Bering installation on DT 240 Rear Hub – does not spin under load

Good evening, I’m in the process of servicing DT 240 rear hub – bearings had to be replaced. I’ve got them out, put the new ones in. Tonight assembled the wheel together, everything looks good and spins nicely when in my hands. Got them into bike frame, pulled tight the quick release and the wheel does not really spin anymore. Well, it does, but stiffly – I can hear how it spins and it does not spin for long. Also the freehub does not rotate as well. As soon as I release the quick release – no friction and wheel spins forever, even with freehub clicking.

Could it be due to the new bearings? I’ve got angular contact bearings (http://endurobearings.com/products/bearings/angular-contact/) – these are not symmetrical, but I’ve installed red seal out on both sides, as instructed.

Anything I should check?

I don’t know these hubs at all but it’s always a missing spacer from behind the freehub

http://ep1.pinkbike.org/p4pb10708885/p4pb10708885.jpg

Have you remembered to put no 36 back in

Yep, checked that – all the spacers are there. These hubs don’t really have a spacer as per usual spacer – spacer between hub internal bearing and the ratchet rings. And that is in place. For reference, schematics are here: https://www.dtswiss.com/Resources/Support/HUBS/DT-Swiss-Hubs-240s-Technical-Manual scroll to page 15, “240s 135mm Disc Brake”.

@nonk It is slightly different hub, but yes, that spacer number 36 is in place.

Oh hold on you’ve put angular contacts in there
That’s not going to work in that hub it’s just gonna load it up to tight
Yep you need radial bearings for that hub

Sounds like an assembly issue, there’s 3 things i can think of…

there’s a flat washer on the driveside, that goes on top of the bearing then the star ratchet thready thing gets threaded down on top. Is that present, and is the threaded doofer the right way up? (it has a recess on one side for the washer)

The other is the cylindrical spacer that goes over the axle, and sits inside the star ratchets; if that’s not present then when you tighten the axle it’ll squeeze the freehub onto the hub body.

And lastly, is the seal in the hub fully recessed?

TBH I wouldn’t put enduro bearings in anything I own, and those hubs are designed for standard radial bearings not for acb… but I don’t know if that’s the issue here.

@Northwind Flat washer over the bearing and and under the ratchet thready thing – it is present. Thready thingy would only go in one way, so could not get it in wrong way in. The cylindrical spacer is present. I did miss it the first time, but the freehub would not spin without it at all.

How would I check if the seal is recessed? it sits pretty deep and I could not push it anymore further.

I suspect it is the bearings indeed. @Nonk confirms the same issue.

I’ll put in old bearings into the hub tomorrow and assemble the same way – if it spins, then bearings at fault.

trailmax – Member

How would I check if the seal is recessed? it sits pretty deep and I could not push it anymore further.

It’s probably OK then. (It’s a bit late for this, but the freehub makes a perfect seal driver when it has no bearings in, or before you fit the axle)

I think the old bearings are the way to go then. I’ll be honest, I’d have assumed that the ac bearings would work OK since all the sideloading etc is managed by solid parts. But it’s got to be your #1 suspect. I can see them working in, say, a Crossmax hub with that weird adjustable sideload thing they do.

@Northwind see the seal photo http://imgur.com/a/MiY2C and full assembly http://imgur.com/a/6rZXN (both images are zoomable)

The seal is sticking out from the hub body for about 0.5mm, but the connection with the freehub is very good and feels right.

I’d want to take a look at one of mine to be 100% but I think the seal is standing a bit proud. But also, there shouldn’t normally be that much of a gap between seal and freehub. That could just be that the freehub’s not quite fully in place in the photo though so I don’t want to read too much into it.

That’s a good picture with details – thanks! And the freehub is as close to the hub body as it was possible. I’ll try whacking it in a bit further tomorrow.

Thinking about it a bit more – angular bearings suspect does make sense, but these should not block the freehub from moving when under load. And freehub barely moves when QR is locked. Thus suggesting it is not just bearings – something else is creating friction on freehub.

Looking on this image:

There should be almost no gap between freehub and hub body. I’ll do more whacking!

It’s the bearings ,the hub has to be able to adjust the load on the bearing and then be locked off to use angular contact bearings such as mavic , King etc

@nonk – when I had King hub, their bearings did not look like the bearings I got now – that’s what puzzles me.
I’ll put the old bearings in to double check before ordering new ones. I’m getting pretty good now with dismantling this hub now 🙂