Shimano WH-M775 wheel set servicing

jairaj

I need to replace the bearings in my hub I know they are bearing number 6804 and 6902 but these seem to come in a few different flavours with respect to material and sealing type and I'm not fully sure I understand all the options correctly.

Material question:
The bearings come in 3 popular materials, steel, chrome and stainless steel.

Is my assumption correct that stainless steel versions are the best as they will be less likely to corrode than an chrome bearing? Due to the chrome only being a thin plating surface.


Sealing question:
Again these come in 3 popular versions: non sealed, rubber seals, metal seals.

I know sealed bearings are better than non sealed but which seal do I go for metal or rubber? Any previous cartridge bearings I've bought in the past have come with rubber seals is this what I want or is metal better?

Many thanks, Jai

ps Here are links to the actual bearings I am looking at:

Steel sealed bearing:
http://www.ebay.co.uk/itm/1-X-6804-2RS-61804-2RS-SEALED-CYCLE-BEARING-20x32x7w-/251072349551?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item3a7514056f

Chrome with double metal shields:
http://www.ebay.co.uk/itm/1-X-6804-ZZ-61804-ZZ-20X32X7-CHROME-BEARING-/251055913015?pt=UK_Motorcycle_Parts&hash=item3a74193837

Stainless steel with rubber seals:
http://www.ebay.co.uk/itm/1-X-6804-2RS-61804-2RS-20x32x7w-STAINLESS-SEALED-BEARING-/261022980642?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item3cc62e9a22

nicklouse

2RS.
metal of choice steel can be harder than SS.

SS can still corrode. it depends on the grade.

chrome is it really chrome plated or.......

jairaj

so out of the links I gave above would you go for the first link? Steel with rubber seals?

mrmonkfinger

As above, 2RS on hub bearings, pick some made by a decent manufacturer if you can.

nicklouse

jairaj wrote:

so out of the links I gave above would you go for the first link? Steel with rubber seals?

i would not. I would go to my bearing person.

I wonder why there is 20p difference in the postage costs and is it per bearing or for a set or......

Sorry I hate Ebay.

jairaj

The prices on ebay were for 1 bearing only.

I don't have any bearing bearing shops nearby also tried some of the hardware and tool shops nearby but nobody seems to do bearings so online is the next best option.

I've had a look on simplybearings.co.uk (don't know if they are any better than the shops on ebay)

They have their quality budget versions made by KG International (don't know if they are any good?) for £6 each:
http://simplybearings.co.uk/shop/p170073/68042RS+Budget+Rubber+Sealed+Thin+Section+Deep+Groove+Ball+Bearing+20x32x7mm/product_info.html

And they have branded ones for £13 each
http://simplybearings.co.uk/shop/p1043/68042RSR+Rubber+Sealed+Deep+Groove+Ball+Bearing+20x32x7mm/product_info.html

Do these options look any better to you?

Neither gives any indication as to the grade of the bearings, I was hoping for the price difference the non branded ones from ebay would do. I thought this was going to be simple.

Darkstalker420

How about here mate (hate ebay also :roll: ):

http://www.cyclestore.co.uk/unbranded

Thanks.

jairaj

thanks for help guys. I decided to just play it safe and get the branded ones from simple bearings in the 2RS versions.
Hopefully these should be of good quality.

jairaj

Ahh more bearing related questions, might as well tag them along with this thread.

I was reading the Shimano tech docs and I have a couple of questions regarding servicing the hub bearings.

Looking at the manual for the rear wheel:
http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/WH/EV-WH-M775-R-2769B_v1_m56577569830728616.pdf

Can part 5 the Ball Retainer just be replaced with loose ball bearings of 3/16" in size? I can't find any shops with this part in stock at the moment but can find many shops with ball bearings.

The manual shows part 4 as loose ball bearings of 3/16" inch in size. The diagram states 13 pieces while the table at the bottom states 20 pieces. Any one know which one it is?

Not sure how many to order? Should I just take the worst case of 20 balls each side so 80 for the whole wheel set?

Thanks.

mister p

jairaj wrote:

I need to replace the bearings in my hub I know they are bearing number 6804 and 6902

Are you sure about those sizes? Where did you find the info?

nicklouse

what hub are the bearings for?

was not aware of shimano using any cartridge bearings.

mister p

jairaj wrote:

The manual shows part 4 as loose ball bearings of 3/16" inch in size. The diagram states 13 pieces while the table at the bottom states 20 pieces. Any one know which one it is?

You use 13 in the hub but they are supplied in a pack of 20. That is a generic pack of bearings rather than a specific pack of 13 for that wheel.

jairaj

Sorry I have confused people, I should have been more clearer. The cartridge bearing was for a different wheelset. I am servicing more than 1 wheel set. I thought I would add the Shimano wheel related questions to this thread rather than start a new thread.

You use 13 in the hub but they are supplied in a pack of 20. That is a generic pack of bearings rather than a specific pack of 13 for that wheel.

Cool thanks for that.

And for the caged bearings part 5 in the tech document, is that OK to be replaced by loose bearings? just fill up the cup and remove 1 bearing similar to what you do with headsets?