Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-21-11, 10:02 PM   #1
jimmuller 
What??? Only 2 wheels?
Thread Starter
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Bikes: '73 Raleigh Carlton Gran Sport, '72 Peugeot UO-8, '82 Peugeot TH8, '87 Bianchi Brava, '76? Masi Grand Criterium, '87 Centurion Ironman Expert, '74 Motobecane Champion Team, '86 Gazelle champion mondial, '81? Grandis, and lots of uncertainty on some
Posts: 10,511
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
What to do about a thumpy wheel

I have a rim (front wheel, a Sun 27" M-13II) which was made poorly. The two sections don't line up well at the joint. As a result one edge sticks up above the other and on one side of the rim it catches on the brake pad. I've tried polishing it down and have made it better but it still isn't perfect. Even after I've cleaned the surface it seems to get worse as I ride, as if pad material were building up on the braking surface.

Bombing down switchbacks at 30+ mph on Cadillac Mt. in Acadia Natl Park this past week made me realize how problematic the seriously thumping front brake could be. I gotta' fix this!

I can try polishing it more with special emphasis on getting the surface smooth as opposed to just lining up the two surfaces on opposite sides of the joint. Of course it will end with a slight depression in the surface, even more than it already has. Or I can simply buy a new rim and rebuild the wheel.

Have any of you ever tackled a problem like this? Is it possible to fix, or should I just get a new rim and be done with it? (Yes, I can build the wheel.)

I thought about whether to post this in C&V or mechanics, decided it was a virtually-old rim on a truly old bike, so C&V it should be.

Last year I posted a thread about the trouble I had getting new wheels built. I'm now down to this last unsolved problem. For various reasons I can't go back to the store who sold me this rim and who built not what I wanted and who screwed up a few other features. Long story, not worth repeating. But I'm just going to build all my own wheels from now on.

And for what it's worth - two loops around the Park Loop Road plus one run up and down Cadillac - 45.6 miles, 3440ft elevation gain. Got lots of attention for the "beautiful old bike", my Raleigh Gran Sport.

Mileage + age of bike + age of rider + elevation gain (in 100's of ft) = 180!
__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline   Reply With Quote
Old 09-21-11, 10:41 PM   #2
auchencrow 
Senior Member
 
auchencrow's Avatar
 
Join Date: Apr 2009
Location: Detroit
Bikes:
Posts: 10,330
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
I think I'd attack that one with my orbital sander - that is, provided the step is no more than 20 thou or so.*
If it was worse than that likely I'd just replace the rim.

(*Such surgery would have to be done on the laced-up, tensioned wheel - the joint may sit a little differently as a raw rim.)
__________________
- Auchen
auchencrow is offline   Reply With Quote
Old 09-22-11, 12:01 AM   #3
rich rice
Senior Member
 
rich rice's Avatar
 
Join Date: Jul 2010
Location: chicago burbs
Bikes: too many to list
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I'd try smoothing it down with some 320 grit wet-or-dry sandpaper on a block, then go to finer grits to polish it back to a nice shiny finish. Just try to get it to be as smooth and even a transition as you can without creating a low spot. Most times this will work with satisfactory results.
rich rice is offline   Reply With Quote
Old 09-22-11, 12:16 AM   #4
bigbossman 
Dolce far niente
 
bigbossman's Avatar
 
Join Date: Dec 2004
Location: Northern CA
Bikes:
Posts: 10,777
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Let me get this straight - you're "Bombing down switchbacks at 30+ mph" on a front wheel that you know is defective?

Yikes.

Ever see what happens when a front wheel fails at speed? Don't try to "fix" it - get a new rim and rebuild.
__________________
"Love is not the dying moan of a distant violin, itís the triumphant twang of a bedspring."

S. J. Perelman
bigbossman is offline   Reply With Quote
Old 09-22-11, 12:58 AM   #5
3alarmer
Can'tre Member
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Bikes: old ones
Posts: 14,017
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 838 Post(s)
Quote:
Originally Posted by bigbossman View Post
Let me get this straight - you're "Bombing down switchbacks at 30+ mph" on a front wheel that you know is defective?

Yikes.

Ever see what happens when a front wheel fails at speed? Don't try to "fix" it - get a new rim and rebuild.
Yeah, what he said ^^^^^^^^^^

Or possibly:
3alarmer is offline   Reply With Quote
Old 09-22-11, 03:54 AM   #6
rich rice
Senior Member
 
rich rice's Avatar
 
Join Date: Jul 2010
Location: chicago burbs
Bikes: too many to list
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It doesn't sound that serious to me from the OP. If it is really out of whack, then obviously destroy it. If it is a matter of a sloppy joint but it's solid, it simply needs to be dressed with a sanding block and polished out. None of us can see it, feel it, or ride it. I'm not so quick to trash a wheel over something that I can adjust. Only the OP can decide if a correction will be safe. Then again, I ride on 40+ year old wheels all the time...
rich rice is offline   Reply With Quote
Old 09-22-11, 04:43 AM   #7
rootboy 
Senior Member
 
rootboy's Avatar
 
Join Date: Apr 2005
Location: Wherever
Bikes:
Posts: 15,889
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 152 Post(s)
I had to do exactly as rich rice said Jim, on the very same model rim. Worked fine. Try to concentrate on the "high side" with the sand paper first, necking it down to the lower surface, then smooth out the whole braking surface to about 3 to 4 inches either side of the joint. As I remember I started with 220 grit and went up from there, to maybe 400 grit, to match the scratch pattern on the braking surfaces. Easier to do, of course, with no tire mounted. I'm picking up another pair of these rims from the LBS this week, and this reminds me to carefully check the joints before I pay, thanks.
rootboy is offline   Reply With Quote
Old 09-22-11, 10:29 AM   #8
jimmuller 
What??? Only 2 wheels?
Thread Starter
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Bikes: '73 Raleigh Carlton Gran Sport, '72 Peugeot UO-8, '82 Peugeot TH8, '87 Bianchi Brava, '76? Masi Grand Criterium, '87 Centurion Ironman Expert, '74 Motobecane Champion Team, '86 Gazelle champion mondial, '81? Grandis, and lots of uncertainty on some
Posts: 10,511
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
Quote:
Originally Posted by bigbossman View Post
Let me get this straight - you're "Bombing down switchbacks at 30+ mph" on a front wheel that you know is defective?

Yikes.
Thanks for the concern, bbm, but you got it backwards. Bombing down the switchbacks wasn't a problem. NOT bombing down was the problem!

Switchback? What switchback?



Here is the rim joint in question:



__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline   Reply With Quote
Old 09-22-11, 10:45 AM   #9
southpawboston 
Senior Member
 
southpawboston's Avatar
 
Join Date: Aug 2008
Location: Somerville, MA and Catskill Mtns
Bikes:
Posts: 4,008
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
There's a thread going on right now on the CR list about this exact question. The response from JP Weigle was that back in the day, this was never cause for getting rid of the rim. Filing the weld down smooth to get rid of the brake thump was something riders just did as part of tuning their machines. Coming from JP Weigle, I'd put stock in it. Keep the rim and just try filing it down smooth, as some others have suggested.
__________________
Velo Lumino - Lighting components and integration solutions for fine hand-built and classically inspired bicycles

Riding the Catskills blog

Flickr

1971 Mercian Olympic | 1972 Jeunet 630 | 1982 Jack Taylor Tour of Britain | 1984 Shogun 1500 650B | 2013 Rawland Stag | 2014 Jeff Lyon L'Avecaise | 2015 Bike Friday Haul-a-Day
southpawboston is offline   Reply With Quote
Old 09-22-11, 10:57 AM   #10
fender1
Senior Member
 
fender1's Avatar
 
Join Date: Jan 2006
Location: Berwyn PA
Bikes: I hate bikes!
Posts: 5,642
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 64 Post(s)
If it were me, I would replace it. $30 is not that much if you re-do the wheel yourself. Also save the old rim and "work" on it if you feel you need too but I would feel that if a rim got out of the factory with this kind of defect, there maybe additional unseen issues. Per what Weigle said above, this is not the era when alloy rims are super expensive and some what high tech.

http://www.comcycle-usa.com/ProductInfo.aspx?id=6389740
fender1 is offline   Reply With Quote
Old 09-22-11, 11:07 AM   #11
Andycapp
Senior Member
 
Andycapp's Avatar
 
Join Date: Aug 2011
Location: Puyallup, WA
Bikes: Tommasini Super Prestige, Kamra Triathlee, Nishiki Tri-A equipe', Sakai 2000
Posts: 446
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If the rim were reversed, it wouldn't "cure" the problem, but would it reduce it? The brake pad would " fall" off the edge instead of catching it. Just an idea, I'd still try to smooth it out as well as I could.
-Andy
Andycapp is offline   Reply With Quote
Old 09-22-11, 11:21 AM   #12
rhm
multimodal commuter
 
rhm's Avatar
 
Join Date: Nov 2006
Location: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Posts: 15,818
Mentioned: 29 Post(s)
Tagged: 0 Thread(s)
Quoted: 107 Post(s)
I would just attack it with a fine, clean, flat file. There's a small triangular area, maybe an inch long, that need to come down a little bit. After one or two swipes with the file, clean the aluminum crud out of the file before taking another swipe. Then fine sandpaper, mostly to see what it feels like. For best results, remove the tire/tube before filing; if lazy (I'm lazy), just let the air out and flop the tire over to the other side while filing.

I like Andy's idea of reversing the wheel; but what does the other side of the join look like? It may be exactly the same, in which case reversing the wheel will not change anything.
rhm is offline   Reply With Quote
Old 09-22-11, 12:06 PM   #13
jimmuller 
What??? Only 2 wheels?
Thread Starter
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Bikes: '73 Raleigh Carlton Gran Sport, '72 Peugeot UO-8, '82 Peugeot TH8, '87 Bianchi Brava, '76? Masi Grand Criterium, '87 Centurion Ironman Expert, '74 Motobecane Champion Team, '86 Gazelle champion mondial, '81? Grandis, and lots of uncertainty on some
Posts: 10,511
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
Such a plethora of answers! Thanks all.

Quote:
Originally Posted by Andycapp View Post
If the rim were reversed, it wouldn't "cure" the problem, but would it reduce it?
Flipping the wheel would just make the other side catch, since the two "halves" are offset from each other. Flipping the wheel would also earn me the wrath of the C&V style gods who insist that both tire label and wheel label be readable from the drive side. Can't have that, can we?

In any case, I have previously tried cleaning it and have already sanded it down quite a bit from the original. If I could make it stop building up rubber so quickly it might just be okay. But what the heck, a new rim isn't so expensive either. It's my time either way.
__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline   Reply With Quote
Old 09-22-11, 12:09 PM   #14
3alarmer
Can'tre Member
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Bikes: old ones
Posts: 14,017
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 838 Post(s)
If you are dead set on smoothing/filing this as a fix, try the
sandpaper on the brake blocks method and see if it gets you
anywhere after some riding and squeezing.

Start as coarse as you're comfortable and go finer as desired. YMMV
3alarmer is offline   Reply With Quote
Old 09-22-11, 12:17 PM   #15
rootboy 
Senior Member
 
rootboy's Avatar
 
Join Date: Apr 2005
Location: Wherever
Bikes:
Posts: 15,889
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 152 Post(s)
Quote:
Originally Posted by jimmuller View Post
C&V style gods who insist that both tire label and wheel label be readable from the drive side. Can't have that, can we?
I solved that problem. I removed the stickers from my M13's, thinking they were ugly and non-C&V looking. Update; just picked my second set of these rims from the bike shop (I like these rims ) and the joint is a whole lot better on this pair ...though the polish is not as good on this set. Whaah!

Last edited by rootboy; 09-22-11 at 12:21 PM.
rootboy is offline   Reply With Quote
Old 09-23-11, 04:59 PM   #16
jimmuller 
What??? Only 2 wheels?
Thread Starter
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Bikes: '73 Raleigh Carlton Gran Sport, '72 Peugeot UO-8, '82 Peugeot TH8, '87 Bianchi Brava, '76? Masi Grand Criterium, '87 Centurion Ironman Expert, '74 Motobecane Champion Team, '86 Gazelle champion mondial, '81? Grandis, and lots of uncertainty on some
Posts: 10,511
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
I've now spent some considerable amount of time sanding both sides of this wheel. I haven't taken either side down so far that the weld joint disappeared but it is starting to on both sides. After the first go at it yesterday I rolled the bike slowly past that spot with the brake applied lightly/ It seemed to grab slightly as if the rim were wider there. Rode it around the block and observed not only that it thumped but that it quickly built up pad material there.

I believe what is going on is that the rim is effectively wider right at the joint. The leading edge of one side's pad is pressing against the part sticking out on that side while the trailing side of the other pad is pressing against the part sticking out on the trailing side. Also the buffing may have left it with a slightly rougher surface causing it to accumulate pad material.

So today I spent more time hitting it with 600, with an emphasis on both further taking down the high side and smoothing out the finish before and after the joint. It feels nicer now but I haven't had a chance to ride it. It's been raining all day... I'm in bike withdrawal already.
__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline   Reply With Quote
Old 09-23-11, 05:10 PM   #17
photogravity 
Hopelessly addicted...
 
photogravity's Avatar
 
Join Date: Aug 2009
Location: Central Maryland
Bikes: 1949 Hercules Kestrel, 1950 Norman Rapide, 1970 Schwinn Collegiate, 1972 Peugeot UE-8, 1976 Raleigh Sports, 1977 Raleigh Sports, 1977 Jack Taylor Tandem, 1984 Davidson Tandem, 2010 Bilenky "BQ" 650B Constructeur Tandem, 2011 Linus Mixte
Posts: 5,008
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by jimmuller View Post
Is it possible to fix, or should I just get a new rim and be done with it? (Yes, I can build the wheel.)
Yes, though my solution would be to put a drum brake hub on the bicycle. In all seriousness though, the answers others are offering make perfect sense and would be similar to the approach I would take with this kind of issue.
__________________
--
Ridding the world of derailleurs, one bicycle at a time.

46 Hercules Roadster, 49 Hercules Kestrel, 50 Norman Rapide, 51 Hercules Lion, 52 Hercules Windsor, 56 Hercules Royal Prince, 61 Fiorelli Tandem, 67 Carlton Super Race (IGH), 70 Schwinn Collegiate (IGH), 71 Hercules, 71 STF Hercules, 72 Peugeot PX-8 (IGH), 76 Raleigh Sports, 77 STF Raleigh Sports, 77 Jack Taylor Tandem, Early-80's Mike Appel SC, 84 Davidson Tandem, Late-80's Alpine, 10 Bilenky "BQ" Signature Tandem
photogravity is offline   Reply With Quote
Old 09-23-11, 05:16 PM   #18
rootboy 
Senior Member
 
rootboy's Avatar
 
Join Date: Apr 2005
Location: Wherever
Bikes:
Posts: 15,889
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 152 Post(s)
It can be a real chore Jim. I worked on mine a while. Someone suggested a flat file and I think if I had to do over again I would have started with a very fine file. Remove material fast, get it flat, then bring the scratch pattern back with various grits of sand paper. That bump you describe is troublesome however. Rim extrusion could have been deformed during manufacturing and that might be very difficult to get perfectly flat. Also, if you haven't done it, I would sure remove the tire and work on it. Do you have a very fine smooth file?
rootboy is offline   Reply With Quote
Old 09-23-11, 05:43 PM   #19
rich rice
Senior Member
 
rich rice's Avatar
 
Join Date: Jul 2010
Location: chicago burbs
Bikes: too many to list
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Sounds like you're gaining on it. If it's too bad, then a new rim is in order. I should have prefaced my initial post with the fact that I build custom guitars for a living, thus have loads of experience at making problems go away, many long hours of hand sanding/shaping/smoothing/finishing every week, and plenty of very fine tools with which I can attack this sort of problem. However, a bulge is different, insofar as there could be structural problems. Most likely not, but you don't want to weaken the rim- just smooth it out. A very slight bulge would be insignificant, but a hefty one would require the removal of too much material, thus weakening the rim. It would be a good idea to measure the width of the rim in several spots with a digital caliper, to make sure you know what your target is. A brand new fine toothed flat file would be fine for leveling the surface, but be sure to only file in the cutting direction and have a file cleaning brush on hand to constantly keep the file immaculate. I would end up polishing the rim (once it is flush and level) down to about 2000 grit wetsand paper, then use a polishing compound such as Meguiar's No.9 Swirl remover to bring it to full mirror finish. Another step would be to use even finer MicroMesh before the compound, up to about 12,000 grit.
rich rice is offline   Reply With Quote
Old 09-23-11, 05:49 PM   #20
rootboy 
Senior Member
 
rootboy's Avatar
 
Join Date: Apr 2005
Location: Wherever
Bikes:
Posts: 15,889
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 152 Post(s)
Sage advice Rich. I will detour a bit from your good advice to say that the Sun M 13 sidewalls aren't polished. The rims are but the sidewalls seem to be about 400-500 grit. I matched mine up pretty well going to 500 is all. Good caution on the bump, though.
rootboy is offline   Reply With Quote
Old 09-23-11, 06:03 PM   #21
rich rice
Senior Member
 
rich rice's Avatar
 
Join Date: Jul 2010
Location: chicago burbs
Bikes: too many to list
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
From the pics I don't think it looks too bad, I'd keep riding the rim- but my wife thinks I'm nuts.. probably some merit to her thoughts.

I'm not familiar with Sun rims, although I have a set on my Bottecchia. Guess I'll have to go out and see what they look like, and what model they are.. They were on the bike when I bought it, and I haven't done any serious work on it yet. Just a few rides, which convinced me I love the bike..
rich rice is offline   Reply With Quote
Old 09-24-11, 06:30 AM   #22
wahoonc
Senior Member
 
wahoonc's Avatar
 
Join Date: Jan 2005
Location: On the road-USA
Bikes: Giant Excursion, Raleigh Sports, Raleigh R.S.W. Compact, Motobecane? and about 20 more! OMG
Posts: 16,687
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Got a set of calipers? Measure the amount of the bump compared to some other areas on the rim. I have ground down my fair share of rims over the years. On some bikes I just don't bother, on go fast road bikes or tour bikes I do. This is a measurement that I take when I buy a new set of rims. Some can be ground down some can't, I consider one with an excessive bump or edge to be a manufacturing defect. If the wheel is getting hub brakes I don't worry about it.

Aaron
__________________
Webshots is bailing out, if you find any of my posts with corrupt picture files and want to see them corrected please let me know. :(

ISO: A late 1980's Giant Iguana MTB frameset (or complete bike) 23" Red with yellow graphics.

"Cycling should be a way of life, not a hobby.
RIDE, YOU FOOL, RIDE!"
_Nicodemus

"Steel: nearly a thousand years of metallurgical development
Aluminum: barely a hundred
Which one would you rather have under your butt at 30mph?"
_krazygluon
wahoonc is offline   Reply With Quote
Old 09-24-11, 01:51 PM   #23
jimmuller 
What??? Only 2 wheels?
Thread Starter
 
jimmuller's Avatar
 
Join Date: Apr 2010
Location: Boston-ish, MA
Bikes: '73 Raleigh Carlton Gran Sport, '72 Peugeot UO-8, '82 Peugeot TH8, '87 Bianchi Brava, '76? Masi Grand Criterium, '87 Centurion Ironman Expert, '74 Motobecane Champion Team, '86 Gazelle champion mondial, '81? Grandis, and lots of uncertainty on some
Posts: 10,511
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
I thank you all for your replies. The brake bump I spoke of is attributable, I believe, to the offset between leading and trailing halves of the weld.



The offset from one side to the other creates a momentarily wider rim between the leading part of one side's brake pad at the trailing part of the other side's pad. Even when the ridge has been smoothed down to a mere ripple the widening effect remains.

I've been working on it and am quite certain it will be just fine eventually. All it needs is sufficient patience, beer, elbow grease, more patience, some test riding (long after the beer is finished), more beer, and perhaps more patience.

I'd ridden this wheel 76 miles a few weeks earlier and while it wasn't smooth braking it wasn't terribly thumpy either. The run down Cadillac is what made me decide to address the problem. I have no desire to cheat death again, even if it really wasn't much of a cheat the first time.
__________________
Real cyclists use toe clips.
With great bikes comes great responsibility.
jimmuller
jimmuller is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:14 AM.