replacing bitex RAR9 freehub bearings

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alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Grease and seals, fill rate.

I see some people using the ceramicspeed grease to improve performance.

I read that some greases "liquify" with the temperature increase that comes from the bearings spinning. I don't know if that effect can be observed in cycling but sounds cool.

You don't want it to pour out of the bearing but you want it nice and thin.

Anyway, skf/ntn with low contact seals and replace the grease with a low fill rate of something good and you should be very competitive.

Remember that the seal is the only thing keeping those bearings alive, so use low contact rather than no contact. A bearing that loses it's friction advantage after 50km and spins twice as gritty after 200km is completely useless.

About the extraction i'd try applying some heat to the freehub body, and/or try to devise a press from a threaded rod to press the bearing put.

If you use the socket method I said you dont really need to fear the bearings coming out crooked as it's using two contact points. Apply some heat and you'll have both bearings out in under 20 seconds. No need to fiddle around with pullers.

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

by JoO

alcatraz wrote:
Sun Mar 10, 2019 3:04 pm
Grease and seals, fill rate.

I see some people using the ceramicspeed grease to improve performance.

I read that some greases "liquify" with the temperature increase that comes from the bearings spinning. I don't know if that effect can be observed in cycling but sounds cool.

You don't want it to pour out of the bearing but you want it nice and thin.

Anyway, skf/ntn with low contact seals and replace the grease with a low fill rate of something good and you should be very competitive.

Remember that the seal is the only thing keeping those bearings alive, so use low contact rather than no contact. A bearing that loses it's friction advantage after 50km and spins twice as gritty after 200km is completely useless.

About the extraction i'd try applying some heat to the freehub body, and/or try to devise a press from a threaded rod to press the bearing put.

If you use the socket method I said you dont really need to fear the bearings coming out crooked as it's using two contact points. Apply some heat and you'll have both bearings out in under 20 seconds. No need to fiddle around with pullers.
I received a dozen Enduro 6802 + 4 TPI 6802 when I bought the bitex hubs at a sale.
The TPI are a lot smoother than the Enduro's. Even when I took the seals of the Enduro's.
NSK VV are smoother than the TPi's.

I have bought ceramic speed general and TT grease.
I will replace the grease in an enduro bearing just to please my curiosity.

Right now I am running SKF bearings with trimmed seals (misordered with standard 2RS seals). Will see how log these last.

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

I had my phase with bearings and it ended with me rejecting ceramic (full/hybrid) and noname brands and brands with excess play.

I was lusting for enduro zero bearings but after playing around I noticed I really needed something solid and low play, high tolerance to get the chinese hub to perform adequately. I also have the dreaded 6802 :(.

It ended with me avoid touching the seals as it seems just looking at them they were losing precious mileage. Also after trying ntn/skf/nsk and noname hybrid noname full ceramic, nsk full ceramic that skf steel were the best for me.

They solved a play issue that I couldn't get rid of with the other brands. I also had to use retaining compound. The skf's have given me the mileage I couldn't get with non industrial bearings (possibly because I stopped lifting the seals to change the grease). But in any case they do offer the least amount of play which I needed because my hub doesn't have a preload mechanism.

I also suspect that the high tolerance no play approach helps to keep the lip of the seals in the right place that's how it relates to the bearing life being extended.

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

by JoO

alcatraz wrote:
Mon Mar 11, 2019 12:15 am
I had my phase with bearings and it ended with me rejecting ceramic (full/hybrid) and noname brands and brands with excess play.

I was lusting for enduro zero bearings but after playing around I noticed I really needed something solid and low play, high tolerance to get the chinese hub to perform adequately. I also have the dreaded 6802 :(.

It ended with me avoid touching the seals as it seems just looking at them they were losing precious mileage. Also after trying ntn/skf/nsk and noname hybrid noname full ceramic, nsk full ceramic that skf steel were the best for me.

They solved a play issue that I couldn't get rid of with the other brands. I also had to use retaining compound. The skf's have given me the mileage I couldn't get with non industrial bearings (possibly because I stopped lifting the seals to change the grease). But in any case they do offer the least amount of play which I needed because my hub doesn't have a preload mechanism.

I also suspect that the high tolerance no play approach helps to keep the lip of the seals in the right place that's how it relates to the bearing life being extended.
What type of seals do your SKF bearings have?
2RS have are full contact seals with a lot of drag
2RSL was hardly any better (in the hands)
2RZ I have been unable to find in the EU

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

2rs

Need it on a rear hub because those bearings take a lot of abuse. At least on my bike.

sfo423
Posts: 736
Joined: Fri Dec 22, 2006 6:12 pm
Location: San Francisco

by sfo423

A: speaking of Novatec, I have a F482 rear hub and one of the crush washer looking things on the free hub are chewed up and toasted. I was thinking it would probably be cheaper to replace the free hub vs buying parts and putting it together.

Are there other compatible free hubs? I see the new oem freehub is a 4 pawl vs the 3 I currently have.

Also, anyone in the US carry the free hubs?

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

I found pedal thread washers to be close to the diameter of (many but not all) axles, 15mm. It just needs a grinder spun around inside for a minute to be large enough to fit over the axle. They are available in 0.5 and 1mm thicknesses where I live.

sfo423
Posts: 736
Joined: Fri Dec 22, 2006 6:12 pm
Location: San Francisco

by sfo423

Thanks. I don't think these two rings/washers would be v=compatible. I can't even find an exploded diagram on the web to get a part # of what they are called. Looks like two wavy wire washers and possibly they go over a notched short spacer in the freehub body. Crap; I may not even need them to rebuild.

Here are the two washers and the notched spacer. I assume the two washers go in the two notches on the spacer?

alcatraz wrote:
Sun Mar 17, 2019 4:14 am
I found pedal thread washers to be close to the diameter of (many but not all) axles, 15mm. It just needs a grinder spun around inside for a minute to be large enough to fit over the axle. They are available in 0.5 and 1mm thicknesses where I live.
Attachments
IMG_1694.JPG

alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Those are some funky looking washers/springs. I wish I knew more about this system. Do they have something to do with the freehub/pawl/coast mechanism?

sfo423
Posts: 736
Joined: Fri Dec 22, 2006 6:12 pm
Location: San Francisco

by sfo423

I spoke to Novatec US today and he was a tad confused; likely a spacer (in the freehub closer to NDS).

The freehub is stamped "HHM-T03062300027-B2" and (Novatec US) part # is shsh-b2-10s-4p. They do not retail but their US partner (Bike Fetish) wants $80. Absurd.

You can find them online in the $40 neighborhood.


alcatraz wrote:
Mon Mar 18, 2019 12:26 pm
Those are some funky looking washers/springs. I wish I knew more about this system. Do they have something to do with the freehub/pawl/coast mechanism?

kafreeman
Posts: 170
Joined: Thu Jul 23, 2015 8:46 pm

by kafreeman

sfo423 wrote:A: speaking of Novatec, I have a F482 rear hub and one of the crush washer looking things on the free hub are chewed up and toasted. I was thinking it would probably be cheaper to replace the free hub vs buying parts and putting it together.

Are there other compatible free hubs? I see the new oem freehub is a 4 pawl vs the 3 I currently have.

Also, anyone in the US carry the free hubs?
BDop Cycling has freehubs.

http://bdopcycling.com/Wheel%20Parts-FR ... 011SPD.asp

Did those come from inside the free hub? Generally there is just a spacer tube in a free hub to keep the bearings located correctly.

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

by JoO

Bike24 ships to us i believe

Tenlegs
Posts: 289
Joined: Wed Jul 16, 2008 10:37 am

by Tenlegs

sfo423 wrote:
Sun Mar 17, 2019 4:17 pm
Thanks. I don't think these two rings/washers would be v=compatible. I can't even find an exploded diagram on the web to get a part # of what they are called. Looks like two wavy wire washers and possibly they go over a notched short spacer in the freehub body. Crap; I may not even need them to rebuild.

Here are the two washers and the notched spacer. I assume the two washers go in the two notches on the spacer?

alcatraz wrote:
Sun Mar 17, 2019 4:14 am
I found pedal thread washers to be close to the diameter of (many but not all) axles, 15mm. It just needs a grinder spun around inside for a minute to be large enough to fit over the axle. They are available in 0.5 and 1mm thicknesses where I live.
Your bearing has disintegrated, the wavy washers are the cages that hold the balls in place.
https://www.youtube.com/watch?v=qwmINJYTfzM

sfo423
Posts: 736
Joined: Fri Dec 22, 2006 6:12 pm
Location: San Francisco

by sfo423

Ahhh....

That makes sense (and why I could not find fourth bearing).
Tenlegs wrote:
Wed Mar 20, 2019 1:03 am
sfo423 wrote:
Sun Mar 17, 2019 4:17 pm
Thanks. I don't think these two rings/washers would be v=compatible. I can't even find an exploded diagram on the web to get a part # of what they are called. Looks like two wavy wire washers and possibly they go over a notched short spacer in the freehub body. Crap; I may not even need them to rebuild.

Here are the two washers and the notched spacer. I assume the two washers go in the two notches on the spacer?

alcatraz wrote:
Sun Mar 17, 2019 4:14 am
I found pedal thread washers to be close to the diameter of (many but not all) axles, 15mm. It just needs a grinder spun around inside for a minute to be large enough to fit over the axle. They are available in 0.5 and 1mm thicknesses where I live.
Your bearing has disintegrated, the wavy washers are the cages that hold the balls in place.
https://www.youtube.com/watch?v=qwmINJYTfzM

by Weenie


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alcatraz
Posts: 4064
Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

Oh my god. :lol: loooool

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