RC Tank Warfare community hobby forum

I apologize if this has been asked an answered. If it has, please feel free to point me to the other thread and delete this one.

I have a 7.0 Challenger 2. Two upgrades I'd like to do right away are metal drive sprockets with anti-slip rings and drive shaft support bearings. I've already found eBay listings for the drive sprockets, but after doing a search and reading several threads, I still have some questions about the bearings.

1. I've seen listings for bearing holders that show compatibility for either 5.0 or 6.0 models (not both).
   However, I've heard there were some chassis changes between 6.0 and 7.0.
   Is the size of the opening different between the two generations?
   The opening is ~12mm, and I've attached a photo for reference.
2. If the opening is the same, is there a reason to use a separate bearing holder vs. directly placing a bearing?
   If the opening size is different, would the bearing itself be the same size? Somewhere I saw a suggestion of 12mm O.D., 8mm I.D. 3.5mm thick.
3. I've seem some threads for other tank models that mention putting a bearing inside the chassis instead.
   Is that something I need to do as well, or is that specific to a different gearbox/chassis design?

Thank you in advance for any assistance.

I'm still curious if the bearing carriers I've seen serve a secondary purpose, or if they're only because v6 and earlier tanks had a different size drive axle opening. I'd appreciate if anyone can answer this.

However, just to share some information, a 12mm O.D., 8mm I.D., 3.5mm thick bearing will fit the drive axle opening of a v7 Challenger 2. I used MR128-2RS deep groove bearings from Uxcell.

I think the "carriers" were just a holder for the bearings. Personally I would forgo the carrier and just install a flanged bearing.

Well, I feel dumb. Was just going through my manual again, and realized the last two pages were stuck together. You know, the two that start with "How to install the bearing of drive shaft".

This one?

These moments to lead to humor! However, you have actually done me a favor: I have a Challenger (6.0) and I didn't even know the support bearings are available. Now when I turn to the Challenger (and Leopard, and Abrams) I will see if I need to get and install the bearings.

Aussie wrote:

DSCN0527.JPG

This one?

Yep.

tankme wrote:I think the "carriers" were just a holder for the bearings. Personally I would forgo the carrier and just install a flanged bearing.

I have been fitting Gearbox output shaft support bearings since my first Tiger 1 always from Dave---www.forgebeartanks.com
That is until I bought a Taigen Panzer 4 metal hull which was not really suited to them so after a bit of reading I fitted "Flanged bearings",
With a little attention to detail and a touch of fettling they are a very good alternative and cheaper.
The only warning I would offer is that because unlike the regular support bearing the flanged version is external so when you fit them do make sure they do not interfere with the tracks alignment,
Hence the fettling

tankme and jarndice, thank you for your information.

You mentioned making sure the flanged bearings don't interfere with the tracks, that's what concerned me about some of the 3rd party bearing carriers I was seeing. They stuck out quite a bit, and at least on mine, there's not a lot of clearance between the new built-in bearing carrier and the flat spot on the drive axle. I was concerned the ones I'd seen would push the drive sprocket out. If I pick up an older model again, I will use flanged bearings on them.

good morning, heres the flange bearing as fitted to my challenger 2