Lower Triple Tree Bearing

discussion about the 750 Sport and '89/'90 900SS, which share many mechanicals with the Paso series
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jpitz31
Posts: 84
Joined: Fri Aug 15, 2008 4:10 pm
model: 750 Sport
year: 1990
Location: Escondido, CA
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Lower Triple Tree Bearing

Post by jpitz31 »

Anyone have any idea on how to remove the lower bearing and seal from the triple tree. It appears to be pressed on. I want to bead blast and powder coat the tree. But I am afraid that the heat will destroy the rubber seal.

Thanks

Joe
1990 Ducati 750 Sport (mine)
2007 Piaggio BV 500 (mine - daily driver)
2008 Piaggio MP3 500 (wife's)

My Ducati Blog site
http://projectducati.blogspot.com/

Stupidity is not a crime, your are free to go ;-)
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Lower Triple Tree Bearing

Post by paso750 »

what rubber seal ? The seal is in the frame at least normally it is. I doubt there is any way getting the bearing race from the steering axle w/o destoying it. Trying to pull it off, hit it or heat it up may ruin it. I`d replace it.
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jpitz31
Posts: 84
Joined: Fri Aug 15, 2008 4:10 pm
model: 750 Sport
year: 1990
Location: Escondido, CA
Contact:

Re: Lower Triple Tree Bearing

Post by jpitz31 »

Underneath the bearing there is a black aluminum looking spacer. The top bearing and seal came right off. By looking at the top spacer, there is a rubber seal on the inside of the spacer. I am assuming that the bottom spacer is the same. Looks like a dust seal.

To remove it do you suggest hitting it with a cold chisel and splitting the bearing?

I should clarify that I am using a 750 Paso triple tree on the Sport. There is thin aluminum wrapped around the fork legs to take offset the difference in fork diameter.

Thanks

Joe
1990 Ducati 750 Sport (mine)
2007 Piaggio BV 500 (mine - daily driver)
2008 Piaggio MP3 500 (wife's)

My Ducati Blog site
http://projectducati.blogspot.com/

Stupidity is not a crime, your are free to go ;-)
dtm79

Re: Lower Triple Tree Bearing

Post by dtm79 »

Just one thing to add on getting the old bearing out the way .. I use a grinder to at least start the removal process after first wrapping up the stem and yoke .. but go easy . Haven't done one for a while but from memory it does seem to lessen the grip the old bearing has .. also put the yoke in the freezer over night .. should help the new brg go on easy ...
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jpitz31
Posts: 84
Joined: Fri Aug 15, 2008 4:10 pm
model: 750 Sport
year: 1990
Location: Escondido, CA
Contact:

Re: Lower Triple Tree Bearing

Post by jpitz31 »

Sounds like a good tip dtm79

Thanks

Joe
1990 Ducati 750 Sport (mine)
2007 Piaggio BV 500 (mine - daily driver)
2008 Piaggio MP3 500 (wife's)

My Ducati Blog site
http://projectducati.blogspot.com/

Stupidity is not a crime, your are free to go ;-)
crmac

Re: Lower Triple Tree Bearing

Post by crmac »

Only way I could get mine off was to use the angle grinder to cut through most of the bearing, then a cold chisel to finish it off. I previously tried hot, cold, chisel etc etc etc.
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Lower Triple Tree Bearing

Post by ducinthebay »

Most of the time you can use a cold chisel to get underneath it, but sometimes its just too stubborn. I always assume that the bearing will be damaged, and plan on replacing it.

Yo, Joe, I gotta ask. Why are you using a set of Paso clamps on a Sport? The stock Sport clamps are just as strong as the Paso clamps, but don't have the silly ears for the bars. If you are going that far, get the forks too. Big upgrade from the stock M1bb fork. Ideal shim stock is stainless, or brass.

I have the Paso clamps on my Sport, but also have the M1R forks from a Paso. The fork stops work just fine, but the steering lock won't quite reach to work. (not that I need it)

Cheers,
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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jpitz31
Posts: 84
Joined: Fri Aug 15, 2008 4:10 pm
model: 750 Sport
year: 1990
Location: Escondido, CA
Contact:

Re: Lower Triple Tree Bearing

Post by jpitz31 »

Hey Phil,

The guy I purchased the bike from put the Paso triple and bars on as the sport clip-ons were bent. I have a complete set of 900CR triple clamps and forks that I will put on when the sport forks go.

They are not as nice as the 900ss adjustable forks but I got them on ebay for cheap.

Joe
1990 Ducati 750 Sport (mine)
2007 Piaggio BV 500 (mine - daily driver)
2008 Piaggio MP3 500 (wife's)

My Ducati Blog site
http://projectducati.blogspot.com/

Stupidity is not a crime, your are free to go ;-)
User avatar
ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Lower Triple Tree Bearing

Post by ducinthebay »

Joe,
You are headed in the right direction. I wouldn't wait for the Sport forks to die. Put that 900ss front end on while the snow is falling. then the switch to 17" wheels is as easy as bolting it all back together. but like any project, there's always that time commitment thing. (said the guy with a set of forks apart on his bench for a month now.)

Cheers,
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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