Sticky Novatec 712 freehub

mrb123

I have some handbuilt wheels on my winter bike which are built on Novatec 711/712 disc hubs.

After a long winter of use I believe the freehub could do with a service as it doesn't seem to be operating as it should. If I try to turn the pedals backwards after the bike has been stood for a while, the freehub sticks and doesn't allow the cassette to turn and the chain to run freely. Also if I get the back wheel spinning and release the pedals, the cranks continue to turn a bit.

I'm a bit of a dope when it comes to maintenance but would like to have a crack at sorting this myself rather than taking the wheel in to a shop. Would anyone be kind enough to let me know the steps I need to follow to carry out a service of the freehub?

I've had a look on YouTube - there is a GCN video showing a Mavic freehub service but I'm not sure if the procedure is the same for the Novatec.

Thanks in advance for any advice.

rozzer32

https://www.youtube.com/watch?v=5CSDz5hitbs

Shows bearing replacement for the 772 hub which is the update to the 712 hub. The principal should still be the same though. Take the free hub off and give it a good clean and re-grease.

cycleclinic

If the bearing are worn (take the freehub off by undoing the end caps with 2 5mm allen keys) then replace the freehub they are cheap. To check the freehub bearing put you finger inside the bearing and rotate if it is smooth then all is well any roughness bin it.

With the freehub off turn the axle by hand anything less than smooth take a rubber mallet to the DS end of the axle and whack it and knock the axle out. The NDS bearing will come with it. Knock the DS bearing out. Press a new 6902 DS bearing in and put the axle back from the NDS. No press the new NDS bearing in over the axle. The old bearing can make a decent drift but it is easy to get that stuck so a drift slightly smaller is better. I use a proper over axle bearing press kit but the cost for the home mechanic is prohibitive.

If there is nothing wrong then leave it alone. I have the same hubs I have ridden then in all the shitty weather over winter and I do not intend to service them until bearings are rough. The first mistake people make is service things that dont need and then create a problem by messing up.

mrb123

rozzer32 wrote:

https://www.youtube.com/watch?v=5CSDz5hitbs

Shows bearing replacement for the 772 hub which is the update to the 712 hub. The principal should still be the same though. Take the free hub off and give it a good clean and re-grease.

Thanks for the link Rozzer.

The comments for that video seem to suggest the video for the F482SB-SL hub may be a closer match for the 712.

mrb123

thecycleclinic wrote:

If the bearing are worn (take the freehub off by undoing the end caps with 2 5mm allen keys) then replace the freehub they are cheap. To check the freehub bearing put you finger inside the bearing and rotate if it is smooth then all is well any roughness bin it.

With the freehub off turn the axle by hand anything less than smooth take a rubber mallet to the DS end of the axle and whack it and knock the axle out. The NDS bearing will come with it. Knock the DS bearing out. Press a new 6902 DS bearing in and put the axle back from the NDS. No press the new NDS bearing in over the axle. The old bearing can make a decent drift but it is easy to get that stuck so a drift slightly smaller is better. I use a proper over axle bearing press kit but the cost for the home mechanic is prohibitive.

If there is nothing wrong then leave it alone. I have the same hubs I have ridden then in all the sh!tty weather over winter and I do not intend to service them until bearings are rough. The first mistake people make is service things that dont need and then create a problem by messing up.

Thanks for that Malcolm.

The wheels are actually a set that you built for me last year.

They've only done about 1000 miles so far so hopefully the freehub and bearings don't need replacing yet, although admittedly they have all been winter miles.

I'll have a go at taking the freehub off and give it a clean and check the bearings as you suggest.

veronese68

I did mine last winter, just had to take the freehub off and regrease it then all was well with the world. I'll have to try to save Malcolm's little guide somewhere for when I need it.

arlowood

Just to give you the opportunity to cover all the bases in terms of hub construction/design. Here is my post (about 2/3rds down the page) on how I replaced the bearings on my 482SB hub a couple of years back.

viewtopic.php?f=40004&t=12933141&p=18457044&hilit=Novatec#p18457044

You will note also that there is a link to a Novatec video on replacing the 482SB hub bearings

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

Once the axle is removed you can easily slide the freehub body off and check the feel of the bearings. As Malcolm suggests above it's probably more faff than it's worth to try to remove and replace the freehub bearings - best to just buy a new freehub. However the hub shell bearings are pretty straightforward if you decide to tackle that.

arthur_scrimshaw

rozzer32 wrote:

https://www.youtube.com/watch?v=5CSDz5hitbs

Shows bearing replacement for the 772 hub which is the update to the 712 hub. The principal should still be the same though. Take the free hub off and give it a good clean and re-grease.

I've got a 772 rear hub and I've watched that video a few times. That guy doing the work is hopeless!

mrb123

Thanks everyone. All extremely helpful as always.

A couple of questions if anyone can assist...

1) Can I get the freehub off with two 5mm allen keys or will I also need a 10mm one (as I'll have to buy one of those)

2) Is normal bike grease ok for the freehub or do I need to buy something else?

cycleclinic

I forgot about the 10 mm allen key you will need that to get the NDS end cap off.

cycleclinic

I forgot about the 10 mm allen key you will need that to get the NDS end cap off. Only do that if bearings fell rought though with the freehub off.

mrb123

Ok, thanks Malcolm.

Anyone able to answer my question number 2 above?

ugo.santalucia

MrB123 wrote:

Ok, thanks Malcolm.

Anyone able to answer my question number 2 above?

Yes, fine

mrb123

ugo.santalucia wrote:

MrB123 wrote:

Ok, thanks Malcolm.

Anyone able to answer my question number 2 above?

Yes, fine

Molte grazie.

mrb123

I had a go at removing the freehub yesterday but didn't manage to get it off. Can anyone kindly suggest where I might be going wrong. Excuse my uselessness!

I did the following:
1. removed skewer from wheel
2. Removed the cassette
3. Used two 5mm Allen keys on either side to remove the drive side end cap
4. Used a 10mm and a 5mm Allen key on either side to remove the non drive side end cap.

That was as far as I got. The freehub would not slide off the axle and I couldn't work out what else I could do to get it off.

The Novatec YouTube video seems to show a couple of parts which come off the non drive side of the axle after the end cap is removed when he shakes the hub but nothing else would come off from mine.
https://m.youtube.com/watch?v=kpjSclC0STQ

Thanks in advance.

ugo.santalucia

You probably have a rusty freehub bearing which is seized on the axle. Pull harder or tap the axle on the DS... although this will dislodge the bearing on the NDS in that model