Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Seat Clamp Woes

Notices
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.

Seat Clamp Woes

Old 02-03-15, 02:49 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Jan 2011
Location: South Whidbey Island, WA
Posts: 112

Bikes: 2000 Raleigh M50, 2010 Specialized Roubaix Elite, 1973 Peugeot UO8, 197X Mercier 300, 196X Bottecchia Giro D'Italia

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked 1 Time in 1 Post
Seat Clamp Woes

So I finally got up the gumption to lace up my Ideale No.45. To do it I wanted to take it off the seat post so I could measure it up nicely, which meant I had to monkey with the clamp (Ideale no. 2, which is the run-of-the-mill standard clamp).

I got the saddle into good shape, put it back on the bike, set the angle, and tightened that horizontal bolt TIGHT, and left for my morning commute. I was fine until I hit a bump and the saddle pitched 20 degrees nose-up in traffic.

At work over lunch I re-set it, tightened the clamp as far as my little stubby wrench will let me. The seat rotates again right as I'm pulling out of work (with another rider witnessing...embarrassing). Then again this morning. Looking at the setup, it looks like the teeth of the clamp have stripped and rounded off, so I'm down to friction holding it.

At this point, I'm starting to get annoyed with the old clamps. When mine aren't rotating or slipping down the seatpost (22mm post), they creak.

I was curious how many, if any had given up on the old style clamps, and what they got to replace them.

I'm either going to get a modern seat tube (UO-8 with I believe 25.4mm post hole after shim is removed), or consider springing for one of those Ideale No.3 setups with the micro-adjust.
Aurorabucky is offline  
Old 02-03-15, 03:38 PM
  #2  
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,355 Times in 862 Posts
you talking regular tubular post and separate saddle clamp..


it's currently made for typical 7/8" 22.2 tops of post .. Brompton, Penta clip, Part# QPENTACLIPA

mostly aluminum stepless holds with a multiplate clutch.. , 1 bolt.
fietsbob is offline  
Old 02-03-15, 05:36 PM
  #3  
rhm
multimodal commuter
 
rhm's Avatar
 
Join Date: Nov 2006
Location: NJ, NYC, LI
Posts: 19,808

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...

Mentioned: 584 Post(s)
Tagged: 0 Thread(s)
Quoted: 1908 Post(s)
Liked 574 Times in 339 Posts
They are all the same design, more or less, but not all of the same quality. The cheaper Idéale ones are pretty bad. The nicer ones, and the better Brooks ones, are really quite nice.

I have a whole box of them, mostly cheap but functional ones. I can send you a few for the cost of shipping if you want.
__________________
www.rhmsaddles.com.
rhm is offline  
Old 02-04-15, 02:12 PM
  #4  
Senior Member
 
randyjawa's Avatar
 
Join Date: Apr 2007
Location: Thunder Bay, Ontario, Canada - burrrrr!
Posts: 11,674

Bikes: 1958 Rabeneick 120D, 1968 Legnano Gran Premio, 196? Torpado Professional, 2000 Marinoni Piuma

Mentioned: 210 Post(s)
Tagged: 0 Thread(s)
Quoted: 1372 Post(s)
Likes: 0
Liked 1,747 Times in 937 Posts
For bikes I ride on a regular basis, the old saddle clamp and straight seat post are gone! Same with rat traps, in favor of SPD.

That said, some of my bikes are original and I hope to keep them that way. Old technology is acceptable in such cases, even though the old T does not work as well as modern stuff, in my opinion. Seat posts can be a pain in the butt, for sure.

Saddle clamp...





Modern post...



The rotation problem is, sometimes, caused by mounting the clamp too low, catching part of the taper on the seat post. This will dramatically reduce the ability to prevent rotation.

To prevent rotation, if it possible to do so, ensure that the clamp is touching at all points on the seat post. Preventing rotation is not just a matter of tight. It is a matter of "area of contact". If enough of the clamp is not in contact with the seat post, the clamp will rotate. So...

Clean and ensue that the part are fitting together as required. This might mean rounding out the clamp or seat post, believe it or not.
__________________
"98% of the bikes I buy are projects".
randyjawa is offline  
Old 02-04-15, 02:47 PM
  #5  
Ride, Wrench, Swap, Race
 
dddd's Avatar
 
Join Date: Jan 2010
Location: Northern California
Posts: 9,172

Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.

Mentioned: 132 Post(s)
Tagged: 0 Thread(s)
Quoted: 1560 Post(s)
Liked 1,279 Times in 851 Posts
Good advice there, randyjawa.

Also one should be on the lookout for mis-matched ratcheting parts from different posts, so the teeth mightn't line up effectively.

And I believe I have had one or both toothed plates come off of center with their mating teeth on the clamp itself, such that the round pattern of teeth weren't concentric with the teeth on the clamp. I don't recall what brand it was that allowed such improper, non-concentric assembly (and subsequent slipping), but I suspect some design fault at least partly to blame.

I always feel lucky when the coarse position "indexing" allows the saddle to be set at just the right tilt!

And I'm always (and still) looking for a just-right position for my headset's indexing, gotta get lucky some day!
dddd is offline  
Old 02-04-15, 03:25 PM
  #6  
Thrifty Bill
 
wrk101's Avatar
 
Join Date: Jan 2008
Location: Mountains of Western NC
Posts: 23,520

Bikes: 86 Katakura Silk, 87 Prologue X2, 88 Cimarron LE, 1975 Sekai 4000 Professional, 73 Paramount, plus more

Mentioned: 96 Post(s)
Tagged: 0 Thread(s)
Quoted: 1236 Post(s)
Liked 961 Times in 626 Posts
+1 This is one of those situations where the modern replacement is a definite upgrade performance wise over the old school method. Just get a vintage indexed seat post, save the old one for when you retire the bike.
wrk101 is offline  
Old 02-04-15, 05:24 PM
  #7  
Senior Member
 
Lascauxcaveman's Avatar
 
Join Date: Nov 2011
Location: Port Angeles, WA
Posts: 7,922

Bikes: A green one, "Ragleigh," or something.

Mentioned: 194 Post(s)
Tagged: 0 Thread(s)
Quoted: 1627 Post(s)
Liked 630 Times in 356 Posts
Take RHM up on his offer. Or, based on your location, if you ever take that ferry over to Pt Townsend, you can hike or bike up to the Recyclery and they will give you one cheap.
__________________
● 1971 Grandis SL ● 1972 Lambert Grand Prix frankenbike ● 1972 Raleigh Super Course fixie ● 1973 Nishiki Semi-Pro ● 1979 Motobecane Grand Jubile ●1980 Apollo "Legnano" ● 1984 Peugeot Vagabond ● 1985 Shogun Prairie Breaker ● 1986 Merckx Super Corsa ● 1987 Schwinn Tempo ● 1988 Schwinn Voyageur ● 1989 Bottechia Team ADR replica ● 1990 Cannondale ST600 ● 1993 Technium RT600 ● 1996 Kona Lava Dome ●

Lascauxcaveman is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
scale
Classic & Vintage
18
07-15-18 08:47 AM
SethB
Bicycle Mechanics
20
09-30-16 05:38 PM
dweenk
Classic & Vintage
34
02-06-16 02:10 PM
Ol Danl
Classic & Vintage
6
10-23-11 04:47 PM
JUST WANNA RIDE
Bicycle Mechanics
6
10-16-10 08:02 AM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.