V7Goose

Absolutely. Goose

Nothing to send back - I would not own such a poor tool! But they all rattle - even yours. They have to - that is a specific design feature. And it is even referenced in the instructions; although, I don't think they actually use that word. But in whatever words they choose, the instructions specifically tell you that if you cannot see the rods rattling in the plastic tubes, then you cannot trust the reading. Goose

Besides being the only tire on the Royal Stars that tends to "frequently" have large chunks of tread separate completely from the rest of the tire (frequently compared to any other brand), the 880s seem to cup quickly and badly. That statement is based on my unscientific observation of the various tires I have helped change for many members of this site. I recently had over 30 tires from these bikes sitting in the back of my truck waiting for me to make a run to the recyclers, and every single Metzeler rear tire was BADLY cupped, while not a single rear tire from any other brand showed significant cupping. Of course, suspension and balance problems on the specific bikes could have caused the problems instead of just junk tires, but I do not believe that any more than I believe Metzeler's claim that every one of their customers who has a tire problem is an idiot. Goose

Obviously there is a huge difference in design - the mercury stix can spill or break easily, and the mercury can even get sucked into the engine, where the vacuum gauges are practically indestructible. Both measure actual vacuum quite accurately, unlike the Carbtune that measures just the amount of air being pulled around a rattling metal rod. The vacuum gauges come with plastic valves that are placed in-line with each gauge to adjust the amount of needle bounce - you should set them so that the needle just slightly wiggles. If you turn them all the way down so the needle does not wiggle at all, you won't know for sure that they aren't closed a little too far and, therefore, showing incorrect vacuum reading. The reason any vacuum measuring tool will show a large bounce at idle is that the vacuum is only present during the intake stroke, which is just 25% of the time on a four cycle engine. The slower the RPM, the worse the bounce because there is so much time between each intake stroke. You control the bounce by restricting the vacuum line so that only a very small amount of vacuum in the gauge can bleed off between intake strokes, but there is a very fine line between enough restriction and a tad too much, which doesn't let the gauge read the full vacuum. While the little plastic valves work well enough, you will find brass valves with screw knobs much easier to find just the right point. You can find those at some hardware stores in the plumbing section, or look at some internet aquarium supply outlets (I'll try to find a link and edit this post). Update on brass valves - it seems that quality in-line brass aquarium valves with a knob for precision adjustment are a thing of history. The only thing I can find now are valves with a 1/8" NPT on one port designed to screw into a manifold. See the item labeled "Brass Valve" here: http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=8165 That kind of brass valve will work fine, but you will also need an adaptor to screw onto the 1/8" NPT side that will let you use it with a vacuum hose. You can find that at any hardware store. You do NOT want a lever valve - they are very difficult to get adjusted correctly in this application. Goose

This problem is not unheard of, but it is not particularly common either. If the cowling has not been hit by anything it should be handled by warranty without argument. I did have the left one crack on my 05 somewhere around 50,000 miles and had no problem getting my shop to replace it. The main cause of this is misaligned mounting points that cause you to push te plastic around to find the right positions when putting in the screws. This causes stress on the cowling. It is easily fixed. The mounting brackets behind the cowling are easily bent (very soft metal. This is particularly true for the top one that is part of the same bracket that holds the air filter. Start by attaching the cowling with the lower lug into the rubber grommet, then loosely insert the rear screw (the one above your floorboard). Just start the threads, but do not tighten. Now see if the bottom screw hole in front lines up - it probably will, so go ahead and insert that screw. You can gently move the cowling around a bit tl align that hole, just watch it to make sure you don't move it enough to flex or bend the plastic at the edge. Finally, look in the hole on top and see which direction the bracket needs to be bent to line up properly. After you take the cowling off again you can bend it easily with long-nose pliers. It may take a try or two, but once you get them to line up without having to shove the plastic around, you won't have any more cracking. Last comment - you cannot over-tighten the front screws because they tighten down on a metal collar that fits through the cowling. You can, however damage things if you over-tighten the rear screw, so just snug it up good. Goose

That thread Squidley noted above has some good information in it (and an awful lot of pointless bickering). As for how to find the problem, see particularly my writeup in post #46 in that thread. Trailers have a LOT of ways they can be misaligned, and just having the axle square with the hitch is only one of them. The frame needs to be perfectly square, the tongue needs to be perfectly straight and square with the frame, and most importantly, the tires themselves must be perfectly square with the hitch. On many cheap trailers, the wheel spindles, and therefore the tires, are NOT perfectly straight with the axle. That is why I use the method I described that bases all measurements on a straight line from the outside face of the tires. The longer your straight edge for this process, the easier it will be to spot any misalignment. And on an unrelated note, V7 was the model designation of the first Moto Guzzi touring bikes sold in this country back around 1970 (V twin engine, 700cc and 750cc), and a Guzzi is generally called a Goose by those who love them. They dropped the V7 designation when they introduced the 850 Eldorado in '74, so only an old fart would remember it. I still have the first V7 Ambassador I bought back then, and it is still my favorite bike. And I have never found anyone else who beat me to the "V7Goose" userid. Ride safe, Goose

First, I think we can all agree that the only part of a tire that can wear away the rubber is the part that touches the ground. Second, I think we can all agree that car and trailer tires that are over inflated for the load will bulge in the center, meaning that only the center of the tire will touch the road (ALL motorcycle tires are shaped this way, no matter what the pressure). Third might be a little harder to get everyone to agree upon, but the logic is irrefutable if you think about it: misaligned trailer tires will quickly scrub off rubber from ANY PART OF THE TIRE THAT TOUCHES THE ROAD. So if a tire is inflated just enough that the tread face is flat and touches the road all the way across and the tire is misaligned so that it is dragging, ALL of the tread will be scrubbed off quickly, but if the same tire on the same misaligned axle is over inflated so that only the center of the tire is touching, then only the center of the tread will be scrubbed off in the same amount of miles. In the case of a misaligned tire, the fact that the center of the tire is worn bald has almost nothing to do with the over inflation, and EVERYTHING to do with the misalignment. The fourth point is the kicker that ties it all together: properly aligned tires on a lightweight two wheel trailer will last MANY thousands of miles without showing wear. I do not have hard numbers for this, but I would expect a minimum of 50,000 in this application. And I do know from first hand experience that 8" tires on a properly aligned small trailer will not show perceptible wear in 10,000 miles. The last point is probably the most contentious (and it is mostly just a repeat of #4): TIRES ON A LIGHT WEIGHT TWO WHEELED TRAILER WILL HARDLY WEAR AT ALL IF THEY ARE PROPERLY ALIGNED. The best example of this is the thin bicycle-like tires fitted on a Bushtec trailer - you never hear of people complaining about tire wear on this quality-built trailer, but those tires have a very thin contact patch, just like an over-inflated little tire on a cheap trailer. In fact, the higher the air pressure and the thinner the contact patch from a trailer tire, the less rolling resistance the tire will have and LESS wear. So the bottom line is that tires on a motorcycle trailer should never show significant wear in just 15,000 miles. If they do show wear, it is only because they are misaligned. If the tires were overinflated but NOT misaligned, they will not show any significant wear in only 15,000 miles. If they DO show wear, IT IS THE ALIGNMENT THAT CAUSES THIS, NOT THE INFLATION! Goose One last comment trying for absolute clarity on this point - if you keep small trailer tires at maximum pressure so only the center of the tire is in contact under normal load conditions, then when they eventually do wear out, no matter if it is in 3,000 miles from a defective trailer or 70,000 miles from lots of riding, they WILL only be worn in the center. We all know that, and it is not a problem UNLESS you think the tires should have lasted longer. In that case, reducing the tire pressure will NOT make the new tires last longer, it will simply make them look better when they are worn out in the same number of miles as the first set!!! The ONLY way to make trailer tires last longer is to ensure they are properly balanced, properly aligned and turning with the least resistance. Two-wheeled trailer tires should last almost forever simply because there are no acceleration, braking or steering forces that cause them to rub on the road. So when someone says that a tire worn only in the center shows that the tire was over inflated, they are correct. But they are NOT correct if they suggest that lowering the pressure will make it last longer. It will simply leave you with a better looking corpse. And if everything else is equal, larger diameter tires will last longer than smaller tires simply because they turn slower and fewer revolutions for the same distance. So any particular point on the tread spends less time in contact with the ground during each mile.

You may be expecting a longer tire life from the lower pressure, but you will be much better served by actually finding the source of your problem. Your tires were not worn out from too much pressure - you have an alignment problem. goose

That is great news - glad you got is sorted out. And glad we got the information on this here - it is a new "quirk" about these bikes that we did not know until now! Goose Oh, just in case you get the urge to figure out if it was too much or too little air, here is an easy way that should show it instantly. Just tape a piece of paper over the intake of the filter box, with tape only on one side and the free edge of the paper just barely touching the other side of the opening. Now when you get up to speed the flap of paper should wither obviously be sucked into the opening or be pulled away from it. I'd probably do that with both filters, but reverse the side the tape is on (meaning on one the free edge of the paper is on the tank side, and on the other the free edge on the out side). This might show the issue more on one and not the other.

I just put the following clarification in my first reply to this thread, but because it involves an apology to Yammy, I wanted to put it in a new reply also to make sure that he and others see it: CLARIFICATION EDIT: Note here that I was comparing stock 150/90-15 tires with the most common alternate size 170/80-15. When I first read Yammy original post, my brain completely glossed over the fact that he was actually asking about a 150/70-15 tire (a size which I do not think actually exists, at least not from Avon, Dunlop or Metzeler). All of my comments remain valid, but my apologies to Yammy for not noting this before. A 150/70-15 tire would probably be about two inches less diameter than the stock tire, just like he calculated, but that is just a guess - like with any tire, you would still need to look at the manufacturer specs to know for sure. Goose

That would be an excellent choice for a trike if you can find one that fits. Goose

I would not have thought it would make any difference at all, but based on the report above and the fact you also have them off, I'm wondering . . . I can imagine the possibility that the air flow pattern around the fairing, forks and tank could create a current that would stream by the air box intakes in such a way as to work like a vacuum to lower the pressure at the filters. Next time I take the lowers off of mine I may take it out for a spin to test it. Goose

There is really no way you can damage the rotors by taking them off - the risk is when they are on the rim and something pushes against them. The only thing special about removing the rotors is to mark the position so that you put the same rotor on the same side in the same orientation (best insurance that runout will not be different). Other than that, taking them off is no different than removing any other bolts. When putting them back on, be sure to use blue locktite and not exceede the torque spec (it's quite low, and an air ratchet will instantly over-torque them!). I mentioned using tire lube (such as Ru-Glide) in my post above - this is critical. Although it makes little difference when using tire irons, on a machine the rubber will not slide over the rim without it. And it is every bit as important when taking the old tire off as it is to put the new one on. Some people use oil or other stuff, but I would never consider that, especially on a two wheeled vehicle. If you buy a gallon of rubber lube at the auto parts store it will last seven lifetimes. Ru-Glide used to be about $20 a gallon, but the NAPA house brand was more like $7. Lastly, you have to make sure the bead on the bottom of the rim is NOT hung up on the rim shoulder as you try to get the top bead to slide on or off. If it is not pushed up into the center of the rim, the tire will not have the ability to move sideways enough to allow the bead to easily slip over the rim, even with lube. Goose

The faster steering and lighter feel that a 130/90 front tire gives to a normal Royal Star is a function of how the rounded profile of the tire behaves when the bike leans so that the contact patch moves off of center. Since a trike does not lean, all you are getting is a smaller contact patch with less breaking traction, less holding power in a corner, and faster tire wear. A better choice for a trike is the worst possible tire for a two wheeled Royal Star - the stock Brickstone 150/80-16. This tire has a wider cross section and less rounded profile than any other available tire (it is close to a full inch wider than some other 150/80-16 tires). In addition, the center is a much harder rubber compound than the sides, so the tire will last much longer. Goose

Low pressure, like 10-15 lbs, will provide the softest ride and would be sufficient as long as the weight in the trailer did not produce much of a bulge in the sidewall. HOWEVER, some of us do not feel that is the best choice, even though it is an acceptable choice. A much higher pressure, even at the sidewall max, will provide the lowest rolling resistance and the longest tire life on a two wheeled trailer. This is my personal preference. Goose

You guys can speculate all you want on what the numbers are supposed to mean. I think research is good, as is trying to understand the intent behind something. But the facts are thus: two tires with the same number on the sidewall rarely measure the same unless they are the same brand and model. Sometimes the difference is small, sometimes it is large. I have physically done the measurements to prove this, but even that is besides the point. Just look it up in the manufacturer's documentation. If Avon says their 150/90-15 tire is 6.3" wide and 25.4" in diameter while Dunlop says their 150/90-15 is 6.05" wide and 25.6" in diameter, you are pretty much going to have to accept that they are different sizes. Goose BTW - if you want to quickly see just how inaccurate that TireRack.com explanation can be if taken literally, just take a quick look down the tire width column for any brand of tire. I just did this for the Avon Venoms, focusing only on tires that have a nominal section width of 150 (such as the 150/90-15). Those tires, ALL Avon Venoms in various 150 sizes, range in width from 148mm through 159mm. The reason this is so is that tire sizes are called "NOMINAL" sizes, which means roughly that the size is an approximation, or something close to the actual measured size.

If you want to know the actual width and diameter of a tire, you need to check with the manufacturer - each one is unique. That is why I provided the actual published specs for several tires. As I said before, any one particular brand in 150/90-15 is NOT the same actual size as any other particular brand in the same "size". I have found tires of the same size (as stamped on the sidewall) that varied by as much as a full inch in actual measured width between brands and tire series. The same is true with diameter. Goose

Well I guess you should sell yours to someone who cannot buy a new one now? Personally I think it is an excellent tool for the cost. I have changed close to 100 tires on mine (many for members on this site), and I have not made a single modification or bought any additional tools. It is very quick and easy to use IF you know what you are doing with it and remember to properly lube the tire (BOTH the one coming off and the new one!). Our rear wheel fits it fine without removing the brake rotor - you simply need to make sure none of the bolts that hold the rotor are on top of the tool arms. I personally do not mind removing the front rotors - it takes only about 1 minute per side with my air ratchet, and it protects the rotors. I have changed a couple with the top rotor still in place, but frankly, I just don't like having to be so danged extra cautious about not accidentally applying some pressure to that rotor and ruining it. Especially when I am helping others change tires, I do not want any chance at all that they could develop and problem with a warped rotor and think that maybe I did it! So if I am going to remove one rotor no matter what, I cannot see any negative at all to removing both of them. I would like to have one of those fancy bars with the nylon ends, but at the stupid ridiculous prices they want, ain't no darned way I'm ever going to buy one. Instead I just slip the side of a plastic shampoo bottle between the rim and the bar and grab that with the bar so it slides around under the bar. Simple and it adds only about 10 seconds to the job. Although I have changed many many motorcycle tires with irons alone, this machine is a joy to use and so much easier. And I would caution anyone who uses that method to be sure to support the wheel on a couple of long 4x4s to ensure the brake rotors never touch the ground. There are few better ways to damage a rotor than simply leaning on one side of the rim when the rotor is touching the floor! Goose

I'm not buying your calculations, Laddie. First, you do not specify what specific tires you are comparing (they are NOT all the same size), so I cannot specifically check your math. But for the most part, there is very little difference in the diameter between 150/90-15 and 170/80-15 tires. CLARIFICATION EDIT: Note here that I was comparing stock 150/90-15 tires with the most common alternate size 170/80-15. When I first read Yammy original post, my brain completely glossed over the fact that he was actually asking about a 150/70-15 tire (which I do not think actually exists, at least not from Avon, Dunlop or Metzeler). All of my comments remain valid, but my apologies to Yammy for not noting this before. A 150/70-15 tire would probably be about two inches less diameter than the stock tire, just like he calculated, but that is just a guess - like with any tire, you would still need to look at the manufacturer specs to know for sure. For example, the Avon Venom 150/90-15 has a diameter of 25.4", and their 170/80-15 is actually 1/2 inch TALLER at 25.9". This means the rear of the bike would actually be raised by 1/4". The same sizes in the Dunlop D404 have diameters of 25.6" and 25.43" respectively, for an even smaller difference. I am going to look at a 170/80-15 rear tire when I need the next one, but I am much more concerned about the side clearance before I make up my mind.

For anyone reading this old thread that has not taken the time to look up the great amount of detail on this subject in even older threads out there, I thought I would briefly summarize my personal experience and thoughts about the tire size issue on the Royal Stars. First, not all 150/80 or 130/90 tires are the same size or shape (profile), so your experience with one does NOT mean that other brands of tire in the same size will feel the same. Some 150/80 tires are almost the same size as some 130/90s, while there is a huge difference between others. Second, the behavior of the front tire is HUGELY affected by the rear tire on the bike. With a good rounded rear tire, the 130/90 feels really nice, especially at parking lot speeds. But as the rear tire wears, you get more squirrelly stuff happening. Third, I feel the combination of the 130/90 front tire is generally a bad idea with suspension links that raise the rear. While the bike will feel pretty good when the tires are new, it goes down hill fast as the REAR tire begins to wear and develops a more square profile. This is basically the same thing I said above, but raising the rear end greatly amplifies this problem. In extreme cases where the rear tire develops a very flat center and relatively sharp edges on the side of the tread, the 130/90 front tire will make this bike downright dangerous if you encounter significant ridges and edges in the pavement like you see when they are resurfacing a road. These comments are not based on theory - they are the results of my personal testing with different tires in the conditions described. Goose

Sounds like you may have a problem with your air intake - look for a dead rat or other unnatural objects. Or just really bad air filters. 5,000 miles may not be much, but for an 06, that bike has been sitting a LOT. All sorts of things could be in the air filters, and the fuel filter could easily be clogged from varnish (not to mention lots of potential problems inside the carbs). If all the header pipes are truly too hot to touch in 30 seconds after a cold start, then your problem must be either sufficient volume of fuel or sufficient volume of air. Goose

This is a very common problem - people mess them up on the showroom floor before the bikes are even sold. The backing plate on the left side where the support strut is located is simply bent away from the back of the trunk. As stated, all you need to do is gently push the trunk all the way open so it reaches full vertical. Now you can either let the lid sit on the support arm or open it all the way and it will stay straight up by itself. Goose

Not for me it's not! I absolutely hate the Morgan Carbtune. I think it is poorly designed and very prone to problems. It does not function on vacuum at all; it functions on the volume of air flow being sucked by the rods, and the rods regularly stick and give false readings unless you are constantly tapping on them. This has been discussed at depth in several older thread where the various options are also given. Goose

6,500 RPM Very easy to hit in 1st and 2nd, but few people will hold 3rd that long (just under 100 MPH). Goose

Most likely your problem is the REAR tire, not the front. This is especially true if your bike came with the HORRIBLE Brickstone tires. Get something better on there ASAP, like E3s or Venoms, and you will be absolutely blown away by how much better the bike handles. Goose