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Discussion Starter · #1 ·
I'm fixing a friend's bike. This RTS-1 was used so infrequently that the grease in the shifter dried up and caused shifting problems. A bit of cleaning and lube fixed it. Must be all of 250 miles on it. Just wanted to share some of the old designs... I can't believe how complicated this suspension is.
 

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BundokBiker said:
I'm fixing a friend's bike. This RTS-1 was used so infrequently that the grease in the shifter dried up and caused shifting problems. A bit of cleaning and lube fixed it. Must be all of 250 miles on it. Just wanted to share some of the old designs... I can't believe how complicated this suspension is.
Yeah, that's the one... missing a pivot in the the dropout area. Relied on the stays flexing to achieve travel. We had about a dozen of the come back cracked at the drops. Like any GT, they sure looked neat though, regardless of functionality.
 

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Doesntplaywellwithmorons!
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Cracking wasn't from flexing, it was from the rather under-spec tubing they used for the swingarm. They were afterall trying to compete with Mongoose Amplifiers as one of their main competitors. Travel was 3" btw. Its just a high-pivot monoshock using a rocker link to actuate the shock, a pivot at the dropouts would make very little difference as its not intended to be a 4-bar or mac-strut bike.
 

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Re: Missing the point.

DeeEight said:
Cracking wasn't from flexing, it was from the rather under-spec tubing they used for the swingarm. They were afterall trying to compete with Mongoose Amplifiers as one of their main competitors. Travel was 3" btw. Its just a high-pivot monoshock using a rocker link to actuate the shock, a pivot at the dropouts would make very little difference as its not intended to be a 4-bar or mac-strut bike.
You just keep right on talking, Mr Suspension engineer, you're doin great. go ahead and tell us all what we're really looking at.


...under-spec tubing... nice.
 

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I hope I'm not sticking my foot in my mouth here, but actually, the RTS-1's had an aluminum rear triangle and had a pivot in the HL position on the chainstays, I'm pretty sure. My first "real" mountain bike was a purple '94 RTS-3 that's still hanging around here. The RTS-2 and RTS-3 had steel rear triangles without pivots. I always dreamed of getting an aluminum RTS-1 rear triangle to upgrade my bike :) . It actually had 2.5" rear travel, and there was a company you could get an aftermarket link from (can't remember which company) to increase the travel to 3", whoa!
 

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Discussion Starter · #8 · (Edited)
correctamundo

el-cid said:
I hope I'm not sticking my foot in my mouth here, but actually, the RTS-1's had an aluminum rear triangle and had a pivot in the HL position on the chainstays, I'm pretty sure.
I'm not familiar with the RTS-2 or 3, but this one does have a horst link. I'm going to take it out for my regular group ride this sunday and see what kind of reactions I get from my friends. Most of them we're not riding when this bike was designed. I've only seen 3 or 4 RTSs on the trail... that was many years ago. Not a common bike in soCal.

I was always curious how this particular design handled and it will be fun comparing it to "modern" mtbs.

el-cid, would you say that the RTS had the "feel" of a hardtail? wasn't that the purpose of all the linkages... to lockout the rear while pedaling? Also, the elasomers are original and they've become quite stiff as well. It'll be like riding a rigid, although a very heavy one.

shiggy mentioned the canti setup... I had a closer look at the design and it seems quite an elegant solution to the cable routing problem brought on by the suspension design. although, it's heavy and seems beefy. I think v-brakes would have solved the problem had they been around at the time.

always fun to get a close-up of early f/s designs and how they've evolved. I believe this model was riden to a world championship... there is a world champion sticker on the top tube.
 

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el-cid said:
I hope I'm not sticking my foot in my mouth here, but actually, the RTS-1's had an aluminum rear triangle and had a pivot in the HL position on the chainstays, I'm pretty sure. My first "real" mountain bike was a purple '94 RTS-3 that's still hanging around here. The RTS-2 and RTS-3 had steel rear triangles without pivots. I always dreamed of getting an aluminum RTS-1 rear triangle to upgrade my bike :) . It actually had 2.5" rear travel, and there was a company you could get an aftermarket link from (can't remember which company) to increase the travel to 3", whoa!
No, you're right, the ones we had fail were the steel models, and the al rear got the pivot. It's visible in the 1st pic. Which makes D8's explanation even funnier...
 

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I had a 94 RTS3 thats sticking kicking around ( a friend has it now)...and oddly hasnt cracked despite alot of abuse. I must have gotten a good one or something :p

I loved my RTS....I thought it rode great
 

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The 1993 RTS-1, when there was ONLY an RTS-1, had the steel rear end. And they did under-spec the tubesets on them, that's what I was referring to, and all the RTS's with the steel rear ends shared the tube specs of that first year version (which includes the RTS-3 and 4 versions, the four was that awful purple color mainframe). The diameters and wall thicknesses used for a rear swingarm were picked for the weight and cost, not for durability.

Course I only owned one, and had friends who owned them, so hey, think whatever you like. In any case, a dropout pivot wasn't a requirement for that sort of swingarm. Its funny how you started laughing and commenting on what I said, when you're the one who brought up a lack of dropout pivot first in this thread, for a bike which the pictures showed wasn't the chromoly rear end version. And then you tried saying I didn't look at the pictures too?! Wow...incredible how much you'll try and deflect attention away from your own failings.

Are you sure you really worked at a shop that had so many frames returned for cracking, or were you pulling that out of your arse too?
 

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el-cid said:
I hope I'm not sticking my foot in my mouth here, but actually, the RTS-1's had an aluminum rear triangle and had a pivot in the HL position on the chainstays, I'm pretty sure. My first "real" mountain bike was a purple '94 RTS-3 that's still hanging around here. The RTS-2 and RTS-3 had steel rear triangles without pivots. I always dreamed of getting an aluminum RTS-1 rear triangle to upgrade my bike :) . It actually had 2.5" rear travel, and there was a company you could get an aftermarket link from (can't remember which company) to increase the travel to 3", whoa!
You're not. The model construction depending on the model year. The original 93 version was a chromoly rear end. Polished silver and clearcoated 6061T6 front, gloss black painted chromoly back. Later the RTS Team and -1 versions did get an aluminium rear end with a pivot but those versions didn't survive too long, with the LTS getting all the glory and attention by about 1995/96. I remember the purple one too, but I thought it was a -4 for some reason. The 96 version of the -3 was supposed to be candy red according to the catalog I have but I've never seen one that I can recall.
 

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BundokBiker: I loved the way mine rode. The way the suspension's set up with the high pivot encourages the rear tire to "dig in" when you're honking on it climbing. I whipped everyone's butt on the climbs every time I rode that bike. It wasn't exactly plush, or neutral pedaling, but it was a great bike. I went from that to a titanium GT Lightning in 1998, then on through more suspension-to-hardtail-to-suspension cycles; not sure why, but that bike stayed around. I'll have to go dig it out and take it for a ride :) .
 

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Round II.

DeeEight said:
Course I only owned one, and had friends who owned them, so hey, think whatever you like. In any case, a dropout pivot wasn't a requirement for that sort of swingarm. Its funny how you started laughing and commenting on what I said, when you're the one who brought up a lack of dropout pivot first in this thread, for a bike which the pictures showed wasn't the chromoly rear end version. And then you tried saying I didn't look at the pictures too?! Wow...incredible how much you'll try and deflect attention away from your own failings.

Are you sure you really worked at a shop that had so many frames returned for cracking, or were you pulling that out of your arse too?
Yep, I was talking straight out the heinie, much like I would be doing if I said I could take your posts seriously anymore. No, we did have a number or probably around a dozen of those come back cracked at the drops. We dropped GT shortly after.

I also owned up that I missed that, being more familiar with the steel model than the al. Especially after I saw they fixed the issue with the Al rear. But then to see you come along with your theory (which I'd still like to hear) that the rear triangle (which flexes, and compiles the stress at the bottleneck, [the dropout welds], under actuation, due to a substantial deviation between the trajectories the lower swingarm pivot has to follow) is without a fatigue effect when those frames are known to fail in that very way, was entertaining. Also, this issue of "under-spec" is interesting. Under specified? Were the project engineers vague? Was it a quality control issue? I'd put money on it being a design issue.

I go back and forth about trying out the "ignore" feature with you, but like the best train wrecks, I just can't think of what I'd miss if I looked away. Hugs, n kisses.
 

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el-cid said:
BundokBiker: I loved the way mine rode. The way the suspension's set up with the high pivot encourages the rear tire to "dig in" when you're honking on it climbing. I whipped everyone's butt on the climbs every time I rode that bike. It wasn't exactly plush, or neutral pedaling, but it was a great bike. I went from that to a titanium GT Lightning in 1998, then on through more suspension-to-hardtail-to-suspension cycles; not sure why, but that bike stayed around. I'll have to go dig it out and take it for a ride :) .
What's particularly amusing is that as Jim Busby's first effort for GT, it employed anti-squat geometry to the suspension, much as Dave Weigel does today with his DW-link rear ends, to make the bike pedal well, without needing a fancy shock with stable platform damping. It also exhibited good behaviour under braking, without any undue stiffening of the suspension. Other than being non-active in general, it'd still be a viable concept today.
 

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flyingsuperpetis said:
But then to see you come along with your theory (which I'd still like to hear) that the rear triangle (which flexes, and compiles the stress at the bottleneck, [the dropout welds], under actuation, due to a substantial deviation between the trajectories the lower swingarm pivot has to follow) is without a fatigue effect when those frames are
Its not a theory. Its reality. The RTS is a high-pivot monoshock design. This is no different than early mantis profloaters, or Nishiki FS-2s, or a host of other similar bikes of the period. There is no deviation of trajectories in the lower swingarm. It simply swings thru an arc, just as any other single-pivot design does. You seem to be easily duped into thinking its a linkage setup of some sort like a 4-bar, just by the presence of a rocker link under the bike (as opposed to higher up, as rocky mountain has with their RMX design). Its not though, all the rocker does is allow the shock to be compressed by the swingarm arc'ing backwards and upwards as the wheel hits a bump. There's simply no need for an extra pivot to handle an eccentric range of motions between
the chainstay and seatstay because there aren't any.that the rocker link isn't already taking care of.

Only on monoshocks where the shock is RIGIDLY secured to the main frame, and not free to move do you require any sort of additional eccentric pivots to handle the extra deviations (Boulder's frames all employed an eccentric cam between the swingarm and shock shaft, as did the Santa Cruz Tazmon, because in both cases the shock body wasn't free to move away or towards the frame as the shock shaft compressed and extended). These aren't theories. They're established principals of suspension design. Its a pity you fail to understand them.

Putting a horst-link on the later Al swingarm version was to attempt to fix some of the non-active traits of the suspension under pedal loads and transform the platform from a monoshock design to a 4-bar design. It failed though, and the whole RTS family was dropped after only a few short years of existence.

known to fail in that very way, was entertaining. Also, this issue of "under-spec" is interesting. Under specified? Were the project engineers vague? Was it a quality control issue? I'd put money on it being a design issue.
See.. its really amazing that you fail to understand these simple things. Its comical really. Fine, I'll explain in simple language for your simple mind. The RTS's swingarm, and for that matter, the whole bike was NOT designed for DH riding. Yes it like Mongoose Amplifiers did see some success when used that way, but the company didn't design them for that sort of regular usage and abuse. So the tubing picked for the frame was not picked for ultimate strength and durability. But to hit a target frame weight because at the time, buyers were starting to become really concerned over a bike's overall weight, and the frame makes up the largest single chunk of that weight. So they were not under-spec for the motions and stresses of the suspension actuation as you seem to think, but for the type of regular riding that owners put them through. Every single local racer I knew who owned an RTS, used it as their DH race bike, not as their XC bike. This is how racers perceived the bikes to be used, but its not how the designers and engineers intended them to be used. They were perfectly well built and spec'ed for XC, but not for DH. Same goes with Amp's. They were built for XC racing, and got used for DH and DS racing instead. They tended to fail as a result (headtube seperations being the most common issue with all the double-downtube Amps, usually failing DURING something other than XC riding).

The main frames of GT's were fine for the loads, being similar to the hardtail front ends, but that's not to say they didn't have problems too. Hell, the simple fact GT's first upgrade offered for the RTS was a titanium kit to reduce the frame weight should have been an obvious clue to anyone that they weren't marketting them for DH riding.

I go back and forth about trying out the "ignore" feature with you, but like the best train wrecks, I just can't think of what I'd miss if I looked away. Hugs, n kisses.
Perhaps you should, I'd have to respond to less of your moronic replies then.
 

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Coooooool! I remember when those came out. They rocked!

Okay, well, they looked cool anyways. :p Saw one on E-Bay this past week or so, as well as a Lobo.

Let's not forget that the complication was via "Formula 1 technology", eh? :p :D :rolleyes: Just like all of today's "latest and greatest".

I love seeing all the oldies and goodies here. Thanks for sharing the pics! ;)
 

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The lobo on ebay this week was an NOS condition wall-hanger frame. I was pondering it myself but its the wrong size.
 
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