XR10 Bearing Upgrade - 5x10 Flanged to Replace Puny 5x8s

[LincolnBlack]

After looking at the motor plate on the XR10, this upgrade looked rather feasible. I couldn't find anyone else that has actually done it, plenty of talk, but no photographic evidence, though I see this morning a few 9mm bearing upgrades . Anyway, if 9 is good, 10 is better, right? :-P

Bearings come from Acer. I opted to upgrade the outboard bearings with the '5X8MM Polyamide Sealed Ball Bearings' and replace the motor plate bearings with '5X10MM FLANGED Polyamide Sealed Ball Bearings'. The reason I went the regular steel bearings over the ceramic versions is because despite the hype, the steel ones are actually better at handling static load - like something you would experience when bound up. Even with the outboard bearings being the same size as the ones they're replacing, a higher quality bearing will give you better static load ratings.



So anyway here is the method:

Pull the gearbox out and apart. Getting the gearbox out is easy if you've made the notch in the bottom of the motor plate so it comes out without the need to pull an axle.



Motor plate ready for its procedure. You can actually see on the middle hole where the flange has been rubbing on the plate. If I didn't know any better, I would say that the entire bearings has been spinning in the hole.



And the holes drilled out to 10mm. They're 8mm standard. I used four drills to work my way up to 10mm - 8.5mm, 9mm, 9.5mm and 10mm. Stepping up in sizes means that the drill is less likely to wander or cause the hole to go oval. The finish is also better. I hardly ever use the drill press, but I used it for this to get the holes nice and perpendicular to the plate. Though if you don't have access to one, a hand drill and a keen eye will still give you a good result.



I was expecting the flange of the middle 5x10 bearing to overlap the coutersunk hole, but perhaps not as much as it did. On a side note about the bearing fit: If you're careful with your drilling, the bearings actually fit beautifully. If you are finding that you have to tap the bearing to get it in, STOP, take the bearing out and open out the hole a little with the dremel. Forcing the bearing into a slightly undersize hole with cause the outer race to deform and will make your bearing fell notchy and sticky. You want it silky smooth, so open out that hole a little extra.



So the solution to the overlapping flange is a pretty easy one. Simply screw the back part of the gearbox case back on (the part held on with the screw in question) until its nice and tight. Then get the Dremel out (if not out already) and grind off the part of the screw head that is impinging into the bearing hole. Make sure that the screw head is clear of the hole as to not cause the bearing any tightness when seating. Also make sure that the head of the screw does not sit proud of the motor plate, you don't want the bearing sitting up. If the screw head is a little proud, just countersink the hole a little more. I found I didn't need to do anything extra with the hole.



Here you can see it all nice and out of the way, ready for some extra beef.

And here is the beef. I'm pretty confident now I wont have any gear failures caused by collapsed bearings.



The thicker flange makes getting the larger gear on main shaft on a bit tight, and likewise the whole gearbox back into the axle because that main shaft pushes the gear cover out a little. But it will go without too much trouble. :thumbsup:

[ittybitty]

great write up...rated!

[ruffryder]

Nice write up Linc

[losichris]

Very nice.. I did 9mm in mine .. I think 9mm might be alittle easier but looks really good.

[squish72]

Wow now I need to buy 10's guess the 9's will work for a bit

[losichris]

Originally Posted by squish72

Wow now I need to buy 10's guess the 9's will work for a bit

The 10s are nice but overkill.. keep the 9mm if you have them.

[BEELZEBOB]

Id go 10.

why go 9 if you can just as easily go 10?


bigger beefy better right?

thats what my lady says.

[Robbs2001tj]

She's lying to you

[BEELZEBOB]

I usually dont listen when her mouth is full

[Highlucks]

Great write up linc. Hope fully they hold up to your heavy left finger.

[motorman1600]

The 5x9 and 5x10 are rated the same. The 9mm mod is a little easier to do.Plus the width is 3mm on the 5x9 bearing . no clearance issues. I did 9mm. no problems at all. I used Avid bearings

[LincolnBlack]

Cheers guys for the comments.

The 4mm width of the bearing is no issue at all. The back side of the bearing sits flush with the back of the motor plate so nothing is saved by using a skinnier bearing. It's only the extra thickness of the flange itself - maybe 0.5mm if that, that makes the shaft assembly a little snug to go back into the gearbox.

[ol' gravy leg]

Originally Posted by LincolnBlack

Cheers guys for the comments.

The 4mm width of the bearing is no issue at all. The back side of the bearing sits flush with the back of the motor plate so nothing is saved by using a skinnier bearing. It's only the extra thickness of the flange itself - maybe 0.5mm if that, that makes the shaft assembly a little snug to go back into the gearbox.

Nice writeup. The flange on the 10s is only 0.2mm thicker. I did the 5x9 Avids myself.