replacing bitex RAR9 freehub bearings

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JoO
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by JoO

I am a bearing/friction nerd and I would like to change out the bearings in my Bitex freehub for some super smooth 6802 NSK VV bearings.
What is the best way to remove these bearings (not the easiest or cheapest way). I don't mind buying a tool for the job.
Inside the freehub there is a sleeve sandwiched between the bearings. So bearing removal tools that hook behind the inner race are likely not going to work.
Are there any other options aside from pushing the sleeve to one site and using a punch and hammer and gently work your way round. I am afraid I will damage the freehub because the bearing will not come out straight.
My experiment with a novatec freehub was not very succesfull.

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alcatraz
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by alcatraz

That's what I did many times, push the sleeve around and gently punch. I use a socket from a socket wrench that just barely fits the hole. This way at least you spread out the load a bit with two contact points on the inner bearing race.

I don't have the same hub but it's got the same design it seems.

I'd take note of how tight the sleeve sits between the bearings. It will determine the preload of the bearings and what kind of play to aim for. When pressing in the bearings you don't necessarily want them all the way in, as it may preload the bearings too much and it won't spin freely.

It's easy to think that by swapping bearings the hub will spin forever but a rear hub is harder to get like that. I think because it's got more parts and more crucial tolerances that aren't perfect. If it isn't perfect, chances are it's not the bearings causing that small amount of friction. It's slight misalignments/flex/uneven preload.
Last edited by alcatraz on Fri Mar 08, 2019 1:16 am, edited 1 time in total.

bm0p700f
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by bm0p700f

Your a friction nerd well why buy a bitex RAR9,? you should buy a hub like royce and have there non contacing sealed bearings or maybe Shimano Dura Ace, Campagnolo Record with CULT bearings.... So many that are genuinely low friction with bearing made for the hub.

Your picking a hub with bearing seats of unknown tollerances and expect to shoe horn in any old bearing (NSK may be a top end of any old bearing) and hope that bearing seat ID and the bearing OD are a perfect match. They might be or they might not be.

Bearing friction has alot to do with bearing seat alignment and dare I say it the size of the bearing. Hubs with bigger bearings roll better in general so if you a friction nerd dont bother with the low cost light hub but all they are really good at is being low cost and light (there nothing wrong with that by the way they are low cost and light).

JoO
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by JoO

bm0p700f wrote:
Fri Mar 08, 2019 12:21 am
Your a friction nerd well why buy a bitex RAR9,? you should buy a hub like royce and have there non contacing sealed bearings or maybe Shimano Dura Ace, Campagnolo Record with CULT bearings.... So many that are genuinely low friction with bearing made for the hub.

Your picking a hub with bearing seats of unknown tollerances and expect to shoe horn in any old bearing (NSK may be a top end of any old bearing) and hope that bearing seat ID and the bearing OD are a perfect match. They might be or they might not be.

Bearing friction has alot to do with bearing seat alignment and dare I say it the size of the bearing. Hubs with bigger bearings roll better in general so if you a friction nerd dont bother with the low cost light hub but all they are really good at is being low cost and light (there nothing wrong with that by the way they are low cost and light).
I am afraid you are right. It is hard to balance lightweight/cost/quality.
My other wheels have miche primato hubs with SKF bearings and they spin forever. But those are heavy.

I guess I just want to get the best out of the bitex hubs. I got the hubs at a sale for a fraction of the normal cost so it is worth a shot trying the NSK bearings.

If only campagnolo would make 20/24 H record hubs I'd buy them in an instant.

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Miller
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Location: Reading, UK

by Miller

To get bearings out of a Novatec hub, which I suspect is very similar, I bought a Wheels Manufacturing 6002, 6802, and 6902 Sealed Bearing Extractor. It's easily available online for £15. It locks into the inner race of the bearing then you can knock the bearing+tool out.

Doesn't address replacing with a new bearing though.

JoO
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by JoO

Miller wrote:
Fri Mar 08, 2019 11:46 am
To get bearings out of a Novatec hub, which I suspect is very similar, I bought a Wheels Manufacturing 6002, 6802, and 6902 Sealed Bearing Extractor. It's easily available online for £15. It locks into the inner race of the bearing then you can knock the bearing+tool out.

Doesn't address replacing with a new bearing though.
I have a bearing press to press the bearings in.
I think the sleeve that is placed between the bearings will prevent the extractor tool to catch ‘behind’ the inner race of the bearing.

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Miller
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by Miller

No it won't. The extractor doesn't catch behind the bearing, it locks into the inner bearing race. It will work.

JoO
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by JoO

Great! I will try to find one in the EU.
Thanks for the tip!

alcatraz
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by alcatraz

You can also try an appropriately sized concrete anchor that you can find at your hardware store cheap. For 15mm id you can try a 14mm anchor.

You expand it inside the bearing and then punch it out together with the bearing.

Cost, 1usd?

JoO
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by JoO

alcatraz wrote:
Sun Mar 10, 2019 8:38 am
You can also try an appropriately sized concrete anchor that you can find at your hardware store cheap. For 15mm id you can try a 14mm anchor.

You expand it inside the bearing and then punch it out together with the bearing.

Cost, 1usd?
I tried that technique with my my miche primato hubs. Worked for 2 of the 4 bearings. I ended up using a cheap bearing tool from enduro
https://all4bikes.be/shop/nl/gereedscha ... 78704.html

That tool did not work very well.It slipped using u punch. I had to resort to using it in combination with the largest flat screwdriver i could stick into it.
It did remove te bearings but it was a bit of pain get the screwdriver out of the tool once the bearing was knocked out.

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

JoO wrote:
Sun Mar 10, 2019 9:45 am
alcatraz wrote:
Sun Mar 10, 2019 8:38 am
You can also try an appropriately sized concrete anchor that you can find at your hardware store cheap. For 15mm id you can try a 14mm anchor.

You expand it inside the bearing and then punch it out together with the bearing.

Cost, 1usd?
I tried that technique with my my miche primato hubs. Worked for 2 of the 4 bearings. I ended up using a cheap bearing tool from enduro
https://all4bikes.be/shop/nl/gereedscha ... 78704.html

That tool did not work very well.It slipped using u punch. I had to resort to using it in combination with the largest flat screwdriver i could stick into it.
It did remove te bearings but it was a bit of pain get the screwdriver out of the tool once the bearing was knocked out.
Cool. I haven't seen those before.

Can it grab the freehub bearing with the sleeve still inbetween? Seems like you need to get the bearings started moving first to get this puller to grab the bearing.

bm0p700f
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by bm0p700f

The wheels manufacturing extractors are good. I use them in the shop.

bm0p700f
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by bm0p700f

My experience of high end bearings is they don't roll better than cheaper bearings in hubs like novatec of bitex. Bearing life is not changed much by the higher quality bearing either. Personally I would just stick a cheaper bearing with non contacting seals in there, (enduro or tpi like what bitex spec) and accept the hub for what it is.

Initially a cheap bearing and an expensive one roll well the differences start to show themselves with use.

JoO
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by JoO

alcatraz wrote:
Sun Mar 10, 2019 12:11 pm
JoO wrote:
Sun Mar 10, 2019 9:45 am
alcatraz wrote:
Sun Mar 10, 2019 8:38 am
You can also try an appropriately sized concrete anchor that you can find at your hardware store cheap. For 15mm id you can try a 14mm anchor.

You expand it inside the bearing and then punch it out together with the bearing.

Cost, 1usd?
I tried that technique with my my miche primato hubs. Worked for 2 of the 4 bearings. I ended up using a cheap bearing tool from enduro
https://all4bikes.be/shop/nl/gereedscha ... 78704.html

That tool did not work very well.It slipped using u punch. I had to resort to using it in combination with the largest flat screwdriver i could stick into it.
It did remove te bearings but it was a bit of pain get the screwdriver out of the tool once the bearing was knocked out.
Cool. I haven't seen those before.

Can it grab the freehub bearing with the sleeve still inbetween? Seems like you need to get the bearings started moving first to get this puller to grab the bearing.
No, the tool has a 'lip' that needs to catch behind the inner race of the bearing. The sleeve would prevent that - hence my question.

JoO
Posts: 439
Joined: Thu May 04, 2017 7:30 am

by JoO

bm0p700f wrote:
Sun Mar 10, 2019 1:19 pm
My experience of high end bearings is they don't roll better than cheaper bearings in hubs like novatec of bitex. Bearing life is not changed much by the higher quality bearing either. Personally I would just stick a cheaper bearing with non contacting seals in there, (enduro or tpi like what bitex spec) and accept the hub for what it is.

Initially a cheap bearing and an expensive one roll well the differences start to show themselves with use.
I have already bought the NSK bearings. These spin a lot smoother in the hands than the enduro bearing I have. I know that this has little value because they is no pressure applied (from hub and rider weight).

According to the friction facts report is the grease in the bearing is accountable for a large percentage of the friction. Buying cheaper bearings and changing the grease might be the smartest thing to do.

by Weenie


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