After my recent accident I decided to give my bike a good once-over. The only issue was that the rear wheel had a little hop in it. The wheel's always had screwed up tension on all the spokes, so I decided to do it right (sorta) and fully detension and retighten the wheel. Anyway, I had about 1/5 of the wheel's circumference that was too close to the hub, while the other 4/5 was pretty consistent. No accurate measuring because my truing stand is my brake and the rim's full of little dents anyway. (hence the "sorta" comment above) But that 1/5 was definitely too low. My method of fixing it was to mark off that section and slowly tighten the remainder of the wheel while backing off the marked area. Seemed to work up to a point, got about half way to where it ought to be. But then I quit making progress. Question is: could I keep going the way I was going and pop that part of the rim out, or will I need to loosen it up again and do a little hammering? Or, third option, can I just live with it? Unless I'm creeping along and looking for it I really don't notice the hop anymore and spoke tension seems to be even. So can I expect this to be reasonably stable or will it make itself worse in short order?
It sounds to me like it's time to get a new rim. Have you checked the tension on the spokes? If the spokes where you're low are of equal or greater tension than the other spokes your rim is bent. If you can afford it, get a new one. If not then live with what you have. You will wind up over tensioning spokes and will possibly start breaking them. You could even wind up with a complete failure and have the wheel collapse. I've seen that happen before.
Zog The Undeniable 19 March 2005 12:49:17 [ permanent link ]
B.B. wrote:> After my recent accident I decided to give my bike a good once-over. > The only issue was that the rear wheel had a little hop in it. The > wheel's always had screwed up tension on all the spokes, so I decided to > do it right (sorta) and fully detension and retighten the wheel.> Anyway, I had about 1/5 of the wheel's circumference that was too > close to the hub, while the other 4/5 was pretty consistent. No > accurate measuring because my truing stand is my brake and the rim's > full of little dents anyway. (hence the "sorta" comment above) But that > 1/5 was definitely too low.> My method of fixing it was to mark off that section and slowly > tighten the remainder of the wheel while backing off the marked area. > Seemed to work up to a point, got about half way to where it ought to > be. But then I quit making progress.> Question is: could I keep going the way I was going and pop that part > of the rim out, or will I need to loosen it up again and do a little > hammering?> Or, third option, can I just live with it? Unless I'm creeping along > and looking for it I really don't notice the hop anymore and spoke > tension seems to be even. So can I expect this to be reasonably stable > or will it make itself worse in short order?> There is nearly always a bit of hop at the rim joint (whether pinned or welded). Is the 1/5 there?
In article <1111229252.941505.15970@f14g2000cwb.googlegroups.com>, "bikeguy11968" <bikeguy11968@yahoo.com> wrote:
Ummmm, perhaps I'm stating the obvious here..>
Hire a professional?>
(Oooh, ahhgggg...he said it! spend 20$ to have something done right!>Flame him flame him! banned from the newsgroup for life!)
Yeah, that was pretty obvious. I considered it and had a good reason to not take it to a shop. Kind of implies I won't do it right, too, which is just rude. And it doesn't really answer my question so much as it tries to answer a whole other question along the lines of "Should I take it to a shop?" If that reply was meant to be helpful it really wasn't.
B.B. Wrote: > After my recent accident I decided to give my bike a good once-over.> The only issue was that the rear wheel had a little hop in it. The> wheel's always had screwed up tension on all the spokes, so I decided> to> do it right (sorta) and fully detension and retighten the wheel.> Anyway, I had about 1/5 of the wheel's circumference that was too> close to the hub, while the other 4/5 was pretty consistent. No> accurate measuring because my truing stand is my brake and the rim's> full of little dents anyway. (hence the "sorta" comment above) But> that> 1/5 was definitely too low.> My method of fixing it was to mark off that section and slowly> tighten the remainder of the wheel while backing off the marked area.> Seemed to work up to a point, got about half way to where it ought to> be. But then I quit making progress.> Question is: could I keep going the way I was going and pop that part> of the rim out, or will I need to loosen it up again and do a little> hammering?> Or, third option, can I just live with it? Unless I'm creeping along> and looking for it I really don't notice the hop anymore and spoke> tension seems to be even. So can I expect this to be reasonably> stable> or will it make itself worse in short order?>
Balanced spoke tension, on a per side basis, is very important. You can use the tone as your indicator.
You were going in the correct direction.
Quantify the amount of hop in 0.1ths of a mm if you can. If it is less than 0.5 mm, I would tend to let it go.
Replacing the rim with one of the same Effective Rim Diameter (ERD) is an option you should consider.
If you are going to attempt to remove any distortions in the rim, you might want to get a copy of "the Bicycle Wheel" by Jobst Brandt ISBN 0-9607236-4-1. Many library systems can get it for you or you can buy it at some bicycle shops/or on line. A few diagrams in the book will help more than words I can convey. You will need to remove (or at lest detension spokes) in the bent area(s). Using a rubber mallet and blocks of wood as shown in the book is the way to try. Be careful not to overshoot. Position the supporting blocks on the outside of the rim under the area you are working and use a wood block on the inside of the rim where you strike it in the desired direction. I agree with the telling statement in the book: "Although some dents can be repaired satisfactorily this procedure is generally used only to make a wheel usable until a new rim can be obtained." David Ornee, Western Springs, IL
In article <daveornee.1m5cpa@no-mx.forums.cyclingforums.com>, daveornee <daveornee.1m5cpa@no-mx.forums.cyclingforums.com> wrote:
[...]
Balanced spoke tension, on a per side basis, is very important. You>can use the tone as your indicator.
Yup, I gave it the spoke test after I finished futzing with it and it came out all even. Tension's even, wheel doesn't wobble side-to-side much,
You were going in the correct direction. >
Quantify the amount of hop in 0.1ths of a mm if you can.>If it is less than 0.5 mm, I would tend to let it go.
I think it's around a 1/16th of an inch, or about 1.5mm difference between highest and lowest. It seems to me that the tire itself is capable of taking up the difference when moving.
Replacing the rim with one of the same Effective Rim Diameter (ERD) is>an option you should consider.
These are old 27" steel wheels. Once it's financially possible I plan to just replace the wheels & hubs as a set. Until then I'll have to keep 'em working.
If you are going to attempt to remove any distortions in the rim, you>might want to get a copy of "the Bicycle Wheel" by Jobst Brandt ISBN>0-9607236-4-1. Many library systems can get it for you or you can buy>it at some bicycle shops/or on line.>A few diagrams in the book will help more than words I can convey.>You will need to remove (or at lest detension spokes) in the bent>area(s). Using a rubber mallet and blocks of wood as shown in the book>is the way to try. Be careful not to overshoot. Position the supporting>blocks on the outside of the rim under the area you are working and use>a wood block on the inside of the rim where you strike it in the>desired direction.>I agree with the telling statement in the book:>"Although some dents can be repaired satisfactorily this procedure is>generally used only to make a wheel usable until a new rim can be>obtained.">David Ornee, Western Springs, IL
1. If you knew how to do it right, you likely wouldn't have to ask. Why aren't you taking it to a shop? Even if it's a beater wheel you woudl only get charged a few bucks to get it done right? Is it possible that your local shop sucks so bad that you won't even bring in a damaged wheel to get repaired? That is just pathetic. (for them)
On Sat, 19 Mar 2005 21:13:00 -0600, "B.B." <DoNotSpamthegoat4@airmail.net.com.org.gov.tw.ch.ru> may have said:
In article <423be768.0@entanet>,> Zog The Undeniable <hrothgar19@yahoo.com> wrote:>
There is nearly always a bit of hop at the rim joint (whether pinned or >>welded). Is the 1/5 there?>
Nope. But one end of the 1/5 is at the valve hole.
Be cautious when straightening in the vicinity of the valve hole; the rim is weaker there for obvious reasons.
-- My email address is antispammed; pull WEEDS if replying via e-mail. Typoes are not a bug, they're a feature. Words processed in a facility that contains nuts.
It saddens me that customer service and mechanical skills have become so lacking that regular civilians feel the need to become completely self sufficient.
are knobbies mounted? if so that's a no feel situation with knobs taking the abuse. also cancels out this fact-the saveable bent rim when tightened way beyond the elysium field equal spoke torque final result tends to self heal over 0ne or more additional truings following a hundred or two hundred more miles consider the bent rim/wheel goinmg down the road on high pressure tires and more or less true that is acceptable without excessive wear to the wheel's components-takes a pounding just like an experienced craftsman beating it gently with a plastic hammer. and lo! the rim does go back toward being true without the excessive torques to drag it over there! the equal torque concept is available only for the gifted, lucky or experienced-25% +/- is more likely.
before this slides out of sight to resurface later mark the spokes overtightened and replace when the next spoke breaks caws now those spokes are next after.
