Bicycle Mechanics - Rim rubs when hammering out of saddle

Guys,

I notices the rear rim would rub against the rear right brake pad when I'm hammering the bike out of the saddle(left down stroke). Usually, it occurs on a steep uphill. I had to open up the caliper to avoid the contact. But I like closer brakes. So what to do? My rear wheel is an Easton Orion 2 with a 28 hole rim. It's pretty much brand new, round and true. Two cross on drive side and straight pull on non-drive side. I have another older set of the same wheels on my other bike, they don't have the rubbing problems. Help?

Aero-X

Dial down your wattage a little bit or open up the brake caliper a little or buy a new bike?

I'm not really sure what response you are looking for. Try another wheel and see if it does it. If it doesn't then use a different wheel or don't and just open the brake caliper a little more. If it does it with another wheel it's an issue with the bike.

I like to keep the rear brake caliper a little further from the rim than the front anyway to remind me it's the rear as to not overuse it and bias the front more.

if the wheel is not true, truing the wheel may help. it could, but probably not, be caused by loosely tensioned spokes too. so a general tightening of the spokes could help.

otherwise, as mentioned, a stiffer frame, or easing off the 'roids. :)

indeed, spin lower gears.

Aero-X, Easiest way to find the problem is to switch rear wheels as it's either the wheel or frame flex. If it's frame flex you'll just have to open the rear caliper 'till there's no more rubbing.

Brad

It's time to carefully inspect your frame and all of the welds for signs of cracking. bk

Check your spoke tension, and frame as mention in the above comments. I'd also make sure that the wheel bearings and axle aren't loose.

If the all of the above checks out then I'd ask if the "older wheel" is spoked in the same way (i.e. 28 spokes with 2 cross on drive side and straight pull on non-drive side)?

If not, then I'd say that your 28 hole wheel, and particularly the 2 cross on drive side and straight pull on non-drive side setup, is too weak to deal with the torque you're feeding it.

It should normally take quite a bit of stress to cause much deflection of the rear caliper in relation to the rim, as they tend to move in the same direction under stress. If the two wheels have the same spoke, pattern and tension, and bearings are adjusted then obviously the variable is the frame. In that case you only have three choices - move one gear lower, widen the brakes or tolerate brief rubbing.

Guys,

I notices the rear rim would rub against the rear right brake pad when I'm hammering the bike out of the saddle(left down stroke). Usually, it occurs on a steep uphill. I had to open up the caliper to avoid the contact. But I like closer brakes. So what to do? My rear wheel is an Easton Orion 2 with a 28 hole rim. It's pretty much brand new, round and true. Two cross on drive side and straight pull on non-drive side. I have another older set of the same wheels on my other bike, they don't have the rubbing problems. Help?

Aero-X

While all the other suggestions are valid, check the obvious first. Check that the wheel is properly engaged in the dropouts and that the quick release skewer is tight.

I had that problem before with specific frames. Had a lemond Z-team that was doing that with one of my wheelsets, my best guess was that the frame was too stiff in the rear and since couldnt flex the wheel was taking all the work and flexing more than usual. When i was using a set of wheels with straight pull spokes I never had the problem because straight pull wheels spoke tension is usually larger and evenly distributed than in regular hubs wheels.

Check tension, what rims do you have in the wheels? Some wheels are more flexy than other ones too. As the other guys, test with another wheel and then do the mods in the one giving you problems.

Assuming the basics, true wheel, tight hub,centered brakes, etc, then it's a question of rigidity.

Either your frame is flexing, or the wheel is flexing. Given that you're riding on 28 spokes, I suspect that may be your problem. The only thing that stiffens a wheel is more steel. Either more or heavier spokes or both. Once a wheel is reasonably tight more tension doesn't make it stiffer, so don't bother tightening it.

You have two choice, either modify the stress by adjusting your riding style, or reduce the deflection with more steel.

If it's right at the margins, and only rubs on one side, you might try off centering the brakes a bit, because rims tens to deflect to the left slightly more than the right. Otherwise if you have brake release in the lever (like Campy), consider releasing the brake to climb or sprint. I don't suggest this if the release is at the brake because you might forget to reset and be without brake when you need it.

Check the rim carefully for small cracks in the rim near the spoke holes. This is most often where failure starts. While you're at it check the drive side hub flange for cracks. That's where my last wheel failure occurred.
Good advice from others, above.

I'd say that your 28 hole wheel, and particularly the 2 cross on drive side and straight pull on non-drive side setup, is too weak to deal with the torque you're feeding it.


This!

If not, then I'd say that your 28 hole wheel, and particularly the 2 cross on drive side and straight pull on non-drive side setup, is too weak to deal with the torque you're feeding it.

It has little to do with torque since torque related deflection is miniscule in built properly wheels. Odds are the deflection and rub happens becuase the OP leans or rocks the bike when hammering. The side loads this creates will flex a rim and can cause rub.

How much do you weigh?

Are you a very strong rider?

What cadence does this happen in?

What frame material and what is the manufacturer/model?

Are your cones tight?

A little late to respond here, but I'm looking for an answer about my Easton Orion, and I think you have the same problem. The R3 hubs on the Orion and Ascent wheels did NOT have a bearing adjustment, and they tended to be too loose. They are supposed to be adjustable with the quick release, but I've never found that to be sufficient to take all the play out of the bearing in my front hub, while my rear is ok. My pair is mismatched, Orion in front and a rebuilt Ascent in the rear so I have 24/24 instead of 24/28 or 20/24.

I think the answer is that the bearings need to be pressed in more, but you don't want them to be tight of course. I wouldn't do it myself either, and would want someone that knows what they are doing. They are supposed to be replaceable too, I've seen ceramic bearing advertised for Easton hubs, but maybe that's only for the R4 hubs that have adjustments.

I also have an earlier pair of Velomax Tempest wheels, and never had any problems with them. Easton bought Velomax and uses their designs, or at least they used to. This is already a few years back. The twin threaded spokes are a PITA, if you break one you can't just buy one from a shop unless they have a threading machine, and most don't. They also need to be glued in place at the hub with a type of Loctite that is not available in most hardware stores. It's all just too non-standard.

I thought those Orion/Ascent rear hubs have an adjustable cone on the left side(non-drive). That's for adjusting bearing pressure. The bearings get pretty tight if you keep turning the cone. According to the manual, you suppose to find a sweet spot where there's no play, but bearings still spin smoothly.


A little late to respond here, but I'm looking for an answer about my Easton Orion, and I think you have the same problem. The R3 hubs on the Orion and Ascent wheels did NOT have a bearing adjustment, and they tended to be too loose. They are supposed to be adjustable with the quick release, but I've never found that to be sufficient to take all the play out of the bearing in my front hub, while my rear is ok. My pair is mismatched, Orion in front and a rebuilt Ascent in the rear so I have 24/24 instead of 24/28 or 20/24.

I think the answer is that the bearings need to be pressed in more, but you don't want them to be tight of course. I wouldn't do it myself either, and would want someone that knows what they are doing. They are supposed to be replaceable too, I've seen ceramic bearing advertised for Easton hubs, but maybe that's only for the R4 hubs that have adjustments.

I also have an earlier pair of Velomax Tempest wheels, and never had any problems with them. Easton bought Velomax and uses their designs, or at least they used to. This is already a few years back. The twin threaded spokes are a PITA, if you break one you can't just buy one from a shop unless they have a threading machine, and most don't. They also need to be glued in place at the hub with a type of Loctite that is not available in most hardware stores. It's all just too non-standard.

I think that is only on the later R4 hubs. Mine have no adjustments.