68C

Those silencer ends are exactly the kind of thing I hate on a bike, they are pretending to look like something rather than being it. Dishonest.

Altough I mentioned this as an aside in a centre stand thread I thought I would repeat it here. Has anyone tried fitting/modifying a Grisso or Breva 2:1 exhaust system to fit a V11. I imagine the header side of things would not be too difficult assuming clearance around the oil cooler - might have to be moved but hopefuly not into the ugly side mount. I thought to rotate the conection pipe to the silencer to exit on the right, more usual for left hand drive roads and to ease fitting of a centre stand so the lever 'wot yew stand on' fits close. I suppose going out to the left clears the drive box and enables a closer silencer fit. Could feel a bit odd having the centre stand on the 'wrong' side but could live with it. Obviously all this this requires some welding and won't be a simple swap. Many bikes have the end can bolted up to a three bolt flange, might be possible to fit that and have a wealth of silencers to choose from.

I ran into much the same problem making up a stand, my gash prototype was too far behind the center of gravity, probably need to be near the rear of the sump. Also placement of the lifting handle difficult due to widthe of silencer feed pipe. Made me start to think along the lines of fitting/modifying a Grisso/Breva exhaust. Having the 2into 1 exiting on the left is not ideal for folk who drive on the left but was probably needed to suit the CARC. I was wondering if it would be possible to modify the crossover so that it exits on the right and so make the centre stand easier to operate as I could have a nice big lever to step on to lift it by. I like centre stands, the bike is narrower in the garage, it is easier to wash and maintain, much simpler to get your luggage balanced and less risk of knocking it over, the kids can play on it!

Oh...., dustbin FAIRING, I wondered why the black plastic stuck to the exhausts.

Hi Warren, did not mean to steal your thread. As stated I think I agree with you. Incidently, the company I work for set up an operation in Australia some ten years ago - they have proven the stronger section. We have just had a bunch of Aussie senior managers come over and restructure the original UK section. Are all Aussie managers so tough and brutal? - make the Americans seem positively benign.

As is becoming obvious I am not a frame designer. I am trying to get my head round why those Grisso tubes are considered more rigid as the arch over the heads, I accept the large diameter advantage but still don't get a curve being stronger than a straight tube. Perhaps a frame can be too rigid - was'nt this a problem with early carbon frames on race bikes? I understood perimeter frames fitted to inline fours evolved as a way of allowing almost vertical carb/throttle bodies to access a large airbox - nothing to do with handling, they are made of a thin wall large cross section construction partly to give the extra strength needed to accept the extra stress of being curved. Modern manufacturing made their use possible, perhaps it was'nt in the mid '70s. My first Guzzi, a T3 new in '79 felt like a Brit bike always should have, torquey - good fuel consumption - leak free - reliable - excellent handling and brakes, something my Norton Commando was'nt. I got the 750 Combat engined Commando new in '72, picked it up in London and drove it the seventy miles home. My Dad asked why the rear indicator was hanging off - the bracket had snapped. The following week the center stand snapped. 2000 miles later the disc brake pad suddenly flew out of the front of the caliper requiring frantic pumping to move the piston to contact the disc. Excellent design, the pads are not pinned in, the thickness of the backing material is the same as the gap between the caliper and the disc, when the friction lining wears out the pad moves. I was lucky it flew out, a mate had his jam the disc! At 3000 miles the main bearings failed, upping the traditional Brit bike rev limit of 6000 to a heady 7000 meant the crank flexed causing the edge of the the roller bearings to dig in - cured by fitting barrel shaped rollers. As for legendary Norton Handling - the rubber mounted swinging arm ensured you always had a story to tell. Having said all that I still have the bike, now halfway through the Great British Winter Rebuild of '98. OK, not a Guzzi story but it is mine. No, the T3 was a relevation although over the years it became clear Guzzi had spent all the money on the engine, gearbox and running parts. Not much left for the seat, electrics, switchgear etc. The new Guzzis are far better bikes than their predecessors, but then they should be, perhaps they have changed the focus on where they spend the money now. I just hope they are not wandering off down a path of cosmetics and follow my leader and lose their soul.

Ain't that the truth, they are certainly richer than I am. As with all rants it is important to stir plenty of egg into the mixture.

I am so glad to see this thread. I don't much like the look of the newer (post V11) Guzzis either. I have always liked honesty in design, it should be designed to DO a job, not LOOK like it does. Function really should determine form, I cannot believe those tubes running along the side of the Grisso are truly efficient, I suspect they are just shiny bits. I also have an early Hinkley Triumph with it's version of a spine frame which sadly has an adverse effect on the breathing of the centre cylinder, however it is more honest than the T595. At first I fell in love with those lovely swooping alloy tubes - similar to handbuilt Spondon alloy frames - until I put my hand behind one and found it was only half a tube and cast at that! It was just lies. The V11 Dr John inspired frame may not be pretty but it works - albeit by weighing a ton. Why put covers over ugly bits of a bike, why not make the part attractive in the first place - it really does'nt cost that much more. I am talking to you late model Tonti California with all your little fake plastic chrome bits. Surely a starter motor can be made to look OK without the need for a cover, even if it is in Carbon Fibre - hardly a weight saving if it is an unneccesary extra. I like 'sanitary' bikes, if you can take a part off and the bike still runs and is legal - you did'nt need it.

What wonderful diagrams, well laid out and easy to understand. Thanks. Hope this is a part of a series of such gems.

Beautiful colour, first saw it on a pair of early V7s at the Isle Of Man TT in 1973, on my black Commando at the time. When I got home I painted it in the nearest colour I could get - Ford LeMans Green. Although the shade not exactly admired by others I was ahead of the times with the name. Finally got a T3 in '79 - black again, all they had in stock, soon painted it bright Bristow Helicopters red. Black bikes are like white cars - always look dirty.

Hi GuzziMoto, I think I understand your main point that we can arrange things to scavenge well on one cylinder but not on both, unless we swop the pipes around every revolution! You mention the point where the two pipes meet is more important than pipe length, do you mean that acts as a venturi, the passing gasses suck on the other pipe rather than the void left be the passing slug of gas causing a depression? I tried to draw a sine-wave graph of the position of the piston and valve opening over 720' of crank revolution but bogged down completely as I could'nt work out where to start the other cylinder, 90' before, 90' after, 630' ... ??? I suppose I like the idea of a lighter system, however my mate reckons the twin exhaust looks cool, my wife thinks weight could be lost from another part of the bike/rider set up.

Does anyone on this forum have a good understanding of vee twin exhaust design and so help me get my mind round how our systems work? Parallel twin four strokes with 360' cranks output one exhaust pulse per crank revolution. When running these exhaust pulses are evenly spaced prompting the use of two-into-one exhaust sytems whereby the first pulse is followed by a drop in pressure which helps the second pulse leave its cylinder and so on. Vee twin four strokes of course don't have evenly spaced pulses so to make the pulses extract the next exhaust charge the exhaust pipes would have to be of different length before joining at the 2-1 so that the pulses appear evenly spaced. Most of the exhaust systems on our V11's have equal length pipes before the 2-1,or crossover/balance pipe in our case. I imagine this tuned exhaust system will only be most efficient at one rpm and possibly throttle position but it must have advantages, look at the snakes nest of exhaust pipes on a racing car. The Buells appear to have some attempt at altering the pipe lengths from the original Sportser. So why don't we have 'tuned' manifolds or exhaust systems on our Guzzis?

In hindsight I now realise I should have posted this as "Carbon Fibre rots metal", rather than refer to Ohlins forks as it not a specifically Ohlins problem. Moderator, please ammend as you think fit.

Hi PDOZ, Thanks for following my thread. My original point was to hi-lite the unexpected nature of carbon fibre, in that allthough not a metal is does conduct electricity and so causes problems akin to the disimilar metal corrosion you referred too. The corrosion does not take place on or within the CF itself, it happens to the metal it is contact with. As an aircraft maintenance engineer I spend a lot of time grinding and polishing out corrosion, treating it chemicaly and ensuring the metal is reprotected adequately. Apart from the loss of metal caused by corrosion it is the rough uneven surface that act as stress raisers and can cause premature failure that is the biggest problem - hence the polishing. Although I had a basic knowledge that CF can cause these problems I had not seen it myself, mainly because I work on older aircraft that do not have CF, I was thus suprised at the damage to the forks on a bike made in 2004. I thought it worth raising the issue. I mentioned this corrosion to a friend who told me of similar problems with a carbon fibre hugger he fitted to the alloy swinging arm of a modern Triumph, his had corroded within a year.It may be wise to look at any CF parts such as alternater covers which are very exposed. Have fun.

Ah, I think I know where this going.

Where did you get that photo of me?

Now you've got me worried, I started on a quick fork seal job to carry on riding in this unusually warm weather, without oil soaked brake pads! If I'm not carefull I will end up following minor defects along the bike to the tail light, don't want it to end another Great British Winter Rebuild with yet another dismantled bike in the shed. Yes, I know your in there Commando, Intercepter, kickstart Sportster, FZ750, BSA Sunbeam and the rest of you!

Just stripped down my Ohlins forks to change the seals, had to drill out one of the bolts holding the mudgaurd. Thats when I found moderate corrosion on all four lugs that support the mudgaurd, thankfully once cleaned up and treated the fork seems usable although there is some material loss. Can't even begin to think how much Ohlins would charge for new lower legs. I mention this as the corrosion was not obvious until dismantled, may be worth other folk with carbon bits taking a few minutes to remove the bolts to check. An internet search shows carbon fibre is a problematical material within the aerospace and boating world, carbon fibre is a very good electrical conducter and when in contact with many metals in the presence of an electrolyte (dirty water ) will rapidly corrode due to galvanic action. Apparantly it is all to do with where the metals lie in the galvanic table, aluminium alloy in particular - but also stainless steel give problems. I have found that cheap stainless bolts will corrode in alloy unless well greased - had loads of fun drilling out the sheared stainless bolts I used to hold my old T3 exhausts pipes to the cylinder head. The solution is to keep carbon fibre parts well insulated electrically from all metals, use thick paint, plastic washers, mylar film, jointing compounds even grease. Its carbon or graphite - not plastic! http://www.eaa1000.av.org/technicl/corrosion/galvanic.htm http://www.boeing.com/commercial/aeromagazine/aero_07/corrosn.html http://www.corrosion-doctors.org/Aircraft/aircraft-design.htm http://www.deskeng.com/articles/aaahzz.htm

Many thanks John, I can see how it works now.

Hi all, I fancy fitting a centre stand, have seen various types mentioned on the forum. Are these fitted permanantly to the bike or merely collapsible paddock stands that you carry with you? Some folk have noted problems with some aftermarket cross-over pipes - any advice? Finally I have been thinking about making my own permanantly fitted stand, has anyone elso done this, any drawings available? Many thanks.

Thankyou Cliff, I had to do a web search to find out what an LC1 is, I now know it is a wide band sensor controller. Many thanks, a new trail to follow. I am off on holiday for two weeks with my family to the Pyrenees, in our motorhome - not the Guzzi! Please don't be offended if I don't reply to any posts for a while.

Sorry to hear about your experiences, to be honest I was worried about getting myself in much the same situation which is why I raised the original post. Good luck.

I have'nt decided where to take the bike yet, there are a few around here, most seem to be DynoJet franchise. I can't see the point in fitting a PowerCommander if the stock ecu can be reprogrammed and wonder if they will only set up the Dynojet product. I have also been looking at the MyEcu from Australia which may mean I am on my own when it comes to applying the results of a run. In all things its best to know what you want before going to buy it, hence my original post asking for advice. There seems to be two distinct types of Dynos, absorbtion and inertia. The absorbtion being much more expensive and thus rarer but able to load your engine to any torque or HP figure and hold it while air/fuel ratios, gas analysis and any tendency to knock etc can be observed, it's what most multi-discipline engineers would regard as a true dynamometer. The inertia type (as used by the PowerCommander folk) detects the rate at which your engine can accelerate a heavy drum. I understand the original weakness of the inertia type was the short time span the test covered, once accelerated up to the max RPM its over, small engines will of course take longer than more powerfull engines but it will not record a constant state. I gather modern dynos and software have improved things though. Still not sure how you would discover what is happening at all the (240?) points of a typical map with the inertia type. Any advice on what I should look for? Cliff, if your there, what would you recommend I ask the dyno operator to do if using an MyEcu?

I am thinking of taking my bike for a dyno run to set a baseline before I start tinkering. 1/ What should I do to the bike before I go, other than basic TPS setup and valve clearances? 2/ What do I ask the dyno people to do? I am a road rider and interested in low to mid range rather that max power. 3/ Do they normally map my ecu for me as it is before any changes? 4/ Do they normally make changes to the map or just suggest them? 5/ What should I expect to happen when I go for this run? 6/ What should I watch out for, how do I know if they know what they are doing? 7/ How long does it normally take? Am I right in thinking the idea is to run the engine with the throttle set to specific positions to match the cells of the map and then load it to a particular RPM and so find out what air/fuel ratio is actually being generated at these points of the map. You may ask why I want to do this dyno run, curiosity is probably the strongest reason - to find out if there are any noticeable changes they can make to set my individual bike up for the way I normally ride. I don't like very noisy exhausts so will probably stay standard, may mess around with the intake side of things, freer flowing. My bike has the front balance pipe. So how do I normally ride? Not too much around town, 25 mile commute of which about 15 is along the busy dual carriagway over the New Forest and the rest twisty lanes, fifty mile rides with friends - we rarely exceed the ton - they like the twisty bits so I will need good drive out of forty mph corners.