DiabloScott

Agreed - the serial number location under the dropout ended about 1990. The "top of the tube" downtube shifters ended in the mid-80s. I don't have comprehensive serial number decoder but the number is about the right time frame as well. I *think* the C might mean "custom" because the similar ones in my database start with S or P.

Pantah

I had the opportunity to get a bunch of bike work done this weekend.
The old Quantum, the one getting the fork repaired, got further teardown. Removed the stem from the handlebar, which means stripping the bar tape and pulling the shifter on at least one side. Fully cleaned the cassette, chain and chainrings plus a general cleaning. It wasn't terribly dirty to begin with as I keep all my bikes relatively clean as I'm nitpicky about my maintenance but made it squeaky clean. Working on a clean machine is far better than working on a dirty one.
It also needed minor repair to the driveside rear dropout. It's become ever so slightly oblong over the years due to the soft nature of aluminum, causing the tire to sit closer to the non-drive side chain stay. I built it up with a bit of JB Weld and will do some filing to make it perfect later in the week. This is a repair I've done before on a Cannondale with good success.

The new Quantum II got a full teardown to a bare frame. The exception being the headset bearing races are staying since I'm re-using the very nice 6400 headset and the bottom bracket bearings. They feel ever so slightly no perfect but after pulling the seals and finding the bearings and grease to be spotless, I squirted some fresh grease in there and called it good.
I left the internally routed cables in place to make running new ones vastly easier.

Two silly things I found during disassembly. First, the crank bolts were obviously generic hardware store purchases, no idea what happened to the originals. Second, the newer Thompson Elite seatpost had a wingnut for one of the saddle bolts in place of the original log shaped nut, probably got lost.

Here's a photo of that wingnut plus the frame fully disassembled before cleaning.

WaveyGravey

I purchased an older Klein several years ago. I believe it is a 1986 Quantum Racing. But it has no head badge and I always wondered if it may have been altered in some way. Thanks.

Force 

Pantah Thanks for the information about this frame.

masispecial

The bearings need to be C3 tolerance or they will tighten up when pressed into the BB shell.
BITD we used Loctite 608 on the axle and bearings

Pantah

Not much to update on the '91 Quanutm with the broken fork steerer. I've done all the prep I can on the frame and fork for the threadless conversion. Brand new 1" threadless FSA headset arrived a couple of weeks ago and I've got the cups installed on the head tube. Removed the old crown race from the fork and now just waiting on the frame builder to get the time to do the work. He's a busy guy so it might be a while.

In the mean time, I've working diligently on the Quantum II so I can finish it and start riding the thing. I forgot to take a picture of the current status but it's looking like a bicycle again. Cranks, brakes, headset, rear derailleur and wheels have all been gone through, thoroughly cleaned, regreased and installed. Didn't actually overhaul the front hub as once I got the bearing pre-load set correctly, it was buttery smooth so I left it alone. The rear hub felt not precisely perfect and I could feel the grease had thinned out so that got a full service.

As for the rear derailleur, had a bit of fun with that. Since I converting to a triple crank, I need medium cage rear derailleur (a GS cage in Shimano speak). I really wanted to retain the look of the original Shimano 600 6400 but those were only ever made in short cage. Thankfully, the mid-90's was still a time when Shimano components could be extensively disassembled and everything shared a great many similarities and even identical engineering. So, I picked up a mid-90's RX100 A550 medium cage rear derailleur with the plan of grating the two together.

Start with two:




And make one. I present the never made RD-6401GS:




It's installed on the bike but I'm going take it off this week for one more modification to the pulley cage plate. I'm not a fan of the relatively low quality and lack of seals on the A550 pulleys. The 6400 pulleys are much higher quality and sealed well so I'd like to use those. I tried, but the A550 pulleys are wider at the center than the 6400 versions and due to this difference, the pulley cage plate is slightly different. The g-pulley fits and works fine but the lower pulley gets just barely pinched and won't spin. A few minutes with a die grinder will solve that problem.
My other complaint, which is minor, is that the A550 pulley cage plates are stamped steel compared to the aluminum of the 6400 and is significantly heavier. No way around that, is what it is.

I'll have a photo later this week of how the Quantum II currently sits. I should easily be able to have it completed by the end of the month. The final big hurdle is up next with the rebuild of the original STI shifters. It's been a while since I've done a set but I remember it being fairly straightforward.

romperrr 

That is a very cool work you're doing on the rear derailleur conversion. It's inspiring me.

Pantah

Conversions and modifications like this are something I particularly enjoy. It's all about the details.

I'm in the process of doing the same thing to the shifters. I can use the original 8 speed 6400 rear just fine but the double shifter has to be replaced with a triple. The 6400 series was never made as a triple so I have to run a 1055 shifter. All the first generation Shimano STI shifters share the same fundamental design and engineering but there are subtle differences that make some of the key components not interchangeable. I do know that the main shifter housing and hoods share identical dimensions, even if the finish/texture is slightly different. So at the least, I can run the 1055 shifter in the 6400 housing with the 6400 hood, both have a different finish. I'd love to run the 1055 triple internals with the 6400 levers and front plate (the forward facing part that has the series designation printed on it) as those are different between the two but I believe that's where I'll run into compatibility issues. I'm picking up the tool today from my brother to remove the proprietary 4 prong nut that holds the shifter internals together on the back side of the levers. I'm going to have to take apart both the double and triple to compare and see what can be interchanged. They have to come apart anyways thanks to the classic case of factory Shimano grease having turned to peanut butter. Same with the rear shifter, though that also has a tiny spring on a pawl that has magically popped out of place on one end, something which makes no sense given the lack of space for that to happen. I'll post a picture when I dig into it but it really is bizarre. My brother and I are both scratching our heads about it because common logic is that the spring would break first, or at least bend significantly, before being forced out of place in the way it did.

romperrr 

Pantah , very interesting thank you. I look forward to your investigation. I have a few brifters that I need to take apart and refresh. I've never done anything like that before, but I figure if they're already not working, me tinkering around in there can't hurt!

daverup 

Pantah There is an old guide for the A410 RSX STI levers on here,
https://www.bikeforums.net/bicycle-m...ti-levers.html
Those are pretty close to the 1055 Levers, so maybe that would help.
I've never been into the 6400 levers, so I can't help with those.
I did recently have to get into a ST-6500 lever since it had stuck pawls, that one was more difficult than the A410 to re-assemble.
Good luck

Pantah

I've actually rebuilt a set of 6400 levers before, though that was 10 years ago. Still, I did it back then with no instruction manual or walk through, I'll be fine this time around.
Additionally, my brother is a wizard with these first generation STI shifters, he's rebuilt every version ever made and knows them inside and out. If I do run into any issues, I can just talk to him. If there's any broken parts, we both have a stash of parts shifters.

The 9 speed shifters are tricky in that they can't be fully and completely disassembled in the way the 8 speed (and 7 speed first gen RSX) can be. They've got more plastic in them so they're also not nearly as durable.

Pantah

A busy training and race (running actually, not biking) schedule, on top of regular life duties, has kept me from getting any meaningful work done the last two weeks on any of my bikes. Finally had a 6 hour chunk of time yesterday to catch up on stuff.

On my Quantum with the broken fork steerer, I'm still waiting for the frame building to get the chance to fix the original. However, I realized that I can just run a temporary replacement fork until the original is repaired so I can at least ride it. It's slim pickings online for a quality and inexpensive 1" threadless with at least a 280mm steerer. Then I remembered an early 90's 60cm Allez bare frame I have hanging at my brother's shop, checked it and it has a strangely long steerer at 285mm, just perfect for a 61cm frame. Crown race goes on today, then I can bolt the front end back together and all it needs to finish it up for now is fresh bar tape. The silver fork and black stem won't quite be the eye catcher it was originally but it'll be perfectly rideable until I get the original fork repaired and the new stem painted to match.

The Quantum II, which I will have progress pictures of eventually, got a little bit of love too. Stripped all the old bar tape adhesive off the handlebars.Finally rebuilt the spare 1055 triple shifter. I'd forgotten how peanut butter-like the factory Shimano grease gets. Here's a good photo of that sticky brown grease.




Everything was going smooth until just after that photo. Got it disassembled too far and released all the pre-load on the spring buried at the base. Did the same with the spring behind the face plate on the front of the shifter. Wrestled with it for an hour trying to keep tension on two springs with very short engagement tangs that liked to pop out at the same time was a battle I lost. Hands got tired and I was hungry and I've learned that being tired, hungry and a bit frustrated is the best time to stop, eat, relax and rethink the problem.
Worked wonders.
Went back at it 20 minutes later and began to think more outside the box. Eventually came up with a solution that worked rather well.




That twisted safety wire was the key to success, combined with the circlip keeping that small pawl in place. It kept everything sandwiched together enough to prevent the loaded spring from popping out of place. That freed up my hands to tension the face plate spring properly. Still a bit of a dance to get everything lined up perfectly but it worked. Once the big lever, face plate and those base internals were all bolted together, neither of the springs could pop out of place. The safety wire was just barely a small enough gauge to clip and wiggle out. Rest of assembly went smoothly.
Ironically, it still doesn't work right. It didn't work before so it's possible something is broken, missing or worn. I've got a couple more identical triple shifters floating around so I'll compare it to those and see what's different.

Sonofamechanic 

Pantah, I’ve had good results with the Hylix carbon fork (1” steerer, threadless, long uncut steerer tube) for Klein Quantums. I have two builds (one is a 60cm frame) and they ride and track beautifully.


You do have to sometimes clean up (de-burr) the bottom race (integrated into the carbon) and after a few days of riding re-tighten the headset (it seems to settle into place over the first week of riding). I now prefer them to the overly rigid aluminum originals that Klein’s came with (I have those builds too). They are ~$90 and out of China, so lots of strong forum opinions on such fork options, but my experiences have been solid.

Sonofamechanic 

Lamont, what size bike do you ride? Cannondale was typically a much harsher ride than the Klein and while likely as stiff as the Klein for bottom bracket (lateral) flex, they never seemed to have that feeling of acceleration that Kleins have. There are solid Quantum frames out there for $3-400 if you have the parts to build them up (or just strip your current bike for a frame upgrade.)

Pantah

Sonofamechanic , good to know about those Hylix forks. I did see those as one of the few new options. I may get one some day as a backup or possible future upgrade (before new 1" threadless forks become extinct) but for now, I'll run the fork off my Allez and use the original once it gets repaired. The ride of the aluminum forks has honestly never bothered me.

I've actually found the higher end Cannondales from the late 90's to be on par with Kleins. I had a 1999 R4000 and that bike was fantastic. Very responsive and, while it had the expected stiffness of aluminum, wasn't what I would call harsh. The carbon Slice fork that it came with new made for a good ride quality. I'd still have it today if it had been a 61cm instead of a 58cm.
That bike was top of the line at the time, full Dura Ace, some carbon bits, weighed in under 19lbs as I recall and I picked it up for $300 in working condition. Kleins are fantastic but Cannondales are great bikes too and honestly are the far more affordable way to get into classic aluminum frames. If you can find a Klein for under $500, definitely go for it if the budget allows. But, that's about the entry point for Kleins.

Ironfish653

I already had a couple of Cannondales when I added an ‘88 Pinnacle to the fleet a couple summers ago. (It was at a flea market tagged at $100; I didn’t really need it, but I wasn’t walking away from that!)

It doesn’t directly compare with the Dales (a 3.0 Criterium and a 97 CAAD-3 F-1000)

Its lighter on it’s feet than I was expecting for a big, Marin-style MTB, and while it’s not as willing to punch up into Full Attack as the admittedly more racy Dales, it’s as competent as you can ask of a rigid MTB. On a good flow trail, with a little bit of old school handling nous, it’s hard to outride the bike.

Id love to get my hands on a Quantum to compare it to the 3.0, but I don’t really need another bike like that, except maybe for the eye candy

Sonofamechanic 

Fair…I rode an R600 with an aluminum fork, so perhaps that was a poor example to compare to the early Klein Quantums of that same era, but are you saying the “late 90s” Cannondales (R4000) are comparable to the Quantum Pros of that era? I don’t see riders coveting old R4000s the way they do a 90s Quantum Pro.

Pantah

I'd say they're comparable to Quantum Pro's, they were certainly marketed as direct competition to them. However, while Cannondale had a few neat paint schemes, the paint was otherwise nowhere near comparable to what Klein had to offer. I've found that's what really makes these older Kleins collectible is the linear fade and other wild paint schemes available. Kleins with fairly bland paint, such as silver, sell for about what similar aged Cannondales sell for. I'm certainly not paying a premium for a color found in every bike manufacturer catalog.

Another driving factor for collectability is rarity and the fact that Klein no longer exists. On the whole, Cannondales sold in higher numbers than Klein, though I'd argue that the top of the line models probably had similar sales numbers to top of the line Kleins. It was the mid and entry level Cannondales which sold the best. So, Kleins are a bit rarer and look cooler, making them more valuable and collectible. They're certainly made to a high standard of quality, further pushing value.

Klein is one of my favorites and is why I started this thread, but it's not my only favorite. Cannondale is another one, I own three, so I'll sing praises of them as well.

Pantah

Got some real progress on the broken fork Quantum last night. Got the temporary fork installed, stem, bolted the handlebars and right side shifter back up, front brake, chain and both wheels. Lost about an inch of height with the temporary fork/stem combo so the front brake cable has a goofy long bend to compensate but it'll work for now. All that's left is to tape up the brake cable housing on the right side shifter, strip the bar tape off the left side and throw on the new bar tape when it shows up early next week.

As for the Quantum II, I figured out my shifting problems with the new triple and I simply installed a spring slightly wrong but that's all it takes with these things. If any part is installed in any other way than exactly how it is supposed to be, it won't work. Thankfully, it's easy to get to so I'll be fixing that over the weekend. If luck is in my favor, I'll have the time to overhaul the rear shifter too.

After comparing the medium cage 1055 rear derailleur on the older Quantum and the cage off the RX100 derailleur, I've decided that the RX100 cage sucks and I've ordered a 105 rear derailleur to replace it. The RX100 cage is quite a bit lower quality. The 105 has an aluminum inner cage plate, just like the 600, but a steel outer. The RX100 is a steel inner and outer and the pressings don't look great to be honest. The 105 cage, by all appearances, will take the higher quality 600 pulleys while the RX100 will not due to a wider design.
I'll likely be ordering a 105 front derailleur as well to replace the RX100 I got. It looked good in the photos but has more surface blemishes than I'd like, which isn't actually a big deal, unlike the excessive wear on the plate front a ton of chain rub. Looks like it was run for a long time with the chain constantly rubbing the front derailleur and grooving it pretty badly. No bueno.

Anyways, I'll actually have the chance to take a photo of both bikes late this afternoon, so photos coming soon.

Steve B.

This is interesting as I purchased a new Quantum in ‘91, had the shifters on the top of the downtube design, internal cabling. I was told it a was an ‘89 model year and had been sitting unsold on the shop floor, is why I only paid $700. Seemed a good price at the time. It had Shimano 600 components, they put a new rear wheel on it, it had been a 6 spd freewheel. They upgraded me to a 7 spd cassette and system. Now I wonder if perhaps it was older then I was told and had sat a long time, is why I got a good deal. It was a great bike,

Sonofamechanic 

Just completed in time for 4th of July! . 6700 grouppo, will swap the al stem and al bars out as they are too flexy…the carbon set up I had on it earlier (Easton) seemed stiffer. Frame was an old custom painted for a race team out of Indiana—it was missing its MC2 1 1/16 fork so had to retrofit a 2000 1 1/8 fork into it…required a reducer on the top cap but otherwise fits fine!

Pantah

Neither Klein is finished but getting close.

Here's the '91 Quantum. Fork is, as mentioned, temporary. The stem may be as well, don't know yet.



And the '95 Quantum II. Not sold on the stem, I'll have to try out a few others I have. I'd like a combination of aesthetically pleasing and tall enough to be comfortable. I think everyone here can agree that the stem I have on it now is rather ugly. I think I can comfortably ride it with an inch less rise, won't be hard to accomplish.

Sonofamechanic 

Pantah is that first quantum a red to purple fade or orange to purple? I’ve never seen that fade combo before—looks great! The moonrise is, of course, just stunning. I think the stem looks fine—put some bright/paint match bar tape (maybe go old-school cello tape?) on there and the stem will blend right in.

MooneyBloke

I don't know that model. I do remember the old brochure with the Stage and the Team Super. Local guy rode a Super Record equipped Team Super in that same dark teal Imron. It now belong to a wrench at my main LBS.

Pantah

Sonofamechanic - It's a very unusual dayglo orange to metallic purple fade with a bit of pink at the point where the colors change. I've looked in the catalog and this was definitely not a standard paint option, the original owner (who I purchased it from) custom ordered it that way and probably waited several weeks to get it. Photos make it look more red than it is. I've never seen another Klein like it, either in person or in photos.

The stem is in excellent condition and is the same generic silver color as the original, just with actual rise to it. I always color match bar tape as well as cable housing and once I get the shifters installed with the cabling, it shouldn't stand out as much. Lowering it a tough might help too. Thinking of getting it powder coated to match part of the frame but if I do, that will come much later, after it's complete and I've had a chance to put some miles on it. I chose a stem with a removable front section that clamps the handlebars, rather than the conventional single pinch bolt, for the expressed purpose of being able to remove the stem or change it out without having to strip the bar tape and shifter off just to remove the stem. Makes life much easier.