs to be re-welded), a muffler for the header (I like being able to ride around my neighborhood all day without upsetting the all the neighbors lol), a smaller sprocket (I'm thinking 60-65 teeth, I want more top speed w/o grenading my engine or sacrificing too much torque), I really need to fit my rear fender, I would love to upgrade the pathetic foot pegs, I probably need a new rear tire soon lol, and a longer carb stud so I can swap out my old broken air box for a brand-new newer style one that came off of a hemi (that I cut and modified BEFORE I found out that the studs are different lengths on older predators).

Open to any questions, tips, and constructive criticism!

-Ben

 

[KMC3420]

Welcome. Glad you joined and bike looks like a great bike, I'm sure the predator hauls you around just fine. That hydraulic brake is a nice upgrade from the cable operated caliper :thumbsup:

 

[TDB]

Welcome. Glad you joined and bike looks like a great bike, I'm sure the predator hauls you around just fine. That hydraulic brake is a nice upgrade from the cable operated caliper :thumbsup:

Yeah I'm a small guy so it just books with the predator. The top speed isn't as high as the pos 80cc that was on it because I'm leaving the governor in, but now I don't have to flintstone it from every stop or up every hill lol. The hydraulic brake will lock up the wheel at any speed, I love it! Its almost the same as the one from hotrodminibikes, but I found it on eBay for a little cheaper. I'd recommend the hot rod unit though because mine came all rusty and crusty. Oh well what can ya do

 

[KMC3420]

Yeah I'm a small guy so it just books with the predator. The top speed isn't as high as the pos 80cc that was on it because I'm leaving the governor in, but now I don't have to flintstone it from every stop or up every hill lol. The hydraulic brake will lock up the wheel at any speed, I love it! Its almost the same as the one from hotrodminibikes, but I found it on eBay for a little cheaper. I'd recommend the hot rod unit though because mine came all rusty and crusty. Oh well what can ya do

haha, the predator should do just fine. If you need more top speed, here is a gearing calculator to get you in the ball park of what rear sprocket teeth count you could shoot for. Gear Ratio Speed Calculator (MPH)

OldMiniBikes sells a split sprocket adapter for the rear tire so you can run split sprockets and swapping gears is much faster.
https://www.OldMiniBikes.com/doodlebug-sprocket-adapter-4.html

 

[TDB]

haha, the predator should do just fine. If you need more top speed, here is a gearing calculator to get you in the ball park of what rear sprocket teeth count you could shoot for. Gear Ratio Speed Calculator (MPH)

OldMiniBikes sells a split sprocket adapter for the rear tire so you can run split sprockets and swapping gears is much faster.
https://www.OldMiniBikes.com/doodlebug-sprocket-adapter-4.html

Yeah I plan on getting a 60-65 tooth sprocket. I want to hit about 40 with the governor still in so it stays reliable, but I also don't want to loose any torque. The split sprocket doesn't sound like a bad idea.. I might look into that, Thanks!

 

[KMC3420]

Yeah I plan on getting a 60-65 tooth sprocket. I want to hit about 40 with the governor still in so it stays reliable, but I also don't want to loose any torque. The split sprocket doesn't sound like a bad idea.. I might look into that, Thanks!

Hopefully they make a variety of sprockets for your bike. I'm not familiar with it, but the rear wheel is the same as a doodlebug and there are not many sprockets that I have found. So get the adapter and split sprockets are 10-20 bucks each, I bought a 72 tooth sprocket for a doodlebug rear wheel for $40 if I remember right. Gearing will be crucial for you to get it where you want it.

Sprockets

Sprockets

 

[TDB]

Hopefully they make a variety of sprockets for your bike. I'm not familiar with it, but the rear wheel is the same as a doodlebug and there are not many sprockets that I have found. So get the adapter and split sprockets are 10-20 bucks each, I bought a 72 tooth sprocket for a doodlebug rear wheel for $40 if I remember right. Gearing will be crucial for you to get it where you want it.

Yeah I haven't been able to find much so I was considering just getting a blank sprocket and cutting out the bolt pattern myself, but if I can get split sprockets then I can change my gear ratio easily... I like this plan a lot.

My end goal would be to get a CVT but that would be a little bit expensive and I don't want to cut up my frame to make it fit right now. Hopefully some day.

Thanks for linking those hub adapters, I would've never known about them! I didn't realize doodle bugs had the same hub so I kept looking for parts under monster moto and Motovox!

 

[KMC3420]

Yeah I haven't been able to find much so I was considering just getting a blank sprocket and cutting out the bolt pattern myself, but if I can get split sprockets then I can change my gear ratio easily... I like this plan a lot.

My end goal would be to get a CVT but that would be a little bit expensive and I don't want to cut up my frame to make it fit right now. Hopefully some day.

Thanks for linking those hub adapters, I would've never known about them! I didn't realize doodle bugs had the same hub so I kept looking for parts under monster moto and Motovox!

I have your exact rear wheel on my Gilson, my sprocket is the same as well. I'm working on making an adapter for split sprockets.

 

[KMC3420]

Decent Read

 

[TDB]

I have your exact rear wheel on my Gilson, my sprocket is the same as well. I'm working on making an adapter for split sprockets.

That's a nice looking bike, and thanks you've been a huge help!

 

[KMC3420]

That's a nice looking bike, and thanks you've been a huge help!

Thanks and vintage Gilson is one of my top choices. Your bike is a great start and looks like a fun ride :thumbsup:

 

[TDB]

Thanks and vintage Gilson is one of my top choices. Your bike is a great start and looks like a fun ride :thumbsup:

Yeah the Monster Moto and Motovox bikes are the gateway drugs into a mini bike addiction LOL! Me and my cousin started out with them and now he has a 1970 Rupp roadster as well and I'm looking to buy something vintage for another project. The reason we even got the bikes in the first place is because we couldn't ride our fourwheelers around town, and mini bikes were definitely the best alternative!

 

[KMC3420]

Yeah the Monster Moto and Motovox bikes are the gateway drugs into a mini bike addiction LOL! Me and my cousin started out with them and now he has a 1970 Rupp roadster as well and I'm looking to buy something vintage for another project. The reason we even got the bikes in the first place is because we couldn't ride our fourwheelers around town, and mini bikes were definitely the best alternative!

Lol, you gotta start somewhere. They are addicting from a cost stand point at first, relatively cheap for a whole bike. Then you build and spend money and turns out you have 700-800 in a mini bike lol. But it's a bad mini

 

[TDB]

Lol, you gotta start somewhere. They are addicting from a cost stand point at first, relatively cheap for a whole bike. Then you build and spend money and turns out you have 700-800 in a mini bike lol. But it's a bad mini

Yeah whatever I do next has to stay super budget, I found out there is a guy with a 73 GMC Sierra grande with a big block 454 just sitting outside waiting for some love...

I think I should be able to find something vintage that's fairly complete for cheap, my cousin bought the Rupp (which was 100% complete minus the engine) from a guy for just 100 bucks, and I think that guy has some more bikes.

 

[KMC3420]

Yeah whatever I do next has to stay super budget, I found out there is a guy with a 73 GMC Sierra grande with a big block 454 just sitting outside waiting for some love...

I think I should be able to find something vintage that's fairly complete for cheap, my cousin bought the Rupp (which was 100% complete minus the engine) from a guy for just 100 bucks, and I think that guy has some more bikes.

Yep and if you can find a hoarder it's a good thing,for him, bad for you, 4 minibikes later. Hold off for the 68 c10....short wheel base, 2wheel drive. Just sayin.

 

[TDB]

Hold off for the 68 c10....short wheel base, 2wheel drive. Just sayin.

Ohh yes, a 67-68 c10 is my dream truck, but I'm in MN and everything here is rusty. This truck is actually pretty clean (for a MN truck) and it is a 2wd so it would make a nice hot rod. Ah what the heck I'll link a pic.


Not nearly as good looking as a 67-68 but still pretty darn cool

 

[KMC3420]

Nice, body panels look straight, but I'm sure there is some rust hiding in there somewhere for certain, Cab Corners and Rockers for certain.

 

[syn]

[MENTION=56292]TDB[/MENTION] Which rear sprocket did you end up going with? Thanks KMC3420 for the links to the hub and split sprockets. I too was going to modify a different sprocket until I saw your link to the hub. Split sprockets are cheap enough to buy a few different sizes and test. Current plan is to drop the rear to 65t but I'm wondering how much torque will be sacrificed and what we can expect the top speed to be (stock 212 predator). Great thread with good info!

 

[TDB]

[MENTION=56292]TDB[/MENTION] Which rear sprocket did you end up going with? Thanks KMC3420 for the links to the hub and split sprockets. I too was going to modify a different sprocket until I saw your link to the hub. Split sprockets are cheap enough to buy a few different sizes and test. Current plan is to drop the rear to 65t but I'm wondering how much torque will be sacrificed and what we can expect the top speed to be (stock 212 predator). Great thread with good info!

I actually haven't ordered it yet. I've been putting the mini bike project aside to work on my car and on school :/