JamesInSJ

I have Shimano DA 9000 wheels on my road bike, and after 2 years of use, ~6000 miles, I decided to clean out the bearings and rebuild. The front came together with no problems. The rear on the other hand... I'm experiencing chain suck when I freewheel, most frequently when I need to make small 1/8 rotation backpedal movements which we do regularly while riding.

• I first rebuilt it using my tub of Lucas Xtra Heavy Duty Grease (thick green stuff) which is great for many spots on bikes where grease is appropriate. I did not replace the bearings...everything looked very good, no signs of pitting or wear, etc. Upon rebuild, I tightened it up just to the point of no apparently movement in the hub when pushing on the sides of the wheel. Wheel rotation was about normal, but freewheel rotation was slow and immediately caused chain suck to the point that it couldn't be ridden.
• I loosened it up to the point where there was just a small amount of play in the hub...not sure how to measure it, but it's there. It's more than I think is right, but I don't recall exactly what it was before it and don't have someone else with DA9000 hubs to check with as a reference. I still get chain suck when riding on the large front gear. In the small front gear...most of the time no chain suck. This is still not acceptable to me.
• I cleaned everything out again, and ordered some Phil Wood grease as people seem to swear by it. Not sure it's much thinner than the Lucas grease I use, but why not. Same problem...to make the wheel usable, I have to loosen it up enough that there is some play.
• I also tried loosening up to the point that I could freewheel without any chain suck at all. There was definitely too much play in the hub for my comfort.

Other things... I replaced my chain. I checked the derailleur guide sprockets...spin freely. Derailleur isn't bent. Cassette and front rings are all good. This did NOT happen before I rebuilt the hub, with the old chain, so everything points to the hub just not freewheeling as easy as it should after the rebuild, but don't know of a fix besides loosening it up more than I think is correct.

Anybody out there who has rebuilt DA or Ultegra hubs experienced this? Comment on how much play is okay? I could probably get a video of the play I have now...but it would be hard to see though you can definitely hear it click back and forth when I push on the wheel from side to side.

Thanks!

blamester

wschruba

Page 11 of this PDF covers the exploded view/vital information for that hub. There isn't much you can do to mess up the reinstallation of the parts. Unfortunately, it sounds like the freehub itself needs some lubricant or work. If you take it down as far as the EV notes (the freehub is held on with a, I believe, 12mm hex, normal RH threading) you can then drop some light oil/mineral spirits into the gap to help flush any contaminants out. When it's running clear, relubricate with some 20wt oil, or so.

BarryVee

JamesInSJ

Thanks for the PDF explosion and references about light oil. I'll try to drip a little into the freewheel and see if that loosens it up. If not, might need to flush it as suggested and go from there.

trailangel

Light oil/mineral spirits... not the same as mineral oil

davidad

https://si.shimano.com/pdfs/dm/DM-HB0003-05-ENG.pdf

woodcraft

New chain/used cassette can result in chainsuck.

JamesInSJ

Used chain (nearing end of life) and used cassette had zero chain suck before I rebuilt the bearings. New chain actually reduced the chain suck, and the cassette doesn't show any wear that would indicate it's nearing end of life (about 6k miles...should be good for about 10k). I can loosen up the bearings enough to eliminate chain suck, but that creates too much play, so it just seems that the freehub isn't spinning as freely as it should.

Tri-Flow arrives in a few days and I'll try getting that into the freehub to see if that loosens things up.

blamester

woodcraft

Chain suck is the chain failing to disengage from the chainring. I don't follow how the new chain reduced the problem to less than the zero that it was before.

If you greased the freehub when it should have light oil, that could be corrected. Some freehubs have a washer inside that is easily misplaced, & the freehub binds if it's not there.

masi61

JamesInSJ

Thanks for all the input. I'll update the thread when I have a chance in the next few days to pull it all apart and re-do it again, and a little tri-flow dripped down into the hub.

Chain suck...follow the order: 1) used chain/cassette, no suck. 2) rebuilt axle bearings, got lots of chain suck. 3) put new chain on, less chain suck, but still there.

If I loosen the axle bearings enough, I can eliminate chain suck. Anybody know if the Shimano DA grease is significantly lighter than Phil Wood? Perhaps it's really that simple that Shimano uses a thinner grease?

fietsbob

Freehub driver (solvent) flushed of grease and re lubed with 90wt gear oil? cold grease can do it..

reverse it in warmer weather, maybe pick up a spare driver.. ?

JamesInSJ

Grease on the axle bearings, and tightness of that settings, changes how easily the freehub spins. So 2 things changed: my grease (using Phil Wood), and the tightness (I think it's actually lighter now, with more play, than it was before). I'm not comfortable running the axle any looser than it is right now, but I can loosen it up a little more and eliminate the chain suck. I worry that it's way too loose given the amount of axle play, so I'm currently at what I consider an acceptable balance of chain suck and axle play until I get this sorted it.

Trakhak

What several posters have attempted to explain (see, e.g., post #14 ) is that, whereas hub bearings should be lubricated with grease, freehubs are designed to be lubricated with oil. The grease that you used is likely causing the freehub to rotate with the hub, resulting in what you're describing as "chain suck." (That term is usually reserved for chains hanging up on chainwheel teeth.)

So, as suggested, replace the grease in the freehub with medium-weight oil.

blamester

JamesInSJ

Okay, using the picture from the Shimano doc, I put grease on the cups/cones and balls only of the axle bearings. Those are A, B, C and D in red here, plus the cups of the hub itself (a little bit of grease at F in the axle bearing cup, and the other side near A).

I did not touch the internal workings of the freehub, no cleaner/solvent, and didn't touch the locking bolt.

CliffordK

The term "Chain Suck" normally isn't applied to the rear cassette.

There are two different issues:

1) Coasting chain slack. This would be a friction issue with the freewheel or freehub.

2) Backpedaling slack. I find this is generally due to either cross-chaining, or a derailleur that is poorly adjusted. Anyway, make sure you aren't cross-chained, and if you feel the slack, then check your gears.

Kimmo 

Sure is a weird one.

My only thought is that maybe one of the seals in the DS cone is slightly out of place, or perhaps the dustcap in the freehub body has shifted, causing excess friction between the two. Did you remove the dustcap when you lubed the cup? If it's a similar design to earlier ones, it's easy to deform.

JamesInSJ

Thanks for helping with terminology. I would say main issue is #1 , because short backpedal movements that are fairly common in regular riding immediately cause chain slack (and slap against the chainstay). While backpedaling, it typically isn't any worse, though there is enough friction to still cause varying amounts of slack.

The other comment about a deformed seal is interesting...gives me one more thing to look at while I'm rebuilding again.

fietsbob

Then part # F may be where the excess drag is ... see my reply # 14..

ljsense

You left out the spacer between the hub shell and freehub cassette body. That's why tightening the hub causes the problem -- you're making the freehub cassette body bind.

If it were a problem with what lubricant or grease you used, adjusting the hub would not cause the issue to present in this way. Your freehub body can only spin freely when the hub is loose. Disassemble and reassemble following the parts diagram.

The new chain is a red herring -- it sounds like you were doing other troubleshooting before trying the chain, and I'd bet that part of that was loosening the hub adjustment.

BarryVee

blamester