[Electric_City]

My freehub was shot on my 340 hub after running a 105 cassette on it for 2 seasons (the hub is a 150x12 from my '07 Sunday). The 6-7 individual cogs had dug into the body (aluminum) almost all the way through the skinny spline. I contacted DT and they sent a schematic with all the part numbers for my exact hub including the steel freehub.
I ordered the steel freehub and a replacement dust wiper. The wiper gets pressed into the hub shell between the fixed spine in the hub shell and the freehub body that slides on the axle. I put it on the correct way so the groove is facing out. I put the springs in correctly, the spacer is in, the ratchets went in and the freehub slides on like always. Perfect!
Until I put it in the frame. When I tighten the thru axle it pinches the freehub in to tight and the bike becomes a fixie.
I've had this hub apart the past 9 years and did nothing different except replace the freehub.
Side by side, the freehub are the same. I'm not finding any rub marks or points where there's friction. What am I missing?

 

[OBB]

In every instance of seeing this issue, the spacer, or lack thereof, was the culprit. The FH body is bottoming out on the hub as you tighten your rear axle. It's possible the new FH has a slightly different spec and requires a wider spacer.

**Just realized it's a star ratchet model. I've seen this before where the ratchet springs aren't seated correctly, or maybe you stretched them to get more a more positive engagement. The springs tend to sit funny when you do that.

 

[Sandwich]

Try shock oil?

 

[Flo33]

Try gear oil?

Ftfy.

 

[Sandwich]

In every instance of seeing this issue, the spacer, or lack thereof, was the culprit. The FH body is bottoming out on the hub as you tighten your rear axle. It's possible the new FH has a slightly different spec and requires a wider spacer.

**Just realized it's a star ratchet model. I've seen this before where the ratchet springs aren't seated correctly, or maybe you stretched them to get more a more positive engagement. The springs tend to sit funny when you do that.

i believe the 340 is a standard pawl engagement, while the 350 is the star rachet.

did you check if there's any spacer between the bearing and freehub? I feel there there should be something to separate the two in order to allow everything to spin.

 

[Electric_City]

The 340 is the star ratchet. The bearings are original and being 9 years old, I'm impressed they're still spinning smoothly.

The bearings are in place.

The spline part that threads in is still in place.

The dust cover was replaced this time (second one I replaced).

The spacer over the axle is still there.

The spring goes into the FH and the hub body, fat side in, leaving the small side to push on the ratchets.

The ratchets go on the axle.

The FH slides on and the dust cap is last.

 

[FlipSide]

There is no 340 hub. There is the 240 and the 350.

Is it possible the 240 and 350 use different freehubs and you are not using the right one?

 

[Sandwich]

http://www.cheapbikeparts360.com/products/dt-swiss-340-is-disc-hubs/

they are real, and he's right (as he should be) that they are star ratchet.

I thought that the 340 was basically the 350 with pawls, but that's now the spline 1900 hubs. I could have sworn there was a pawl system 300 hub though.

 

[OBB]

Given the new parts are the seal and the FH body, then these are the likely culprits. Install without the seal to see if it's the problem. If your hub is still a fixie without the seal, then the FH is the problem. Something is up with the bearing bore depth on the FH where the inside bearing is not contacting the spacer over the axle, therefore bottoming out on the springs and pawls first.

 

[jstuhlman]

 

[FlipSide]

http://www.cheapbikeparts360.com/products/dt-swiss-340-is-disc-hubs/

they are real, and he's right (as he should be) that they are star ratchet.

I thought that the 340 was basically the 350 with pawls, but that's now the spline 1900 hubs. I could have sworn there was a pawl system 300 hub though.

Wow! I stand corrected then! Thanks! I never heard about those 340.

I thought there we only the 180, 240, 350 and 540...and ~10 years ago there was also a 440 (I had a set) and 15-20 years ago there was the Hügi or something like that.

 

[StiHacka]

Moar shimz.

 

[Sandwich]

Hurr sure it's the dt 370 I was thinking of.

There is an exploded diagram of the 340 available on the day Swiss website. I'm on mobile or I'd link it, but a quick search should help.

 

[Electric_City]

340

New vs Old

 

[Electric_City]

Spacers and springs

You can kinda see where I took a yellow paint marker around the FH and put it on the axle and spun it. It looks like it's rubbing the middle ring of the FH where it sits in the groove of the seal. I'll have to see if I can seat that better somehow...

 

[BihariG]

My freehub was shot on my 340 hub after running a 105 cassette on it for 2 seasons (the hub is a 150x12 from my '07 Sunday). The 6-7 individual cogs had dug into the body (aluminum) almost all the way through the skinny spline. I contacted DT and they sent a schematic with all the part numbers for my exact hub including the steel freehub.
I ordered the steel freehub and a replacement dust wiper. The wiper gets pressed into the hub shell between the fixed spine in the hub shell and the freehub body that slides on the axle. I put it on the correct way so the groove is facing out. I put the springs in correctly, the spacer is in, the ratchets went in and the freehub slides on like always. Perfect!
Until I put it in the frame. When I tighten the thru axle it pinches the freehub in to tight and the bike becomes a fixie.
I've had this hub apart the past 9 years and did nothing different except replace the freehub.
Side by side, the freehub are the same. I'm not finding any rub marks or points where there's friction. What am I missing?

My freehub was shot on my 340 hub after running a 105 cassette on it for 2 seasons (the hub is a 150x12 from my '07 Sunday). The 6-7 individual cogs had dug into the body (aluminum) almost all the way through the skinny spline. I contacted DT and they sent a schematic with all the part numbers for my exact hub including the steel freehub.
I ordered the steel freehub and a replacement dust wiper. The wiper gets pressed into the hub shell between the fixed spine in the hub shell and the freehub body that slides on the axle. I put it on the correct way so the groove is facing out. I put the springs in correctly, the spacer is in, the ratchets went in and the freehub slides on like always. Perfect!
Until I put it in the frame. When I tighten the thru axle it pinches the freehub in to tight and the bike becomes a fixie.
I've had this hub apart the past 9 years and did nothing different except replace the freehub.
Side by side, the freehub are the same. I'm not finding any rub marks or points where there's friction. What am I missing?

Hello! i had a similar problem with my DT Hügi hub until one mechanic found out that the spring did not coiled enough to fit exactly to iťs pit. Nuances are matter!