DT Swiss Hub service

[yeboabe]

Hi, anybody got any details on servicing of a DT Swiss hub, feels like the freebody slips every now and then it needs to engage!?!?

[Johan Bornman]

It is not difficult to do. Remove the discs and cassette. Remove the axle over a container with the freehub body facing upwards.

You'll notice a bunch of rust and dust. In between you'll find some stupid little roller bearings that will be all rusted and pitted. Clean and polish them, replace in retainer, grease and reassemble.

Dont bother looking for the seal. Whether it is there or not doesn't matter, since it doesn't work.

 

[Weight Weenie]

And one would think the Swiss would do a better job, but it's probly made in china anyway ?

[techguy]

There is nothing wrong with  the hub's design if you service it at regular intervals, same as any other component...the problem is most people/shops see it as a "sealed bearing" hub and therefore needs no servicing until its too late as in this case...

[The expat cyclist]

I just had my DT Swiss bearings replaced with "another kind" which spins more freely.

Of dit die gemors gaan uit hou? Wel ons sal maar moet wag en sien.

[Plentipotential]

Hi' date=' anybody got any details on servicing of a DT Swiss hub, feels like the freebody slips every now and then it needs to engage!?!?[/quote']

 

Best someone helps you out with some proper advice.

 

1. Remove cassette

2. remove nut on drive side

3. remove disc

4. remove freehub

5. where the freehub locates is a plastic cage with 12 rollers, remove cage and rollers and clean in solvent

6. check the teeth inside the freehub body, they might be worn which is causing the pawls to slip. If badly damaged you will need to replace

7. clean the parts and the pawls on the axel do not dislodge the retaining springs

8. spray some q20 on the pawls

9. make a mix of grease (motorex) and motor oil and smear inside the freebody

10. use same mix and replace the cage and rollers and then the freebody

11. replace the disc and nut

 

You may need new bearings, get some from the bearing guys much cheaper than the bike shop and make sure to get the 2RS (rubber seals)

 

If you use grease only the pawls will stick to the axel and leave you in neutral or worse they will partly engage and wear the teeth off the freebody. Make sure that the seal inside the freebody is not twisted otherwise it will not fit right up against the freehub/cageandrollers.

 

Not a great explanation I know but thats what kept my freehub going a lot longer than it would have lasted if I had left it alone. Eventually you will get shot of that piece of sh*te and get something that keeps water and sand out.

Plentipotential2010-05-19 03:14:23

[Headshot]

Sure, its a good design if you ride in clean conditions and/or have the time to spend servicing hubs. It could howver be a far better design if it was sealed properly like a Shimano XT and others which require far less maintenance and work just as well in other respects.

[Johan Bornman]

Lots of misunderstanding here and elsewhere on The Hub (and indeed the entire industry) about "sealed bearings".

 

Most people confuse the term for cartridge bearings. A cartridge bearing can be sealed or not sealed. A journal bearing can be sealed or not sealed. A cup-and-cone bearing can be sealed or not sealed. Ideally we want a seal on our wheel bearings and most bikes owned by people on this forum have seals on their wheel bearings.

 

DT Swiss uses sealed cartridge bearings as does Mavic, Novatech, Joytech, Token, Hope and a million others.

 

However, having a sealed cartridge bearing in there by itself is a very poor design. A single seal cannot separate two liquids - grease and water in our case. A bearing therefore has to be protected by two seals with a neutral zone in between.

 

Most wheel designers get this wrong and rely on the cartridge bearing's seal. This is stupidly optimistic, as we see in the short lifespan of these bearings.

 

If a DT Swiss wheel's bearings were replaced by another kind, as mentioned above, it simply means that someone popped out the one cartridge bearing and put another one in. If that seal is still the only protection against water, it is also doomed. Only by fitting another seal away from the bearing can water intrusion be limited.

 

Shimano, Campag, Chris King and a select few others know this. The rest have selling points such as pretty colours and light weight.

 

Unfortunately people ask how much the hubs weigh, instead of asking about the double seal.

 

The DT Swiss seal that is supposed to protect the roller bearings in the freehub body are poorly designed and of the single type only. They are not even good at keeping dust out, which indicates that gaps develop in use.

 

And yes, it has a "sealed bearing" on the outboard side as well.

 

Here's a photo of a sealed and unsealed cartridge bearing.  The seal is not adequate protection against water and requires another layer of protection by way of a labyrinth seal.

 

 

Here's a tiny picture of a labyrinth seal. it is the double U-shaped bit on the top left corner of the picture. It is from the Sheldon Brown website, go read up about it there.

 

 

 

 

 

 

Johan Bornman2010-05-19 05:21:53

[yeboabe]

Wow, thanks been lots of info and i shall try the service tonight.

 

 

 

Thanks

[Wyatt Earp]

A 240 s hub does not have the cage with the rollers.

[yeboabe]

Had a look last night there are no nuts on the drive side to remove, do you need a special tool or am i missing something..!?!?

[Johan Bornman]

That's why I was circumspect in my somewhat facetious reply. I can't remember how it opens. However, a rule of thumb with rear hubs is to always start on the left (as they say around here, non-drive) side. That is because most cone spanner flats on the cones are hidden inside the hub on the right hand side and it is impossible to open from there unless you do something drastic.

 

Some hubs require two 5mm allen  keys each side of the axle. Others use cone spanners - a 14 and say 17mm to undo two locknuts. Mavics use spit and pull methods....it all depends.

 

DT Swiss has good manuals online. Find your model and get the PDF.

 

No special tool is neccessary for that operation. It's all standard stuff.

 

[Goodbadugly]

The 240s free hub can be removed without tools. Pull hard (really hard if it has never been opened) on the cassette. Wiggle it from side to side.

What might also help if you have removed the cassette, is to insert the tip of a SMALL flat screwdriver between the free hub and body. Carefully work your way around (wedging it off) without denting the aluminum. Clean it and reassemble it. I use oil (not grease) on the working parts. It should not rust, as it is made of stainless steel and aluminum. 

[jugheaddave]

I service my 370's once a month, all ways wet and dirty inside!!!

[yeboabe]

Thanks for all the info.

 

 

 

I started the process but when there was no bolts and the DT Swiss manual was not 100% clear, i took it to Anton B at Summit cycles and he did a good job thanks.

 

 

 

It seems you need a specific tool for one section inside the hub, the rest basically pulls apart and all the bearings are sealed - they needed to be replaced and there was some sticky thick grease on the spawls.