Dart Knowledge...

The Cagiva era Morinis
Gary D
Posts: 195
Joined: 29 May 2016 20:31
Location: Stoke Golding, Warks

Re: Dart Knowledge...

Post by Gary D »

Hi Tom & Norbert, and all!

Thanks for your continued help & information. It's all exciting stuff! Tom's right Norbert, it's not an issue to build extra units as it'll all help when it comes to commissioning sufficient pressings & machined parts. We can discuss all that as the project gains a firm spec & the quote gets sorted.

Tom, I take your point about the fittings. However, the tank neck offers 2 ways forward:

1/ A machined threaded ally neck, to suit the existing cap. I'd need a cap as well as a tank, in order to assess the cost & viability of this with my machinist & fabricator. Threads are funny things & when in plastic, can become rather rolled & rounded. This makes them hard to identify for threading the ally male effectively. We'd also have to assess the strength & stability of the neck base area in ally, if we choose this route. What happens if someone cross threads & so on?

Question: Is the O.E. cap readily available, or already in short supply? Is it made in plastic, steel, or ally?

2/ The bolt on (in?) neck approach. This would require a laser cut inner ring, that needs to be either threaded or nutserted, in order to accept the mounting screws. This option gives concerns as follows:

a/ The ring would need to be pretty thick if just tapped, in order to avoid stripping the threads. That'd make it tricky to weld to a thin ally pressing. The trickier the weld, the greater the probability of a leak. Nutserts may also provide several points at which a leak risk is increased. We should be aware that the tank skin is very unlikely to be strong enough, to allow us to weld some securing nuts directly onto.

b/ This option could be expensive as it would require two 2 parts, and may add a little labour..and that's always the expensive bit! It would also add time & money to the test procedure.

Regarding the fuel tap, now would indeed be the time to re-specify this. Bare in mind that while we can screw a steel tap into an ally union, it'll be prone to corroding in. That may be a risk we have to concede, unless a stainless or brass bodied fuel tap was available? That would negate, or at least radically reduced the risk involved.

Lastly, does anyone know if the plastic tank is internally baffled...?

Tom, it'd be good to meet up, say hi & grab a moment to discuss matters. I work in Rugby, so maybe somewhere halfway between us for a beer & a chat? I'll let you know my mobile number to facilitate.

S'all for now folks.

Cheers

Gary
Gary D
Posts: 195
Joined: 29 May 2016 20:31
Location: Stoke Golding, Warks

Re: Dart Knowledge...

Post by Gary D »

Hi Tom & Norbert, and all!

Thanks for your continued help & information. It's all exciting stuff! Tom's right Norbert, it's not an issue to build extra units as it'll all help when it comes to commissioning sufficient pressings & machined parts. We can discuss all that as the project gains a firm spec & the quote gets sorted.

Tom, I take your point about the fittings. However, the tank neck offers 2 ways forward:

1/ A machined threaded ally neck, to suit the existing cap. I'd need a cap as well as a tank, in order to assess the cost & viability of this with my machinist & fabricator. Threads are funny things & when in plastic, can become rather rolled & rounded. This makes them hard to identify for threading the ally male effectively. We'd also have to assess the strength & stability of the neck base area in ally, if we choose this route. What happens if someone cross threads & so on?

Question: Is the O.E. cap readily available, or already in short supply? Is it made in plastic, steel, or ally?

2/ The bolt on (in?) neck approach. This would require a laser cut inner ring, that needs to be either threaded or nutserted, in order to accept the mounting screws. This option gives concerns as follows:

a/ The ring would need to be pretty thick if just tapped, in order to avoid stripping the threads. That'd make it tricky to weld to a thin ally pressing. The trickier the weld, the greater the probability of a leak. Nutserts may also provide several points at which a leak risk is increased. We should be aware that the tank skin is very unlikely to be strong enough, to allow us to weld some securing nuts directly onto.

b/ This option could be expensive as it would require two 2 parts, and may add a little labour..and that's always the expensive bit! It would also add time & money to the test procedure.

Regarding the fuel tap, now would indeed be the time to re-specify this. Bare in mind that while we can screw a steel tap into an ally union, it'll be prone to corroding in. That may be a risk we have to concede, unless a stainless or brass bodied fuel tap was available? That would negate, or at least radically reduced the risk involved.

Lastly, does anyone know if the plastic tank is internally baffled...?

Tom, it'd be good to meet up, say hi & grab a moment to discuss matters. I work in Rugby, so maybe somewhere halfway between us for a beer & a chat? I'll let you know my mobile number to facilitate.

S'all for now folks.

Cheers

Gary
SupermotoDave
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Joined: 13 Apr 2006 18:38
Location: Reading UK
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Re: Dart Knowledge...

Post by SupermotoDave »

As usual I agree with Tom
Re the fuel taps It would be nice to spec a modern alternative that anyone could get spares for from a local supplier, the difficulty being that it attaches to the side and not the bottom of the tank. If anyone knew a suitable tap from a modern bike that would be useful. I was considering a removable plate so people could fit whatever they wished, either a standard tank thread, or perhaps an outlet pipe for a flexible hose that could lead to a remote tap.
The filler cap is the same, fit a modern bolt in one ideally, perhaps have a replaceable plate so people could chose their own if the procure one from ebay. I have seen a nice flush filler on a custom tank with a Cagiva elephant on it which would keep it in the family, or Demon Tweeks do a weld in screwcap with neck http://www.demon-tweeks.co.uk/motorspor ... -with-neck for approx £20 as an alternative but it would need to be cut down as there is not masses of clearance between the filler cap and the opening body panel.

David
morini_tom wrote:Hi Gary,
Regarding the fuel tap, as it's also a very hard to get item it might be better for us to spec a modern available alternative and have the tanks made to suit that, rather than commit us to the original taps. What is everybody's consensus in that regard?
Similarly the fuel filler cap is a moulded threaded cap so would need to be something different for the ally tanks. My suggestion again would be to spec a modern bolt in filler cap and make the tanks to suit that.
Gary- you're in the midlands aren't you? I could probably get a tank to you after work one day in the week if that's any help?
Norbert- absolutely please spread the word that we are looking into this- the more dart owners we can help the better, and the more people who can commit at an early stage the more viable it becomes.
Thanks all,
Tom
Gary D
Posts: 195
Joined: 29 May 2016 20:31
Location: Stoke Golding, Warks

Re: Dart Knowledge...

Post by Gary D »

Good morning all.

I hear Tom & David's thoughts & appreciate where they are coming from regarding the fittings.

Now is certainly the time to assess & & identify the be,st options. Ultimately though, whatever we choose must be practical to fit into a fuel tank, that won't enjoy the benefits of mass production manufacturing processes. They'll be no robotic welding or trimming, no laser cut pressing blanks..& no automated leak testing. Bare in mind that what's on offer here is a tank tooled by drawing a mould from the sample provided. Therefore anything that's unrepresentative of that shape, means extra work & extra cost. It'd also be a time consuming (re:costly) process to bolt in a cap for each tank when being leak tested. Screwing a cap on would be quicker & cheaper. While I'm sure something could be made to aid the process of testing the tank..this would mean more tooling & more cost, amortised over a very limited production run.

Gents, I'm pleased we're having this discussion. It confirms that we'll make the best decision on all aspects, going forward. It may be that compromise is required by all & that's fine, providing all the pros & cons are known in advance. That said, manufacturing can always throw up some unexpected additional "surprises"! We are already making good progress though & with everyone's input, we'll conclude the best plan.

Cheers

Gary
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Ming
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Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Dart Knowledge...

Post by Ming »

Don't know if it's of use here, but I've just come across a recent post in ' Tre e Mezzo' under the title ' Colander Tank' which mentions a company in India that will produce tanks in steel, fibreglass or aluminium if given a sample. Might be worth a look?
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corsaro chris
Posts: 1162
Joined: 13 Jul 2006 21:28
Location: Berks, UK

Re: Dart Knowledge...

Post by corsaro chris »

Hi All;

First off - a few comments on Darts as they relate to your questions;

1. It's a great bike, and Tom & Paul have nailed most of the points you raise.
2. I prefer my Dart to the Sport (no bias, as I'm lucky to have access to both).
3. Over distance the Dart is probably a more comfortable bike.
4. Frequent application of the front brake (well, mine anyway, but I am heavier than I used to be) may lead to fade, which in turn can lead to a lovely warm feeling as you approach the obstacle in front a little too quickly. Cure - plan your braking and concentrate on your riding...
5. 11 litres in the tank relates to 120 miles or so if ridden solo. If two up, it'll just cover the 100 at motorway speeds (you can guess how I know this). If we made more tanks and needed more capacity the way to go would be to make them slightly higher, as there is an "under lid" air space for the tool box and oily rag. I'd need to get together with Super Dave and talk this through. But 120 miles is quiet a lot on a small bike!
6. Two up; go careful with this one - size matters, and compressing the rear shock can bring the rear hugger into contact with the frame which results in unsightly rub marks. BUT - my pillion prefers sitting on the back of the Dart to the back of the Corsaro.

In terms of making a small batch of tanks - this sounds like a MRC product, and we could do these at a discount to Club members, subject to consent of t'committee (and include a discount to our fellow overseas Morini clubs as well, Norbert). I'll leave it to others to comment on the source, but personally, I'd prefer one sourced in either the UK or Germany over India or China...

Good riding,

CC
"I'll use the Morini"
Gary D
Posts: 195
Joined: 29 May 2016 20:31
Location: Stoke Golding, Warks

Re: Dart Knowledge...

Post by Gary D »

Hi Chris & all

That's another helpful appraisal of the Dart experience, thank you Chris. It does sound like a lovely bike..though that rear hugger sounds a bit alarming! I'm "taking the fifth" on any further effects that may be caused by taking the lithe & lovely Jo on the back though!

Tom & I are endeavouring to progress matters on the tank. Plenty of questions are being raised along the way though & we're tackling these, as best we can. Tom & I are doing this against the background of very busy day jobs, but are still maintaining some progress regardless of the headwind. There's a reason that the tank hasn't been cracked to date though & being frank, that's based around costs & volumes (that's quantities, not capacities).

The Dart may not be an expensive machine to purchase, but it's subject to the same costs as all low volume machines when it comes to making parts in small volumes. Lets just say it'd be rather easier to keep the fabricator interested, if the tank enjoyed the margins of a Norton Inter, or an MV! I'd therefore respectfully caution against talk of discount at this juncture, as it'll be a minor miracle if we actually manage to bring this product into being. The will is there though & with patience, it can be done. Commercially, they'll be a moment of clarity & reckoning, but the specification & quote need settling in the first instance. We'll keep working at it & keep everyone posted. It'd be very satisfying to keep these bikes on the road where we belong. Here's hoping!

Best regards

Gary
morini_tom
Posts: 919
Joined: 05 May 2006 13:47
Location: Northampton

Re: Dart Knowledge...

Post by morini_tom »

Thanks for the reminder about the rear shock Chris, that's one I forgot.

I've never had the hugger touch the frame before, but I have seen plenty of rear huggers shortened at the end, and with witness marks inside from the tyre edges rubbing (hence the shortening st the tapering end). This could only happen if the wrong tyre profile is fitted, and I have seen 130 not 120 tyres fitted to the rear of a dart... so possible this is the root cause?

Anyway, to put the shock issue to bed, the original marzocchi PBS with dual rate spring was a tad soft,and age hasn't helped here. A couple of years ago I had Wilbers make me up a custom shock, adjustable and with a carefully selected spring rate. It has absolutely transformed the bike. Well worth the (several hundred) euros. And it is firm and adjustable now so I imagine 2 up riding is a joy.

Tom
EVguru
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Re: Dart Knowledge...

Post by EVguru »

morini_tom wrote:I have seen plenty of rear huggers shortened at the end, and with witness marks inside from the tyre edges rubbing (hence the shortening at the tapering end). This could only happen if the wrong tyre profile is fitted, and I have seen 130 not 120 tyres fitted to the rear of a dart... so possible this is the root cause?
The C9/C10 Freccias had no more than a 110 section rear tyre fitted and the C12 had a different shape hugger.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
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72degrees
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Joined: 31 Aug 2007 21:24
Location: West Midlands

Re: Dart Knowledge...

Post by 72degrees »

corsaro chris wrote:6. Two up; go careful with this one - size matters, and compressing the rear shock can bring the rear hugger into contact with the frame which results in unsightly rub marks. BUT - my pillion prefers sitting on the back of the Dart to the back of the Corsaro.
CC
My pillion wouldn't even consider sitting on the back of my Corsaro :) She did many miles on the back of the 2C/375 years ago but definitely prefers the ER6n with Bagster comfort seat now ;)
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