Check tru without a stand?

[bikeoutback]

Since the trails haven't rode I'm filling my spare time by tuning up the bike essentially when I have spare time. I'm trying to check everything and make sure everything is in proper working order and also anticipating what I need to replace on the bike possibly now or in the future, proactive maintenance I see it as. One thing while checking the disc brake pads last night I found was that when I spin the front wheel the rotor is has the appearance moving side to side.... it's slightly warped is my guess but. This lead to a couple of things I'd like to check and questions I have that I'm not sure about:

1. Can I check the tru on the wheel without a stand or is there an easy way? I'm assuming if it comes up out of tru I'll just have to take it in as I don't have the tools yet and not sure I want to attempt wheels yet.

2. Logical question: whether the wheel is tru or not this shouldn't have any effect on the rotor correct?

3. When looking down at the entire wheel/tire setup it seems the new tires have a line down the middle of the tire that is very distinguishable but I think it's just off of center of the fork, is this normal with having disc brakes? Logic would say the room for the disc on one side might put the tire just off center possibly.

Thats it for round 1 tonight I think I check everything on the back of the bike.

[biking_stickman]

1. Can I check the tru on the wheel without a stand or is there an easy way? I'm assuming if it comes up out of tru I'll just have to take it in as I don't have the tools yet and not sure I want to attempt wheels yet.


Hold a sharpie marker against the fork/frame and spin the wheel. As the wheel is spinning slowly move the sharpie towards the rim. When the sharpie first touches the rim, hold it in place for a full rotation. The length of the line should indicate if the wheel is true.

[gordanfreeman]

its pretty normal for disc rotors to have a bit of a wobble. nothing to worry about unless its causing a lot of pad rub or problems fitting through the caliper.

[CrazyKid]

Yes, the rotor may be untrue. What you do to fix this is take a crecent wrench and in the light and a quiet place listen to see if the rotor is rubbing against the pads. If you start to listen and you don't hear any sound you may have to adjust the barrels on the levers to make the pads go closer together so you can hear the ringing. If it is already ringing you need to look and see what side it is rubing on and mark the place on the rotor that it is rubbing. Then with crecent in hand adjust it to fit the rotor and bend the rotor slightly the opposite direction from which the rotor is rubbing on the pads. You dont want to bend it too far or it may crack off, so you may have to just bend it out slightly, but bend it a few times to get it to even out. once it looks good listen again to see if you still can hear ringing if you cant your done and the rotor is true. This is very common and you should check your rotors to make sure they are not rubbing about once a week during the hard summer riding.

To answer Q. #2 yes you are rite the trueness of the wheel cannot affect the trueness of the rotor, because the rotor is bolted directly onto the hub which can never be untrue.

[patches]

to answer question 3, your wheel my be out of "dish". regardless of the rotor, the rim (and tire) should be aligned with the center of your fork, first check to see if the wheel is seated properly in the dropout (it probably is) then ask your local shop to check the dish on your wheel and re-dish as needed. bringing the bike might also help as a reference point.

[bikeoutback]

to answer question 3, your wheel my be out of "dish". regardless of the rotor, the rim (and tire) should be aligned with the center of your fork, first check to see if the wheel is seated properly in the dropout (it probably is) then ask your local shop to check the dish on your wheel and re-dish as needed. bringing the bike might also help as a reference point.

Thanks for the replies. The rotors dont' rub currently as I have the pads adjusted just off so the rotor never rubs, it is just barely out of true on one side so I'm gonna leave it for now.

The guys at the LBS said it's normal for the wheel to be just slightly off center of the fork due to the rotor.... thus taking it to my local shop might not work... guess I'll just ride it and see if anything seems off at all.

[El Chupacabra]

Thanks for the replies. The rotors dont' rub currently as I have the pads adjusted just off so the rotor never rubs, it is just barely out of true on one side so I'm gonna leave it for now.

The guys at the LBS said it's normal for the wheel to be just slightly off center of the fork due to the rotor.... thus taking it to my local shop might not work... guess I'll just ride it and see if anything seems off at all.

I couldn't deal with my wheel not being centered in the frame/fork. They can dish it properly.

[bikeoutback]

I couldn't deal with my wheel not being centered in the frame/fork. They can dish it properly.

That's the odd part, I never noticed it till this year. I've had the bike 3 years and only noticed it cause I put new tires on last year and there is a line down the middle of the tire... mayabe it's not down the middle. That was when I started looking and trying to determine if it was centered or not. I'll just ride it and if nothing feels off then go with it. I also don't think the wheels are out of true, I think it's more of that effect when tire has light colored dust on it. When it's spinning it appears to wobble but in reality it's the dust line that is not straight on the tire, not the rims themselves. Now just need dry weather so can go riding.

[patches]

The guys at the LBS said it's normal for the wheel to be just slightly off center of the fork due to the rotor

the guys at the lbs are wrong, disc wheels are dished the same as non disc wheels.

try taking the tire off and seeing if the rim is on center with the frame.