Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Can a heavy (270lbs) rider reasonably ride an EL OS frame?

Notices
Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

Can a heavy (270lbs) rider reasonably ride an EL OS frame?

Old 05-30-24, 05:28 AM
  #1  
Senior Member
Thread Starter
 
Join Date: May 2008
Location: Toronto, Canada
Posts: 909

Bikes: (shortlist) Cyclops, Marinoni, Mariposa, Air Firday, Pocket Rocket Pro, NWT, SLX Fuso, Claude Pottie (France) x3, Masi Team 3v, Lemond Zurich, Bianchi OS

Liked 38 Times in 30 Posts
Can a heavy (270lbs) rider reasonably ride an EL OS frame?

I had a fellow inquire about a 62cm Bianchi EL OS frame I have for sale.
it is "Freuler" style (with headtube and seat tube extensions that I think allowed the top tube to be lower so the frame was more rigid)

but he said that in addition to being tall he is also pretty heavy, 270lbs.

I am not a frame builder and so I don't know what goes into making one "sound" for heavier riders.
I do know that Marinoni almost always used SP or SPX tubesets for frames bigger han 60cm .

But comparing specs of tubesets I see:
EL OS: seat tube 0.6/0.9 and downtube and top tube are 0.7/0.4/0.7
Versus
SP: seattube 0.7/1 and DT and TT 1/0.7/1

But The OS it has been pointed out to me has a bigger OD and so is more rigid.

Could a 270lbs rider reasonably ride an EL OS frame?

​​​​​​​Is stouter SP tubing used when the frames get big because the longer tube lengths are more fragile? Or because of a riders presumed extra weight ? (Probably the former)
pstock is offline  
Old 05-30-24, 07:29 AM
  #2  
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,189

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Liked 3,997 Times in 2,376 Posts
"Could a 270lbs rider reasonably ride an EL OS frame?"
Sure but if they are a stomper pedaling squares they likely would find a stouter frame to be a nicer ride. There's no real black and white line of when one "has to" go with stouter tubes.

"Is stouter SP tubing used when the frames get big because the longer tube lengths are more fragile? Or because of a riders presumed extra weight ? (Probably the former)"
I've talked about this with other builders before and some will begin to mix thinner walls with thicker walls in the 56-58cm size area. By 58cm I would be suggesting thicker walls all around unless the rider was a bean pole (and at 270lbs that's not the case here).

Fred Parr (who here remembers him?, who could forget him.) was one on the earlier proponents of OS tube diameters as being a better solution for larger/heavier riders, independent of wall thicknesses. My own take on "frame stiffness" (written with quotes as the meaning varies from reader to reader) is that the fork's steerer is way overlooked as a factor to overall bike handling. The steerer is the only frame member that isn't contained at both ends. So it sees a lot of bending forces, it's cantilevered design isn't the best for resisting these forces. I've noticed a large difference in the likelihood of speed man's shimmy starting up with the larger 1.125" steerer (compared to a 1" steerer) as example.

I think both the bike's load (be it rider or baggage) and the longer tube lengths affect the feel but I speculate the rider's weight and strength are more the issue Andy (trying to answer these questions that has no one answer)
__________________
AndrewRStewart
Andrew R Stewart is offline  
Likes For Andrew R Stewart:
Old 05-30-24, 07:37 AM
  #3  
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,525
Liked 3,821 Times in 2,603 Posts
I feel like Columbus would tell you that rider is too heavy for those tubes. True Temper would have. Unexpected Freddy Parr sighting in a thread. I still have some flux he sold me.
unterhausen is offline  
Likes For unterhausen:
Old 05-30-24, 04:50 PM
  #4  
blahblahblah chrome moly
 
bulgie's Avatar
 
Join Date: Apr 2009
Location: Seattle
Posts: 2,106
Liked 2,767 Times in 1,146 Posts
I used to weigh north of 270 (now down to 240 and still working on it), and I've always been happy on 531 frames with .8/.5-ish TT in 1" diameter. Others would feel that's too whippy, but I prefer it over stiffer frames.

EL-OS will be a little stiffer than that, probably, not doing the calculations, but I have in the past. The problem is the very thin walls, which can be a problem if the FB didn't do all they could to eliminate stress-risers. If there's a local discontinuity, watch for fatigue cracks. That could be at a water bottle or shifter BO, but more often on the bottom of the DT at the HT joint. The bike won't break all at once though, so it doesn't worry me much safety-wise, the crack grows slowly enough at first that you'll have time to spot it.

Tell him to buy the bike and try it, move it along for what he paid for it if not, and try something else. It might just be in the goldilocks zone for him.
bulgie is offline  
Likes For bulgie:
Old 06-02-24, 11:57 PM
  #5  
Junior Member
 
Join Date: Mar 2023
Location: Bandon, Oregon
Posts: 175

Bikes: Dave Tesch Model 100 Custom Reynolds 753 / Custom Panasonic built by Takao Ono (1973)

Liked 173 Times in 97 Posts
Ah, yes, who could forget Fred Parr. Used to see him in shops in the Santa Monica/W LA area. Might have sold a one or two of his frames at Marina Del Rey Bike in the early(?) 70ís. He had some ideas that were edgy for the time. Also quite a contrast to another local, Art Stump.
stoneageyosh is offline  
Old 06-10-24, 07:07 PM
  #6  
Senior Member
 
Nessism's Avatar
 
Join Date: Jun 2004
Location: Torrance, CA
Posts: 3,064

Bikes: Homebuilt steel

Liked 429 Times in 341 Posts
A mellow 270 lb'er would be far less stressful to a frame compared to a "strong" rider of lesser weight. Don't ask me where the balance point would be.
Nessism is online now  

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 - Your Privacy Choices -

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