SuperMini Evaluation - Part 1
01/28/04 - Report by Hench
OK, after letting the bones and muscles recover, it was time to tear down the Super Mini and see what broke, wore out, came loose, or needed adjusting. First step is to do the normal maintenance stuff, and see what turns up. The second would be to make a more detailed inspection, and the third would be to resolve any problems, plus take care of the one glaring defect noticed in the Cal City RoostFest - the still-way-too-soft suspension. All-righty-then, let's get to it.
General maintenance: First, the bike got washed and the bodywork/seat/tank/subframe removed. Since it was the bike's first real shakedown run since being completely rebuilt from the frame up, there'd be some extra stuff to check for play, etc. Number one, the steering head, since it had all new bearings and races. A combination of good work by ProValve installing the races in the frame and getting them seated properly, and careful assembly and torquing by HENCH meant that even after all those jumps and berms, the steering head was still perfect, no play, no tightness or binding anywhere. A HUGE improvement over the pre-Super Mini ride.
Since the chain was brand new, you know that thing stretched with the incredible forces put on it by HENCH. (Read: lard-ass.) First gear was too low, the engine could easily pull it from idle, and it revved out too quick. The motor has so much power, it could pull much higher top speeds, so the rear sprocket was changed from a 55 to a 51 tooth, and the chain had a couple links dropped and was re-tensioned. Surprisingly, it stretched much less than I would have thought for a new chain in that small size.
The airbox mods worked to keep dirt from hitting the motor, but it still needs a complete re-engineering. The filter cage is too small, and doesn't force the filter against the seal, requiring LOTS of grease to do the job. There's not too much that can be done about the small size of the airbox, but the filter/cage/seal deal sucks shit (pun intended) and is going to be reworked in a later project after the suspension is sorted.
Nothing leaked, and the only things that required attention were the lower radiator shroud clip that HENCH snapped off unloading the bike, and the clutch side bark buster came loose and required a little blue Loctite.
Deeper inspection: The inside of the intake manifold was sampled, and there was absolutely no micro-grit, indicating the airbox did it's job, despite it's horrible design. That means HENCH gets the credit for saving the motor. (Crowd cheers, bows taken.) Both the pipe and plug showed signs of the conservative jetting HENCH went with for the first run. While spot-on in it's performance, there's no doubt extra power is there to be had simply by carefully leaning the mixture. The clip was raised one, and the main jet dropped to a 128 from a 130 for the next run.
Both brakes were bled and showed no signs of air, and the fluid was clean. The brakes work great, which is a good thing considering the warp speed this thing will now do.
The frame showed no signs of cracking anywhere, despite repeated bottoming due to the soft suspension. The wheels remained true, and the spokes are still tight. Every nut and bolt was checked, and nothing other than the bark buster came loose.
On to the suspension: First things first, we need some springs. The folks at BBR make stiffer springs for the CR80, since they put a four-stroke YZ250F motor in the CR80 chassis! The stock fork springs are .27. The ones ProValve put in were .31, way too small a change. The new fork springs from BBR are .44, which by my calculations should be close for the weight of the Super Mini and it's "large" rider, perhaps a tad stiff. The bars come off, the fork caps undone, one locknut on the damper rod assembly, and whoosh, the springs are out and in. For right now, the 5wt. oil ProValve put in stays, but that'll have to be changed out for some 7.5wt to compensate for the stiffer springs before the next ride.
The rear suspension won't be so easy. First, it's even softer than the front, the proportion is WAAY off. My guess is ProValve didn't take into consideration the Super Mini's one inch longer swingarm, that results in about 10% more leverage on the rear wheel. The stock spring rate is 4.6, ProValve went to a 5.2, again, nowhere near stiff enough. Fortunately, BBR comes to the rescue again, with a perfect (by HENCH calculations) rear spring rate of 6.2. Shock off, spin the preload collars, spring off, new spring on, preload collars tightened, and the shock is back on. A quick bounce on the bike indicates the springs are pretty close, and the front isn't too stiff. The next ride will tell for sure.
While the spring selection by ProValve was well, "weak," their valving literally blows. Even after they were done, they had the clickers set within a click or so of the stiffest settings, allowing no room for adjustment, unless you wanted everything softer. I don't know what they were thinking, (or in this case, NOT thinking,) but it doesn't matter. The pooch was screwed on this one. The frame paint came out great, but they outsourced that. They did manage to get the steering head races right. For the meantime, all clickers have been clicked the last click to help out. The front will probably be tunable by changing the oil weight and level, but the rear will need to be completely redone if the new spring overpowers the existing damping. (Very likely.)
The tires will have to be changed for future Cal-City runs. The soft compound Dunlops on now would be fine for loam at the track, but the hard pack and loose sand at Cal-City is going to require something a little harder, and with more tread surface area, instead of deep wide grooves.
OK, let's evaluate the products/services used on the Super Mini project so far:
RPMs - Rick Peterson Motorsports. 10 points. Not only are the folks (including Rick himself) great people who are very professional, but their work is beautiful, fairly priced, and bang on schedule. The 112cc conversion they did on the 83cc CR80 engine is nothing short of miraculous. The power rolls on right from idle, builds smoothly through the midrange, and then explodes up top with a burst that will have you praying your fingers don't snap off the bars. And that was with the conservative, first-time-out jetting! The jetting, fuel, and oil ratio specs were spot-on, and they had the spare parts I wanted in stock. You simply can't ask for more, and they get the highest recommendation of the review.
Castrol A747 Two-Stroke Oil. 9 points. This is the way synthetic two-stroke oil is supposed to be. It's ugly dark brown in color, so you know when your gas has oil in it, it's so thick and sticky I'm thinking about testing it as an air filter oil, and it smells great when it burns. It also leaves a nice telltale burn signature on the end of the pipe to help you tune the motor. But the best thing is the way anything it touches is left with a slimy coating, which makes it liquid gold for pistons, rings, cylinders and cranks. At $22 a liter, it costs as much as liquid gold as well, but cheaper than a new crankshaft.
Atomic22. 9 points. No more goo! This trick exhaust port flange not only seals against leaks like a frogs ass, but looks great too. No goo means no leaks, which means no dirt being sucked into the cylinder on the downstroke. It also has the spring hole on the other side so the spring doesn't rub against the pipe. Someone did their homework on this one, only the relatively high price ($75 with a spare set of o-rings and shipping) keeps it from being a "10."
VP C-12 Racing Fuel. 9 points. Manning Fuel are the guys to call 818-767-3835 for VP Racing fuel products in this area. 100% synthetic, very stable for race gas, it mixes well, and runs great. It probably is the single biggest performance increase you can make, but to get it's full effect, you'll have to have your piston/head clearance/squish set precisely. VP also makes several other fuels specifically designed for racing two-strokes. There's only two drawbacks - it colors your plastic fuel tank a bit the first time you fill it, and at $6.25 a gallon including tax ($173.70 plus tax for a 30 gallon drum) it drains your wallet.
Moose Racing. 8 points. Moose doesn't make all their products, they pick out the best products and label them. The gold chain in 420 is probably made by Regina, and seems a lot tougher than I thought it was going to be. At $20 a chain, it's so cheap I'll never even lube it, just throw it away. Moose's riding gear is very high quality, and in particular their pants are it. They're wide enough to clear the EVS knee braces, (just barely) thick in the right places, well padded, and say "Moose" on them. What more could you ask for? Unfortunately, the chest protector that they say is red is pink. Oh well, just cover it up with an oversize Moose jersey.
Dunlop Tires. 8 points. Dunlop makes a range of different compound tires for the Super Mini wheel sizes (19" front, 16" rear) just like they do for the bigger bikes. Not only that, but in these sizes they're so cheap a front AND rear is cheaper than a 21" front! The only problem is the soft compound I chose is designed for loamy track surfaces, and the desert is going to require some experimentation, but it'll be with Dunlops first.
BBR Motorsports. 8 points. BBR came through with springs that should be workable by HENCH calculations, if they turn out to be right they'll get an extra point. The tall seat kit foam is excellent, both the proper shape and density. I also bought some original CR80 parts from them, (tank, shrouds, seat) that were promptly shipped, well packed, and cheap to boot. It's too bad they don't make more parts for the CR80 chassis. They do make an aluminum frame kit, but before you leave a puddle, it's $3,000 for the frame, or $8,500 for a complete bike with stock Honda engine and chassis parts. For $13,000, you get the YZ250F/CR80 that looks wild.
Braking Rotors and Pads. 8 points. Trick, lightweight, and theoretically superior brake performance. Do they actually work? Yep! But since I installed the rotors and the pads at the same time, I can't tell if just the pads on the stock rotors would do just as well. Also, the rotors look easily damaged by rocks or ruts compared to the stockers.
Renthal Sprockets. 7 points. Renthall has been making sprockets and bars forever, and they make some nice stuff for the CR80. They make a VERY trick 428 conversion kit for the CR80, but it's unavailable here in the States. So far the 420 is holding up well, but if problems develop, this conversion will be sought out by one of my relatives in England, who will remain anonymous, for a few pints of lager. Are you listening Neil? The drawback is they have a limited number of gear ratios for the CR80.
Moto Tassinari V-Force. 7 points. This trick reed block with carbon reeds helps the power in the low and midrange, and it looks super cool. It's hard to tell how much it helps since the RPM 112cc motor is in another world compared to the stocker, and the gaskets that came with mine just reeked of cheese.
FMF. 7 points. The Fatty pipe and Turbine Whore spark arrestor look trick, add power, and save weight. The extra hit the pipe provides is a kick, and the only reason FMF doesn't score higher is that I had to fab two spacers to mount them to the bike so that the pipe didn't burn through the rear brake fluid hose, and the rear tire didn't hit the silencer at full compression.
EVS Web Knee Braces. 7 points. Carbon fiber knee braces with adjustable hinges are just the ticket for over-the-hill Super Mini riders with knee problems. The only problem is I'm right in between sizes, so I had to get the larger one, and modify the Velcro straps to fit my legs. I also had to do quite a bit of custom trimming on the padding and straps to stop them from rubbing. They're also bulky, and it's difficult to find a pair of pants that'll fit over them. They also have a protrusion on the inside of the knee that helps wear your graphics out. Why do they get 7 points then? Because the protection and sense of comfort they provide is worth all the hassle and discomfort they create. I'd feel naked (believe me, THAT'S an UGLY Picture!) now without them.
Acerbis Mini Handguards. 6 points. The perfect size and shape for the SuperMini, these bar-end mounted bark busters have two problems. First, the hardware that mounts to the bars is cheesy, one of the holes stripped under the lightest of torque. Second, the "Honda Red" looks more like a dark blood red, better suited to old Huskys. Too bad Husqvarna never made a SuperMini!
Maxima 80 Weight Gearbox Oil. 4 points. I don't know whatever happened to the Torco line of oils, their lightweight gearbox oil was the shit, thin enough so it didn't drag, viscous enough to survive the most ferocious clutch fanning. It also had the smell of real gearbox oil, in other words, it smelled awful. Maxima's product doesn't smell as bad, but looks similar to the Torco. Unfortunately, it looked bad when I drained it, and I'm looking for the Torco again. If anyone knows where you can get it, e-mail me!
PC Racing. 4 points. These guys have some good ideas, but they're either overpriced, or simply useless. Their fork brace for trailering your bike is brilliant, but it's just a piece of plastic, and they charge about double what they should. Their carb breather kit is not quite as brilliant, but a good old factory race trick. The problem is the breather box is too big, there's already almost no room in the CR80 airbox, so it had to go on the frame under the tank, and it's $20 for a couple tees, some hose and the ventbox. You could build your own for a couple bucks. The Filterskins seem like a good idea, but the "pull-the-string" trick tugs on the seal area of the filter, a critical area already. By the time you pull the seat to put on a new 'Skin, you could just change out the air cleaner. There's also no room in the CR80 airbox to get your fingers around to install them. PC's airbox filter seal is down near the useless end of the scale as well. It's way overpriced for a piece of neoprene cut to the shape of the filter seal. The adhesive backing on it is a joke, I had to glue mine to the airbox with silicone. The real kicker on this product though are the nubs on the neoprene - a bumpy surface for the filter to seal on? I don't think so. I coated the nubs with a thin layer of silicone to smooth the surface. It'll be thrown out when the airbox gets re-engineered.
BelRay GearSaver Oil. 3 points. This stuff is red, not because it's Honda blood, but because it's probably based on automobile automatic tranny fluid, the wrong stuff. I used it to break in the engine, but drained it and flushed the gearbox before it or the clutch got used.
ProValve. 2 points. The only reason these zeros don't get a zero is the frame actually came out right. Of course, they didn't paint it, and it took a while for it to happen, since first they told me they could have it nickel plated, then they told me they couldn't. The steering head bearing races were R&R'd properly, but the important stuff, the suspension work, was worthless. I told them my weight within a few pounds, (my gear turned out to be a little heavier than I thought - knee braces, boots) assured them I was an intermediate rider that wasn't going to be doing the X-Games or Supercross, but would do some fast desert racing and motocross, but the suspension was nowhere close, and substantially unchanged from before the re-valve-re-spring. Setting it so there was no more compression or rebound adjustment at either end is a joke, right? Prediction: They'll be looking for a new day job soon.
No-Toil Filter System. 1 point. Should be renamed "All-Toil." Claiming to be the next generation of air filter oil and maintenance, this line of products is more like a genetic mutation gone wrong. First, the oil is too thin, and runs off the filter continuously, puddling in the bottom of the airbox and drooling out on to the swingarm, etc. Second, they claim their hand cleaner removes the biodegradable oil from your hands with no effort. The gritty cleaner when mixed with water gets hot enough to burn your hands, it doesn't remove the oil from your hands, and when you're done, you have sore, greasy hands. I don't know what in the bio can degrade it, but I had to use automotive hand cleaner and a lot of effort to remove the shit. Why do they even get a point? Because at least they sent me a free air filter so I don't even have to clean this one, just throw it away with the remaining oil and "cleaner."
Motul TransOil 10W30 Gearbox Oil. 0 points. I bought this at a cycle parts store when it was the only thing they had, and I wanted to break in the motor. When I found out it's made in France, I immediately threw it out without ever putting it in the bike. Of course, since they're French, they would have gotten a zero anyway, unless they had re-labeled the Torco.
OK, there you have it, the unabashed version of the truth on the Super Mini products and services. Stay tuned, we'll continue to update you on the progress of the suspension and airbox, and any damage HENCH can inflict.