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Are Tri Bike drivetrains noisier than Road Bike's?

edywouldgo's picture
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84 days
started by edywouldgo on July 23, 2008

Hi Guys/Gals,
I just got a new QR tri-bike with complete Dura Ace drivetrain. I noticed that there are lots of vibrating/rough noise from the drivetrain when going to the top 3 gears due to the chain alignment from the Big Ring (53) and 3 smallest rear cogs(11, 12, 13). The rough noise and vibration is really noticable on the big ring and smallest rear cog. With the chain at an angle, this is causes the bottom pulley to rub against the side of the chain as it gets fed into the rear, the loudest noise source. The bike shifts great, no bent derailleur hanger, no gear slipping, no rubbing on derailleur cages, no loose fasteners….just noise you get from having your chain at the 11 o-clock while everything else is facing 12 o'clock. It is MUCH quieter when in the middle gears.

Do many of you also have this? Bike shops have said that the short chain stays on tri bikes make the angles more exaggerated. This is my first high end bike with a double. Anyways, just wanted to see if this is "normal" with many of you out there. Thanks in advance for any input.

chris91180's picture
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191 days
chris91180 posted 12 weeks ago.

I get a lot of noise on my Soloist when I'm on the small ring (39) and the smaller cogs (11-13). It seems to be from the chain rubbing the big ring. I also wondered if this was a big deal, but the two bike shops I've had it in for tuneups haven't said anything. This is more of a road bike though, but designed to be retrofitted easily for tri.

chrisgood1's picture
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chrisgood1 posted 11 weeks ago.

That is caused by cross-chaining being in you small gear up front and small gear in back it causes a steep chain angle and will cause rubbing on most 10sp systems. Watch out for it because it shortens chain and chain ring life.

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gshuldes's picture
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268 days
gshuldes posted 11 weeks ago.

On the contrary, my GURU has the quietest drive-train I have ever ridden. The shorter chain stay issue that bike shops are telling you about can make it difficult to use the smallest rear cogs while on the small front ring, or the largest rear cogs while on the big ring, but should not cause the problem you are describing.

It all depends on how the crank is aligned to the rear wheel. If the bottom bracket (the part of the frame that the crank mounts to) is misaligned, then you will have a bad chain line. Since the front chainring spacing is about twice the spacing of the cassette cogs, the small ring should point between the 4th and 5th cogs and the big ring should point between the 6th and 7th cogs ... this would mean that the center of the crank is pointing at the center of the cassette, and the chain line is as good as it can be.

Leroy Bonkers's picture
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Leroy Bonkers posted 11 weeks ago.

I have a QRoo Tequilo with DA, and have no problem in the 53x11. All smooth and quiet.

Perhaps you need a better shop. Can you take it to a place that sells QRoo? They have probably adjusted a million just like yours.