Wheels and road vibrations

[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.