|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Can't true my wheel (roundness)
I got the side to side down. But when I work on the roundness, I can't get
it right. The wheels only have about 800 miles on them. I trued them according to the repair manuals and parks web site. They are rideable though. First I do lateral (which comes out good, but not perfect). Second , i do roundness . I tighten at the high spots to pull the wheel inward towards the hub and loosen at the low spots on the opposite side. Then I go back and check the lateral . I can't get the roundness good enough to where I want it. ( You defiinetely see the wobble up and down in the roundness). Could the rim be bent that way? Or can they only be bent laterally? Thanks |
Ads |
#2
|
|||
|
|||
Can't true my wheel (roundness)
chrisc wrote:
I got the side to side down. But when I work on the roundness, I can't get it right. The wheels only have about 800 miles on them. I trued them according to the repair manuals and parks web site. They are rideable though. First I do lateral (which comes out good, but not perfect). Second , i do roundness . I tighten at the high spots to pull the wheel inward towards the hub and loosen at the low spots on the opposite side. Then I go back and check the lateral . I can't get the roundness good enough to where I want it. ( You defiinetely see the wobble up and down in the roundness). Could the rim be bent that way? Or can they only be bent laterally? Thanks try roundness first, then lateral. this is particularly easy on dished rears where the drive side spokes essentially take care of roundness, the non-drive side, true. |
#3
|
|||
|
|||
Can't true my wheel (roundness)
Chris C? writes:
I got the side to side down. But when I work on the roundness, I can't get it right. The wheels only have about 800 miles on them. I trued them according to the repair manuals and parks web site. They are ridable though. First I do lateral (which comes out good, but not perfect). Second , i do roundness . I tighten at the high spots to pull the wheel inward towards the hub and loosen at the low spots on the opposite side. Then I go back and check the lateral . I can't get the roundness good enough to where I want it. ( You definitely see the wobble up and down in the roundness). Could the rim be bent that way? Or can they only be bent laterally? Thanks I prefer to get the wheel round first, this being the more forceful adjustment when trying to pull in a high spot. Besides, although it isn't likely, you should either stress relieve to see that the wheel is not too tight already or measure tension with a tensiometer. Make sure you have lubricated the spoke nipple to rim joints and the spoke thread to spoke nipple point. These spokes should turn freely. You didn't say how many spokes you wheels have but that could be a problem. Fewer than 32 spokes makes this greatly more difficult. Lateral alignment is simple compared to roundness and can be aided by pulling the rim toward the side the spoke in question is pulling. This unloads the threads and makes adjustment easier. Unless you got a ding in the rim from a hole in the road, I doubt that it is bent beyond truing. Jobst Brandt |
#4
|
|||
|
|||
Can't true my wheel (roundness)
chrisc wrote: I got the side to side down. But when I work on the roundness, I can't get it right. The wheels only have about 800 miles on them. I trued them according to the repair manuals and parks web site. They are rideable though. First I do lateral (which comes out good, but not perfect). You probably want to do a bit at a time - fix the worst roundness error, then the worst lateral, then repeat. Make sure to check the dish at some point as well. Second , i do roundness . I tighten at the high spots to pull the wheel inward towards the hub and loosen at the low spots on the opposite side. Ah, that might be part of your problem. There isn't necessarily a low spot opposite every high spot. Try going round just tightening at the high spots, and remember to check it regularly to make sure you haven't overcorrected - it's surprisingly easy to do. Then I go back and check the lateral . I can't get the roundness good enough to where I want it. ( You defiinetely see the wobble up and down in the roundness). Could the rim be bent that way? Or can they only be bent laterally? Thanks It's possible that the rim isn't radially true, but you should be able to correct for it with spoke tension (unless you remember whacking the rim off a kerb recently). |
#5
|
|||
|
|||
Can't true my wheel (roundness)
"chrisc" wrote:
I got the side to side down. But when I work on the roundness, I can't get it right. Is there one particular spot where it's out of round? With some rims, there will be a slight hop at the point where rim ends are joined (opposite the valve hole). If that's the case, and the variation is less than 1mm, I wouldn't sweat it. Art Harris |
#6
|
|||
|
|||
Can't true my wheel (roundness)
read JB-experience teachs that
me ? not much experience like you. problem is the axle-determines actual spoke length in relation to total wheel- the axle floats with your so called adjustment. your problem is to get the axle in the center. but to do this the spokes need be much tighter than the spokes are for getting lateral correct. lateral correct is done with the first 1/4 turns tighter than lightly seated. very low torque. minimal. problem is-that lateral trueing torque will not stretch the spokes into a running-on road-seated position to center the axle. so where's the point A where spokes are seated and lateral true is more or less in order? that's where the roundness correction begins IF!! the rim and axle are in agreement for center at this point and agree that the rim was fairly round to begin with. IF NOT!! then the roundness trueing takes place somewhat before point A. if the whole rig is out of whack then your in for a round dance whatzit a dozee dough? in and out of the Point A with both lateral and round until you pass Point A with both rim, axle, and your general good mood intact. the roundness trueing starts with full 360 sections. say you have a 40 degree lump (using a magic marker held stationery on turning braking surface) sticking out. i'll bet that's a place also under some lateral out of whack pressure. the other 320 is loosened, and the axle moves toward the loosening section-possibly bringing the lump with it. you see, some people will reef on the lump trying to force it down-but there's nowhere for it to go! its an interesting game. buy 3 rolls of colored tape, each different. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Rec.Bicycles Frequently Asked Questions Posting Part 1/5 | Mike Iglesias | General | 4 | October 29th 04 07:11 AM |
New bicycle idea | Bob Marley | General | 49 | October 7th 04 05:20 AM |
Spoke Over-Tension and Drifting Wheel Alignment | mCrux | Techniques | 6 | August 25th 04 04:29 PM |
Wheelbuilding issues | Nate Knutson | Techniques | 13 | May 9th 04 03:29 PM |
A physicist's question about tensioning a wheel | Sergio SERVADIO | Techniques | 35 | January 5th 04 03:27 PM |