Bicycle Mechanics - Noisy drive train - Al brand new Dura-Ace

I just finished up a major upgrade on my Roubaix Comp during which I upgraded from an Ultegra 6503 triple to a Dura-Ace 7800 and I also upgraded its wheelset to a brand new set of Zipp 404s. The upgrade went very smooth and everything works great. Everything fits perfectly. It shifts nice and crisp. However, it now has a noisy drivetrain that I've been trying to nail down the source of for the last 24 hours.

The noise sounds like it is coming from the rear cassette and chain, and it seems at its worst with the bike in the 53t front sprocket. It starts when the cranks are spinning at a fairly high rate of speed, and right at that point when there's not a lot of load on the pedals. When there's a load on the pedals, it's quiet. It's just at that point where the crank is spinning with just enough load to keep up the speed, but not quite enough to increase it (sort of cruising, for lack of a better term, if that makes sense).

The sound is sort of a grinding rattle, and it does it to some degree across the entire range of gears.

I've checked and rechecked everything. I readjusted both derailleurs numerous times. I've checked and rechecked chain length numerous times. I followed the instructions when assembling. I've read Sheldon's site, Park Tools site, Zinn's book of bike repair, and Barnett's book of bicycle repair. I've searched BFN and googled this thing numerous times. Everything is brand new.

Any ideas??

Steve

It'll quiet down. New Dura-Ace tends to sound a little "grindy" at first. Same thing goes for most high-end Shimano stuff. It's always troubling to customers who just dropped a lot of cash on new stuff, but once the sharp edges on the cogs round off a little, the noise will go away.

Enjoy your new bits and pieces. Sounds like a gorgeous bike.

My guess is that you didn't put enough torque on the cassette lockring. Check the torque spec shown on the lockring or just add a bit.

Al

My guess is that you didn't put enough torque on the cassette lockring. Check the torque spec shown on the lockring or just add a bit.
Al

Hi Al, and thanks for the response. I thought about that. I took the cassette back off the bike completely and checked everything out again. There is a spacer that shimano includes with the cassette that is for mounting it on a 9 speed hub. At first it wasn't on there, but as the hub is a 9/10 speed compatible, I thought maybe it needed to be on there. After installing it, it didn't seem to make a difference one way or the other. I did recheck the torque and it didn't change anything.

Thanks for the reply!

Steve

It'll quiet down. New Dura-Ace tends to sound a little "grindy" at first. Same thing goes for most high-end Shimano stuff. It's always troubling to customers who just dropped a lot of cash on new stuff, but once the sharp edges on the cogs round off a little, the noise will go away.

Enjoy your new bits and pieces. Sounds like a gorgeous bike.

I hope it is that simple. It's mounted on the trainer right now and is about to get hammered for the first time. I'll see if it gets any better (or worse).

Thanks for the response!

Steve

Do you have another back wheel that you can try? If so, move the cassette to that wheel so that you can eliminate that zipp cassette hub as the source. That will help you nail things down a bit.

Is the b screw adjusted properly so that the top pulley isn't too close or too far away from the cogs?

Is the b screw adjusted properly so that the top pulley isn't too close or too far away from the cogs?
Beat me to the B screw.


Now there is an outofcontext.

Do you have another back wheel that you can try? If so, move the cassette to that wheel so that you can eliminate that zipp cassette hub as the source. That will help you nail things down a bit.

Is the b screw adjusted properly so that the top pulley isn't too close or too far away from the cogs?

Yes, I believe so. I've been through the adjustment procedure a few times. It seems fine. After putting some miles on it on the trainer, it seems to be quieting down. It also doesn't seem to make as much noise under load as it did on the stand.

Thanks for all of the suggestions!

Steve

It'll quiet down. New Dura-Ace tends to sound a little "grindy" at first. Same thing goes for most high-end Shimano stuff. It's always troubling to customers who just dropped a lot of cash on new stuff, but once the sharp edges on the cogs round off a little, the noise will go away.

As a followup, it indeed seems to be quieter after a few rides on the trainer. I can see where a customer would be concerned - you'd have every right to expect something top of the line like DA to sound like a Swiss watch, not a cement mixer :)

Take care,

Steve