Rear wheel axle question

ducapiero · Post by **ducapiero** » Fri Oct 26, 2007 1:32 pm

Hi guys i bought a 750 ss rim,and as i said before i'm planning to swap to 17 wheel on rear,now the question is what are the size of the wheel axle???
i have to machine a new one but i don't have the measure....

many thanks
Piero
P.s.
i'm mounting also a steering dampner of a 999 and 4 piston brembo caliper with radial pump

Post by **paso750** » Fri Oct 26, 2007 5:15 pm

if I recall correctlz its not necessarz to make a new axle. Its possible to use a new one, but you need different bearings and a new spacer.
I may be wrong but when I thought about doing that years ago I think this would have been one of the first steps.

G.

Desmo_Demon · Post by **Desmo_Demon** » Fri Oct 26, 2007 6:33 pm

What year is the SS rim? If it is an early 90's rim, it probably is already for a 17mm front axle and a 20mm rear axle. If it is a newer rim, it is for the 25mm axles. If this is the case, as Gerhard states, you will need to replace the bearings and center spacers for a 17mm front and 20mm rear axle.

ducapiero · Post by **ducapiero** » Sat Oct 27, 2007 12:02 am

mmmi don't understand why new bearings???
i'll investigate on the year of the rim and i give you notice when the rim arrive......
lamps
Piero

ducapaso · Post by **ducapaso** » Sat Oct 27, 2007 7:06 am

Nel senso che un cerchio con un perno di 25mm ha sedi cuscinetto più grandi dell'equivalente cerchio per perni di 20mm.
Comunque la sede più larga può essere compensa con cuscinetti di misura speciale. (ad esempio un 6205 per perni di 25 si sostituisce con un 6304 per perni di 20)
Se mi dici il codice del cuscinetto sul cerchio di 17" sarà facile dirti quale è il cuscinetto equivalente.
Per i distanziali esterni, come già ti dissi, è necessario avere tutte le misure e provare.
This mean that different rims for different axles require different bearings.
Anyway, the different gauge in the rim can be fitted with special bearings (a 6205 for 25mm axles switched to a 6304 for 20mm ones)
If you tell me the standard number of the bearings in the 17" rim, it's easy to tell you whch is the bearing you need.
For external spacers, you need all the measures and then calculate the gauges.
________________
Have a nice work, Nicola

Post by **paso750** » Sat Oct 27, 2007 4:07 pm

Terry, thanks of helping me out. I only have a rough memory of this

G.

ducapiero · Post by **ducapiero** » Mon Oct 29, 2007 10:38 am

Tell me if i undetrstand....
i can use my paso old axle with diferent bearing to comparate the differnces in diameter between the old rim and the new one...
right???

many thanks
Piero

Desmo_Demon · Post by **Desmo_Demon** » Mon Oct 29, 2007 2:44 pm

ducapiero wrote:Tell me if i undetrstand....
i can use my paso old axle with diferent bearing to comparate the differnces in diameter between the old rim and the new one...
right???

Correct.

If the old axle is 20mm and the new rim is for a 25mm, then you have to replace the bearings in the new rim with ones that have the same thickness and outer diameter as original, but with an inner diameter of 20mm for the axle diameter. You will also need a spacer for inside the hub with a 20mm inner diameter, also, which gives the inner races of the bearings support. The spacer can simply be made out of a steel tube with a 20mm ID, but the length must be the same as the original spacer, or you run the risk of binding the bearings when you torque the axle.

Note: When changing wheels, you also need to make sure that the spacers on either side of the wheel are correct to avoid binding of the bearings and to make sure that the wheel is centered. If the new rim is the same thickness and has the same off-set, this won't be a problem, but you need to check it to avoid potential trailing and handling issues.

ducapiero · Post by **ducapiero** » Fri Nov 09, 2007 5:00 pm

Hio guys today arrived to me the new rim....it's a gold wheel from a ss and it has 17 mm diameter when is located the axle......
what bearings i have to buy ???

many thanks
Piero

Desmo_Demon · Post by **Desmo_Demon** » Fri Nov 09, 2007 7:01 pm

ducapiero wrote:Hio guys today arrived to me the new rim....it's a gold wheel from a ss and it has 17 mm diameter when is located the axle......
what bearings i have to buy ???
many thanks
Piero

If the wheel was from a bike that originally had a 17mm axle, then you are in luck, because it'll fit on the Paso axle with no mods other than spacers, if necessary. If you need new bearings, then the easiest way to find out what you need is to knock one out and get the number off of it. I'll surf another Ducati forum and see if I can find the dimensions or a bearing part number for you.

Edit - This is what I found...

"The stock bearing for the early SS wheels is a 62203-2rsc3, which measures 17mm IDx 40mm OD x 16mm wide. This in an odd bearing size in as much as its 16mm wide. A 6203 bearing is only 12mm wide, and pretty readily available. A 6203 is what is in the newer wheels (at least the ones with 17mm axles still). "

It looks like either the 62203 or 6203, depending on whether it is a 16mm or 12mm wide bearing, so.....you'll have to remove one from the wheel to find out.

ducapiero · Post by **ducapiero** » Sat Nov 10, 2007 11:34 am

thanks guys!!!

How i can check the state of the rim bearings???
then code on the bearings is 6303-2rs1/c3....
lamps
Piero

ducapaso · Post by **ducapaso** » Sun Nov 11, 2007 8:12 am

ducapiero wrote::
How i can check the state of the rim bearings???

lamps
Piero

If they aren't absolutely worn, it's hard to see a great difference.
I'm quite surprised that you found a low tolerance (/c3) bearing!
Anyway, you'd better change them: they're available in any A.C.M.E. shop. Choose a quality brand!:thumbup:

Se non sono proprio corrosi all'interno, è difficile vedere una gran differenza. E' strano che tu abbia trovato cuscinetti a bassa tolleranza (sigla /c3)!
Comunque cambiali, non costano un gran che e li puoi trovare in qualunque fornitura industriale. Scegli una marca famosa!

ducapiero · Post by **ducapiero** » Tue Nov 13, 2007 6:27 pm

thanks for the answers

i'm thinking to mount a sprocket of 38 teeth to make the engine not at high rev on travel....what do you think??
lamps
Piero

Desmo_Demon · Post by **Desmo_Demon** » Tue Nov 13, 2007 6:34 pm

ducapiero wrote:i'm thinking to mount a sprocket of 38 teeth to make the engine not at high rev on travel....what do you think??

It all depends on what you will use the bike for. If you will do a lot of commuting and long distance trips, the 38-teeth sprocket will be nice, but if you spend most of your time in the mountains, a 40 may be better. What is on it, now? I think the 750 came with a 38 from the factory. I have a 38 on mine and may put a 40 on it if I decide to not use it much for commuting to-and-from work.

ducapaso · Post by **ducapaso** » Tue Nov 13, 2007 6:36 pm

It depends of the measure of the tire...
Just measure themwith an adesive tape in the larger circumference and make some calculation...
A too long ratio will make clutch work hard at starting!

Dipende dalla misura della gomma.
Misurale tutte e due alla circonferenza massima e fai 2 calcoli.
Un rapporto troppo lungo farà soffrire la frizione in partenza!