Bob Jackson is Back!
#26
Senior Member


Joined: Nov 2013
Posts: 1,966
Likes: 1,137
From: Southern California
Bikes: 1981 Univega Super Special, '80s Custom Chris Pauley, 1972 Fuji 'The Finest'
Well the 853 frames I've had flex significantly less than my 531s have. They don't necessarily draw the tubing so thin that you end up with the same stiffness at the end of the day. Depends on frame angles and tube lengths and standard vs OS and all kinds of other things too, but that's been my experience in general.
853 is supposed to have significantly more strength than 531 but generally you only save about 10% of the frame weight with the thinner tubes. The rest of that strength difference accounts for an increase in stiffness (assuming the frame is designed to accentuate that strength).
As the Reynolds website advertises:
"This heat-treated version of 631 is the pinnacle of Reynolds ferrous steels.
It allows frame builders to make very strong, stiff frames with a low frame weight
It can be used in a pure 853 frame to produce a very stiff, light frame with excellent performance for a pure road bike."
853 Steel - Seamless Air-Hardening Heat-Treated Steel (reynoldstechnology.biz)
853 is supposed to have significantly more strength than 531 but generally you only save about 10% of the frame weight with the thinner tubes. The rest of that strength difference accounts for an increase in stiffness (assuming the frame is designed to accentuate that strength).
As the Reynolds website advertises:
"This heat-treated version of 631 is the pinnacle of Reynolds ferrous steels.
It allows frame builders to make very strong, stiff frames with a low frame weight
It can be used in a pure 853 frame to produce a very stiff, light frame with excellent performance for a pure road bike."
853 Steel - Seamless Air-Hardening Heat-Treated Steel (reynoldstechnology.biz)
All steel has the same stiffness. Some are stronger, and can be drawn into thinner tubes which will reduce stiffness. Larger diameter tubing will restore stiffness, allowing high stiffness and low weight in comparison to less fancy steel. What reynolds means when they say 853 'allows frame builders to make very strong, stiff frames with a low frame weight' is that the stronger 853 steel can be made into thin/oversize tubing that attains strength/stiffness of smaller diameter tubing that is thicker.
A straight gauge frame of 531 in 0.9mm is stiffer than double butted 0.8mm/0.5mm 853 of the same diameter because the 531 tubing is thicker throughout. But by increasing the diameter of the 853 tubing, you can create a tube that is both stiffer and lighter than the 531. The greater strength of 853 allows for this.
#27
It is stronger, but that's not the same thing as stiffness.
All steel has the same stiffness. Some are stronger, and can be drawn into thinner tubes which will reduce stiffness. Larger diameter tubing will restore stiffness, allowing high stiffness and low weight in comparison to less fancy steel. What reynolds means when they say 853 'allows frame builders to make very strong, stiff frames with a low frame weight' is that the stronger 853 steel can be made into thin/oversize tubing that attains strength/stiffness of smaller diameter tubing that is thicker.
A straight gauge frame of 531 in 0.9mm is stiffer than double butted 0.8mm/0.5mm 853 of the same diameter because the 531 tubing is thicker throughout. But by increasing the diameter of the 853 tubing, you can create a tube that is both stiffer and lighter than the 531. The greater strength of 853 allows for this.
All steel has the same stiffness. Some are stronger, and can be drawn into thinner tubes which will reduce stiffness. Larger diameter tubing will restore stiffness, allowing high stiffness and low weight in comparison to less fancy steel. What reynolds means when they say 853 'allows frame builders to make very strong, stiff frames with a low frame weight' is that the stronger 853 steel can be made into thin/oversize tubing that attains strength/stiffness of smaller diameter tubing that is thicker.
A straight gauge frame of 531 in 0.9mm is stiffer than double butted 0.8mm/0.5mm 853 of the same diameter because the 531 tubing is thicker throughout. But by increasing the diameter of the 853 tubing, you can create a tube that is both stiffer and lighter than the 531. The greater strength of 853 allows for this.
Please note that in my initial post you quoted I said a "stiffer frame," not "stiffer steel."
-Gregory
#28
Senior Member


Joined: Nov 2013
Posts: 1,966
Likes: 1,137
From: Southern California
Bikes: 1981 Univega Super Special, '80s Custom Chris Pauley, 1972 Fuji 'The Finest'
Well, we're talking from two different perspectives here. I agree entirely that "all steel has the same stiffness" if your measurements are identical. However, I am talking from the perspective of a built frame. The stiffness of the frames I've had - and the advertised utility of a frame - made from 853 has in general been greater than my 531 frames. The inherent strength of the frame material allows that to be accomplished.
Please note that in my initial post you quoted I said a "stiffer frame," not "stiffer steel."
-Gregory
Please note that in my initial post you quoted I said a "stiffer frame," not "stiffer steel."
-Gregory
Since they asked (as you noted) a well-trodden question and your response had some assumptions about an 853 frame that he may not be aware of, like how oversize tubing affects stiffness.
#29
Sunshine
Joined: Aug 2014
Posts: 18,702
Likes: 10,237
From: Des Moines, IA
Bikes: '18 class built steel roadbike, '19 Fairlight Secan, '88 Schwinn Premis , Black Mountain Cycles Monstercross V4, '89 Novara Trionfo
I'm not sure about that thing on the head tube/lug in the fourth picture but I assumed it was something that will not remain on the frame... Maybe I'm wrong. If it is staying I assume it's to protect the paint from cable rub but that strikes me as excessively excessive.
#30
Piff I gotcha'. Bob Jackson had used OS tubing for a lot of their builds up until the closer in 2020, and apparently Woodrup is carrying on that tradition with standard OS tubing and 1 1/8" steerers for the re-released models. In any tubing choice these are bound to be stiffer than classic standard sized 531 frames, and as long as they're made using higher strength steel like 725 or 853, almost certainly lighter despite the increased tube dimensions.
-Gregory
-Gregory
#31
framebuilder


Joined: Dec 2009
Posts: 1,788
Likes: 2,710
From: Niles, Michigan
One of the problems of explaining the differences between tubing types is that all things are not equal. Reynolds 531 was made with different tubing wall thicknesses from very thin to thick (22/25 to 19/22 wire gauge). It is the thickness and diameter of the tube that effects stiffness and not the alloy being used. Also tubing is made with different butting profiles (longer and shorter lengths) and where a builder chooses to miter the tubes within the butting profile might make a little difference too. This is why it is a meaningless explanation to say one bike with 531 rides differently than one with 853. They may will ride differently but the reason has to do with wall thickness and tubing diameter and not the alloy the tubes were made with.
#32
Doug Fattic Thank you, and of course. If I had to re-word my initial response to the question, I suppose it would be something like:
"Generally, frames made using 853 tubing are lighter and stiffer than historical 531 frames because they are constructed using thinner walled tubing with oversized dimensions."
That being the case, this is why I generally think of 853 as "lighter and stiffer," which is precisely the way that Reynolds markets the tubing.
If one intends to replicate the dimensions of an historical 531 frame, the advantage of strength that 853 alloy possesses may be minimized or even adversely affect the ride quality compared to the ideal.
-Gregory
"Generally, frames made using 853 tubing are lighter and stiffer than historical 531 frames because they are constructed using thinner walled tubing with oversized dimensions."
That being the case, this is why I generally think of 853 as "lighter and stiffer," which is precisely the way that Reynolds markets the tubing.
If one intends to replicate the dimensions of an historical 531 frame, the advantage of strength that 853 alloy possesses may be minimized or even adversely affect the ride quality compared to the ideal.
-Gregory
#33
Senior Member

Joined: Apr 2005
Posts: 17,196
Likes: 761
From: Ann Arbor, MI
Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8
I'm pretty sure the special training/certification applied to 753 back in the '70s. Haven't heard about such a thing for 853, which was developed in the 1990s after most frame builders using it were already backed into a pretty niche market. I have a 1999 Schwinn made in Taiwan with an 853 frame, from just a few after the tubing was released.
-Gregory
-Gregory
#34
Sunshine
Joined: Aug 2014
Posts: 18,702
Likes: 10,237
From: Des Moines, IA
Bikes: '18 class built steel roadbike, '19 Fairlight Secan, '88 Schwinn Premis , Black Mountain Cycles Monstercross V4, '89 Novara Trionfo
^ per an oldtimer frame builder who was building when 753 was around and 853 was introduced, and has forgotten more than most any of us will ever know.
#35
Full Member

Joined: Feb 2016
Posts: 209
Likes: 75
They're charging a lot more for these frames than they used to. Granted, everything is more expensive now that it was a few years ago. But the Bob Jackson frames right before they closed up shop were significantly less. Just from memory, the (Reynolds 531) Audax was under $1000USD.
#36
Senior Member

Joined: Jul 2013
Posts: 2,590
Likes: 909
From: So Cal, for now
Bikes: 1974 Bob Jackson - Nuovo Record, Brooks Pro, Clips & Straps
I apologize. I asked what I thought was a simple question, a side issue to the Bob Jackson offerings, and it has entirely derailed this thread.
#38
Senior Member


Joined: May 2019
Posts: 955
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From: Santa Rosa, CA
Bikes: Bianchi Campione d'Italia, Lemond Poprad, Kona Hei Hei (converted to drop bars), Felt F1PR, Specialized Sequoia, various other projects
Was that directly from Bob Jackson? Because I can remember going on their website and seeing a figure of 600 - 700 pounds for the Audax / "End to End" frameset, converting that to under $1000, and thinking it was a very good deal. Now, I don't remember if that was three years ago or five years ago, but it wasn't as far back as 2008.
#39
Full Member

Joined: Feb 2016
Posts: 209
Likes: 75
Was that directly from Bob Jackson? Because I can remember going on their website and seeing a figure of 600 - 700 pounds for the Audax / "End to End" frameset, converting that to under $1000, and thinking it was a very good deal. Now, I don't remember if that was three years ago or five years ago, but it wasn't as far back as 2008.
#40
Senior Member

Joined: Apr 2005
Posts: 17,196
Likes: 761
From: Ann Arbor, MI
Bikes: 1980 Masi, 1984 Mondonico, 1984 Trek 610, 1980 Woodrup Giro, 2005 Mondonico Futura Leggera ELOS, 1967 PX10E, 1971 Peugeot UO-8
Welcome to Bike Forums and C&V! I must say, I have learned a LOT here about cycling, and I hope I've been effective (and diplomatic?) in sharing what I know.
Please stay.
Last edited by Road Fan; 04-10-23 at 08:13 AM.
#41
Newbie
Joined: Jan 2023
Posts: 5
Likes: 8
Nice to see one of 'my' Cyclo Sportife's hopefully still being enjoyed.
After some 52 years of pro frame building for the likes of Bob Jackson, Woodrup and Thorn I am now making 'Sayles' frames from my workshop in North Lincolnshire.
Cheers
After some 52 years of pro frame building for the likes of Bob Jackson, Woodrup and Thorn I am now making 'Sayles' frames from my workshop in North Lincolnshire.
Cheers
#43
Senior Member

Joined: Jul 2013
Posts: 2,590
Likes: 909
From: So Cal, for now
Bikes: 1974 Bob Jackson - Nuovo Record, Brooks Pro, Clips & Straps
No matter, really, I am an original owner have enjoyed the heck out of it for almost 50 years. It has been everywhere and I have done everything with it.
#44
Newbie
Joined: Jan 2023
Posts: 5
Likes: 8
There is a chance I made your frame, but at that time there were three or four other builders. At Woodrup's I always stamped the frame number on the left hand side of the BB shell, and in recent years added a KS.
#45
Senior Member

Joined: Jul 2013
Posts: 2,590
Likes: 909
From: So Cal, for now
Bikes: 1974 Bob Jackson - Nuovo Record, Brooks Pro, Clips & Straps

I could not resist posting this. As you are aware, the paint is not original but the owner is. Also, it is a genuine Bob Jackson, I just never got the 531 decal after the repaint (~1980).
This set of decals were handed to me by Bob Jackson's son (?) during a visit to his visit to a Santa Monica, California bicycle shop. He wanted to see the frame before he handed them over, so I made the drive and showed him the proof.
It's a great bike. I've had several bikes during my lifetime but this Bob Jackson is the best.
Thank you!
Last edited by Bad Lag; 07-20-23 at 09:36 AM.
#46
Senior Member


Joined: Jun 2006
Posts: 21,814
Likes: 3,720

I could not resist posting this. As you are aware, the paint is not original but the owner is. Also, it is a genuine Bob Jackson, I just never got the 531 decal after the repaint (~1980).
This set of decals were handed to me by Bob Jackson's son (?) during a visit to his visit to a Santa Monica, California bicycle shop. He wanted to see the frame before he handed them over, so I made the drive and showed him the proof.
It's a great bike. I've had several during my lifetime but this is the best.
Thank you!
his wife was the apartment manager when I returned from the exile of the San Fernando Valley. We might have received the nod to rent the apartment (Mom’s income was marginal) as I saw the BobJackson bike in the living room and I made comment I had a Jackson track bike and won a number of races on it. Learned Harold was Bob’s son.
#47
Senior Member

Joined: Jul 2012
Posts: 1,066
Likes: 1,048
From: PNW
I certainly was building Jackson frames in 1974. I was at Bob Jackson's from May 1971 till Christmas 1976.
There is a chance I made your frame, but at that time there were three or four other builders. At Woodrup's I always stamped the frame number on the left hand side of the BB shell, and in recent years added a KS.
There is a chance I made your frame, but at that time there were three or four other builders. At Woodrup's I always stamped the frame number on the left hand side of the BB shell, and in recent years added a KS.
#49
Senior Member


Joined: Aug 2015
Posts: 537
Likes: 624
From: Murrieta Ca.
Bikes: Teledyne Titan, Bob Jackson Audax Club, Bob Jackson World Tour, AlAn Record Ergal, 3Rensho Katana.
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Booyah Hubba-Hubba!!!
Booyah Hubba-Hubba!!!





