[TankTheory]

Hi all. You may remember me from other posts such as, "Honda Monkey Baja with a touch of Motocompo" and "Join me as we build a C70". Today I bring you, "I have an addiction and the only cure is another dirt bike."

So, I wanted a 70 because...well, why not. So I snagged one for next to nothing and I wasn't sure why it was so cheap. Started up, run, stopped...okay, sold.

Well, check out photo #4 and you'll see why he was so eager to get rid of it!

Surprise, it's cracked! Well aren't we all lucky that I happen to have a welder, that I've used once (look for my headlight mounting bracket in my C70 thread). I'm not entirely sure flux core is the way forward here, I think it should be MIG'ed with gas to ensure a good penetration with the weld.

Any who, so here are my plans.

1. Front end:
   1. HD springs, 20W oil.
   2. Find top clamp for a 70 and get bars.
   3. New tire
2. Frame:
   1. Fix weld.
   2. Powder coat; Black, silver, pink? Not sure yet.
   3. Tall seat
   4. Find a set of wider pegs
3. Engine:
   1. Have a TB 88 with RH ready to go.
   2. HV Oil pump
   3. HD auto clutch springs
   4. Already tossed on the spare Big Gunz CDI
   5. Have a TBR M6 exhaust.
4. Rear:
   1. BBR spring on OEM shock (comes in a kit with the front HD springs)
   2. New tire
5. Misc:
   1. CRF tank + Plastics
   2. Or do I keep it XR and find my missing side plastic?

So, yeah that's where I'm at. I'll keep you all in the loop. It's not going to be some crazy fancy build, just practical and fun.

 

[stunt-ur]

70's are a blast, and so light. To do CRF plastic swap the tank and shrouds are direct bolt up, but the subframe would have to be changed to the slimmer crf shaping. There is many different write ups on here on how to do that ranging from garage hack, to custom made subframe from scratch. As it appears your subframe is cracked, yours might be a good candidate for the crf subframe swap. As for your missing number plate, noone made aftermarket plastics so you will have to try your luck on ebay. I found a set recently for my xr. As for the rest, sounds like it will be a nice stock mod build.

Fast 50s/Fastminis is the only remaining top clamp manufacturer that I know of.

 

[chubbs]

You forgot to add buy parts from me.

 

[TankTheory]

70's are a blast, and so light. To do CRF plastic swap the tank and shrouds are direct bolt up, but the subframe would have to be changed to the slimmer crf shaping.

Fast 50s/Fastminis is the only remaining top clamp manufacturer that I know of.

Shoot! I didn't know you had to swap subframes. Guess I'll just keep it XR, not a big deal, old school is cool. Appreciate the insight.

You forgot to add buy parts from me.

FEED ME SEYMOUR.

So, tried my hand at this welding thing again. Not terrible but not great..I'm not going to be sending it. I've never been that guy, so I think this will hold up. Did some practice on about the same thickness flat stock and then went for it. It looks a tad less ugly in person.

 

[TankTheory]

The turbo on my car went, so that kind has this on the immediate back burner. My new tires showed up tho, so that's cool. Probably order all the parts I need at the beginning of April when I get paid again, made a post on FB but literally no one replied/had anything I needed for sale.

 

[TankTheory]

Found a little free time today and took it down to the frame / triples.

Got the wheels off and rims cleaned up a little. Had to cut off the rear, that thing was ON there. It was a CST Surge tire and man was it THICK. I'm planning to order a rim lock for the rear and I got too lazy to mount the front so they sit for a little bit.

XR70 in a box.. most of it.

Motor is going to stay apart until I get a HV oil pump and HD clutch springs. Then the TB 88 w/ RH is going on.

It's amazing how lazy some people are. Someone at one point sprayed the frame white (to cover up rust) and there is over spray on the chain, rear brake linkage/pedal, wheels. I'm debating powder coating ($$$) or just another driveway spray jobber. I'm a big fan of saving money on something I'm just going to beat up anyways but having nice things is cool too.

 

[TankTheory]

Totally not having a good time. It's going pretty quick, I only have maybe an hour and a half in. Good prep means good finished product! Which I put this kind of effort into my C170... Anyways, probably gonna go black. I found an SDG swing arm in a box which is a touch longer, I might toss that on? I just got the new bearings for it in the mail. We'll see!

 

[Crf50r88cc]

thing looks sick, you should defiantly put a mono swinger on it too

 

[TankTheory]

Got my Tbolt order and went to put in my HD clutch springs and HV oil pump....Now where is my clutch nut socket. Looks some where between Colorado and Japan in the last 3.5 years it's gone MIA. So, the motor waits.

Rear bearings are in the freezer, I'll knock them in today. Front bearings were sold out from Tbolt so I had to get them else where, wont be here until next week. EBC pads are on the front and rears. I'll probably toss the BBR HD fork springs in today. I heard something a while back that some people only do one HD spring because both were too stiff? Can someone confirm or deny these allegations? It's not too hard to pull out or add one in but figured I'd get some input now while everything is apart.

 

[stunt-ur]

The 1 spring thing is mainly a klx110 mod. The stock 70 forks are pretty soft, I'd do both and if it's too stiff, replace one with a stock spring. They also make dampers to raise the front end and change valving.

Are you PCing the frame? If so you may be just wasting a lot of time on prep as it can be stripped in acid and sandblasted really quickly.

 

[TankTheory]

Thanks for the info about the fork springs!

So, I didn't PLAN on having it PC'ed but it turns out there is a dude 15 minutes away from me that my buddy just told me about. So yeah, I spent probably 2.5 - 3 hours stripping down the frame and cleaning up the swingarm to polish...such is life. I'm just having him do gloss black. I was going to have him do the bars but then I realized that I'll eventually find a triple clamp and run aftermarket bars, so pointless there.

I've never had anything PC'ed, so I'm not sure what a fair price is? He's charging me $250 for frame+swingarm and he has VERY minimal prep work to do. I think one side of the subframe and the bottom half of the frame where the swingarm mounts was all that I had left.

Got my side plastic today and the dude threw in a red vent cap which was dope.

Also, all my bearings came in and are currently on ice for when I have time to put them in. As soon as my clutch socket comes in I can finish up the motor and have everything ready to go for when the frame is done.

 

[stunt-ur]

Powdercoat will be much better protection. Last I checked Fast50s still had the 70 clamp. Price on PC may be a hair on the high side, but not by much. And like anything, you get what you pay for. I know you stripped it but there is still a decent amount of prep needed. The sand blasting is for adhesion, and then the parts needs to be de-gassed, cleaned, masked off, and hung. Knock the swingarm bushings out and bearing races for the frame out before you bring it there. The finished product will be much better. Then I highly recommend the Pivotworks Swingarm Bearing Kit. It eliminates the rubber bushing style pivot and gives you needle bearings. That kit also includes the knock out tool which is very handy to remove the oem bushing.

 

[TankTheory]

Hmmm... I already bought new 6200RS's for the swingarm. Reminder I'm a filthy casual and not a serious racer, so I don't really need the best out there. Needle bearing setups are nice, my Takagawa on my Z50 and my BBR swingarm both run needles. I wasn't planning on doing PC like I said, so I had to pull the new bearings back out. I had the old ones laying around still so I just gentle half put them in to act as plugs if need be.

Got a little more done today. Knocked in the All Balls Bearing kits in the front and rear, also mounted tires and put the rimlock in the rear.

I also put in the BBR HD fork springs ( forks already had 10..or 15wt oil in them). I did the first one and compared between HD Spring+Oil, stock spring+oil, and stock (had a spare set). What a huge difference between each set up. It's a massive jump between stock and just adding oil then tossing in the spring, it's like a poor mans SP5.

 

[TankTheory]

Did some more stuff and things while waiting on the frame. Cleaned up my plastics and put decals on most of them, still need to do the rears. I suck at before at after photos, you think by now I'd remember. I did black vinyl on the side plastics, it's absolutely not perfect but it's good enough for me. The vinyl was at least 5 years old and was terrible to work with. The thick graphics came from Ebay and they are actually pretty nice. I did the right side of the tank perfect and the left I was a little off but again, I'll live with it. Pulling out all of the perforated holes was pretty lame tho.

 

[TankTheory]

Back from leave and digging in. I've been around for a while but I've never messed underneath the clutch side cover of anything. Too many moving pieces, scared to mess stuff up. Well, today that changed. Time for the HV oil pump and HD clutch springs.

Off to a great start. Already ordered a new one off Partzilla.

1.5mm then 2mm, easy peezy.

Finally broke down and got a in-lb torque wrench. I've been building bikes and engines nonstop since last year, I figured it was time. 108 in-lb for the oil pump screws!

I gave up for the night because I can't get the dang ole clip ring back in place. I fought it for 20 minutes and then just gave up. Any tricks or tips?

Oh and the powdercoating guy has had my frame/swinger for almost a month. I FINALLY get it back tomorrow. Probably wont be using his services again.

 

[dirtbkr188]

Insert one end of the retainer ring in place and work it into place one slot at a time, pulling it toward you as you press down on the clutch plates enough to allow it to pop into place, if that makes sense.

 

[TankTheory]

Oh trust me, I've tried that! I even used my quickclamp and a small socket to depress the plates and I'm still having trouble seating the ring all the way around. Maybe I put the clutch pack together wrong? I'll verify, I have the manual out.

 

[TankTheory]

Figured out my c-clip issue. It was tedious but I came up with a way to make it work, fully seated all the way around now. Moving on..

Bike is starting to look like a bike. First was the rear end. I had to drill out the lower shock bolt for the swingarm and find a longer bolt. Took a trip to HD on the Baja to find the bolt and a few minutes with a GOOD set of drill bits Milwaukee>Black and Decker, what a difference.

Forks feel great, so I might as well dress them up, I mean they are baaassicallyy SP5's at this point anyways!

Mocked up the plastics/tank, think it looks halfway decent. My tank decals started to bubble, I think it's cause I used the heat gun and stretched them a bit. Oh well.

Did run into one issue, which is why the rear wheels isn't on. The drum brake tab on the swingarm was 3mm too thick. I started with grinding down the inside of the rear brake drum but my grinding wheel is beveled and wasn't evenly grinding it down. Sadly, I had to grind down the tab and take off some of that sweet sweet powder coating. I'll mask it off and hit it with a few coats of primer and then some black gloss and then clear coat. I doubt it'll hold but there shouldn't be too much movement once everything is tightened down.

That's all for today. Should have the rear wheel on tomorrow. I'll rerun the wiring and have the bikes basically ready for when I finish the motor. Stupid 3-ball retainer puck thing.

 

[stunt-ur]

Bikes looking great! Is that another xr70 behind it in pic 2?

 

[TankTheory]

Bikes looking great! Is that another xr70 behind it in pic 2?

Whaaat, no... yes... That's my wife's stock bike. I started her on a 50 and the 10" wheels were super sketchy for her. She's way more sturdy on the 12/14. If you look really closely, you can see a clapped out 110 next to it. That's going to be "our" build we do together. Once I finish up this 70 and get my C170 passport figured out. Here is an older photo, weird to see my garage so empty. No motocompo's hiding in the corner!