[mjdwyer23]

Hi Folks-
I noticed today that my left rear brake pad rubs my wheel when I am sprinting or attacking on a climb. I have a Pedal Force RS2 with Neuvation R28SL wheels -- Which one is flexing? Is there a good way to figure this out? The bike has less than 1,000 miles on it. Thanks,

 

[raymonda]

Most likely it is your wheels. Check your spoke tension. Also how close do you set your brake pads?

 

[JoelS]

Probably the wheels. Check spoke tension as was already mentioned.

 

[Fredrico]

Center your rear brakes! The left brake pad is too close to the rim, so it rubs when the wheel flexes. :idea:

 

[repartocorse40]

I vaguely remember hearing someone report that their pedalforce was flexy in the back. They made the point as to say they enjoyed the bike, just a little noodly at times. Can't remember if it was an rs2 or not.

 

[Hooben]

Those Neuvations are the most flexy wheels I have ever ridden. I would see them flex even while standing to climb. I vote that it's the wheels.

 

[Mr. Versatile]

It's your wheels flexing. Check it by riding slowly 5-10 mph in a flat parking lot. Stand & pedal just 1 stroke swaying the bike from side to side as you would when climbing or sprinting. Your brake pads will likely hit the rim. What to do? There are a couple of options. Adjust your brakes so they're loser-pads farther from the rims. Check spokes for tightness & wheels for trueness. Buy a new pair of wheels that are stiffer than the ones you have.

 

[mjdwyer23]

Thanks for the responses! The brakes are centered, but are pretty close to the rim. I will check spoke tension tonight and open the brakes up a bit in the meantime. Damn, I liked these wheels. Can anyone recommend a stiffer rear?

 

[raymonda]

If it is the wheel you may be able to save them by adjusting the spoke tension. If that doesn't work you can rebuild them with a beefier gage spokes, e.g. 14/15 or straight 14 gage.

 

[Hank Stamper]

How can it be the wheels?

When something is in a fixed position in the middle how can the top be bent when pressure is only coming from the bottom? I would think it would have to be the fork or frame giving a little.
For example if you hold a yard stick in the middle and bend it from the bottom there's no way the top moves unless your hand moves. I know that's a bad example because wheels are round but I can't grasp how the top of a wheel could flex.

 

[Mr. Versatile]

It's not just the top of the wheel, it's the whole rim. When lateral pressure is applied the wheel flexes and takes the shape of a potato chip only to a much, much smaller degree. If the brakes are set too closely to the rim it doesn't take too much flexion to make the pads rub the rim. And of course you're right, the frame, fork and other components are also flexing.

 

[Hank Stamper]

Thanks Mr. V.

 

[Hooben]

I know it's the Neuvation because even my front wheel would flex on sprints. I have never owned a wheel like in 25 years of riding.

 

[mjdwyer23]

I'll take it to my LBS today and see what they can do for me. I do feel the front end flexing when I am out of the saddle as well. Woof.

 

[nayr497]

So the consensus is that it's the wheels? I know everything flexes, but I just find it hard to believe that the frame flexes. Unless you are a gorilla, it just seems crazy. I can understand a wheel flexing enough though to cause rubbing.

I have a pair of those same wheels and they've been solid for me for 4000 miles. Popped a spoke last week, but threw in one of the spares the wheelset came with and I'm back out riding them. For what I paid for them, I have nothing but good things to say about them. I'm a smaller dude though, so maybe my weight has something to do with it.

I have these wheels and I also ride some Campag Record hubs/Mavic OP rims, some Ultegra hubs/Mavic CXP 33s and some Record hubs/Campag Strada rims on my other bikes. For the price, these Neuvations are pretty nice and I don't notice a huge ride quality drop off on them. I don't know if I am just oblivious or if all of my wheels are pretty nice or if I don't notice it as much because I'm only 145 pounds, but I've never thought, "Wow, these wheels suck, I need new ones."

I've even put my Record/OP wheelset on the bike I ride the Neuvations on and didn't notice much of a difference.

 

[Kerry Irons]

Not spoke tension

Thanks for the responses! The brakes are centered, but are pretty close to the rim. I will check spoke tension tonight and open the brakes up a bit in the meantime. Damn, I liked these wheels. Can anyone recommend a stiffer rear?

If a wheel is flexible due to low spoke tension, then the tension must REALLY be low. That is not likely the problem. Most likely is that you have the brake pads set too close to the rim. Lots of people seem to think that braking performance is better when you have instant response to brake lever movement, but in fact you have better braking control if you get maximum lever force nearer to the bars. The most effective setup is when the brake lever almost touches the bar when full force is applied.

Also consider if you might not benefit from a more smooth pedaling style - not rocking the bike so much when out of the saddle.

 

[raymonda]

" Lots of people seem to think that braking performance is better when you have instant response to brake lever movement, but in fact you have better braking control if you get maximum lever force nearer to the bars. The most effective setup is when the brake lever almost touches the bar when full force is applied."



Also, the biggest benifit from backing off the brakes from the rim is the ability to feather the brakes.