BergDonk's DR650

[BergDonk]

FWIW I went to a couple of bearing suppliers in the big smoke this week, aka Fyshwick, and came up with an SKF 3205-2RS. This is a double row bearing that has the same OD and ID, ie 52x25 as the stock 6205 but is 6.6 mm wider at 20.6 mm instead of 15 mm.

I lathed up a new spacer to suit and installed with new cush rubbers and no seal, as there is no longer room for it. The wider bearing is now mostly under the sprocket and has close to twice the load rating of the stock bearing, although only rated to 11 k rpm, which is still 4-5 times what it'll do.

As long as the seal survives I reckon it'll be OK and heaps stronger. As mentioned, my 501 has only ever relied on the bearing seal on the front wheel, and I know of many who have removed their mechanical speedo drives and ended up just relying on the bearing seal without problems.

As I have the original spacer and a couple of new stock bearings and seals I can travel with stock spares and/or a 3205. The seals in the SKF 3205 are difficult to remove without damage, so I will rely on the factory in Austria where it was made for lubrication.

The other downside is the cost. The 3205 was $75 vs $12 for a 6205, ouch! Still, cheaper that a new hub like DRJoe experienced when he let his go a bit far.

Also tested the water carriers on the weekend and so far, so good. Got them plated on Monday along with the footpeg hangers and tank mount. I did manage to snag one of the water containers on something in some tight single track but it was only minor. Just tweaked it back into shape and all good. The advantage of mild steel is it'll take a few tweaks and adjustments and can be easily enough welded if necessary to repair.

Hopefully good to go now, after new wheel bearings and chain and sprockets, and fresh oil, filters and plugs.

Steve

[AdventureXR650]

I think the best riding position for me and I'm guessing you too Rowdy is in FRONT of the Donk. This is so we are not constantly stopping and picking up bits of the behemoth, its ejected punting along the road.

Mr Donk has any of the support vehicle got a hi-ab fitted? I ask so you can pick this sucker up if it is unfortunate enough to end up on its ear?

I hope to have my back from the mechanic with a new top end this week, so will entertain with some picts later.
Cheers
AXR

[BergDonk]

Originally Posted by AdventureXR650

I hope to have my back from the mechanic with a new top end this week

So you've finally got to the root cause and getting a new head to attach to your back

[BergDonk]

So after our 460km run to McKillops on Easter Sunday I pulled the wheel off to make up a better spacer and see if I could get the outside seal working, and see how the double row bearing looked. To my frustration the bearing had been turning a bit in the hub, not good.

The damage done when the bearing collapsed previously was maybe worse than I'd realised, and maybe the reason why I seem to have more problems with this bearing than others.

After contemplating sleeving the hub to repair the damage, and consulting with my machinist/engineer mate it was decided that a sleeve repair was not practical. Should be simple enough to assemble with some pin punch dimples and retaining compound, but I was trying to avoid that.

I scored a replacement second hand hub from the wrecker that looked OK for $45. When I got it home and cleaned it up, the problem was that the bearing had about the same interference fit as the old one, so no improvement. So I decided to set up both hubs for use, one on the bike, and one in the 4wd and I'll swap it in Broome or somewhere.

Whizzed up a couple of seal retainers out of nylon, and a new spacer. maybe this time?

[LukasM]

How loose is the fit? Loctite makes a few different products to glue in bearings that should work for you:

http://www.kraftindustrialsupply.com..._retaining.htm

[DRjoe]

I've been thinking about putting a double row angular bearing in my cush hub as well.
I have a new toy arriving soon that will allow me to make the required mods to the hub so that a double row can be used

[BergDonk]

Originally Posted by LukasM

How loose is the fit? Loctite makes a few different products to glue in bearings that should work for you:

http://www.kraftindustrialsupply.com..._retaining.htm

The fit is such that you can just slide a lubricated bearing in with your hands on the 'new' hub, the original damaged one needs some pressure, and it still allowed the bearing to spin. This was only with the new double roller, the stock bearings did not spin. It wasn't bad, but there was evidence.

I have some Loctite 641 Retaining Compund and that's what I'll use on both of them.

I head off next month with AdventureXR650, rowdy_im and a few other reprobates and expect to do 12-13,000 kms over June/July to the centre and Kimberly and don't want this playing up in the middle of the Simpson. I planned to take some spare bearings and didn't want to use retaining compound as it makes a trail side replacement harder. We have 4wd support for some of the trip, so carrying the spare hub should be OK, so thats why I'll now fix both of them with retaining compound. FWIW, the replacement hub was labelled for a 1990 DR250 and there are some subtle differences in the casting. A new die perhaps? Also, when drilling the holes for the screws for the seal retainer the alloy in the new old hub seemed harder? Dimensionally its identical.

In the picture above you can see that the seal on the RHS sits a bit proud of the hub. This is because of the 6.6 mm wider double row bearing. The seals are 7 mm wide and I ground down the back of the seal to get rid of the taper. They are now about 6.5 mm wide and fit into the hub about 3 mm leaving 3.5 mm exposed. The nylon stepped washer clamps down over the seal to hold it abit better and protects it a bit too. The test ride was without the seal as I wasn't confident that it's stay put with only 3 mm to grip.

The spacer on the left is the original, and the one on the right is my new one. Its stepped down to fit into the bearing and provide some additional support. The second step is for the seal, and the large diameter is just what I started with, 40 mm bar, and means the lip of the seal is better protected than otherwise, maybe.

Originally Posted by DRjoe

I've been thinking about putting a double row angular bearing in my cush hub as well.
I have a new toy arriving soon that will allow me to make the required mods to the hub so that a double row can be used

What mod to the hub do you plan Joe? The only change I had to make was a new spacer to allow for the wider bearing which just takes up the space the seal normally does. Adding the seal just makes me feel better, and may not really make any real difference, dunno.

Steve

[Dirt McGirt]

Yo Donk, where did you get that counter shaft sprocket cover? That's a trick little detail. I never really liked the stock one, but still use it because it's serviceable. Thanks bro Dirt

[BergDonk]

Originally Posted by Dirt McGirt

Yo Donk, where did you get that counter shaft sprocket cover? That's a trick little detail. I never really liked the stock one, but still use it because it's serviceable. Thanks bro Dirt

I made it up myself after the VSM replacement broke, fatigue failure on the creases on the mounting tabs, perhaps facilitated by a little chain contact.

I had a piece of 10 mm alumimium plate lying about that forms the basis. I cut the inner circular shape with a hole saw and then trimmed it up with an angle grinder with an aluminum cutting disc. Put some spacers on the main bolts to centre it on the sprocket, and then had a bit of scrap to make the cover. Took a few hours and is nice and strong and hasn't broken yet.

http://www.advrider.com/forums/showp...&postcount=117

Steve

[Dirt McGirt]

Originally Posted by BergDonk

I made it up myself after the VSM replacement broke, fatigue failure on the creases on the mounting tabs, perhaps facilitated by a little chain contact.

I had a piece of 10 mm alumimium plate lying about that forms the basis. I cut the inner circular shape with a hole saw and then trimmed it up with an angle grinder with an aluminum cutting disc. Put some spacers on the main bolts to centre it on the sprocket, and then had a bit of scrap to make the cover. Took a few hours and is nice and strong and hasn't broken yet.

http://www.advrider.com/forums/showp...&postcount=117

Steve

You've inspired me, and for once I have all the tools to do something from start to finish. Now I'm gonna keep my peepers on for the right piece of alum stock. Thanks good idea, Dirt

[BergDonk]

Originally Posted by Dirt McGirt

You've inspired me, and for once I have all the tools to do something from start to finish. Now I'm gonna keep my peepers on for the right piece of alum stock. Thanks good idea, Dirt

Go for it

Also from memory, the spacer off the case was a bit of sheet that I screwed to the 10 mm plate so its captive.

[Phreaky Phil]

Having the inside of the hubb Bead blasted should create a bit more interference in the fit

[BergDonk]

Originally Posted by Phreaky Phil

Having the inside of the hubb Bead blasted should create a bit more interference in the fit

Yep.

Just did the Loctite thing for the time being and will do a few hundred kms tomorrow and see how it goes using the new/old hub.

Steve

[DRjoe]

The bearing I had found was deeper than yours so I was going to leave the seal and outside spacer stock and then go inwards with the bearing and make a new inner spacer.
But after seeing your mod I'll probably just get the same bearing you got and then do the same as you with the spacer and seal.

Its always nice when someone else try's out a mod first.

cheers

joe

Originally Posted by BergDonk

What mod to the hub do you plan Joe? The only change I had to make was a new spacer to allow for the wider bearing which just takes up the space the seal normally does. Adding the seal just makes me feel better, and may not really make any real difference, dunno.

Steve

[BergDonk]

Originally Posted by DRjoe

The bearing I had found was deeper than yours so I was going to leave the seal and outside spacer stock and then go inwards with the bearing and make a new inner spacer.
But after seeing your mod I'll probably just get the same bearing you got and then do the same as you with the spacer and seal.

Its always nice when someone else try's out a mod first.

cheers

joe

The thing that appeals to me about the bearing going 'out' is that its more in line with the sprocket and reduces the twisting loads applied from chain pull which I think is an issue. And the double row helps to resist the twist too.

My machinist/engineer mate felt that there wasn't really enough meat in the hub to sleeve it properly. I was thinking a steel sleeve about 1 mm thick with a thicker boss on the outside to take the seal. I thought I'd be up for making the sleeve, but my lathe won't take the hub to bore it so I'd have needed his assistance for that. Handy having an expert for a neighbour

I'm hoping its sorted now, got some kms to do soon and am running out of time...

Steve