Since the derbi.... Winter Break Update #2

I put expansion cones in the dumb derpi and now it does 40. Still has only one broken brake lever - need to fix that. Maybe later. Got dio 1500 clutch springs coming for it as well as the nuts I need to make a puller. So, I need to source a stronger contra and throw those springs in. Then I need to do some porting. Hmmmmm.

Did the flame trap on Brownie (no biggie) and ended up needing to do replace the alternator tensioner, water pump (leaking) and re-plumb the oil pressure sending unit on Old Yeller.

Worked on the cb125 and 100 some. Welded a replacement for the broken tank mount on the 100, washed and waxed the tank and did fork oil on both bikes. The cb125 was pretty hilarious.

Did a blow down test on the 125 and it leaked really bad past the rings. Took it apart and guess what? The rings were in a billion pieces. Hard to believe this bike still did 55mph before I tore it down and didn't grenade. The rings were such small pieces, I can't believe they didn't turn and ruin the cylinder. Amazing. I've left the cylinder head sitting with ATF in the dome for about 36 hours now - none has leaked. Thinking this things gonna be a ripper when I get it slapped back together.

The vespa does stoppies now too. So I did that (still have a speedo too woot), re-re-reinforced the exhaust and repaired the rear rack. Reinstalled the foot pegs and STILL having wheel clearance issues with the footpegs installed. Whatever. I'll deal with that tomorrow. I started a thread to deal with the partial pad contact on the vespa brakes and my concern to their longevity. Terry Dean mentioned cutting the pads so they don't hit each other when they wear and I end up with no brakes - good call Terry. Apparently it's fine to run them like this though.

Used my torch for the first time to cut the bracket out for the Vespa disk brake conversion. Worked great. Wish the hoses had gotten here in time to do the exhaust work on the derbi. That would have been fun. My dad came outside to watch and make sure I didn't blow myself up. He also took some video. I'll get that posted later.

Still left to do this break is plenty. Here's the list:

Brownie

• Stud nuts for the A/C compressor (a couple are missing)
• Rear pads
• Tidy the electrical
• Install and wire fog lights

General

• Disassemble engine and repair first speed engagement
• install clutch springs so clutch disengages better
• tidy wiring
• vinyl repair on the seat
• disk brake exploration (drums)

Derbi

• Clutch springs
• Stronger contra spring
• new lens for the headlight

Maxi

• re-assemble top end (raided for metric coupling nuts)
• reinforce frame
• braze/weld bung onto tank so I don't have to use stoppers anymore

CB125

• Reassemble engine
• minimize massive head oil leak
• ride

CB100

• reinforce and clear coat side covers
• inspect before 300mi trip to Desirae's place

Swinger 1

• Go through the engine...
• Considering throwing an E50 on there

Prima

• get that piece of junk fixed and sell it for cheap

Puchonda

• swap SL70 parts in for manual clutch and mechanical advance ignition
• make frame repairs
• increase exhaust backpressure

Getting to know the Derbi Variant TT

So, I've been texting this guy on craigslist lately... He had this Derbi listed for $1200 that didn't run, was missing a pedal, and NO other details. Pretty easy to see why nobody had contacted him.

Me being bored, on craigslist and spazing out about a derbi being in TN and for sale, I text the guy even though it's a low hope situation with it being listed at $1200. I send him a real long, drawn out super tactful text that I'm into the bike, but it's not worth anywhere near $1200. We text, I find he's interested in me and likes that I'm into mopeds, and we agree I'll come kick the tires during my break and that he may or may not be interested in trading me for a project motorcycle or running moped.

I show up to meet the guy and he's much younger than I anticipated - this I was excited about because the dudes who have old mopeds are typically crazy and really do want tons of money for them. We talk, I look it over, we talk some more about what Derbis sell for in their stock condition on MA and chit chat. I got to talking to him about what I could trade him and ask him just for kicks and giggles after our convo what he might want for the bike in cash. He pauses, and says "well, I think my absolute bottom dollar would be $250". I was a bit surprised in how much he had come down, but I'd tried to get him to be half as excited about me owning the bike as I was. I'm not sure what the most I would have paid was, but I was happy with $250. It didn't run, I'd driven from Franklin to Clarksville and $250 I could come up rather quickly.

I had a "fire sale" on MA and raised the money in just two hours. Drove up there the next day and picked it up.

 

After I got it home, I started getting to work getting the thing running. Ended up only needing the points cleaned, point cam polished and lubed, a new plug boot, carb cleaned, fuel line and some other odds and ends. Fired right up.

Then it was time to start getting it road worthy. Greased the chain, changed the gear oil, set the timing, installed a new baffle, installed some tires I had sitting around (17x2.75 rear and had to go .25 smaller in the front with a 17x2.25), cleaned and greased the forks, took some rubbing compound to the whole bike and get a socket so I could take the vario off and mess with the weights!

The stock vario weight caps were pretty heavily worn and out of round and one of them wasn't even making contact with the ramp plate, so I decided to find some new stuff if I could. Got to the hardware store and found some nylon tube that was the right size. Stock outside diameter that presses against the ramp plate was .57 inches and the caps were narrower - finding something that was the same diameter all the way across and still rode correctly means that the nylon tubes I found that were .56 inches in diameter were basically the ideal size - I had to take into account the difference in diameter where the caps rode and where the weight rode against the ramp plate. Then I found some steel spacers that fit inside the nylon tubes and boom - vario weight = created.

Here's the packaging from the pieces I used:

Then I just put it together and did it. I drilled the steel spacers out to 7.5mm to remove ALOT of weight from them and make them extra light.

 Then I put the Nylon spacers on the Steel spacers and cut the nylon down.

They fit quite excelently in the stock vario. Resting height is the same and the width of the steel spacers was PERFECT. I cut the nylon flush with the spacers on each end. I also roughed up the steel spacer surface to get more of a press fit in the nylon, although that probably isn't totally necessary.

The stock design of the derbi was neat, beacause the weights rolled in the caps, but it was also bad, because it wore the caps out and the steel doesn't slide as well on the vario ramps as the plastic does.

Here it is!

 Works great. Half the weight of stock. I'm hitting full variation at 30mph. I took the restrictor spacer out of the vario, but I think I might have a little travel left yet to find. I'm hitting 35 right now. I need to come up with a less restrictive baffle, maybe even a cone insert for the stock exhaust? (stock was missing and had to use the one out of a Sachs) and I need to dial the jetting in on the 14.14. I'm at a 64 right now. I get the feeling it's going to want a 68. No leaks anywhere.

So far so good. Once I get it to 40, I'll be leaving it alone for a while and just riding it. I want to buy or fab a pipe for it, but I don't have a sheet metal roller yet... Was thinking I'd try to steal the homoet 4p dimensions.

It'll be interesting to see how the nylon holds up in the vario. I'll make sure to do an update after a couple hundred miles. Probably won't hit 1000mi until this summer.

ZA50 Crankshaft Measuring Tool Dimensions 905.6.32.107.0

For those of you wanting to make your own shim tool or are curious as to the stock dimensions, here they are. This should be everything you need to build your own.

This is not a critical measurement, the bottom of the midsection piece where the hole is not finished or machined. This measurement just needs to be ballparked to clear the crank.

This is essentially flush - again, the midsection perpindicular to the measuring tube and legs is not machined. It just need to be roughly inset from the tops of the legs.

Gates AX39 Tri-Power finally bit the dust

Alrighty... update. I maxxed out my motor adjustment two weeks ago for max top speed since I was going on a long distance highway ride.

100mi into the ride and we stop for gas... belt starts slipping pretty good and won't start without the decomp pulled. Ride it another 60mi and the header breaks on my piece mealed together circuit pipe. Limp it back home 40mi.

In all fairness though, I have put a ton of miles on this belt - many of them doubles miles. I can't really complain about this belt. I need to try a malossi (because I hear they're the best!) but I've got a warranty replacement on the gates, so I'll at least be trying another one of those...







It's been real with the stock transmission parts, but I think I'm going to be considering getting rid of my stock vario if I can't get the cheeks I got to not bind and balance - def picking up a euro rear.

My current cheeks ride great for about 20-30 mins, after that ONE weight starts sticking after WOT runs. Variates great until then, but gets stuck. Never had this problem in city riding. I'm really anxious to try the polini anyway and see how much of an improvement it is.

The new cheeks I have are the high travel stock cheeks referenced in one of the other vespa threads on mopedarmy - these are cheeks with the 17xxxx p/n on the cheeks. They have roughly 3mm extra travel (I concurred with Allen Halk's measurements). Stock this variator doesn't variate as far as my notched lower travel variator, but the weights are indeed hitting the wall, and the ramps more aggressive, so I'll have increased travel and accel with the new notched vario. Hopefully, doing some things differently to this one yields a variator that doesn't stick.

One thing that is tempting me away from doing another stock notched vario, is that with a stock un-notched bottom ramp, the bike vibrates a WHOLE lot less. I'm thinking this is the vibration that broke my subframe in south carolina and my header two weekends ago. When I put the notched vario in from Allen - it was night and day smoothness difference. If I can do some ghetto cheap dynamic balancing on the notched vario this winter, I may go ahead and run it. Something tells me this is far harder than I think it is though...

Joe is looking to hook me up with some euro parts this winter, so let's hope that pans out ;)

Really looking forward to disk brakes, new notched vario and some smokies trips in the spring.... Can't wait!

Also, brownie turns 30 soon! Gonna have to do a history on him during winter break to let people know how special he is... My mom just found a bunch of paper work pertaining to him, so it should be an interesting write up looking at documentation I've never seen before :)

Vespa Subframe Reinforcement

So this past weekend, I decided I'd reinforce my Vespa subframe on my grande... Earlier this year at THHHEEEEE BUZZARDS rally (which was epic, even in the back of the break down vehicle) I was 25mi into the 100mi ride on Saturday when my right tab broke off my subframe at about 45-47mph. Needless to say this was a harrowing experience and my moped riding for the weekend was over.

The Vespa stayed parked for a while, because I couldn't decide whether to replace or rebuild the subframe. I didn't have a welder, so rebuilding wasn't an option at the time. I had gone ahead and made templates for plates and began to cut them out with my angle and die grinder (very time consuming). I built up an OA rig and was contemplating doing the project with O/A - I'm so glad I didn't do this because the welding would've taken forever. Unfortunately, my cutting torch parts still didn't get here in time so I had to mechanically remove material any way. This past weekend I picked up a miller promig 135 with gas shielding (and a bunch of HID stuff ;) and I decided to go for it since it was my fall break.

I did some work on Thursday when I got home, but it was mostly getting all the kinks out, setting up the welder and riding with nashville's vintage motorcycle group Pseudomoto. The CB100 rode great and got me in shape to work on the Vespa.

My plan consisted of using cold roll steel to inlay the cutout of the subframe. I used 1/8" for the major inlays. It's been over a year since I'd had any time on a welder, so my welds weren't pretty but they should hold just fine... I didn't lay anything that was so bad I had to cut it out, but it definitely could have been better. I made sure to put a bevel on the pieces that would be adjoining to thinner material - this along with torch angle is important to get a consistent heat and penetration when welding together materials of different thicknesses.

Here's some footage from me working... not as epic as I wanted it to be... cam kept dying :/

In my infinite wisdom, I did not do a fit check with the transmission components installed with everything tacked toegether, and I ended up having to remove metal from my main reinforcing plates after welding them in completely. This made it way uglier and take way longer... IF YOU REINFORCE A SUBFRAME THIS WAY, DON'T FORGET THE TRANS CUT OUTS!!!!! This was a HUGE disaster and I would've finished the bike Saturday instead of Sunday (because the paint took a whole day to dry) as I didn't have it in me to finish fabrication Saturday night after this mistake.

From there I did some cosmetic welding and sanded everything down and started prepping for paint (and of course did another fit check before paint lol).  I decided to go with two coats of automotive primer and two coats of Rustoleum gloss enamel.

Re-assembly went fairly smooth except for the 4 bolts that go into the rear transmission housing were too short with the lock washers (I need to get new ones that are long enough for lock washers) and the main bolt up front that the subframe hinges on was too short. Everything else went smoothly and the bike was back together and running.

For Those Thinking About Doing This:

 

I would suggest including the trans cutouts in your design if you decide to go the plate overlay method.

Another thing I would suggest to those who would want to do this in the future is to consider using round stock instead of plate. The plate was incredibly thin in some spots and certainly could have been thicker. Round stock would allow you more flexibility and be way easier to manipulate.

Lastly, I suggest you just make another subframe entirely. After having done a reinforced subframe, I think that if I'd had an oxy-acetylene torch setup functioning or a plasma cutter, I wouldn've just gone this route. It would've been more effective and easier. I'm not sure I'd recommend doing it out of plate either - I really think that maybe next year I'll build a tube sub-frame. I'm not incredibly satisfied with the reinforced stock subframe.

Some how I picked up 5mph during the rebuild...

I took her for some speed runs and I guess she's loving the cold weather and not having a huge gaping crack in the exhaust :) I hit 52mph with stock vario notched with my aluminum weights, gates AX39 tri-power belt and a polini blue contra in the back with a 13mm carb and a DR65. The amount of vibration is still a bit disconcerting, so a mazi crank this winter (thanks for the suggestion Joe) and a homeade dynamic balancer for my stock vario (that'd be fun right??) or a polini vario are in order. I can probably build a ghetto balancing setup cheaper than I can buy a polini vario and weights, so I'm probably going to go that route... would be awesome to offer that as a service to all the stock class racers...

The subframe is fixed, but before next rally season ...

I set some parts on the bike to see how possible throwing a disk brake on the front would be and I think I'm going to go for it this winter since the forks are substantial enough, hyrdaulic and the fork lowers are steel. The setup would be a Z mag with china disk fitted and a honda caliper and master cylinder with a custom stainless line from the local hose manufacturer. With a disk brake, this would be the ultimate doubles bike for knoxville campus or rally bike period. I'm super stoked to bring this bike back up here next semester and rally on it next summer if/when I get out of school :P

Meet "Blue Boy" and the 125

1972 CB100 left and 1974 CB125 right. Acquired from a high school teacher of mine. Looks like I'll be escaping with new batteries, oil change, standard tune-up maintenance/adjustments and floats for the carbs. Everything else has cleaned up really well. CB100 is running (accrued 120mi so far) and 125 is sparking with compression awaiting carb parts.

UPDATE: So, I've put about 500mi on the 100. Despite an oil leak it has developed from the clutch cover, it runs reasonably well. The 125 is leaking badly from the head and is very lacking in power. I haven't done a leak down on it yet, but my guess is at least reseating the valves and a new head gasket. Both the covers on both the bikes were removed to be painted and I'm assuming no new gaskets were used :/ So, some new gaskets on the covers would probably sort the leaks out.
 

July 4th

So it's been a while since I've posted... I got a new co-pilot on Wednesday,

Did an oil change on the motorcycle (eeewwww magnetic drain plug)

Then I tapped the drain bolt up to the next size because somehow I stripped it out???? (still trying to figure out how that happened)

Then I removed the old ball hitch insert from the 78 hitch I installed on Old Yeller that was rusted in place.... An oscillating tile cutter, a tow chain, pb blaster and a sledge hammer were involved...

 

I also helped Sam finish a resurrection maxi that we kitted... fun bike. The 70cc TCCD, circuit, phbg combo really worked well (except for the air filter haha). The weekend isn't out yet... we'll see what else I do ;)

UPDATE: So today is the 6th and I hooked my phone into my bike... So pumped to have non-dead phone at a rally finally. No battery on the bike either - 100% regulated smoothed power straight from the stator. Maxes out at 12.5VDC right above idle and stays there till redline.