Thunking noise when rolling bike

[mtnairlover]

Ok, so that's the best way I can describe this noise...it goes thunk....thunk....thunk...when I push my bike into the garage.

Here's some background:

1. I had new tires mounted and balanced two days before my trip to southwest Colorado a week ago.

2. No noise before the tires, or the trip.

3. The noise only occurs after being ridden when it's hot...which means that if I rolled my bike out and back into my garage now, I would not be able to reproduce the noise.

4. On my long-ass ride, I felt some pretty bad vibration from the bike (at higher speeds only), mostly front end and not part of the typical rough engine stuff from putting the bike through the paces.

5. Not only did my throttle hand fall asleep, but I think it suffered some nerve damage as the palm was numb for a couple of days after the ride, which has never happened before...so I'm not imagining this stuff.

6. I went back to the shop to ask about what could possibly be causing the vibration and the thunking noise when it's hot. The only answer I got was that the front tire was defective. It will be returned and replaced in a week.

Unfortunately, that thunking noise is still there and it happened when I rolled my bike back into my garage after getting home from the shop.

Any ideas? Any guesses? What can cause something like this to happen and only when the bike is hot?

And yes...when I take my bike back to the shop, I will ask again about the thunking noise and cross my fingers that it actually happens to the tech, so he can hear it first-hand.

[Filo]

Kinked chain?
That's all I got.

Ok, so that's the best way I can describe this noise...it goes thunk....thunk....thunk...when I push my bike into the garage.

Here's some background:

1. I had new tires mounted and balanced two days before my trip to southwest Colorado a week ago.

2. No noise before the tires, or the trip.

3. The noise only occurs after being ridden when it's hot...which means that if I rolled my bike out and back into my garage now, I would not be able to reproduce the noise.

4. On my long-ass ride, I felt some pretty bad vibration from the bike (at higher speeds only), mostly front end and not part of the typical rough engine stuff from putting the bike through the paces.

5. Not only did my throttle hand fall asleep, but I think it suffered some nerve damage as the palm was numb for a couple of days after the ride, which has never happened before...so I'm not imagining this stuff.

6. I went back to the shop to ask about what could possibly be causing the vibration and the thunking noise when it's hot. The only answer I got was that the front tire was defective. It will be returned and replaced in a week.

Unfortunately, that thunking noise is still there and it happened when I rolled my bike back into my garage after getting home from the shop.

Any ideas? Any guesses? What can cause something like this to happen and only when the bike is hot?

And yes...when I take my bike back to the shop, I will ask again about the thunking noise and cross my fingers that it actually happens to the tech, so he can hear it first-hand.

[Jmetz]

Yeah I would agree with the possibility of a chain issue. The Duc started making a thumping noise at the end of last season but it did it hot or cold and was easily identifiable as chain slap at speed. New chain solved the issue.

[willb003]

Well first thing is to find out where its coming from.
Get it hot so it reproduces the same sound, then get someone to push it while you listen and try to figure out where its coming from.
If you want give me a shout and I can give you a hand with it.

[Wrider]

Front wheel bearing is a possibility as well. When it's cold the grease is thick enough to hide the thunk. When it's hot, the grease is so thin it doesn't hide it.

[TFOGGuys]

Front wheel bearing is a possibility as well. When it's cold the grease is thick enough to hide the thunk. When it's hot, the grease is so thin it doesn't hide it.

This would be my guess...

[mtnairlover]

Front wheel bearing is a possibility as well. When it's cold the grease is thick enough to hide the thunk. When it's hot, the grease is so thin it doesn't hide it.

Ah...I will have that checked.

Thanks

[Nick_Ninja]

How old is your chain? I have heard chains make all sorts of 'noise' when old and ready to be replaced.

[Mac020]

Something in the tire? Or, You may have gotten another bad one. Anyway, I'd bet on the chain, but you'd think the shop would notice. How many miles on the current one?

[mtnairlover]

How old is your chain? I have heard chains make all sorts of 'noise' when old and ready to be replaced.

I had a new chain installed at 28k miles. The bike is at 41k miles now. The first chain was the stock chain and stood the test of time. The chain was tightened a couple weeks ago and I've put about 1200 miles on it since. I've heard that chain "noise" on other bikes. I can feel the difference in "pick up" when the chain isn't loose. Changing gears feels a whole lot more smooth.