Freewheel ratchet has oscillating click volume

[ampandcamelbak]

Whatup, y'all: I've got Bontrager RaceXLite's on my mountain bike and have a weird clicking sound from the free wheel. The ratcheting sound from spinning the rear wheel oscillates in volume from louder to quiet and then repeats back and forth. The faster I spin it, the faster the loud/quiet cycles. Can anybody tell me what's going on? I've attached a picture of it while the bike was still in its box (ebay). Has anyone come across this problem before? Do I have a major problem here? Thanks in advance for your input. p.s. These smilies rock.

 

[alfeng]

Whatup, y'all: I've got Bontrager RaceXLite's on my mountain bike and have a weird clicking sound from the free wheel. The ratcheting sound from spinning the rear wheel oscillates in volume from louder to quiet and then repeats back and forth. The faster I spin it, the faster the loud/quiet cycles. Can anybody tell me what's going on? I've attached a picture of it while the bike was still in its box (ebay). Has anyone come across this problem before? Do I have a major problem here? Thanks in advance for your input. p.s. These smilies rock.

Well, I think that is as vague a description as you could have provided ...

Put the chain on a different cog than the one shown to ensure that the arm of the rear derailleur isn't slapping against the spokes!

IF having the chain on the other cogs resolves the problem, then adjust the rear deralleur's stop(s), accordingly ... but, be certain that the rear wheel is properly seated in the dropouts BEFORE making any adjustments AND if you have a spare wheel (from another bike/whatever) then put that in the frame, too, OR put that wheel in another frame.

 

[ampandcamelbak]

Well, I think that is as vague a description as you could have provided ...

Put the chain on a different cog than the one shown to ensure that the arm of the rear derailleur isn't slapping against the spokes!

IF having the chain on the other cogs resolves the problem, then adjust the rear deralleur's stop(s), accordingly ... but, be certain that the rear wheel is properly seated in the dropouts BEFORE making any adjustments AND if you have a spare wheel (from another bike/whatever) then put that in the frame, too, OR put that wheel in another frame.

Thanks for the quick reply, Alfeng. The picture I included before was just to show the rear hub; not the particular setup of the chain/gearing. The oscillating clicking sound I'm talking about occurs regardless of the chain or derailler. The wheel will make the oscillating sound even off of the bike. Imagine the bike suspended in a bike stand; then roll the rear wheel in the forward direction. Or, similarly, the sound will occur while just coasting on the bike. The normal "fast clicking" sound of the freewheel (freehub in this case, I believe) isn't constant...it clicks/ticks louder, then quieter, and repeats over and over, cycling along with the rotations of the wheel (one wheel rotation is one loud/quiet cycle). Hopefully, that's a better description of what I've got. I'd like to take a short video of it and try to post that (perhaps in .zip format since I don't see .mpg as an acceptable attachment type?). I appreciate your or any other readers' follow-up. Thanks!

 

[alfeng]

... The oscillating clicking sound I'm talking about occurs regardless of the chain or derailler. The wheel will make the oscillating sound even off of the bike. Imagine the bike suspended in a bike stand; then roll the rear wheel in the forward direction. Or, similarly, the sound will occur while just coasting on the bike. The normal "fast clicking" sound of the freewheel (freehub in this case, I believe) isn't constant...it clicks/ticks louder, then quieter, and repeats over and over, cycling along with the rotations of the wheel (one wheel rotation is one loud/quiet cycle).

DARN! Well, I guess this will require some more sleuthing on your part ...

FIRST. I'm not certain, but based on the hub's appearance AND the history between TREK/Rolf & HUGI, I'm going to suggest that the Bontrager rear hub is a derivation of the HUGI 240 hub ... if that is correct, then the currently unidentified noise coming from the hub-itself would be unlikelyl, to me ... but, not impossible.

I would (with OR without removing the cassette ... and, with the wheel stationary) slowly hand-turn the freehub body, counter-clockwise to determine if I can MATCH the offending sound with the star-ratchet "pawl" mechanism.

I would describe the SOUND from the star-ratchet as being generally muted -- louder than a Shimano hub, quieter than a Campagnolo hub -- and, the feel is "soft" (well, compared with the earlier Hugi star-ratchet mechanism) -- how's THAT for vague?

The Hugi "PAWL mechanism" is actually a reciprocating plate with a "star-ratchet" which subsequently engages the freehub body which has a matching star-ratchet -- THAT explanation doesn't do the elegance of the mechanism justice, BTW. About the only way to adversely affect the star-ratchet is by using the wrong lube during servicing OR if grit infiltrates and subsequently precludes the mechanism from reciprocating.

So, the next thing to do is to check for a single (?) damaged spoke and/or rim eyelet.

Failing that, I'd remove the cassette ... and, the tire & tube ... basically, strip the wheel down to its essentials in an attempt to isolate the sound.

IF, by chance, you ascertain that the problem is with the freehub-hub interface, then it is possible that EITHER someone "serviced" the hub [with slightly incorrect reassembly?!?] OR it is due for service ... the 240 hubs was described as requiring no-tools for disassembly -- THAT requires some effort to make true, IMO (BTW, AFAIK, the KEY is in removing the non-driveside axle end ... if you have a really STRONG GRIP, you can simply PULL it off the hub ...).

FWIW/FYI. HUGI hubs are serviced in North America by DT/Swiss (about $100 -- it sounds expensive, but it includes replacing the bearings, freehub body, star mechansim, etc. -- AFAIK, basically EVERYTHING is replaced except the hub shell & the hollow axle, I think) in Colorado (Grand Junction?). Your local shop can replace the bearings (but, that doesn't seem like the problem AND I'm not sure that the replacement bearings your shop would install are the same grade).

Sorry I can't be more help.

 

[ampandcamelbak]

Thanks for your input everyone. Just in case it isn't just something "typical and common", I checked out the bent skewer hypothesis this evening and found it to be straight as can be. I aligned the skewer with a machined straightedge and spun it carefully to find no imperfection. I also checked for any wobble of the cassette; that, too, appears to be sound.

I believe there are DTSwiss-made Bontragers, but not all of their hubs. I have the link with this info, but left it at work. I can post it tomorrow.

Now what about this...I remounted the rear wheel and set the chain on the highest gear (smallest cog). I lifted the bike by its saddle and cranked on the pedals to get the rear wheel spinning at high speed. The loud/quiet cycle of the ratcheting volume still remains. However, I noticed something else that wasn't apparent at slower wheel speeds or while I was coasting on the bike...there seems to be a slight weight imbalance of the wheel or tire that causes a slight up and down wobble of the bike. Again, I don't feel this when I'm riding it. The rear tire is tubeless and all I've done to it since the bike arrived in the box last week was pump it up. The wheel is true and, by sight, the tire is properly mounted (I don't see it wobble as I spin the rear wheel).

Does this help our investigation at all? Again, I appreciate your input.