Chris Wilson

https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.cycleworld.com/story/bikes/aprilia-anti-dive-fork-patent/&ved=2ahUKEwid4oyHz6P0AhWF63MBHUHAAvQQFnoECAMQAQ&usg=AOvVaw0R7KsnV6pnBE-tEToRVi_Z I guess it's sport bike related. Chris.

Aprilia applied for a patent on a mechanical anti dive system last year so maybe 'abandonment' is a harsh word. Cheers.

Phil, you seem to be in the loop with this so a quick question. (It was explained to me by an engineer who built me a Bimota style perimeter frame back in the 80's that the flex to avoid in all cases was on the roll axis. Pitch is fine as it is thoroughly allowed by suspension and likewise yaw as it is catered for by steering. But roll takes the wheels out of plane.) So the question is how does a swing arm that uses a single cantilever spar resist roll? (I know bridging helps but that can be an aid to all swing arms). Double sided spars would seem to be far superior in resisting roll. Chris.

Ah yes, agreed. It would seem that the elastic nature of steel gives desirable handling qualities to frames rather than the all out rigidity of aluminium extrusions and castings. So I gather that flex with a mono arm gives a semblance of rear wheel steer when it's most needed. Thanks, Chris.

Hi Phil, I really don't want to argue, but please accept that Pete and I do talk and I was aware of the swing arm failure before this thread. Anyhow, how does a single sided swing arm aid tyre wear? Not heard of that one before and am genuinely interested. Chris. P.S. if it's the claim that chain adjustment with a SSSA using a single eccentric cam tube adjustment ensures alignment, obviates twist and chain stretch giving excessive periodic torque then that's not a feature of SSSA's. Ducati had a similar setup back in the 70's with double sided swing arms, the cam was a tube axle located inside of the swingarm pivot - a special tool was provided in the tool kit that keyed into the axle and adjusted both sides evenly provided you released the clamping bolts fully. The exact same system could easily be used in a DSSA and it's the method of adjustment not the carrier that gives the benefit .

Hi Phil, And my main point is that Guzzi had to introduce a point of failure with the secondary operation of added perforation, that is to say, without adding the hole the design is sound. The BMW design needs no such benefit in order to fail, it's purely a lack of cross section and that is definitely something that could not leveled at a CARC drive. Tear along the dotted line failures are more easily rectified by not adding the dots in the first place, where as lack of material or section involves a new cast to be made. Anyhow, from a basic engineering point of view a single sided swing is poor design and is (on road and off road bikes) a purely a nod to fashion. As we all know it came from endurance track racing where rapid tyre changes outweighed the bizarrely monolithic builds needed in order to combat forces imposed, mainly twist. Rapid tyre change with my bike is a joke, no centre stand and muffler removal are just two issues to be resolved before getting anywhere removal. On my K75, yes it was possible to remove the rear tyre more easily but it was hardly classed as 'rapid' dogding around a scaldingly hot stainless muffler that lay across the diameter of the wheel. So again, I will never question the strength of the CARC system and as its impossible to prove a non failure one must use failures of similar to prove the concept. Chris.

2012 models Pete? My Bellagio is a 2012!

I believe that it was rider error in mud!? Even so, it should not have happened. Chris.

I will never question CARC engineering again!

And yet, I reckon that you will see a MK1 Lemans or a pan head Harley thunder down the highway long after the demise of more 'reliable' bikes. Motorcycling has devolved into a 'user' only experience and deviated away from ownership. And it's here that I will quote the dealer who sold me my Bellagio "it's a good day when a Guzzi breaks down as it gives you a chance to make it better than before." "Just like an Italian marriage, when it works it's unbridled passion, but when it fails it gives you the chance to make it better. And I wouldn't have it any other way." Chris.

In regards to the use of titanium fasteners, I see the benefit when used in unsprung wieght, axles, brake rotor bolts etc but really find it hard to justify the use of them on a wieght saving basis with sprung wieght. If I was that wieght conscious then putting myself on a diet would be a far more successful solution - for me and the bike. Chris.

Maybe the key here is to remove, inspect and replace as necessary. Not set and forget until the use by date calenders around to bite you. But ..... I have done similar and welding was evident - long life plugs are a trap for this especially with twin plug Guzzi heads using those as a ploy to excuse poor access to them. Chris.

Oh, and any bolt that lays claim to the ability of stretch in achieving hold is a single use item and should be discarded after removal because the thread will change. I don't want the inconvenience of sourcing new bolts everytime my sump is dropped or valve cover is pulled off. Rant over.

My opinion on all of this is that if you park your bike in a dry space under cover such as a garage, resist riding in wet conditions (and who doesn't) then ANY form of corrosion, galvanic or not, will not present itself. Why? Because you need the presence of an electrolyte ( moisture, preferably salt laden but metal salts will do) is needed to support the process. The point of the original post was to see if any one has experiences to the opposite. To me, if you are regularly fastening and unfastening a fixture due to maintenance then monitoring the possibility of corrosion is so much easier. And here I would rather have a hard metal headed bolt to deal with rather than something made of cheese that burs or turns out when an attempt is made to remove it. Many times I have resorted to an impact driver and 4 pound hammer when attempting the removal of OEM plated mild steel bolts and never have I had to resort to these Neanderthal techniques when using stainless fittings. Light coating of grease, apply thumb and two forefingers only when tightening and never had a thread stripping issue or one come loose yet. Granted internal bolts like engine studs, big end bolts etc need stretch in order to never come loose but then they arent regularly accessed or re-torqued either but external bolts that to need regular removal, I would go for stainless every time and simply be aware of what I am doing. Chris.

Interestingly the chart in the linked article shows that stainless steel and aluminium and alloys are not a galvanic corrosion risk.

Sounds like my Roper windage plate that is made of stainless is destined to be one huge anode then if the current flows along those 14 bolts to the case!

Thanks for all the advice. But please accept that in over half a century of riding motorcycles I have never had an issue with stainless on engine covers. Will report back if my sump falls off but with 14 bolts holding on something that is about 300mm square I think that overkill comes to mind. Chris.

My guess is that since I have second hand bike with no written history or explanation of how it was used/abused that damage to the maintenance cover fixings happened pre-purchase. I have a set of hex drivers that snap onto my socket set ratchet and am running on the assumption that they are indeed the correct and accurate size quoted. I have had issues with plated drivers being oversize resulting in them being thrown out. Cheers.

So Phil, all of your bolts and screws are titanium? I am only replacing bolts to covers that allow maintenance and as noted, at low torque settings or two finger tight leverage. Things like sump, alternator cover, rack mounts, handlebar mounted equipment etc. I like the fact that they have a high Rockwell number as I detest turning out the head of an Allen key bolt. Chris.

Hi all, I am in the process of swapping out any fixings removed whilst maintaining the bike with stainless steel ones. One theoretical issue is galvanic reaction between two dissimilar metals causing corrosion. So far, nothing of note has been witnessed. Latest drama was removing the sump to do an oil filter change. The standard mild steel allen head bolts seem to burr out easily and yesterday it was a cold chisel to the rescue to remove the worn bolts and replace with stainless. Anyone out there have issues with stainless? Thanks, Chris.

The A spec is dual compound not offered with the older ST.

Well explained, thanks.

There will be no living with you now! (But it does feel like a good tyre despite being ripped off a country mechanic who says "it's the last one in stock, do you wannit?" What was I supposed to say? Nah, it's OK, I would rather have the unrepairable flat that's on my bike right now thanks very much."

Hi all, I have a Bellagio and just recently changed my rear tyre from a Pirelli Angle GT II to an A spec version of the same. And must say that I like it. The stiffer side walls seem to compliment bikes with a rear wieght bias and not just bikes over 250kg. Any others out there try A spec tyres and liked them? Chris.

I remember talking to an 8 valve Norge owner in a parking lot near my place on a hot summers day. I complimented him on having such a nice bike and he replied ," thanks but it's a bitch in weather like this as the fuel boils." And you could actually hear the fuel percolating even with the engine off. Heat rejection is not one of its strong points.