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Frame sizing on vintage bikes

Old 08-12-22, 07:09 AM
  #51  
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Man, some folds here should consider smoking some weed. Seriously!
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Old 08-12-22, 07:10 AM
  #52  
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Originally Posted by embankmentlb View Post
Man, some folds here should consider smoking some weed. Seriously!
What's a "fold?"

Sounds like you already did.
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Old 08-12-22, 07:58 AM
  #53  
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Originally Posted by smd4 View Post
What's a "fold?"

Sounds like you already did.
Who does that before 10 in the morning??
😊
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Old 08-12-22, 08:36 AM
  #54  
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Lbxpdx, let me give you my impressions of your bike and fit as a fitter/builder/painter/teacher. It is possible to make almost any bike work by swapping out posts and stems until a position is found to make it ridable. You could do a lot better with a different frame. Your trouble starts with your 74º/74º angles. Let me explain. Your high handlebar position shows you prefer a comfort or "gentleman's fit". In other words your bike position goal is to ride comfortably instead of trying to get another mile per hour faster on your regular bike route. On the other hand performance 1st riders want to be sure they are as aerodynamic and biomechanically efficient as possible and are willing to sacrifice comfort to achieve speed. That usually means they have a lot of distance drop between the height of their seat and their handlebars.

The amount of drop is related to seat angle. The more the handlebar drop, the steeper the seat angle should be. The higher the handlebars the swallower the seat angle needs to be. If we take it to the extremes a tri bike has a really steep seat angle and a Dutch style bike with upright handlebars has a very swallow seat angle. A 74 parallel frame is a copy of a criterium bicycle where the racer is almost always in the drops going fast in circles. I don't think that is the kind of riding you are doing. This kind of design was popular some years ago in the States when they were marketing to the go fast crowd. Races in the States tended to be crits instead of long road races where a different geometry is preferred.

If you were placed on a fitting bike that didn't restrict your saddle's fore/aft position, you would discover that there is a point going rearward where your body became balanced over the pedals. This more rearward saddle position magically takes the strain of holding up your body with your forearms and hands off of the handlebars. It is much more comfortable. However you also need to raise your handlebars when your saddle goes rearward.

I think it is possible that your tilted seat is related to an attempt to take your body weight off of your hands. What I recommend is ditching the bike you have and looking for a frame that has more relaxed angles like 72º/72º angles that can position your saddle much more reward. Your 74º seat angle will always be a problem. You will also want to look for a frame that is as big as you can comfortably straddle . That results in less stem length sticking out above the head tube. That isn't a performance difference but less stem extension doesn't look as out of proportion.
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Old 08-12-22, 08:59 AM
  #55  
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Originally Posted by Doug Fattic View Post
You will also want to look for a frame that is as big as you can comfortably straddle.
Originally Posted by Lbxpdx View Post
It makes sense that the 23” wouldn’t fit. I recall my taint pressing up on the top tube when trying to stand over it with shoes on.
He's obviously riding the correct size frame. As far as the angles...I wonder if they really are parallel 74s.
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Old 08-12-22, 09:10 AM
  #56  
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Originally Posted by embankmentlb View Post
Who does that before 10 in the morning??
😊
I do.
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Old 08-12-22, 09:33 AM
  #57  
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Not sure if this would be helpful to you, but I have an '87 Voyageur and found the frame specs for it. The bike fit is definitely different than any of my other bikes.

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Old 08-12-22, 09:39 AM
  #58  
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Here's a promotional photo of the Voyageur. Not that 'factory' seat and handlebar heights matter too much, but it might give some idea for what Schwinn was going for with 'targeted bike fit' when they produced this model.

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Old 08-12-22, 09:53 AM
  #59  
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Both the frame specs and the image are for the 23 inch frame size. The 74 degree seat angle does seem a little steep for the type of bike it is.

I would definitely not use a catalog image to judge where the seat post height "should" be.
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Old 08-12-22, 10:21 AM
  #60  
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Originally Posted by embankmentlb View Post
Who does that before 10 in the morning??
😊
It's 5:00 4:20 somewhere.
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Old 08-12-22, 11:04 AM
  #61  
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Originally Posted by smd4 View Post
He's obviously riding the correct size frame.
From the OP:
"My nice bike is 56/56, 73/73 with 650b and it fits quite nicely and looks proportionate."
56cm is a 22" frame. Schwinn Voyageur SP in 1982 came in 2" increments.


If the OP wants to ride a Schwinn Voyageur SP in this vintage, 21" is probably the best frame size. If Schwinn had made a 22", that would probably be better. @Doug Fattic's detailed analysis is spot on if you're looking to optimize fit for the OP.

Is it the "right" size"? "My recently purchased Schwinn VSP is a fun ride. Nimble with nothing in the bags, yet planted and comfortable when the bags are filled with groceries." Sounds like he's happy with it, even if it's not optimal.

"I’m trying to figure out why this bike looks small though it fits perfectly the way it is set up." It looks small because we're used to seeing frames BITD without super long stems, so yes, it looks small.


Should the OP ride a bigger frame? Well, if Doug Fattic or most any reputable frame builder were to make the OP a custom frame, I'd bet it would be somewhere around 22". So, yes, it's smaller than ideal.

I think the solution is for the OP to buy another bike, but that's my standard recommendation for anybody, anytime.
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Old 08-12-22, 11:12 AM
  #62  
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Originally Posted by gugie View Post
I think the solution is for the OP to buy another bike, but that's my standard recommendation for anybody, anytime.
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Old 08-12-22, 11:38 AM
  #63  
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Originally Posted by Doug Fattic View Post
Lbxpdx, let me give you my impressions of your bike and fit as a fitter/builder/painter/teacher. It is possible to make almost any bike work by swapping out posts and stems until a position is found to make it ridable. You could do a lot better with a different frame. Your trouble starts with your 74º/74º angles. Let me explain. Your high handlebar position shows you prefer a comfort or "gentleman's fit". In other words your bike position goal is to ride comfortably instead of trying to get another mile per hour faster on your regular bike route. On the other hand performance 1st riders want to be sure they are as aerodynamic and biomechanically efficient as possible and are willing to sacrifice comfort to achieve speed. That usually means they have a lot of distance drop between the height of their seat and their handlebars.

The amount of drop is related to seat angle. The more the handlebar drop, the steeper the seat angle should be. The higher the handlebars the swallower the seat angle needs to be. If we take it to the extremes a tri bike has a really steep seat angle and a Dutch style bike with upright handlebars has a very swallow seat angle. A 74 parallel frame is a copy of a criterium bicycle where the racer is almost always in the drops going fast in circles. I don't think that is the kind of riding you are doing. This kind of design was popular some years ago in the States when they were marketing to the go fast crowd. Races in the States tended to be crits instead of long road races where a different geometry is preferred.

If you were placed on a fitting bike that didn't restrict your saddle's fore/aft position, you would discover that there is a point going rearward where your body became balanced over the pedals. This more rearward saddle position magically takes the strain of holding up your body with your forearms and hands off of the handlebars. It is much more comfortable. However you also need to raise your handlebars when your saddle goes rearward.

I think it is possible that your tilted seat is related to an attempt to take your body weight off of your hands. What I recommend is ditching the bike you have and looking for a frame that has more relaxed angles like 72º/72º angles that can position your saddle much more reward. Your 74º seat angle will always be a problem. You will also want to look for a frame that is as big as you can comfortably straddle . That results in less stem length sticking out above the head tube. That isn't a performance difference but less stem extension doesn't look as out of proportion.

thank you for taking the time for such a detailed response. I messaged the guy I bought the bike from as he had a few Schwinn brochure pages in his listing trying to get the page with the geometry, which he didn’t have anymore. I pulled out my digital angle finder and took my own measurements. I get 72 for the head tube and 75 for the seat, when I zero on the top tube.

thanks everyone for their contributions, it is interesting to see others views.
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Old 08-12-22, 01:06 PM
  #64  
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^^^^^ That's pretty close to the catalog listing. This looks like either a 1984 or 1985 based on the markings, and both indicate 72 for the head tube, 74 for the seat tube (for the 23" frame).
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Old 08-12-22, 01:17 PM
  #65  
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Originally Posted by madpogue View Post
^^^^^ That's pretty close to the catalog listing. This looks like either a 1984 or 1985 based on the markings, and both indicate 72 for the head tube, 74 for the seat tube (for the 23" frame).
it has the parts of an 84, but the serial number of early 85.

I did some adjustments once I got home and while the racks should be leveled, I think it looks and feels a touch better.

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Old 08-13-22, 01:33 PM
  #66  
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I wouldn’t listen to people who say a Brooks needs to be level. If with your latest adjustments, you are sliding forward when you lift your hand off the handlebars, you need to point the saddle up. It looks off, but it is the only way for most of us.

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Old 08-13-22, 02:13 PM
  #67  
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All these ride fantastic all day long, all very different, all good.







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Old 08-13-22, 04:44 PM
  #68  
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A few of us are concerned about the stem. If it's not a Technomic, it looks like you haven't got enough of the stem inserted into the head tube. If so, at best that's not good for the head tube. At worst, it's a safety hazard for you. Set our concerns at rest - does the stem have at least the minimum length inserted into the head tube?

Did you reduce the upward angle of your saddle between the 1st and last photos?

The reason it looks small could be due to optics and the differences between the 27"wheels on this and the 650Bs on your 56 CM bike.

I don't know how anybody rides a level stock Brooks without sliding forward.
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Old 08-13-22, 05:21 PM
  #69  
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I think I’m more perplexed by the bikes I see here with the bars positioned so the brake levers are pointing up at a 45 degree angle. It hurts just to think about wrenching my wrists that way!
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Old 08-13-22, 05:27 PM
  #70  
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Originally Posted by philbob57 View Post
A few of us are concerned about the stem. If it's not a Technomic, it looks like you haven't got enough of the stem inserted into the head tube. If so, at best that's not good for the head tube. At worst, it's a safety hazard for you. Set our concerns at rest - does the stem have at least the minimum length inserted into the head tube?

Did you reduce the upward angle of your saddle between the 1st and last photos?
it is a technomic stem. It is barely above the the bolt that passes through the crown for the front rack.

and yes, I did adjust the saddle between the photos.
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