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Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Fri Feb 13, 2009 7:38 pm
by Finnpaso
Still: If You put more offset to rear sprocket, You HAVE to put SAME offset to front sprocket !!! If U dont do so, then your chain line is wrong! My 750 Paso is just now in such place, that i cant look closer, how much there is space and how much is it possible to take front sprocket "out"(as rear sprocket), but i quess, that its very easy to put same "some mm's" offset to front, as to rear.... With washers, or with lathe from some other Ducati front sprocket.... :smoke:

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Sat Feb 14, 2009 2:02 am
by ducinthebay
I agree with FinnPaso that you need to space out the front sprocket with the back, or your chainline will be bad. This can cause a catastrophic chain failure, and ruin your engine cases. It will also create extra stress on the C/S bearing. If that fails, you need to split the cases.

A full spacer in the back, like an old sprocket turned down, is much better than independant spacers like washers.

Don't be so anxious to put a big space between the tire and the chain. the ideal is "0", or just barely touching. :shock: Stock ST with 180 tire shows signs of tire touching the chain. No problem. Keeps one side of the chain clean. You want that chain as close to the tire as possible. Less stress and strain on all parts involved.:cool:

Cheers,

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Sat Feb 14, 2009 10:07 am
by pompone
Chain line is bad, consequences could be dangerous.... Any solutions? Make an special sprocket with a lathe, How? Any photos or drawings? I'm agree with FinnPaso, the chain line is not ideal, but I think it is tolerable margin of error. At the moment the Paso runs very well, without frictions or noises :thumbup:

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Sat Feb 14, 2009 12:47 pm
by Finnpaso
Dont drive with such wrong chain line!!!! You have to do something to it. Its very easy for lathe man to take metal away from needeed parts, but SURELY You hvae to know, from what part You take metal away! Also you can play with spacers, but You HAVE to know, what to do. As i have written, it would be very usefull to know all Ducati front sprocket offsets to choose easiest way for right chain line. It MUST BE OK, or sooneer, or later You loose chain and broke engine cases! It coast TOO MUCH !!!!!! :thumbup:

More You put offset to front sprocket, more it makes harm to output shaft bearing and its very difficult to change: U have to open engine totally, but some 1-3mm more offset dont make any harm as Paso engine is not powerfull at all..... its easy to play with washers and lathe in front sprocket, if there is space under cover for that. I havent check that space. Its not any harmfull, if chain hits little to side of tire! :smoke:

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Sat Feb 14, 2009 2:26 pm
by persempre907
I would not risk at all.
That wrong offset could be very dangerous. The case could be heavily machined by a broken chain :x :x :x :x :x :x .
So, even if I have the stock chain, sprockets etc..., on both 907s I put those steel protections on the case.
Ciao

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Sat Feb 14, 2009 7:01 pm
by pasoalf
Thanks for the input Pompone,
I just looked at yor 9th foto. It' looks like the tire had some contact with the swingarm. is that possible?
Concerning sprocket,I just figured everything out today. No problem to move it 5.5 -6mm to the left. But it does not work with spacer.
Unfortunately I could not get of the crown (rusty screws) to figure the situation out there.
As soon I have everything together, I'll put it here.
Afterwards I ll ask my collegue to do the parts(will cost me aproxx. 2 invitations to a Brazilian Churrasco at my garden in Summer).
If any of you are interested just let me know by then.
Just a last question. Has any of you the Part Nr. for the 40 Crown which fits on the paso 750 ?
pasoalf

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Tue Feb 17, 2009 10:00 pm
by Brutus
Guys, good thing to read that other people are also looking for alternatives. I'm trying to keep my paso quite original, cause I like the appearance better than for example the 907ie. The bigger 180 tire looks great on the bike as well. So I'm convinced my paso can keep her 16" wheels now. The drive line is also keeping me busy. As I've seen in this post we can try three options:
1. more offset of the drive line
2. 'excenter' the rear wheel
3. Mix of the two above

As for option number 1 we've seen the 180/60 tire fits well. My problem is the offset of the front sprocket. As you might know the early paso's (till enginenumber 4000 or so) have a weak bronze bushing on outgoing axle of the gearbox. I've seen this go wrong with 750 paso's with a lot of miles on it. Mostly the second gear fails. The bronze bushing I'm talking about happens to be right next to the front sprocket. The width of the standard sprocket is allready 12mm (offset a couple of mm's). Any more will put extra stress on the bronze bushing and will eventually destroy your gearbox. Solutions with extra bearings are very costly and therefor not interesting for me.

As for option number 2 it depends how much the rear wheel needs to be 'excentered'. If I understand correctly we're talking about approx 6mm's or less. I think it could be less, because according to the photo's in this post there's a lot of space between tire and chain. My 851 has only 1 mm of space..! :mrgreen: It could even be possible that the wheel needs to be moved 3 or 4 mm to the right. This should not effect driving and it's much easier to accomplish then to create offset sprockets. A new bushing or a spacer on the rear axle at one side and sanding down the alu brakeholder on the other side. Could be done in a couple of hours (will cost you probably nothing) :evil:

Options three speaks for itself. Offset the front and rear sprocket with a few mm's and excenter the rear wheel with a couple of mm's. Maybe the best option. Problem is still an new front sprocket.

cheers! Léon

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Tue Feb 17, 2009 11:22 pm
by frank
New member,

Hi guys,

I think the Paso looks at his best with its original tyre size.


I bought 2 brand new sets (Michelin) just in case...


Frank

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Wed Feb 18, 2009 9:00 pm
by pompone
What is the fabrication year of your "new" Michelin? My rear tire was made in 2008, week 36.

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Thu Feb 19, 2009 9:40 am
by paso750
original Michelins if they still can be found are NOS (new old stock). They may be unused but are at least 4 years old or older.
2. 'excenter' the rear wheel
I really would`nt recommend this. Front and rear wheel should always be in one line. I`ve ridden modified Vespas with a different rear rim which made the front and rear wheel go out of line for a few mm and riding was awkward. I can image that on a fast bike it`s even worse.
G.

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Thu Feb 19, 2009 11:00 am
by persempre907
pompone wrote:My rear tire was made in 2008, week 36.
:shock: :shock: :shock: :shock: :shock: :shock:
Are you sure???
Ciao

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Thu Feb 19, 2009 12:50 pm
by paso750
he`s not using Michelins !

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Thu Feb 19, 2009 7:07 pm
by Duncati
Hallo fellow paso fans, i have been watching this subject with much interest as my paso has used her last pair of rubbers and in Hollland as in the rest of the world we can not obtain new ones :banghead: 17 inch is not the way to go, Avons could be the way but the outlining of the front sproket seems to be the achilles heel, I think I have the solution but does involve using 2 sprokets and some grinding, I am having this done this weeek and I will post photos and results as soon as possible. Duncati

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Thu Feb 19, 2009 10:12 pm
by frank
My nos Michelin tyres are from 2005.
Let me remember you all that the compound was totaly diferent in the '80s than the latest series of A59-M59 tires.
My paso was original fittet with Pirelli MP7S tires who where of a mutch softer compound then the Michelins back then.
The latest Michelins provide better grip,not like the old ones.
If you can find them,buy them!!!

Frank

Darmah '81
Paso '88
900SS '97
Daytona RS '98
996S '01

Re: Paso 750 Rear Tire solution (160/60/16)

Posted: Fri Feb 27, 2009 4:49 pm
by Finnpaso
I hear(rumours), that one Fin guy is trying some "Mezeler 160/70-16" to his 16" Paso . Rear surely! Sorry, that i am too hurry, that i cant look all previous mails and also Mezeler web sites.... Have ANYBODY some experiences about such Mezeler??? :)