rayone

Folks

I purchased a new pair of tires (continental city contacts 26x2.1) and when I spin the rear I notice it's off center, so it's like its got a heaver spot.

Anyway normally I would just return something, but it's a pain getting to the shop, I already returned a bike to them, and I just don't feel like going there again ($20 in gas).

My rims are DT Swiss X1800's

Questions:
Is there anyway to rectify the issue?
Is it common to have bicycle tires unbalanced?...I know car tires can require up to a 100gr on a side to balance them.

Thanks

dabac

Although bike tires can be unbalanced the odds are that what you're seeing is that yours simply hasn't seated properly. Some tires require lubing rim with soapy water and then some overinflation for the bead to settle as it should. Start by getting the tire off and check that there's nothing like a slipping rim strip or whatever that might prevent the tire from setting. Then reinflate in steps, pulling and massaging the tire as you go along to get the bead to align properly.

jsharr

Also, did you install new tubes? If so, are they slime tubes? I find those things allow the slime to settle and create a heavy spot and my wheels are really out of balance when I first start riding. I disliked this so much that I took them out and installed regular tubes again. Just a thought.

ericthered

You can sometimes check the witness line(usually a little rubber ridge a little bit in from the bead) that goes around the tire to see if the bead has seated properly. I know with my continental Sport contact slicks that they had tendency to not seat evenly all around and had to be tweaked as mentioned above.
Eric

Soil_Sampler

tube could be a little too big and is bunched up inside the tire.
switch tubes front to back to verify.

TeddyKGB

This happened to me the other day. It bump was caused by the tube not being seated properly. All you have to do it take out the tube and put it back in. Once the wheel is back on, pump the tube up to about 20 psi and massage the tire and tube so it seats properly. Then pump it up to full pressure. Hope that works for you

DannoXYZ 

Yeah, Teddy is right on. The outside shape is determined by the TYRE. Stuff inside it won't affect its outside shape simply due to the rigidity of the tyre compared to a tube or slime. In this case the TYRE is incorrectly mounted.

Take all the air out and pull the tyre sideways and inspect the gap between the tyre and rim. Make sure you don't see any tube. Then move over slightly and pull the tyre sideways again and inspect. Work your way around the ENTIRE wheel. Then do the other side.

Most likely what happened is a lot of people leave the area around the valve-stem for last. This then pinches the tube at that spot. You have to push the valve-stem INTO the tyre at the end to ensure that the tube isn't pinched at that spot.

rayone

Thanks for your replies.

The tyre is seated all round just fine, but you're right it was a little (very little) bunched up when I put it on, but I figured it would correct itself when I inflated...

I'll give it another go, and try replacing with the front.

- Didn't change the tubes, didn't think I needed to when changing from 26x2.1 to 26x2.1

Thanks again.

Soil_Sampler

conti tires run small, not true to size.

rayone

The tyre is definetely heavier in a spot.

Tried without the tube, just the rim + tyre and it falls to the heavy spot.

Fix: Wrapped some soldering wire around the valve and put the heavy stop on the opposite side... works.

Thanks again for the tips.

dobber

I think you're chasing a problem that isn't really there.

Soil_Sampler

your rim will be heavier in a spot, it won't be balanced.

operator

Is this a typo?

operator

+1

The OP is basically noticing that the rim is heavier in one spot, which is true for 99.9% of the wheels out there which weren't specifically designed to mitigate this.

What a wild goose chase...

BCRider

We just don't ride fast enough to worry about tire imbalances. The only time you would feel the weight is if you did a 40 to 50 kph speed run down some crazy steep hill. And at that point many bicycles get so skittery from other things that you'll never have time to worry about the tire balancing. Meanwhile you're spinning that hunk of solder up to speed every time you pull away from a stop and bleeding your energy into heat each time you stop it again.

I'm not sure I've ever had a tire that ran totally true or was balanced perfectly. If my wheels don't settle to a heavy spot in the workstand I get worried that my wheel bearings are seized.......

Now badly out of round is another issue. Years ago I brought a set of tires home and one mounted up with the usual small wobble. The other one had a huge lump to it. That tire got taken back and replaced. On the size of tires you're talking here if they seat properly as noted by the molding line around the bead area as noted above and if they don't have any lumps that stick out more than about 1/8 to 3/16 then the tire is fine and that much runout is normal. Not desireable but it's not something to lose sleep over.