DT Swiss freehub fix (success story!)

Fatal Swan

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I spent quite a while researching this fix so I thought I'd do a comprehensive write-up on this up in case it helps anyone else in future...

Apparently quite a common issue (judging by other bike forums) with DT Swiss rear hubs that use the 'star ratchet' freehub (like the 240, 240s, 350) is that they appear to be working just fine until you install them on the bike - when you tighten the rear skewer up the freehub locks in place and just turns with the wheel, i.e. not like a freehub at all. There are a few possible causes cited, including the hub bearings not being seated quite correctly, even though everything appears to be done right.

I have a DT Swiss 240 rear hub (branded as a Roval) on a lovely sub-1400g 26" wheelset that's been in the garage unused for a while, but when I came to use it I found it had this issue. It's surely too good to bin (straight, superlight, smooth bearings), but also not really worth enough nowadays to justify spend a lot on getting repaired - I don't have the DT Swiss workshop tool needed to access the bearings and hub I'm rubbish at doing this sort of thing myself.

I read on one forum a report that someone had had success by adding a washer to the axle assembly, so after I'd checked for any obvious problems, removed and reassembled the freehub assembly a few times with no joy, I pursued it as a last resort. Finding the right size washer isn't easy since there are no dimensions for what's required, so a bit of trial and error followed. I measured the axle as 15mm, and so a washer would need to be M15, but also it would also need to be very small in diameter, something like 18mm. A search for this by size online and browsing a hardware store didn't bring up anything that slim, but I did come across this "Sealey Sump Plug Washer M15 set VS15SPW" online, on the basis that they were M15 and just by the look of them they seemed thinner than anything else I'd found:

vs15spw_dfc0379571_wzl6wv8kkfdhw7qy.png


On p7 of the DT swiss manual for this hub there's a picture of the assembly. The extra washer goes on one end of the "RW spacer" part 7:

attachment.php


And it worked 🥳 Even better, it's a completely tool-free fix and extremely cheap.

Many thanks to Sealey's sump plugs for using exactly the right size washer where no-one else seems to manufacture them 😃
 
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Is item 7 always the same length on these or is it different depending on the freehub fitted (ie Shimano/Campag/SRAM)?
 
I bought a reasonably posh DT swiss rear wheel (cheap) for my road bike recently, its got a 240 hub with dicut spokes. I haggled hard as I noticed it would lock up when the ends of the axle were pushed together. A strip and inspection revealed a clean lubed freehub but I thought the tolerances between the two springs and ratchet washers and axle was poor. If the springs aren't sat perfectly square then the tighter coil end of the spring can wedge in the gap between the ratchet and axle. No components show any wear. Careful reassembly and it's good to go but it's a fine line between free movement and seizure. I can only recommend rebuilding the freehub with the wheel mounted horizontally and I did manually resize the springs diameter to prevent jamming. Both springs measured the same inner and outer diameters, both ratchet rings showed no wear on the inner and outer diameters. It sounds like a swarm of angry wasps when you stop pedalling but I was surprised how such a simple set up was so poorly executed on probably a £1000 wheel.
 
I've got exactly the same problem on a DT Big Ride rear hub. It is new and I had it built up recently and have only just tried it in the bike.
Yep, locks up as soon as the axle is tightened......

I have another Big Ride rear hub that came on a second hand bike: this works fine.I

Sealy here I come.....
 
I've got exactly the same problem on a DT Big Ride rear hub. It is new and I had it built up recently and have only just tried it in the bike.
Yep, locks up as soon as the axle is tightened......

I have another Big Ride rear hub that came on a second hand bike: this works fine.I

Sealy here I come.....
I could lock my freehub while spinning the wheel in my hands just by pushing the ends of the axle together. If all the bearings are sat where they should be I'd look closely at the springs, at least the thing just pulls apart with no tools.
 
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