Novatec Rear Hub Bearing Replacement?

arlowood

Have been experiencing a grinding/rumbling noise from the drivetrain over the past couple of weeks. Only seems to manifest itself when applying extra pressure to the pedals (eg when out of the saddle on climbs)

Difficult to pinpoint the source of the noise so initially i thought it was the BB. New Ultegra BB fitted 2 weeks ago with no improvement. Fitted new pedals next - still no difference. Fitted replacement 105 crankset as I was suspicious of the 2nd hand one I had bought on the classifieds - still no change in the problem.

Fitted new chain - grinding still there. Waiting delivery of new cassette to see if that helps

However I am coming to the conclusion that the bearings on my Novatec F482SB rear hub may be shot

Anyone out there have any experience of sourcing repalcement bearings for the hub. Also any advice on how to approach the replacement of the old bearings if they are shot as I suspect

Monty Dog

http://www.youtube.com/watch?v=NNUpXfwjaWI

Shows you how to remove freewheel - to remove bearings, use a soft-faced mallet to tap the end of the spindle and drift the bearings out.

Bearings I think are RS6902 - 15mm ID x28mm OD x7mm width (worth checking)

arlowood

Hi Monty

Many thanks for the video link - much appreciated

My fears were confirmed today I believe. New cassette arrived and when I had removed the old one i took the opportunity to strip the hub based on the video instructions. After removing the freehub body I checked for play in the spindle - nothing to speak of. However when the spindle was rotated using my fingers I could feel a roughness - almost as if I was turning a fine ratchet.

Suggests to me that the bearings, if not completely shot are certainly on their way out.

Re-assembled and fitted the new cassette and went for a test run. The grinding/rumbling is still there.

Will order some new bearings PDQ but will try to double check your recollection of the correct size.

The BDOP website (Novatec Hub supplier) indicates two part numbers for ceramic bearings for the F482SB hub (6802 and 6902) - not sure what the difference is. However for their S/S bearings they only ask you to input the hub model number. No indication of specific sizes anywhere though.

maringirl

Contact Alf Webb at the Bike Inn/Webbline (webbline@btconnect.com) as he is now importing Novatec freehub bodies.

Velonutter

maringirl wrote:

Contact Alf Webb at the Bike Inn/Webbline (webbline@btconnect.com) as he is now importing Novatec freehub bodies.

Cheers for that info, have tried contacting Novatec and their site doesn't list any UK Disty.

I'll send Alfie an email as I need a new axle for my F582SB hub

arlowood

Just for info if anyone else finds themselves needing to replace the bearings on a Novatec F482SB hub.

Feedback from Ugo who built the wheels for me last year has confirmed that this hub requires 2 different sizes of bearing.

On the non-drive side the bearing size is 15 x 24 x 6 and this, in Ugo's experience, is usually the culprit when bearings fail. The drive side bearing is 15 x 28 x 7 - this tends to be much more durable in his experience.

Have now ordered the two sizes and hope to have a go at fitting them this weekend if they arrive in time.

Will update progress as and when.

cycleclinic

use ina bearings the ast longer. not all bearings are ceated equal. the main problem with this hub is the low quality nbk bearings, ther small size does not help either.

arlowood

arlowood wrote:

On the non-drive side the bearing size is 15 x 24 x 6 and this, in Ugo's experience, is usually the culprit when bearings fail.

Just realised my error in the above post. The non-drive side bearing is 15 x 25 x 5 not x6 as stated above. Apologies for the misinformation.

Have ordered SKF replacements from a supplier on Fleabay. Should be here by the weekend when I will attempt the switch.

ugo.santalucia

You need 2 x 5 mm Allen Key and 1 x 10 (I think it's 10, if not, then it's 8 mm Allen key). with the 2 x 5 mm allen keys you undo the cap, then remove the freehub. Now you can check if it is the bearings of the hub or those of the freehub (typically the outer). In the latter case, it might be worth getting a whole new freehub (novatel model B1), firstly because these don't last forever, secondly because bearings replacement in the freehub is less easy. If it is the hub bearings, then slot the 10 mm allen key inside the axle (there is a slot for that) and mallet it to knock off the bearing on the non drive side. This is normally the culprit. Remove the axle and check the other bearing (which is normally fine). Slot the axle back in, fit the new NDS bearing and press it in place (or gently mallet it in place using a washer or a socket to protect it... don't mallet it directly.
Clean and oil the freehub pawls and reassemble. Easy...

cycleclinic

however if you ut SKF or INA bearings in a the main body and replace the freehub you will have standard NBK in there. So it worth while seeking out a shop that can do it for you. It is not easy without the right tools but if you are like me and have the specialised bearing extractors needed for this job and a proper press with drifts it is easy.

Also the old bearings make a good drift for pressing the NDS bearing in over the axle other wise you need the wheels manufactiring over axle bearing press.

this all can be done at home really.

arlowood

Bearings arrived this am and I fitted them this afternoon. Just to finally confirm the sizes as I made a silly error (fat finger syndrome) when I listed them above.

Drive Side - 15 x 28 x 7
Non-drive side - 15 x 24 x 5

Brief description and observations on the replacement process for the benefit of any others who may wish to attempt this refurb.

1. Remove wheel, QR skewer and cassette

2. Insert 5mm allen into each end cap and undo. I found that the non-drive side end cap was first to slacken so this was removed.

3. Insert 10mm allen key into axle on non-drive side and undo the end cap on the drive side.

4. Slide off freehub body and remove rubber seal from hub shell and spacer sleeve from axle. NB The rubber seal is profiled so make sure you note its orientation as it must go back the right way.

5. Lay the wheel flat with the drive-side bearing uppermost. Make sure the hub flange on the non-drive side is suitably supported and there is enough clearance for the axle to drop through.

6. Insert the 10mm allen key into the axle on the drive side and strike the allen key firmly with a wooden (or resin) mallet. The non-drive side bearing should pop out quite easily. The axle is flanged at either end to provide a seating for the two bearings so this flange is a useful means of driving out the bearings.

7. Flip the wheel over and repeat the process to drive out the drive side bearing. This is a larger and thicker beast and did take quite a bit of persuasion to remove.

8 When I examined both old bearings it was the drive side that showed some roughness to the touch. The non-drive side still felt smooth.

9 I started with replacing the new the drive side bearing as I thought that would be the most difficult (Thicker and recessed into the ratchet housing for the freehub). It was difficult to know if the bearing was being offered up flush and true so I guessed as best I could and used suitably sized socket ring and the wooden mallet to tap it into the seating. Once it had gone so far I inserted the axle and I could see immediately that the bearing was at a slight angle.

I then slid the non-drive side bearing onto the axle and used that to correct the alignment of the drive side bearing by tapping it home. Being thinner and more accessible it was much easier to get it correctly aligned and seated.

10 With the axle now properly aligned I was able to drive the drive- side bearing home. Socket rings were no use because of the axle length so i ended up using and old spark plug spanner that was just the right diameter.

11. First attempt at reassembly failed as there was no axle thread protruding from the freehub body to allow the end cap to be fitted. Clearly the bearing had not been fully seated so it was back to more persuasion with the mallet.

12. Eventually after a bit more trial and error it all went back together again.

On refection i should have started by inserting the non-drive side bearing first. This would then have allowed me to use the axle to align the drive side bearing more accurately. But Hey - ho it's all grist to the mill.

ugo.santalucia

arlowood wrote:

Bearings arrived this am and I fitted them this afternoon. Just to finally confirm the sizes as I made a silly error (fat finger syndrome) when I listed them above.

Drive Side - 15 x 28 x 7
Non-drive side - 15 x 24 x 5

Brief description and observations on the replacement process for the benefit of any others who may wish to attempt this refurb.

1. Remove wheel, QR skewer and cassette

2. Insert 5mm allen into each end cap and undo. I found that the non-drive side end cap was first to slacken so this was removed.

3. Insert 10mm allen key into axle on non-drive side and undo the end cap on the drive side.

4. Slide off freehub body and remove rubber seal from hub shell and spacer sleeve from axle. NB The rubber seal is profiled so make sure you note its orientation as it must go back the right way.

5. Lay the wheel flat with the drive-side bearing uppermost. Make sure the hub flange on the non-drive side is suitably supported and there is enough clearance for the axle to drop through.

6. Insert the 10mm allen key into the axle on the drive side and strike the allen key firmly with a wooden (or resin) mallet. The non-drive side bearing should pop out quite easily. The axle is flanged at either end to provide a seating for the two bearings so this flange is a useful means of driving out the bearings.

7. Flip the wheel over and repeat the process to drive out the drive side bearing. This is a larger and thicker beast and did take quite a bit of persuasion to remove.

8 When I examined both old bearings it was the drive side that showed some roughness to the touch. The non-drive side still felt smooth.

9 I started with replacing the new the drive side bearing as I thought that would be the most difficult (Thicker and recessed into the ratchet housing for the freehub). It was difficult to know if the bearing was being offered up flush and true so I guessed as best I could and used suitably sized socket ring and the wooden mallet to tap it into the seating. Once it had gone so far I inserted the axle and I could see immediately that the bearing was at a slight angle.

I then slid the non-drive side bearing onto the axle and used that to correct the alignment of the drive side bearing by tapping it home. Being thinner and more accessible it was much easier to get it correctly aligned and seated.

10 With the axle now properly aligned I was able to drive the drive- side bearing home. Socket rings were no use because of the axle length so i ended up using and old spark plug spanner that was just the right diameter.

11. First attempt at reassembly failed as there was no axle thread protruding from the freehub body to allow the end cap to be fitted. Clearly the bearing had not been fully seated so it was back to more persuasion with the mallet.

12. Eventually after a bit more trial and error it all went back together again.

On refection i should have started by inserting the non-drive side bearing first. This would then have allowed me to use the axle to align the drive side bearing more accurately. But Hey - ho it's all grist to the mill.

That sounds like a walk in park compared to shortening a hard steel fork steerer with a crap saw!

munkster

Holy thread resurrection Batman! Just spotted that Novatec has recently posted this video of precisely how to replace the bearings in one of their rear hubs...

https://www.youtube.com/watch?v=kpjSclC0STQ

...hopefully I've not duplicated this elsewhere, thought it would be a good addition to the thread (speaking as someone who has currently got the same hub disassembled on the bench as I type!) ;-)

arlowood

Ta for that munkster. Should be a great help to others - although I can't see many rushing out to buy one of those fancy bearing press kits. Looks like it would cost more than a new hub + wheel build.

Fraid us mere mortals will still have to mackle together whatever we have available to insert the new bearings.

munkster

Yeah, it looks a tasty bit of kit that installation tool, nothing similar under £100 from what I've seen. Surely someone has cobbled something together like those dirt cheap "home made" headset presses you see on eBay which are basically a bit of thread, a big bolt and some washers??

I haven't even tried a "dry run" to see how they'll fit in yet, but expect it to be a distressing hour or so. Don't know if it was on this thread but someone suggested using the old bearings on top of the new ones to tap on with the rubber mallet, given the important surfaces should align?

rolf_f

munkster wrote:

Yeah, it looks a tasty bit of kit that installation tool, nothing similar under £100 from what I've seen. Surely someone has cobbled something together like those dirt cheap "home made" headset presses you see on eBay which are basically a bit of thread, a big bolt and some washers??

I haven't even tried a "dry run" to see how they'll fit in yet, but expect it to be a distressing hour or so. Don't know if it was on this thread but someone suggested using the old bearings on top of the new ones to tap on with the rubber mallet, given the important surfaces should align?

For Campag freehubs, I use one of the cheap home made headset presses along with the old bearing or an appropriately sized socket (for the inner). Not sure how that would translate to Novatechs though.