A few months ago I bought a 110 honda motor for my atc 70 for $50 from Andy (Poule). I was really excited to put it in but I was having trouble finding someone who would pick it up from so-cal and bring it to me in Reno. (could have had it shipped but couldn't justify paying more for shipping than I did for the engine.) While on the phone with Andy he described his own builds and gave me some advice on my own. (Thanks Andy) I found out the engine had to be picked up from Randy (Stugots)so I called him to set it up and also asked him way too many stupid questions about my build.(Thanks for your advice too,Randy) Little did I know then that I had direct contact with two of the biggest carriers of the dreaded atc70 sickness....I think I may have gotten it from them. I definately got exposed to the virus lurking in this 70 forum for the last few years since I first saw the coverage from the Regatta. Three weeks ago a friend went to a car show in L.A. and picked up my motor from a friend of a friend that picked it up from Randy.Click to view attachmentClick to view attachmentClick to view attachment

Can I at least hate that you uploaded bmp files? Effn rookie.

Keep us posted on the build.

I also heard that there is no cure for the sickness! Looks good!

Wow You just got that!! Hey pm me your address I have the points cover. Good luck with your build If you need any help from me give me a shout.

This place will help your addiction.

http://hondaatc70.com/default.aspx

Click to view attachmentClick to view attachmentUnfortunately for me the motor is not a direct bolt in.....so instead of making it fit I decide to go a much longer route with way more fabrication (I know....its part of the sickness...just bear with me. I'm getting to the build part) I've seen all the pictures of the A+ frames and even drooled over the R55 stuff ( but with all my other interests and the fact that the economy is not what it once was...) but cant seem to get the ok from the boss to shell out the coin for another toy. I know Peewee and Gordon have something really cool in the works but once again the money stops me plus i'm impatient and have time on my hands everytime the weather screws up my plans for a dune trip. So I decide to channel my A.D.D. towards a new project. The sickness in my head tells me to turn this into a atc 70. It is a SDG speed mini 107 with a bent frame and many, many hours of abuse on it.

Nice link Scott, I have 3 in my garage right now and i need to at least get one onf them running soon lol

It never ends I am breaking down my black bike and redoing evrything from the frame up.

Sorry guys about the bitmap files but thats how it comes off my really old phone/camera. Wasn't really planning to make a tech post so I never took real pictures with a digital camera. The pictures are stored this way and I don't know how to operate a computer worth a damn. I didn't want anyone making fun of how the fabrication gets rougher and crappier the closer I get to being able to ride it on memorial day. Things get pretty rushed as that big weekend approached but I figured the hard stuff was done and I could always go back and change the things that didn't work after I shook it down and had a little fun on it. I felt the need to give back to this site and Crappy wanted to see pictures of what I was doing.
On to the build!

First order of business is to start with an easy project: I took an early atc 250r front hub with a three bolt flange that bolted right up to my 7" stock wheel and started there( The small wheel will cause problems later on but we'll get to that story) I chucked the hub in my lathe and gently cut off the mount for the front disc brake rotor so I can use it over once I shorten the hub to the length I need. Once the finished length is determined I needed to rebore a bearing register on the side I just cut off and also make sure that register was deep enough to fit both the bearing and the seal. I managed to salvage both the bearings and seals so the cost for this stage was a whopping $16. Cost of the hagged out pitbike was $200. Just made sure that the motor ran, and that the brakes and suspension were still usable. Click to view attachmentClick to view attachment

Is there an easy way to change these bmp files to jpeg?

GMAN!!!!

Way to go!!!!! Keep the pics flowing....this crazy hobby will meet you all sorts of great peeps and lifetime friendships!! We are going to a gathering @ duffytown next weekend with the entire family and we can't wait!!!

Keep the pics flowing .....OH, and if you are looking for color schemes...BLUE is the way to go!!!!

BLUE HONDA 70's RULE!!!

The front rotor off the pitbike doesn't even come close to fitting on the mount for the hub so I cut out a piece of flat plate to make the rotor mount, tig weld it to the hub and put it all back in the lathe to face it off to true so the rotor will have as little runout as possible. The welding was done in really small sections to minimize warping heat effect.Click to view attachment

This is where things start to get a little crazy from a fabricator's point of view. The rotor and caliper USUALLY mounts inside the wheel. Since I was willing to spend time to make stuff work and didn't want to buy more parts than absolutely necessary I drew up a crazy plan to make it work nonetheless. I decided to widen the triple clamps that I was building so I had room for the rotor next to the wheel. I also had to give it enough room so the caliper wouldn't rub on the tire when installed.Click to view attachmentClick to view attachment

My solution to widen the triple clamps to allow for the caliper/rotor problem unearths another issue. The required width is longer than my front axle will allow. So.....I figure out the total width available to me and there is enough room to widen only one side . The unequal length will make the atc steer really fast one way and slower the other way. So I will make custom spacers that will also be unequal length effectively bringing the tire back to the center point of the steering stem while maintaining the same od since I don't want to re-engineer the seals too. It ended up looking off but it works well. I spent $35 bucks to water jet my blanks out of a piece of billet that was laying around the shop. I could've cut them out manually but since I had no idea what it would be like to ride I felt that having them stored as a digital file that could easily be changed and reproduced in any offset was money well spent. I can now go back and cut out any style again if I didn't allow enough room for the brakes or if I need to change the distance from center to where the forks go to give myself more gas tank clearance when turning lock to lock. I started by mocking up the forks and using cardboard patterns to get myself close. I helped a friend move his waterjet shop when he expanded years ago so I got that done real cheap and he will make future revisions for free if I decide to do this again without the front brakes. Measured the distance that the rotor needed to be away from the fork so I could mount it just like it was on the pitbike.Click to view attachment

Save image as .jpg

sometimes it works by just renaming them with a jpg extension.

I can not wait to ride this beast next weekend see you there


lookin good Gman

I get no chance to save as jpeg. Thanks for making the pic appear without downloading

Now I pressed the original steering stem out of the original triple clamps and drew a blueprint for myself. Total thickness had to be maintained so it would fit back on to the frame. An interference fit on the stem was machined just like the original and all bearing registers had to be spot faced into the new triple clamps. I clamped the two blanks together to machine the center offset holes and also bored the holes that would clamp the forks at the same time to ensure a perfect parallel fit. Used my digital read out bridgeport thats older than most people reading this post to maintain tolerance. Took a while to indicate each hole but I figured it was probably the most important part of the build so I spent a full day making my new triple clamps. I used more bolts to clamp the forks than the original since my billet stock was thicker than the originals. The added thickness allowed me to also incorporate the steering stops to be machined into the clamp as an added bonus.Click to view attachmentClick to view attachmentClick to view attachment

Got out the sawzall and cut the bottom legs off the subframe. Pulled out big dead blow hammer and beat it until I could put the seat and tank on for mockupClick to view attachment

FWIW - I cannot make triple lamps and weld a do hicky thinking about "run out" We each have our thing.

carry on

Thanks for the help Yummi. Thats the kind of support on this site that made me want to spend the time to post more words than I am really capable of. I hope my ideas and solutions are understandable because it is hard to translate what my thought processes were at the time. Remember I had no money for the budget and there was a time crunch till its first ride. I went back and read an earlier post and I sound like a babbling idiot going on and on about ridiculous details that would only matter to someone doing the same kind of project. I guess thats another reason to post, so that no one makes the same mistakes I did and can learn and improve on my design. You have to understand that it is kind of hard to put yourself out there when so many good atc70's have already been built by people infinitely more qualified than me.

Click to view attachmentClick to view attachmentClick to view attachmentThe front is done and functioning well. Gotta start thinking about a swing arm. I machined two identical cups to start with that the bearings from the original swing arm fit into. I started thinking about the torsional load that two tires and a live axle would impart to the swing arm verses that skinny pitbike tire in the center of the arm. I decided to machine the cups twice as deep so I could run two bearings on both sides. They were bolted in place then equal length arms and a cross piece were tacked in place. This put all the load on the 4 sealed bearings and I hope help reduce the ability to twist. Before I could decide on a total length I need to start making the rest of the pieces of the swingarm. I wanted to have a little bit of chain adjustment to allow for different gear combinations etc... so I took a piece of pipe and machined it for two large bearings/seals and a limit spacer between them. Then I found a larger piece of pipe and offset welded them together a little at a time to reduce heat warp again. A small ring with holes on the side was later welded on one side to aid in turning it for adjustment. Its basically a heavy steel copy of a round house carrier. A larger housing piece was center split on the mill and worked perfect for the rear of the swingarm to hold the carrier. All the pieces for the swinger were faced in the mill at the same time so that they were square and uniform. This allowed me to build a swingarm without assembling it in a jig-fixture because all angles were symmetrical and all lengths were an exact match. I will probably build another one out of aluminum with some trick machined side plates but like I warned you before, the fab work starts to get pretty crude as I start to run out of time and want to ride it to see if it works.Click to view attachmentClick to view attachmentClick to view attachment

Click to view attachmentClick to view attachmentFor the rear axle I bought one from an atc 90. I doesn't use the axle tubes like the atc70 axle does and can be held in a traditional style carrier. Keeping it in one place will be important for bearing life, and critical for chain alignment, and the hydraulic rear disc brake that I'm stealing from the pitbike. The 90 axle originally had a drum brake. I machined the drum part off of the hub and was left with nearly a flat plate. I heli-arced the aluminum face where the cooling holes were then machined it perfectly flat in the lathe. As I turned it down I left a small register that was the same size as the center hole in the rear rotor from the pitbike. This gave it a perfect lip for the rotor to line up on and run concentric to the axle. I had to flip the hub backwards so the rotor could be removed without disassembly of the whole axle/hub. This changed the seal size from the original atc90 size and I had to special order one that would work

Click to view attachmentClick to view attachmentTacking the swingarm and mockup for chain alignment

Looking good thanks or sharing!

Dude you are out of control!! I tell you what, if I have any questions im calling you. Great work that trike is going to be awesome.

Click to view attachmentClick to view attachmentClick to view attachmentI moved the upper shock mount location so it didn't interfere with the future mounting of the gas tank. Then I fabbed the lower shock mount off the swing arm. I tried to keep the geometry close to the stock location but with the added leverage of the extended swingarm a raise of 100lbs to 200lbs in spring rate will be necessary to keep it from bottoming out. Called Wes at ishock in San Diego and got a used spring for $20 (score!) The stock shock is not as adjustable as current stuff but it came on the bike and was free. Maybe upgrade at a later time but this will work to get it on the sand.The shock works best when the force is straight on. Any change in angle will decrease the effect of the spring. So any angle other than straight will have to be compensated with spring rate.Click to view attachmentClick to view attachmentClick to view attachment

Thanks Randy, the positive feedback will help me through the looooong wait times while my pics upload and I collect my thoughts to go along with them.

Click to view attachmentI machined a front chain slider out of a piece of scrap uhmw (hard plastic composite). It fits over the front of the swingarm and is actuall designed to be flipped upside down to wear both sides when the primary side wears out. It looks square edged in the picture but it has a guide area in the center of the corner where it is troughed out. By the way, I forgot to mention that while I was thinking of added load of the two tires I decided that the original 420 chain was not strong enough. The bigger trunion and increase axial load surface of the 428 chain seemed to be better suited for my application. A friend of a friend manufactures sprockets for some well known name brands made me a custom 428 aluminum rear sprocket that fits over the hub register and bolts directly to the hub. This effectively eliminated those stupid rubber cushions and that clam shell plate. Cost $26 for a one off. (I know, I know) The 428 front sprockets are available for all the chinese engines on fleabay for $9.99 shipped to your door in a variety of tooth counts. The chain was less than $20 from The Rocket Factory. They also got the paddle tires for me for some custom work I did for them on a Raptor cylinder. Thanks for the good deals Beau. You helped me stay low budget by taking the time to find all the different prices on my parts.Click to view attachmentClick to view attachment[]

Click to view attachmentStarted up for the first time since it was a pitbike. Rode it around the property on the purge bottle from the dragbike with no seat. It was a blast. Heated the pipe and bent it down until I could mount it to the subframe. At this point I'm pretty sure me or one of my friends is going to get hurt on this thing. I guess that was bound to be the end result right? Had it pitched sideways to make it around the corner between trailers at full speed...good times for sure. (Paddles in the gravel, high center of gravity, purge bottle still hanging/bouncing off the handlebars, get the mental picture?) Oh, forgot to mention that I unplugged and removed all electrical components while I was welding on the chassis and tacking the swingarm. Also when welding make sure the path to the ground clamp does not travel through any bearings. Failure to pay attention to this detail will arc the balls and ruin the bearing surfaces, greatly decreasing the life of said bearing and causing a safety hazard. Which reminds me that at the beginning of this tech article I forgot to put the standard disclaimer. Warning! Attempting to duplicate or ride this vehicle comes at your own risk. Operating this kind of machinery will most certainly result in serious injury or death. I assume no responsibility whatsoever for anything even associated with this.

Click to view attachmentClick to view attachmentClick to view attachmentWow....Longest string of posts ever...If you've made it this far through my endless ramblings and are still awake then I applaud your determination. We are almost ready to ride it in the sand and we got just hours to go before I load up and leave. The last project is a little bling to attract everyones attention away from my cobbled up mess of a trike. Found some scrap aluminum in the pile and polished/machined a shiny grab bar/flag mount. The flag holder is blue for Andy's sake.

Click to view attachmentClick to view attachmentClick to view attachmentQuickie repair on the fenders. ( Seriously Does anybody have some plastic they don't want anymore) And still finishing the rear caliper mount.

Click to view attachmentFinished it in time to load for memorial wknd. The weather sucked unless you like rain, snow ,and wind. The trike is fun to ride and people just don't know what to think about it. Waaaay underpowered for adult rider. Could only make it 1/4 way up the drag hill. Was fun on the flats after it rained. Gearing is to tall. Suspension worked well. Was a huge hit with the kids in camp. I let them ride the piss out of it. Carb needs some attention. Let a 9 year old kid who has never ridden anything before ride it inside camp on the kiddie track for hours. Even pissed off some adults because it was annoying them (kinda loud for as slow as it goes) All things considered it was a great first outing for it. I wonder if I could build enough power to tow the drag bike to the hill so we could save the alcohol. I'd bet we could get at least two more runs if we didn't have to ride to and from the hill. Hindsight being 20/20....I shoulda built one of those laydown 250r two stroke motors. Now that would'vd been fun!! Thats all for tonight. Thanks for listening.

WOW, WOW, WOW!!!

Holy Smokes!!!


I just saw this / That is INCREDIBLE!!!!!

I cant wait to see this!!!!

Thats an awesome build! I need to quit my current job and go find a place with all those cool tool and machines.

Click to view attachmentClick to view attachment Thanks Andy... Tried home powdercoating for the first time last week . This is a picture of a formerly rusty stock wheel that I got to replace the wide golf cart wheel and tire that came on my stock 70. It turned out suprisingly good and was easy to do. The other picture is of the rear brake mount. It started cleaner than this but right before I was going to tack it to the swingarm, (I realized that if it was permanent instead of unbolting then the entire axle would have to be removed just to get to the caliper mounts) I changed it to a removable mount. If you guys see changes that need to be made before I get too far (paint+powdercoat) then please speak up so I don't have to go back and change it after its nice. I know it looks like a total beater but I think it should clean up nice

mad fab skills!!!! that is going to be a great ride!

Click to view attachment Thanks Matt. I will be the first to admit that things got a little out of hand from what I originally intended to build but as each problem surfaced I tried to find an equitable solution. The posts are meant to be descriptive enough that the issues that arose while building it can be avoided by someone else who is building something similar. If I had to start over I would do some things different. But I certainly appreciate your comment. Here's a pic from this weekend at Sand Mountain,NV. I tried to take it on a dune ride and the verdict is that it sucks due to a lack of power. I won't be taking it with me to the dunes until I get a boost in the motor department. And maybe some new fenders so people won't point and laugh so much. It is fun on the flats and the suspension is a huge improvement over my stock 70. At the risk of blowing out the shock, I even let Crappy ride it! (he said it needs more motor too)

G, I have this as a start

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debating to finish it as front suspension/hard tail or find a rear suspension frame and add my front to it.

I don't have the fab skills to do it myself!

Finding a donor rear suspension might not be a bad way to go if you have a motorcycle wrecking yard near you to walk through. I might also check your local craigslist for cheap quads with motors that don't run. The thought of adapting something like that was something I was considering but I was way too impatient and decided to use the bent pitbike I bought on the cheap. What you have looks like a good start but since the majority of your weight will be on the rear, I think you should follow through with the rear suspension versus a hardtail. After riding it,I wish that I had used a better rear shock(maybe off a fullsize) because I've already bottomed the rear suspension out trying to jump it. It really becomes worth it when your other friends are getting bucked around by every bump when we're mobbing the campsites at full speed and your just cruising along. Just my opinion but the front benefits less than the rear. I created a few problems by wanting a front brake, and if I had the start you have then I would go without brakes up front. Keep me posted on the build. It looks good so far. Gman

Ya this thing kicks a-s it was a blast to ride alittle under powered but like g-man said that is already being taken care of . It handles great and was alot of FUN .
Oh ya if you think this guy has mad fab skills you should taste his dutch oven bread puuding he makes LOL

Click to view attachment Back on my suspended project after the summer off. Got a 155z with a close ratio trans. I have to stretch the frame and reduce the rake on the front end.

Click to view attachmentClick to view attachment[attachment=
504091:swingarm..._support.jpg]I cut the frame where the previous owner had done a really crappy repair and sleeved inside the whole length of the the tube. Then I capped my repair with the same size as original. The ends were rosette welded to impart strength over a greater area. Now it is twice as stong as before but outwardly it appears no different. Once fit, I put the insert in the tubing bender to adjust the rake of the front end. (Which was always too choppered out) It ended up at 23 degrees and I was shooting for 22degrees per Kaseys advice) What I found while apart was that the added force of two wheels and extended swingarm had broke out the swingarm pivot bolt mounts on the frame. I machined some new supports out of 1" bar stock grade 8 steel and heli-arced them to the frame. Hopefully this stops that problem.

Lookin good

Click to view attachmentClick to view attachmentI found a petcock from a kids polaris quad that had a nice mount and provision for reserve too. The original carb had both fuel inlets on an integrated petcock, unfortunately the new motor takes a MOLKT carb with only one fuel inlet. This $5 petcock off ebay solves the problem. Heres the mount and how it looks with the tank on. Oh yeah, I found some left over silver paint in the shop and mixed some black into it until I got close to a metallic gun metal color. I coated the inside of the tank for rust and did a quick scuff on the tank. I probably should have fixed all the dents but I did a rush paint job because the weather was nice and warm with no wind.

I have a lot more pictures to post so keep checking back. It takes me a while to convert them from my phone camera to a form that I can upload to the post. Please leave me some input on what you like or don't like.

I hope that you guys are enjoying seeing the complete build. If you like it.....could I please ask you to bump up my reputation?

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Put the carb on my new big motor and the bowl just touched the cylinder. To raise it up I cut a intake gasket out of really thick gasket paper and installed it so the carb no longer touched. I also mounted the cdi box under the tank and relocated the coil as well. I spliced in my key switch and kill button to the harness and zip tied it to the frame. All joints were soldered and shrink wrapped.

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The new oil cooler needed to be dampened from vibration so this is how did it. As you can see it is isolated by a large rubber grommet with a steel inner sleeve. The bracket was mocked up so that the triple clamp didn't hit the cooler when the steering is turned all the way to the stop. In retrospect I wish I had stretched the frame before I made the mounts for the seat/fender/tank. The distance throws the proportion off just a little and its a huge pain to change all that now. Maybe later I'll make some air scoops for the oil cooler out of carbon fiber, since the original idea was to build a scaled down ATC 250R.

Thanks Andy for the bump to my reputation.

I just took some pictures with the fenders on, tank painted, and assembled ready to ride. I will post these as soon as I convert them to jpegs. Ready now to take it out for Easter to Sand Mountain. Stay tuned.

As usual you are doing a great job!!! If it starves for fuel and bogs out look at the petcock in my experience that style does not flow very well. I had to drill out the holes inside to get more out of it.

Thanks for the tip Randy. I did not know that. I will look into drilling a larger hole. Information is priceless. Thank you for your kind words as always.

Whats wrong with Hollowen test ride????