Mojave Arrma please stop using the 15x21x4 inner wheel bearings👎

[Sandracer_NL]

Constructive criticism for Arrma.
Arrma please redesign those inner wheel hubs (bearings). I know sand isn’t best friends with bearings, but the 15x21x4 bearings last RIDICULOUSLY short. Just destroyed 3 of them again (one could no longer spin and the other two the rubber seal flew off and have a lot play) after 3 runs, where all four the 8x16x5 were still fine.
FYI 1: I was just bashing with the Mojave EXB, so should be well within the bearings rpm limits.
FYI 2: all wheel bearings (8x16x5 for both the inner and outer wheel hub bearings) on my FTX DR8 were fine after 5 of runs on them. Granted those 5 runs were all on 4s (Mojave 1 on 4s and 2 on 6s) but speedwise not that much between them.

Hope someone of Arrma reads this and (re)designs wheel hubs with bigger bearings.

 

[Senton_Prime]

Are you running factory bearings.. its pretty much a must to swap for fasteddies or Jim's or trb rc bearings, the oe bearings are pretty standard so not much life in them, especially around sand!! Cleanliness is godliness around sand!!

 

[KnowAir]

Constructive criticism for Arrma.
Arrma please redesign those inner wheel hubs (bearings). I know sand isn’t best friends with bearings, but the 15x21x4 bearings last RIDICULOUSLY short. Just destroyed 3 of them again (one could no longer spin and the other two the rubber seal flew off and have a lot play) after 3 runs, where all four the 8x16x5 were still fine.
FYI 1: I was just bashing with the Mojave EXB, so should be well within the bearings rpm limits.
FYI 2: all wheel bearings (8x16x5 for both the inner and outer wheel hub bearings) on my FTX DR8 were fine after 5 of runs on them. Granted those 5 runs were all on 4s (Mojave 1 on 4s and 2 on 6s) but speedwise not that much between them.

Hope someone of Arrma reads this and (re)designs wheel hubs with bigger bearings.

Amen!! I have been saying this since my first Arrma 6s about 2 years ago..they're just too thin. They have SBS,small balls syndrome!!

 

[Sandracer_NL]

Are you running factory bearings.. its pretty much a must to swap for fasteddies or Jim's or trb rc bearings, the oe bearings are pretty standard so not much life in them, especially around sand!! Cleanliness is godliness around sand!!

I started buying those bearings in bulk, because they just don’t last long. IMO they are to thin, like @KnowAir also mentioned. I runs same brand for both the inner 15x21x4 as teh outer 8xThey 8x16x5 bearings. The latter just lasts way longer regardless whether I use Arrma bearings or the ones I have now. It seems the outers slowly get crunchy to let you now it’s time to replace, but the inners just explode after a few runs.
Normally I check them regularly, but on a bash day when running a couple packs I do (did) not, so just found out that 3 inner bearings were completely ‘kaputt’.

 

[Diem Turner]

Constructive criticism for Arrma.
Arrma please redesign those inner wheel hubs (bearings). I know sand isn’t best friends with bearings, but the 15x21x4 bearings last RIDICULOUSLY short. Just destroyed 3 of them again (one could no longer spin and the other two the rubber seal flew off and have a lot play) after 3 runs, where all four the 8x16x5 were still fine.
FYI 1: I was just bashing with the Mojave EXB, so should be well within the bearings rpm limits.
FYI 2: all wheel bearings (8x16x5 for both the inner and outer wheel hub bearings) on my FTX DR8 were fine after 5 of runs on them. Granted those 5 runs were all on 4s (Mojave 1 on 4s and 2 on 6s) but speedwise not that much between them.

Hope someone of Arrma reads this and (re)designs wheel hubs with bigger bearings.

I think it's much more likely that an aftermarket manufacturer like RPM would do it than Arrma.

 

[Sandracer_NL]

I think it's much more likely that an aftermarket manufacturer like RPM would do it than Arrma.

IMO they should seriously consider redesigning it for the next releases. After all “arrma tough” is their slogan.

 

[Diem Turner]

IMO they should seriously consider redesigning it for the next releases. After all “arrma tough” is their slogan.

This is true

 

[Senton_Prime]

This is true

I've mumbled this under my breath over 2 years!!
.

IMO they should seriously consider redesigning it for the next releases. After all “arrma tough” is their slogan.

 

[KnowAir]

Joking aside, I have never had an rc go through bearings as quickly as my 6s Arrmas. The rigs are awesome, some of the toughest I've encountered in 35 years. With that, the only bearings that fail routinely are the inner hub bearings. I do think that the issue is often compounded by the bearings being too thin and cheaply sourced. My brothers Talion EXB didn't make 2 full battery packs before the front inners just literally fell apart. He bought fast Eddie and they've been holding fine since, but we run on a track, so nothing really crazy we're doing.
I think Arrma was more concerned with increasing the axle diameter for strength, but unfortunately that required a really thin wall bearing, which just doesn't last.
It's not the end of the world of course, but is frustrating to have to routinely replace them. And it's really only those bearings that fail like clockwork. I agree with @Sandracer_NL ,Arrma needs to redesign the hub to allow a thicker inner bearing. I have seen aftermarket that uses oversized inners, perhaps it was Hot Racing? I'm not sure, but IIRC, they were aluminum hubs..no thanks.

 

[Sandracer_NL]

I've mumbled this under my breath over 2 years!!
.

Now I understand your profile pic! Ssshhh

 

[Senton_Prime]

Joking aside, I have never had an rc go through bearings as quickly as my 6s Arrmas. The rigs are awesome, some of the toughest I've encountered in 35 years. With that, the only bearings that fail routinely are the inner hub bearings. I do think that the issue is often compounded by the bearings being too thin and cheaply sourced. My brothers Talion EXB didn't make 2 full battery packs before the front inners just literally fell apart. He bought fast Eddie and they've been holding fine since, but we run on a track, so nothing really crazy we're doing.
I think Arrma was more concerned with increasing the axle diameter for strength, but unfortunately that required a really thin wall bearing, which just doesn't last.
It's not the end of the world of course, but is frustrating to have to routinely replace them. And it's really only those bearings that fail like clockwork. I agree with @Sandracer_NL ,Arrma needs to redesign the hub to allow a thicker inner bearing. I have seen aftermarket that uses oversized inners, perhaps it was Hot Racing? I'm not sure, but IIRC, they were aluminum hubs..no thanks.

I'm not sure but what are you replacing these with, I mean it is a legit complaint but it is something that can be rectified by yours truly with a simple upgrade!? This has been a heavy issue for years so most just accept it and buy the better ones, I know a few members that even change them before a the first run!! It is what it is!!

 

[Avyn Nix]

You can’t go wrong with the avid RC bearings or go to hot racing hubs they come with 24x15x5 bearings.

 

[KnowAir]

I'm not sure but what are you replacing these with, I mean it is a legit complaint but it is something that can be rectified by yours truly with a simple upgrade!? This has been a heavy issue for years so most just accept it and buy the better ones, I know a few members that even change them before a the first run!! It is what it is!!

It is accepted, not appreciated though. I'm using whatever I find on Amazon. All I'm saying is it wouldn't be such a common failure if Arrma designed the hub to hold a thicker bearing. You can buy whatever bearing brand you want, I guarantee they all come from china, likey the same plant. Only real difference being with or without oil

 

[Senton_Prime]

Imo i think they were most likely locked in a contract of some sort.. I believe that has ended recently and thats why you see the new released platforms with the rubber shielded bearings now.. just a guess!!

 

[chilly81]

Yeah I was pretty disappointed with those bearings too. I'm on my 4th, and the last one I put in the seal came off on the first run (so far bearing is holding). It's not dust and sand when they fail this quickly on me. They aren't 'wearing out' they are breaking because they are undersized for the spot they are in.

 

[Moirae]

 

[Diem Turner]

View attachment 244654

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[Senton_Prime]

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Haa

 

[RCbuzz]

Oof this is exactly what happens to the old V1 smaller version of the X-maxx rear bearings... Come on Arrma, you can do it!

 

[Dan B.]

I think it's much more likely that an aftermarket manufacturer like RPM would do it than Arrma.

Vitavon. All the way. I often don’t recommend aluminum replacements for bashers, but the hubs often break while bashing and, as mentioned, the inner bearings suck. I’ve spun races in RPM hubs, which I would have never expected. (Even though I’ve historically gone on record to voice my disdain for their a-arms.) I think the Vitavon “redesigned“ 6s hubs with larger bearings are just the best mousetrap. As the hubs in my Arrma rigs eventually fail, they’re replaced with them.