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Discussion Starter · #1 ·
What early suspension systems worked well enough to provide a platform for successful future evolution?

The ROCKSHOX Mag 21 SL was certainly one of the ones that really seemed to point to what suspension could achieve in a light cross country configuration. The first generation of Marzocchi Bombers' plushness and reliability made an aggressive style of cross country riding possible. The Englund Air cartridges showed what could be achieved by light and simple air only systems.

Have these early successful designs been eclipsed by anything so radically advanced that those early standards can't even come close in terms of design sophistication and reliabilty? I am not interested in discusssing the merits of longer travel, more rigid stantions and integrated cast lowers. I am only interested in the actual suspension system internals, whether they are air, oil, springs, or some combination. Have the newer designs really improved radically on their first successful predecessors, or are the improvements merely incremental and minimally better?

I don't claim to be a suspension expert, retro or modern. I am genuinely interested in your more experienced opinions.
 

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It's ironic that the first production suspension fork with oil damping and air pressure for the main spring is still exactly what is at the top of the game today. There was a period where fork makers tried elastomers to get around the reliability issues with sealing in the oil, but the Marzocchi's oil bath system came out and "buttery smooth" became a phrase to describe suspension forks.

The Mag 20/21 forks were really quite good forks. It's too bad they were flexy by today's standards.

I think a fork from today would prove to be hugely better than a Mag21. Imagine riding one day on a Fox fork and then having to ride on a Mag21 without changing your style. You'd find yourself unable to get the front wheel to change direction. Well, it would seem like the front wheel would have a mind of its own.

I think modern forks bring a high level of reliability and stiffness over the first forks.

$0.02
 

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Discussion Starter · #3 ·
ssmike said:
It's ironic that the first production suspension fork with oil damping and air pressure for the main spring is still exactly what is at the top of the game today. There was a period where fork makers tried elastomers to get around the reliability issues with sealing in the oil, but the Marzocchi's oil bath system came out and "buttery smooth" became a phrase to describe suspension forks.

The Mag 20/21 forks were really quite good forks. It's too bad they were flexy by today's standards.

I think a fork from today would prove to be hugely better than a Mag21. Imagine riding one day on a Fox fork and then having to ride on a Mag21 without changing your style. You'd find yourself unable to get the front wheel to change direction. Well, it would seem like the front wheel would have a mind of its own.

I think modern forks bring a high level of reliability and stiffness over the first forks.

$0.02
I agree that the Mag21s were flexy, and had limited travel. Of course you have to consider that many were being sold as upgrades on frames with rigid fork geomtery. They couldn't put a 100mm fork out at that time and expect people to install it onto a frame that was not suspension corrected.

I have tried to limit the discussion to suspension system internals only. You have pointed out that some good modern systems are using air and oil. What modern suspension systems are using air and oil systems similar to the Mag21s? Other than travel and stiffness, are they that much better than the Mag21s?
 

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disease said:
What modern suspension systems are using air and oil systems similar to the Mag21s? Other than travel and stiffness, are they that much better than the Mag21s?
On a basic level, they all kind of are. The valving of all oil damped forks is similar in operation (and similar to basically all oil damped shocks in cars, motorcycles...). It just took a few years for bicycles to get it right.
 

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Discussion Starter · #5 ·
ssmike said:
On a basic level, they all kind of are. The valving of all oil damped forks is similar in operation (and similar to basically all oil damped shocks in cars, motorcycles...). It just took a few years for bicycles to get it right.
What amazes me is why manufacturers experimented with elastomers when all they had to do was scale down already proven motorcycle designs. The same is true for disc brakes. They are just miniaturized motorcycle brakes. I don't know why Shimano, with it's massive manufacturing scale, did not produce disc brakes in the early 1990s.
 

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I have to agree with Mike on this one.

It's funny though...I guess the main technological advancement in suspension forks has been the external part of the fork.

The original Mag 21 has an adjustable air spring in addition to an adjustable platform valve setting. That's the same features all the new race forks have, with the exception of lockout.

On the mag-21's side, however, is that the forks are really easily adjustable internally by a good mechanic to customize the ride precisely to a rider. I'm not aware of ANY modern fork that allows factory-authorized user modifications- better yet, RECOMMENDS THEM!

I personally would love to see a Rock Shox fork based on the externals of a Reba with an up-sized version of the Mag 21 internals and tuning kits available in the aftermarket.

Oh, and a bolt-on steerer...
 

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The Mag 21 changed everything and made people want front suspension. The Manitou 3 was a great fork for its time and made people realize that small bump compliance was desirable. The first Bomber Z1 showed people what a real front fork should feel like. It has been all downhill since...
 

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--"What amazes me is why manufacturers experimented with elastomers when all they had to do was scale down already proven motorcycle designs."

Same argument as people give for Single Speeds - simplicity and light weight are more appropriate for bikes - I disagree with Single Speeds and elastomer suspensions on these very grounds. I love older bikes, but I think retro as a fashion statement or because you're just grumpy is just dumb.

''"The same is true for disc brakes. They are just miniaturized motorcycle brakes. I don't know why Shimano, with it's massive manufacturing scale, did not produce disc brakes in the early 1990s."

Shimano has taken enough heat for trying to "control" the industry. They were prudent about releasing discs until after standards were set up by folks other than themselves...besides, there was no need for them when the bikes were rigid and speeds were only high enough to require rim brakes. As suspensions and riders pushed demands on the equipment, and speeds elevated, then disc brakes were slowly introduced by other companies with LOTS of different ideas of how to mount the calipers and rotors. I think Hayes was the forst to use the 6-bold standard in production today, and they also went through 2 different post-mount standards. The IS standard was only adopted industry-wide in about 98-99.

So, I guess Shimano saved a lot of time, money and energy concentrating on great shifting while all the other smaller companies did the trial and error for them.

Besides, Shimano was making disc brakes in the 70's for road bikes...they never caught on on or off the road.
 

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im biased but the Action Tec fork which came out in 1992 is still the same fork they make today. it's the only suspension that has withstood the test of time unchanged. people still use them on custom applications when limited suspension travel is required like on 29ers. it's reason for not being super popular is it's expensive (back in the day it was at least) and you need a custom made frame for the fork. still though, the other designs had to go though years and years of developments and technology to really work great. to this day it's still my favorite short travel fork and im sure it will stay that way.
 

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Discussion Starter · #10 ·
richieb said:
I have to agree with Mike on this one.

It's funny though...I guess the main technological advancement in suspension forks has been the external part of the fork.

The original Mag 21 has an adjustable air spring in addition to an adjustable platform valve setting. That's the same features all the new race forks have, with the exception of lockout.

On the mag-21's side, however, is that the forks are really easily adjustable internally by a good mechanic to customize the ride precisely to a rider. I'm not aware of ANY modern fork that allows factory-authorized user modifications- better yet, RECOMMENDS THEM!

I personally would love to see a Rock Shox fork based on the externals of a Reba with an up-sized version of the Mag 21 internals and tuning kits available in the aftermarket.

Oh, and a bolt-on steerer...
The Mag21 was infinately adjustable. That was one of it's major strengths. Some people have even modified their old Mag21s to get 3 inches of travel out of them. I assume that you have ridden both the Reba and the Mag21. Do you think a long travel version of the Mag21 could be tuned to perform as well as a Reba, or close enough that it does not matter? It sounds as if you think the Mag21 could be tuned to satisfy personal preferences better than the Reba.

I am disregarding externals, and speaking only of comparing the suspension responsiveness.
 

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i think Rock Shox makes their current forks to work as supplied these days, and only approve of "factory" settings. There are no available valve springs, washers, or any other bypass modifications on record, not to mention the tuning kits they used to make for the Mag series. It was awesome how those forks could be set up.

I have a Reba which I intend to play with over the coming months to see what can be accomplished, but I still say the Mag 21 has a leg up in the tunability department out of the gate because you could play with springs and washers without worrying about "point of no return" issues that could cost you a ton of money...
 

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disease said:
The Mag21 was infinately adjustable. That was one of it's major strengths. Some people have even modified their old Mag21s to get 3 inches of travel out of them. I assume that you have ridden both the Reba and the Mag21. Do you think a long travel version of the Mag21 could be tuned to perform as well as a Reba, or close enough that it does not matter? It sounds as if you think the Mag21 could be tuned to satisfy personal preferences better than the Reba.

I am disregarding externals, and speaking only of comparing the suspension responsiveness.
To jump in with my 2 cents, I'd say would be hard to compare due to how the flex of the Mag21 will impact the performance, but in theory yes. The damping mechanism in a Mag21 isn't that different from the damping in any other Rockshox air/oil fork.
 

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Discussion Starter · #14 ·
IF52 said:
To jump in with my 2 cents, I'd say would be hard to compare due to how the flex of the Mag21 will impact the performance, but in theory yes. The damping mechanism in a Mag21 isn't that different from the damping in any other Rockshox air/oil fork.
I see you are in search of a Total Air kit. I bought one on eBay, and I will be installing it this year. I was amazed at how simple it is. It's basically a few simple plastic parts. I'm sure that a modern air fork is no more complex.

The money that fork makers charge is unreal, considering that the technology is so mature. If the basic concepts were proven over a decade ago, the R&D costs must be minimal. The internal parts themselves are not terribly sophisticated. The external elements are very basic. What do they spend all their money on, advertising? When forks first came out, they were exotic and produced in small numbers. These days every bike comes with one as standard. They probably make them for under $100, even the more high end ones.
 

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disease said:
I see you are in search of a Total Air kit. I bought one on eBay, and I will be installing it this year. I was amazed at how simple it is. It's basically a few simple plastic parts. I'm sure that a modern air fork is no more complex.
The fork on my single speed is an 8 year old White Brothers XC4 that is essentially two aluminum tubes with Englund Total Air internals. I love it, but then I always preferred the increasing spring rate you get from an air "spring" over the linear rate designs (coil springs). I just hope I never have to rebuild the cartridges :p . I also have a modern air fork (Maverick) on my Turner, but honestly, other than more travel it performs no better than my "old" fork.
 

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richieb said:
--"What amazes me is why manufacturers experimented with elastomers when all they had to do was scale down already proven motorcycle designs."

Same argument as people give for Single Speeds - simplicity and light weight are more appropriate for bikes - I disagree with Single Speeds and elastomer suspensions on these very grounds. I love older bikes, but I think retro as a fashion statement or because you're just grumpy is just dumb.

''"The same is true for disc brakes. They are just miniaturized motorcycle brakes. I don't know why Shimano, with it's massive manufacturing scale, did not produce disc brakes in the early 1990s."

Shimano has taken enough heat for trying to "control" the industry. They were prudent about releasing discs until after standards were set up by folks other than themselves...besides, there was no need for them when the bikes were rigid and speeds were only high enough to require rim brakes. As suspensions and riders pushed demands on the equipment, and speeds elevated, then disc brakes were slowly introduced by other companies with LOTS of different ideas of how to mount the calipers and rotors. I think Hayes was the forst to use the 6-bold standard in production today, and they also went through 2 different post-mount standards. The IS standard was only adopted industry-wide in about 98-99.

So, I guess Shimano saved a lot of time, money and energy concentrating on great shifting while all the other smaller companies did the trial and error for them.

Besides, Shimano was making disc brakes in the 70's for road bikes...they never caught on on or off the road.
First some disagreeing. Old bikes didn't go fast enough to warrant disc brakes? Absolutely untrue. Having raced DH back in the day of cantis and early suspension forks, we didn't go much slower, we just had to squeeze the brakes harder. Just a couple years ago there was a guy on a rigid bike at Keyesville that turned in a DH time that was 7th overall. Pros (on bikes with 8" of travel) included. And this full rigid bike had rim brakes and drop bars. At least a third or half of the course is pretty rocky and rough.

Disc brakes didnt happen earlier because of weight concerns and the customer didnt know what they were missing.

The Maverick forks allow full user tunability with the valve shims, oil visc., neg. spring, oil height, etc. Very nice setup - a collaboration between Mike McAndrews (Fox) and Paul Turner.

One main difference between the modern stuff and the Mag 21 is the negative spring. That makes a night and day difference for the small bump compliance and the spring curve. The spring curve was the hard part with air springs. They have it pretty darn dialed now, closely matching the coil spring.

Elastomers were a way to provide a spring that didn't need any damping. The rebound slowly naturally. They werent a whole lot lighter than a coil spring but they could save loads of money by not putting a damping system in. Lots of profit as they sold for the same amount as the RS offerings.
 

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I still ride a Q21R and it seems fine to me. Granted, i've never ridden a modern fork but I do switch between rigid and the Q and i haven't noticed any deleterious handling characteristics.

Because of this I think that suspension "quality" on a XC bike is a bit overrated. Obviously, if you're doing big drops or highly technical riding a good suspension is worth it but how many people take vintage bikes off big drops or down super-technical trails? If you do, the frame geometry is thrown way off by modern forks anyway.

I guess what I should do now is ride a modern fork and then an older fork back-to-back...
 

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jeff said:
I do love that bike. How does it ride?
It rides really well. I haven't taken it for a hardcore run, but after tensioning up the wheels, I did go around the block a few times. It's just cool to be riding a bike that old...:cool:

As for the ties? Yep, loop side is nice and soft on my tender paint, and they last longer than rubber bands, which seem to snap, and this one is critical, without it, the whole front end flops around backwards:eekster:
 
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