Wheels and road vibrations

[ny biker]

I've been riding with Bontrager Race wheels on my Madone. They were the stock wheels that came with the bike in 2010, and they were fine. I could tell that they were a bit faster than the (stock) wheels on my old road bike, based on my speed coasting down hills. I assumed the bladed spokes helped with that. Other than that, I never really thought about them.

After a spoke broke on the rear wheel, and a second one broke a week later, I took the advice of several friends and bought a new wheel set. But I had a big ride coming up in a week so I really needed the wheels right away -- there was no time to do any research into what wheels I might want. Since I was happy with the old ones, I wanted to just replace the rear wheel with the same one that had broken. However Bontrager no longer makes these wheels, so I ordered a set of their current "equivalent" wheels, the Race TLR. There was a bit of a miscommunication with the bike shop which caused a delay, so I did not get the bike back with the new wheels until the night before my big ride.

Now that the ride is over and I've used the wheels for 64 miles, I have to say that I hate them. The road vibration from both wheels is terrible. I was using the same Gatorskin tires at the same pressure as before (100 psi) and I felt like I was bouncing around whenever there were rough patches. Letting some air out of the tires helped a little, but I could still feel more vibration than usual on anything other than totally smooth pavement.

There does not appear to be a 30-day satisfaction guarantee on these wheels like there are with other Bontrager products, so I think I am stuck with them.

Does anyone have any suggestions on how to mitigate the problem, since I can't afford to throw the wheels away and and get a different set? One friend suggested switching to Continental Grand Prix tires, because they are also very flat-resistant but are not as hard as the Gatorskins. My current tires are not worn out yet but they've got quite a few miles on them, so I could justify getting new tires and keeping the Gatorskins for backups. Is there anything else I can do to lessen the vibrations?

Also, does anyone know what it is about a wheel that increases or decreases road buzz? I have no idea what to look for to prevent this problem from happening again with different wheels.

Thanks very much for any suggestions.

p.s. I have to say, if these had been the wheels that came with the bike, I never would have bought the bike. I clearly remember during my test ride, on a section of rough road that I'd ridden many times before, noticing how much smoother the carbon Madone was compared to my old aluminum bike. There's no way I would have had that experience with these new wheels.

[DebW]

Can you use tubeless tires on the new wheels? I've heard that they ride better, but never used them myself. Otherwise you might think about slightly wider tires if they'll work, and go for a supple tire casing. I did try one pair of Gatorskins that I found very stiff.

[ny biker]

I actually only have a vague understanding of what tubeless tires are, and I have no concept of why someone would use them. The impression I have is that they are time-consuming to deal with.

My Gatorskins are 700x25, which are the widest tires I can use on this bike.


These are the new wheels:

http://www.bontrager.com/model/11063

The specs might as well be written in Greek. I have no idea what any of it means or how you are supposed to compare wheels to know what you do and don't want.

I was talking to a friend last night who asked why I couldn't just replace all the old spokes on the old wheel and continue to use it. I have no idea if that's an option or not.

This is all very frustrating. I never broke any spokes on my old bike, and have no idea why this wheel wore out on me. I weigh less 150 lbs and I'm not a particularly aggressive rider. I also don't understand why "comparable" wheels are so very different.

Thanks

[thekarens]

Just an idea, but have you tried running a lower psi in the front?

[ny biker]

I lowered the psi on both tires in order to get through my ride on Saturday without throwing my bike down on the side of the road in anger. That stopped the bouncing feeling but there was still more road buzz than usual.

What I don't understand is why that would be necessary -- why do the same tires need a lower psi on "equivalent" wheels? I am the same, my bike is the same, the tires are the same. When you read recommendations on tire pressure, there's never anything that tells you to factor in the wheel specs.

[thekarens]

Very good question.

[Hi Ho Silver]

My guess - the spokes on the original wheels were under-tensioned. This would effectively make the wheel/spokes absorb more road shock (i.e., the wheel acted somewhat like a spring). That would result in a softer ride, but it would cause the spokes to flex a lot. Flexing a lot causes metal fatigue and ultimate spoke failure. The fact that the new wheels ride harsher indicates to me that the spoke tension is much higher. Higher tension allows less flexing (so you would experience more transmission of vibration and shocks), but the spokes will be subjected to less flexing (and therefore will be less prone to breakage).

[kermit]

Try talking with the LBS and tell them you hate them. Maybe they would do a trade or stick them on ebay. I did a spoke replacement on my wheels after leaving my bike overnight on the pool patio. Chlorine vapors did a number. It was very pricy and I later bought Easton wheels. Good luck.

[pinsonp2]

After reading the Bontrager description, I would think that the vibrations might be caused by the 'improved stiffness'. They probably transfer power well at the cost of comfort.

P2

[DebW]

Your new wheels are ready for tubless tires, if you wanted to go that route. They would be more of a pain to mount and inflate, so you may not want to go that route. Did your old and new wheels have the same number of spokes? New wheels are 18 spokes front, 24 rear. More spokes would provide more strength and ride comfort.

[ny biker]

The old wheels have 20 spokes in front, 24 in back. So it looks like the lower spoke count in front is making a difference, in addition to possible differences in tension (maybe fewer spokes requires higher tension?).

I am planning to go for a short ride tonight for another test. Then I am going to talk to the LBS folks. Maybe I can just return the front wheel and go back to the old one, which I still have (I was was going to donate it to a local nonprofit bike shop). Or perhaps I can swap the new set for Easton wheels, which is among the brands that they carry. The old wheels had white rims and the new ones are black, so using one old and one new would look funny.

(One friend recommended some Shimano wheels to me, but I don't know if they will work with my SRAM components. He did recommend going with a 20/24 spoke count, regardless of the brand.)

Thanks very much!!

[ny biker]

Just an update, my 20-mile ride on Wednesday showed that I was not imagining things -- the new wheels transfer lots of road vibration. I could feel it in both the front and back wheels, so the lower spoke count on the front wheel is not the only thing causing the different feel.

I emailed the guy at the LBS, and he said I could exchange them for something else. He's out of town right now (Interbike, I assume), so I'll talk to him next week when he gets back. In the meantime, I've been comparing the different wheels that they carry to try to figure out which ones I would prefer. Unfortunately all I can do is look at specs -- I don't really know which ones will be best for me.

The wheels I'm looking at are Easton EA 70 or EA 90 SL, or Shimano R501-30. Everything else that they carry is way out of my price range. In fact the EA 90 SL are pushing it -- if I go with them, I would have to only get the rear wheel now, and hope to be able to buy the front wheel early next year. Also there's one possible issue with the Shimanos -- I don't know if they will work with my SRAM cassette.

I've also tried to compare the Bontrager Race TLRs with the old Race wheels, to understand why they feel so different. The new ones have these specs:

Front wheel - 18 spokes - 284mm. Rear wheel - 24 spokes - drive side 294mm, non-drive side 295mm.
Rim - width 17.5 mm internal, 23 mm external. Depth 25 mm.
The sticker on the wheel says "ETRTO 622x17c. ERD 590."

The old ones are:
Front wheel - 20 spokes - 281mm. Rear wheel - 24 spokes - 296mm.
Rim - width 20 mm external, if I measured right. Depth 20mm? I'm not sure how to measure that.
The sticker on the wheel says "ETRTO 622x14c."

Of course the difference in comfort could be due to the materials used for the rims and/or hubs, and the differences in dimensions mean nothing. I have no idea and my attempts to find anything on the internet to help me interpret the specs have led to nothing.

Anyway I've put the old front wheel back on the bike for now. I also spent some time playing with the old rear wheel, removing the broken spoke and figuring out how to use the kevlar FiberFix spoke. I noticed several other spokes on this wheel are clearly damaged and near ready to break. I wonder if they were damaged by my riding for five miles with a broken spoke, or if they were damaged when the mechanic removed the cassette, or if they were just worn out and the wheel was about to fail spectacularly on me??

Oh, and by the way, I did not ride any faster with the new wheels than I did with the old. Maybe someone gets a speed advantage from them, but I don't.

Thanks again for everyone's input.