Mysterious front axle situation....

[reddog]

So, I finally decided to do the belts on my Duc and while I was at it, I opted to replace the seeping fork seals. All went well, much better than I had hoped...until I went to install my front wheel.
I will also add that I had a friend helping me who is the one who removed the wheel form the bike.
I had the wheel in the forks and had the axle in place and was threading it in, when I detected that there seemed to be alot of play between the axle and the bearings. After figuring out that it was not an issue of the axle just not being fully inserted, I pulled it out, took the wheel off and put it on the bench. Here I find that the axle is considerable smaller in diameter than the bore in the inner race of the bearing....huh. I look around for some sort of shim that I had missed since I did not disassemble the front wheel assy.
After looking at the parts diagram for the front wheel, I see that there is a part, #14 on page 47 called the "distance piece". From the picture, this looks to go between the bearings and have a smaller bore than the inner race of the bearings, which would "space the bearings and align the axle. I am not currently at the shop, so I can't check to see if the distance piece is in my wheel, but I suspect it is not, hence my problem.
So here's the mystery. We did not take the bearings out, so this piece did not fall out. Last summer I took a 250 mile ride on the bike at, shall we say, a spirited pace through the mountains with zero issues. If my bike is missing the piece that aligns the front wheel in the forks and brake calipers, why did I not have problems...BIG PROBLEMS????
So, #1, is the "distance piece what aligns the axle in the front wheel/wheel bearings?
#2 IF so, and mine is missing, where do I get one? and
#3 If I cheated fate and have lived to tell this tale, where is the biggest lottery currently so I can go buy some tickets?
Thanks in advance, Doug at 8000'

[paso750]

I don`t have a 907ie but the bearing spacer does not center the wheel, meaning it does not reduce the inner diameter of the bearing to the axle diameter. It`s there to prevent to put load on the bearings when the axle is tightened.
The front wheel bearings are part# 751633268 (SKF 6303 2RSH C3) . They are od 47mm, id 17mm, width 14mm. The front axle is 17mm, too. So there shouldn`t be any play unless someone replaced them with 47x20x14mm which do also exist (SKF 6204 2RSH used on SS/Monster from 1994 on). The bearing type is printed on the outer race. Check that.
If that s the case you wouldn`t have had big problems. The tightened axle holds everything together and if the brake disc to caliper clearance is 3mm these parts wouldn`t have touched. As the bearing spacer and bearings wouldn`t match properly the spacer could be damaged and/or the bearings could wear faster. That`s about all I could think off if the mentioned bearings were used.

The rear wheel bearings are 62203-2RS1/C3 (od40mm, id17mm, w16mm) btw.

G.

[reddog]

G,
Thanks for the info. I'll check the bearing dimensions when I get to the shop. I have never seen a spacer with "collars" that slide into and thereby reduce the inner diameter of the bearing, but from the picture in the parts diagram, it looked like that might be the case. I'll post what I find later today.
Best Wishes, Doug@8000'

[nnnnnnorman]

if you or anyone wins the lottery or a lottery..... how about a lucky pound or dollar for every member of this forum to place on their areas lottery? we could all end up with enough cash to buy up all the neglected paso and paso parts out there!

[reddog]

My plan was to fund the first ever "PasoFest" and transport all members and their bikes to a location mutually agreed upon for a week long Duc-a -thon. Riding, live music, abundant libations...you get the picture. I like the Dolomites, but our euro members might like to ride in my backyard here in Colorado. I'm open to suggestions and I think we are going to need a LARGE airplane. Doug@8000'

[reddog]

So the axle does measure 17mm, and the inner bore of the bearing does measure 20mm, but so does the bore of the spacer. I have never (in 35 years of motorcycle wrenching) seen spacer with a larger bore than the bearing. It makes no sense to have the spacer not aligned on the axle. Not that I question the wisdom of the Ducati Mothership, it just makes no sense. Can anyone with a 907 i.e. confirm the situation?? Thanks, Doug@8000'

[reddog]

OK, I took it apart and now I see the method to their madness. G is correct ( as I am sure he knew he was). The spacer is centered in the hub and not dependent on the axle to center it.
Anyway, I got the correct bearings ordered and all should be good to go by noon tomorrow. Now if it will just get above -1 degrees F, I can go ride. Thanks for all the help and wish me luck on the lottery! Doug@8000'

[paso750]

I`m still wondering about the bigger bearings. Maybe a shop did make the mistake when replacing them as there are newer Ducs with a 20mm axle.
As the bearing spacer does not reduce diameter (like ie the bearing spacer on the P750 rear axle) it has to be shaped that way otherwise it would fall inside the hub when you removed the axle.

G.

[reddog]

Yeah, it's a puzzle. The bearings have been in the bike since I bought it in 05. Never had an issue with them. It will be good to have it put back as it should be. Doug@8000'

[paso750]

after a short coffee break I`m beginning to think the whole front wheel was replaced for cosmetical reasons or a damage. The rims all look the same. If you don´t know or check this could happen. Could that be ?
In that case the spacer would have the same diameter than the bearings and in your case could also be the wrong one (if different ones where used depending on the axle).
Be aware that the spacer should only touch the inner bearing race. That`s the only thing that`s important.



G.

[reddog]

I would have thought that the bore of the spacer should be the same as the bearings, although it would work due to the fact it centers in the hub. One other fact is that the speedo drive slightly hits the blots that hold the brake rotor on, which makes me thing that maybe the spacer is wrong and about 2-3 mm too narrow. I can shim this no problem, but another puzzling issue. Sounds like you may be right again and the wheel may have come off of another bike. Doug@8000'

[paso750]

..., although it would work due to the fact it centers in the hub

but only if the inner diameter of the spacer is smaller than the outer diameter of the inner bearing race.

One other fact is that the speedo drive slightly hits the blots that hold the brake rotor on, which makes me thing that maybe the spacer is wrong and about 2-3 mm too narrow.

this is where someone who actually has a 907ie, maybe even a loose front wheel to measure should chime in...

G.

[reddog]

I considered the possibility that the shoulder on the spacer might hit the bearing seal, not the inner race, something to check when the bearings arrive. The brake rotor bolt heads have actually "eaten" some of the plastic off of the speedo drive. A width measurement of the 907 spacer would be really helpful.

[englishstiv]

1992 907ie the groove in your speedo drive is on mine and is part of it's manufacture as far as I can see with original paint finished surface etc. If you need measurements let me know of what exactly and where and I will get them. Hope these pictures help? If you need more let me know my wheel is fully stripped down awaiting new colour scheme.

Everything seems a tight fit and there are no loose spacers as such

[paso750]

it`s interesting that the pic you posted englishstiv (from the workshop manual) is different than the one in the parts catalogue



G.