Please help w/ ATC 70

[RedRider_AK]

Woot woot, mates! I just found an ATC 70 roller for 75 dollars. New tires all around, the brakes work, good bearings. Quite a find, especially considering I was just talking about making an 70-framed "Pit Trike" of sorts. My plans?


An engine (from 90 to 125cc, hopefully a manual clutch)
New plastics/frame paint
A custom exhaust setup (will a CRF 50 muffler fit on the headpipe?)


Does anyone know how to suspend the ATC 70's? I've seen plenty of full-suspension mini-trikes, but I've seen no kits or full suspension frames on eBay. Any ideas?

[gravelord]

id love to know about the suspension my self. i really wanted to get a atc70, and make it have full suspension and a 125cc engine. bad ass. :-D

[Pete]

I'm curious if the 110 or 125 top ends are bolt on for the 70 bottom end?

[cragster]

http://cgi.ebay.com/ebaymotors/125cc-LIFAN-RACING-ENGINE-MOTOR-HONDA-XR50-CRF-50-PIT_W0QQcmdZViewItemQQcategoryZ35595QQihZ004QQitem Z140023017392QQrdZ1

this is wat i would put in it. BN manual 4 spd and its horizontal so im sure irwould work easly

[RedRider_AK]

this is wat i would put in it. BN manual 4 spd and its horizontal so im sure irwould work easly

Cragster, I was planning on getting a Lifan engine! I bookmarked a 110cc manual clutch variety today, and am planning on buying it as soon as I get paid (in a week or so). The only thing I'm worried about is durabilty issues, I personally don't think a 300 dollar engine will last very long (especially not how I ride :naughty: )

[Vealmonkey]

Firstly, there were never any kits sold to turn an atc70 frame into a suspension frame, you had to buy the frame with the suspension already on it. About all you could do to a stock atc70 frame was buy the suspension front end. I have 3 suspension framed atc70's that were made by 2 different companies. The company names were PK Racing, and A+ Suspension. The frames are built differently and one frame is mild steel and the other frame is chromemoly, not sure if I spelled that right. The aftermarket engines, Lifan and such, will bolt right into an atc70 or suspension frame. An atc90\110 engine will bolt in if you redrill a stock atc70 frame and add the provision to the frame for the front engine mount. The atc125 engine is a little harder to put in than an atc110 but I've seen one of these conversions done very nicely. If you use an electric start engine, people are building battery holders on top of the rear skid plates so the battery fits up inside the frame of a stock atc70, a nice and tidy way to do it and it hides the wiring nicely. People are also doing a conversion to make the engines pull start, just like a stock atc70. It is hard to use the kick start on an atc70, as you have tire clearance problems and rear fender removal is more than just moving a lever. I have posted pictures of my suspension framed trikes on here. Only one is currently a runner and I'm in the process of trying to make an aftermarket 110 engine with pullstart and a manual clutch. You can get an 88cc kit for the atc70 which makes a big difference in how they run. You can get up to an 110cc kit, but people say that it's hard to start with the recoil, but is quite a handful and fun. There are a few people that have made their own suspension frames and the best one I've seen is by a person that posts as Kasey or Casey. His trike is amazing to say the least, and I've only seen it in pictures, but it is well engineered and built very well and look unlike any other suspension 70. I have to telll you a suspension 70 is a blast to ride. I believe someone right now is trying to build a prototype for production and sale, but it is a slow process. Keep your eyes out for suspension 70s' on ebay, because I bought 2 of mine there. Just remember, there will definitely be other people bidding against you though. Also, atc90\110\125 heads and pistons will not fit on an atc70 engine, the placement and spacing of the engine studs won't allow it. Good hunting. If you can't find my pictures in search, let me know and I can post them again. Also, there was or is a gentleman that was doing a conversion to a 200x engine, that would all it to be bolted into and atc70 stock frame, it changed the cylinder to the front instead of on top, and it still was a 5 speed with kick start, pretty sick eh? That would be my dream machine.

[RedRider_AK]

vealmonkey, a couplea questions:

1. Do you think it would be hard for me and my friends (one of which recently built his own go-kart frame and mounted a 700 snowmobile engine/clutch combo on it, entirely by hand and by himself) to fabricate a suspensioned frame for the ATC 70? I think I would like the overall frame dimensions about the same size, albeit a +2 swingarm and some long forks to make it sit higher up.

2. If I do go with this hand-built approach, would the stock kick-start for the Lifan engine work?

3. I'm worried about exhaust mounting. Should I just buy a CRF50 or "pit bike" exhaust?

4. Good material to build frame from? I'm thinking chromoly, but in Nome AK, chromoly 1.5" tubing is kinda hard to come by (and expensive, I'll bet :( ). Also, can you weld Crmo with a wirefeed MIG welder? Should I just chop up some high-quality BMX bikes to get the tubing, then make some hard-core gussets and supports? I have several Haro bikes made from (supposedly) 4130 Crmo that are just begging to get hit with the sawzall :twisted: :naughty:

P.S. A 200X in a stock 70 frame is (in my opinion) **DONT TYPE AROUND WORD FILTERS** extreme. :naughty:

[65TremecGT]

If you were to fabricate your own suspension frame I think that mild steel would be more than enough, unless your talking about hiting big jumps but that would prolly not be the smartest thing to do on a 70! It would be a lot of work, but if you could pattern it after one of the suspended big brother three wheelers and scaled it down, it might be possible! I have two stocker 70's and they are a blast!

[cragster]

You could like find a bent up 200x frame from the front and cut it and weld the back onto the the ATC70 frame (that you cut off most of the back) LOL

[RedRider_AK]

If you were to fabricate your own suspension frame I think that mild steel would be more than enough, unless your talking about hiting big jumps

:lol: I like hitting jumps though! Also, I want my pit trike frame to last years and years of hard use from me and my sister (6) who I've been teaching to drive fourwheelers lately. Anywho, I asked my welding shop teacher about welding cromo, and he said something about not having the correct flux. He also said I could probably do it with my neighbor's wirefeed MIG welder, but it would ruin the look of the chrome, which I don't care about. I'll look into making it out of mild steel though.

[KASEY]

been there!!! and its a blast,,,, 125cc 4 speed manual clutch,,, full suspension atc70!!!! it just can't get any more fun than this!!!!
http://i2.tinypic.com/sv56qs.jpg
http://i1.tinypic.com/rwm9ly.jpg

VERY SOON TO HAVE INVERTED FORKS FOR MY JUMPING PLEASURE!!!! :w00t: :w00t: :w00t: :w00t: :w00t: :w00t: :w00t:

[RedRider_AK]

DAYUM KASEY. That thing looks friggin hawt. :naughty: :lol: What are those forks off of? I was planning on milling out a set of triple trees, but I need a set of forks first.

[KASEY]

forks are 1980 xr 80 ,,,,,,

[RedRider_AK]

Ahh, very nice, very nice. I'll talk to all the "junkyard" people in Nome to see if anyones got anything similar. I have another question: if I tube up a frame, will I need to keep a chain tensioner? Or do I need a custom-made chain slider on the swinger?

Oh yeah, and Kasey, whats with the expansion chamber? You gotta 2-stroker in that thing?

[KASEY]

that pipe is for the ???? WTF???? FACTOR,,, its a sand thing,,, alot of people just don't understand,,,

[RedRider_AK]

that pipe is for the ???? WTF???? FACTOR,,, its a sand thing,,, alot of people just don't understand,,,

Yeah, I've seen plenty of duner machines with those "outboard" pipes on em. I just thought you had a ring-ding in that 70. I guess not. Sounds nice though, huh?

[Vealmonkey]

Like I said, Kaseys' machine rocks. The frames for the suspension 70s' are actually one large curled pipe and the neck, engine mounts and rear suspension hangs from or is welded to the tube. I also have an adaptor swingarm from an cr50 that has the provision for an atc rear bearing carrier, but it's steel and kind of heavy. I tried to repost some pictures of the suspension frames, but the site won't let me and it says the pictures are already shown in other posts.

[mikesutphin]

im in the process of making my own suspensio n 70 im using the stock frame i cut the lower back of the frame off right behind the engine mounting holes and welded a swingarm mounting bracket that i cut off of a motorcycle i used the very front of the motorcycle swingarm for the pivot and with square tubing im welding the bearing carrier from the 70 on the rear end i think its going to work pretty good

[RedRider_AK]

Well, my friends, I've done it. Not only did I find a suitable donor for front forks and triple clamps, but in the process found an ATC 110, complete and running, which the guy offered to sell to me for (deep breath now) 300 bucks. It's a little rough around the edges (busted rear fenders and torn seat), and it's got a blue honda tank off of god knows what, but it does have a set of Dirt Dogs in the back, and it starts on the first pull.

I guess that my ATC 70 project was just kicked into high gear. This is gonna kick ass. :naughty:

[65TremecGT]

Kaseys 70 is very sweet! Sure would be nice to run across a suspension frame from back in the day! I want those 8" rims off ebay for mine but dont want to bone jaring of a ride!

NASCAR tube chassis are mild steel, so I think it would be fine for a 70 size bike! Im not a welder or anything but I believe you should TIG weld Chromoly. Something to do with the material in the metal. Chromoly also has a tendancy to crack and break where mild steel will bend. A properly designed mild steel frame cross braced would be fine and easier to build and MIG weld!

[KASEY]

im in the process of making my own suspensio n 70 im using the stock frame i cut the lower back of the frame off right behind the engine mounting holes and welded a swingarm mounting bracket that i cut off of a motorcycle i used the very front of the motorcycle swingarm for the pivot and with square tubing im welding the bearing carrier from the 70 on the rear end i think its going to work pretty good


this is exactly what i did with my first attempt at homemade suspension,,,,heres a pict,,,, the problem i had with it ,,is it felt like riding a stock 70,, and i wanted more room and a taller frame to create more leg room....
http://i3.tinypic.com/262mt84.jpghttp://i2.tinypic.com/262my3l.jpg
this frame is NOT an aftermarket frame for an ATC70 either,

[RedRider_AK]

Hey Kasey and vealmonkey, here's a thought: Can I pull the back end out of a 1985 Honda motorcycle and use it as a swingarm in the ATC frame? These pics are pretty easy to understand, I think. Take a look.

http://i71.photobucket.com/albums/i130/JokerMachine/framework.jpg
http://i71.photobucket.com/albums/i130/JokerMachine/framework2.jpg

[KASEY]

ONE KEY ISSUE,,, the pivot point has to be inline with the sprockets,,, so your chain adjust ment does not change with swingarm movement,,, that is real simular to what i did on my first,,,, as you can see i scraped it for a different direction

[RedRider_AK]

ONE KEY ISSUE,,, the pivot point has to be inline with the sprockets,,, so your chain adjust ment does not change with swingarm movement

Well, yeah, of course. I'm good enough at engineering (or just plain common sense) to know that...

w00t, getting an ATC 110 on Sunday!:w00t: :TrikesOwn :naughty:

[AlaskanSD]

Good luck with your fabb'n man. Alaska is the place to play! If you didn't already know, http://www.glamisdunes.com/invision/index.php?showforum=50 is about the best "70" resource out there. They should answer most of your questions, and if not, ask!

You'll also become good friends with www.dratv.com

[smyers33]

http://cgi.ebay.com/ebaymotors/WOW-HONDA-ATC-70-CONVERSION-KIT-TANK-FENDERS-FRAME_W0QQcmdZViewItemQQcategoryZ43964QQihZ012QQit emZ220024977435QQrdZ1

[Tres]

http://cgi.ebay.com/ebaymotors/WOW-HONDA-ATC-70-CONVERSION-KIT-TANK-FENDERS-FRAME_W0QQcmdZViewItemQQcategoryZ43964QQihZ012QQit emZ220024977435QQrdZ1

Wow,

Looks like some lucky fool gots himself a suspension frame :D

[RedRider_AK]

UPDATE UPDATE UPDATE UPDATE


After a year long wait, I finally got off my sorry ass and put together my ATC70/110 project. After a first ride, I am convinced that this thing is going to be my favorite toy for a long while yet. Passing up 300's on straights and whoops, shooting roost clouds on every turn, I'm officially hooked on this stuff!

Also, I'm getting another complete rolling chassis with a few stock engines (most of them ruined) for free from a guy tomorrow, in exchange for some engine work on his Quadsport. If I get a stator plate for my SDG 107 engine, that might be the next thing going into it, but if I don't, I have another couple of 110 engines ready for sticking into it.

I need some exhaust recommendations. I have an SDG stock exhaust, which is a very free-flow design. It fits on a 70-style exhaust port, so I'm guessing it will work here too. Thanks!

[bigreddaddy]

Can you post some pics? Did you just stuff the 110cc in the 70 frame or did you go with another frame, swinger, etc? Did you end up with a full suspension?
I'm very curious and would really like to see some pics.

[RedRider_AK]

Bigreddaddy, no I did not go with a different frame. It's a totally stock Honda 70 frame. To fit the 110 engine in there, the top mount on the engine needs to be hacksawed (about 5 millimeters or so, not much) to help it fit into the top mounts on the frame. The rear mount needs new holes drilled in the frame, but that's nothing serious. The front tire does not hit the tire upon turning, but it may after I put a narrow 18 inch tire on the front, so I will provide that information as I get it. The lack of suspension on the frame is kinda rough, especially at the speeds you're usually riding that little beast at, but it's a rush like no other to be tossing a motorized vehicle around like a BMX bike!