What is causing vibration in my pedals?

[Sandy]

I recently purchased the Shimano compact crank and had it installed. I was using the Dura-Ace 10 speed 53/39 10 speed crank. I havenoticed that there is a buzz/vibration/roughness in the pedals as I pedal. If I am not pedaling there is no buzz. I even held my foot down on a pedal at 6 o'clock (pedal position, not time of day) and no vibration. When the crank was installed the bb cups were reused but they were recently replaced, prior to the installation of the compact crank

Today I used for the first time 700x25 tires which, thus far (a 10 mile test ride), I really like. They substantially cut down on road buzz and help minimize roughness in the road. But I still feel roughness through the pedals that I wouldn't expect nor recall noticing with the the 53/39 crank.

My local lbs who installed the crank had no ideas except that maybe it was just a function of the new and different crankset.

Perhaps one or more of you brilliant forum members could help me on this one. THANKS!!


Cranky Sandy

[mflaherty37]

I'm no expert on this Shimano 10speed stuff but old chain on new chainrings might be what you are feeling. If that is the case it will go away as it breaks in.

[Fixed]

bro try putting the bike on a work stand and pedal forwards and back pedal see if you can see what's up .cheers :beer:

[Sandy]

I'm no expert on this Shimano 10speed stuff but old chain on new chainrings might be what you are feeling. If that is the case it will go away as it breaks in.

I had a new chain put on when the new crankset was installed.


STill Cranky ST Serotta Sandy

[Sandy]

bro try putting the bike on a work stand and pedal forwards and back pedal see if you can see what's up .cheers :beer:

I don't have a workstand, but I have held the rear wheel off the floor and did what you mentioned a little. I will try it some more.


Sandy

[Too Tall]

Dr. TT can figure it out in a Heartbeat. Come on down you might even see someone you know...a mystery forum guest. Guest who?

[David Kirk]

If it's a new chain on a used cassette you have your cause.

Dave

[BumbleBeeDave]

Don't worry about it. It's just my invisible bumble bee spy drone follwing you around as you ride. I am keeping tabs on your spring form so I can be sure I'm in good enough shape by Nottrott Weekend (aka "Smiley-palooza") to beat you up the hills! :p ;) :rolleyes:

BBD

[Sandy]

Dr. TT can figure it out in a Heartbeat. Come on down you might even see someone you know...a mystery forum guest. Guest who?

Spectrum Bob?


Sandy

[Sandy]

If it's a new chain on a used cassette you have your cause.

Dave

The chain is new. The cassette probably has about 9,000 miles on it. When I had the new chain installed, I asked them if it needed a new cassette. They said that if it shifted ok, then it did not need a cassette. It seems to shift reasonably well, but with some chain rub in a couple of gears. Theytest rode the bike.



Sandy

[bironi]

Sandy,

You may need a new cassette. Hope you are less cranky soon.

Byron

[Kevan]

you're dragging your pedals on the ground.

Make sure you have both wheels installed on the bike and then try again. That should do it.

[David Kirk]

The chain is new. The cassette probably has about 9,000 miles on it. When I had the new chain installed, I asked them if it needed a new cassette. They said that if it shifted ok, then it did not need a cassette. It seems to shift reasonably well, but with some chain rub in a couple of gears. Theytest rode the bike.



Sandy

Ding -ding -ding.......we have a winner.

What valuable prizes might I have won?

Dave

[fiamme red]

Ding -ding -ding.......we have a winner.

What valuable prizes might I have won?

DaveA cassette with 9,000 miles on it? :)

[Kevan]

A cassette with 9,000 miles on it? :)

Who gave Sandy a cassette with 9,000 miles already on it? Shame on you!

[pdxmech13]

I don't think its the cassette.
Cassettes only will give you a skipping senstation not a buzz.
Does this happen in all of your gears or one in particular ?
My favorite new thing is to find out issues with bikes that drive them bonko's


I guess I'm lucky because I get to do it for a living
new favorite question is why my computer isn't calculating numbers like my riding partners.

Good luck with the noise or buzz or ring or ping or clunk/.

[Sandy]

I don't think its the cassette.
Cassettes only will give you a skipping senstation not a buzz.
Does this happen in all of your gears or one in particular ?
My favorite new thing is to find out issues with bikes that drive them bonko's


I guess I'm lucky because I get to do it for a living
new favorite question is why my computer isn't calculating numbers like my riding partners.

Good luck with the noise or buzz or ring or ping or clunk/.

I also thought that a worn cassette will give a skipping sensation and not a buzz. Interestingly, a couple of members think it is the cassette, including Dave Kirk. He seems confident in that diagnosis. He also seems to normally be spot on about what he says.


Spotted Serotta Sandy

[stevep]

cassette

[Sandy]

I don't think its the cassette.
Cassettes only will give you a skipping senstation not a buzz.
Does this happen in all of your gears or one in particular ?
My favorite new thing is to find out issues with bikes that drive them bonko's


I guess I'm lucky because I get to do it for a living
new favorite question is why my computer isn't calculating numbers like my riding partners.

Good luck with the noise or buzz or ring or ping or clunk/.

It happens in all of my gears.



Sandy

[Too Tall]

chain is too long.

Nope, not BugSplatBuddahBob. Guess again....an outtatowner.

[Moosedryvr]

Sandy,
I've got around 300 mi on my new Shimano compact and have also noticed a "buzzing" feeling with the new crankset (new Wipperman chain, new Ultegra cassette). Thought either I was crazy or that it might be from using a Wipperman chain vs Shimano. For me, I only notice this feeling when I'm "mashing" on the pedals. When I concentrate on a nice, smooth spin the "buzz" goes away. My guess (now that I'm reassured that it isn't just in my head) is that it may have something to do tooth profiles Shimano is using to make the rings compatable with a standard vs. compact-specific front derailleur. FWIW, I have only noticed it in the big ring (but haven't spent much time climbing in the little ring yet). I have been happy with the shifting performance of the new Shimano compact vs my previous FSA (both using std FD), but am not overly keen on either the "buzz" or the aesthetics.

Vr,
SPG

[Sandy]

I was actually thinking of a few others, including four ottatowners:

Keno
Tom Kellogg
Manet
Doofus


Actually, I think that the chain might be too short.



Sandy

[Sandy]

Sandy,
I've got around 300 mi on my new Shimano compact and have also noticed a "buzzing" feeling with the new crankset (new Wipperman chain, new Ultegra cassette). Thought either I was crazy or that it might be from using a Wipperman chain vs Shimano. For me, I only notice this feeling when I'm "mashing" on the pedals. When I concentrate on a nice, smooth spin the "buzz" goes away. My guess (now that I'm reassured that it isn't just in my head) is that it may have something to do tooth profiles Shimano is using to make the rings compatable with a standard vs. compact-specific front derailleur. FWIW, I have only noticed it in the big ring (but haven't spent much time climbing in the little ring yet). I have been happy with the shifting performance of the new Shimano compact vs my previous FSA (both using std FD), but am not overly keen on either the "buzz" or the aesthetics.

Vr,
SPG

Interesting that we both notice it. I feel it in both chainrings if I recall properly. I don't have to be going fast at all. I will pay more attention today, when I ride, as to precisely when it happens.

Thanks for your post. There is a possibility, of course, that both of us are crazy and the rest of the world is fine, or possibly vice versa. :)


Somewhat Sane Sandy

[David Kirk]

Normally cassettes would be tossed with about 1/3 that mileage. When the chain and cassette are used that long the chain stretches and the cassette wears to match the stretched chain.

A new chain has it's pins .500" from each other. When they stretch that distance gets longer. Now your cassette has worn the match that longer chain and the teeth of the cassette are no longer .500" apart. When the new chain rolls onto the old cassette each roller of the chain actually lands on the top of the cassette tooth (instead of falling between the teeth) and then settles in. Each time it does this it makes a small noise and vibration. At normal RPM's this will feel like a buzz.

Toss on a new cassette and it will be wonderful. That and get a new mechanic. Any wrench who says it's cool to put a new chain on a cassette with 9000 miles should be flipping burgers.

Dave

[Too Tall]

Bingo! One of em ;)

[pdxmech13]

I have been using an early prototype crankset for over six months and havn't had the feeling that you two are desribing. Being a proto it may very a little from the finals that you two have. I will call my friend jason at shimano and see if he has any answers on monday for you guys.

And please just to humor a fellow make sure that your cassettes are tight and check to make sure a corresponding chain was installed with the amount of gears on the back. This would usually relate to bad shifting as well but will only take a few minutes of your time.

until next time :banana:

[CalfeeFly]

Toss on a new cassette and it will be wonderful. That and get a new mechanic. Any wrench who says it's cool to put a new chain on a cassette with 9000 miles should be flipping burgers.Dave

Getting a new mechanic was my immediate thought beginning with the first answer of it is because it is the function of a new and different crankset. What crap!

Also Sandy my friend...get a stand. To have the quality bikes you have and rich friends like Kevan and not have a stand... :no: Seriously just to check for cuts in tire after a ride, cleaning off brake pads, cleaning your braking surface and the everday maintenance. Get a good book and you will find that many of the easier tasks you can do well and I'd guess every bit as good as a mechanic that evaluates a cassette with 9,000 miles by saying it shifts in the stand. That isn't even valid for shifting because "stand" shifting and shifting underload are very different.

[Sandy]

Excellent suggestions. I have told the bike shop repeatedly that adjusting a bike in a work stand is not sufficient and that the bike needs to be taken out and test ridden after the adjustment. I very seldom see that occurring.

Thanks for the ideas.



Shifting Sandy

[Sandy]

I have an almost new 12/27 Dura-Ace 10 cassette (about 9,000 miles) for sale. The first $142.27 gets it. You pay the postage! :) :)


Only bad cog in the set,


Slick Sandy

[slowgoing]

Did they adjust the front der. downwards to accomodate the differrent sized rings on the new crank? You might have front der. rub on you chain. Also, don't some crank manufacturers make special front der.s for their compact cranks?