Question for the Klein people. looking at a used Quantum on CL and when I test rode it there was some clanging noise on top tube when ever I hit rough road. Sounds like the integrated brake cable clanging on the top tube. Is that normal for the klein to make noise due to this integrated cable? Or do you think there is something else inside the top tube making the noise. I absolutely loved the ride of the Klein but I can't have a bike that makes noise. THanks.

All old time internal brake cables could cause noise...or not. Luck of the draw. Does the outer run full length through the frame, or are there stops on each end of the internal run? If the outer runs through the frame, all it may take to fix it is an adjustment of the slack inside.

Rode one for 6 years, never had noise or an issue other then the cables were a pain to change until I learned some tricks.

Okay, so most likely there is some loose debris in the top tube causing this noise. Given it is virtually impossible to remove the forks on these frames without damaging something, I will have to pass on that particular frame. But will keep my eyes out for another one because I was really impressed with how it rode and the geometry was good for me.

By the way, would be interested in hearing about the "tricks' to do the internal cable routing. Is there anything documented? Thanks.

One more thing, I noticed the derailler cables as the exit the downtube at the BB had little nylon guides, the brake cable exiting top tube didn't have this. Did the Klein come from factory with these guides and perhaps that is inside the top tube making the rattle?

Why would removing the fork damage something? It is a relatively simple process for either threaded or threadless. I'm sure most bike shops would happily remove the fork to get at some debris for a nominal cost if you don't want to do it yourself.

With regard to internal cable routing, plenty of online guides, like this: Ask a Mechanic: Replacing Internally Routed Cables

A google search will show you others as well. Park Tools also makes a magnetic cable routing kit which can be useful.

The nylon guides might just be there to prevent road grime from getting into the frame easily, which is not really an issue on the top tube. If you like the bike I would just get it and have a bike shop try to get the debris out.

Removing Fork for Kleins form this era (1998 Quantum Pro) is not straight forward. Apparently requires to be hammered out with some special "anvil" tool from Klein as they are pressed on and glued with Loctite. None of my local bike mechanics have any experience with this and they warned following this technique would certainly ruin the headset and possible damage the head tube. This annoyance plus the hassle of the internal cabling is enough for me to give up on the idea of adding a Klein to the quiver. There are just too many other great classic bikes out there without these hassles.

Are you thinking of the bottom bracket ?

My '96 Quantum had a regular 1" threaded fork, I used a Chris King as well as an Ultegra.

The internal shift cable routing ended early 90's, after STI shifting came out. Brake cables were never routed internally, AFAI can recall.

In late 90s Klein used a proprietary fork/stem system called MC3. Anyway, I reviewed the technical manual I found on line and confirmed that it is a PITA.

Well I went ahead and bought the Klein in spite of the top tube noise, got too good of a deal to pass up given it came loaded with 9 speed dura ace and sweet wheelset in very good condition. Turns out there is definitely something loose in the top tube I could hear sliding back and forth if you pick up the bike. My mechanic advised against removing the fork but put squirted some grease inside which stopped that movement. However, upon riding it there is still significant rattle coming out of the top tube when you hit rough pavement (almost all the time when traveling downhill speeds). Again, not sure if this is due to the loose piece(s) in the top tube or just normal noise from the brake cable rattling against the tube from the inside. Frankly I don't see how it is possible for the cable not to rattle against the tube unless you installed some sort of liner all the way through.

Maybe this is the mechanic in me speaking, but I wouldn't feel comfortable owning and riding a bike I couldn't fully service. I would give removing the fork a go. Probably worst thing that could happen is you need a new fork.

Good to know. I love Kleins, they were great riding bikes, I'm always watching on e-bay.

I hear you. But in this case there is no reason to service the fork/headset per se, they are in great shape and will be for a long time. Problem is just that damn buzzing noise in the top tube. I'm going to give it another few rides but good chance I'll put this frame set on Ebay in the not so distant future. Besides the noise, this frame is (not surprisingly) harsher than I like. But it is crazy light and fast and sweet looking. This bike in stock form weighs around 16 1/2 lbs with all metal except carbon fork.

1. Yup, Quantum Pro not only has a Loctite steer tube into the headset, the steertube is also proprietary size:
1-1/16" Changing the fork is not really an option, but it is a damn good fork. I've been riding mine for 15 years with no headset or fork maintenance required.

2. The tubing they put in the internal cable slots of the bare frames are just guides to get the cables through - slide cable in, slide guide out. The top tube brake cable path has stops on both ends, the shifter cable paths have ferrules on the top and open holes near the BB.

3. BB on Quantum Pro is plain old English threaded 68mm.

4. I always had the rattle on rough roads too, but I had a bike shop do my re-cabling for the first time last month and the rattle is now magically gone. I don't know if they used a liner inside or not, they used the Jagwire Pro set I brought in to do the job and that does come with a "slick lube" liner.

Thanks for the input Scott.
So I'll have to look into installing some kind of liner for the rear brake cable. That seems like the only possible way to get rid of the road buzz. Given how stiff this bike is, unless you are riding on freshly paved roads it would seem there is always going to be annoying buzz. I can't believe you put up with that for 15 years, you must really love the Quantum. By the way, what kind of tires and pressure do you use? If I am able to cure the noise and decide to keep the bike, am considering moving to 25c tires from my standard 23.

i've had a similar experience with a frame designed to contain the rear brake cable and housing within the toptube. once i found that i could access the toptube via the seattube, a little expanding foam in there did the job.

i would suggest a few dry runs on some scrap tubing just to get a handle on how much is needed.

BTW, if only the brake cable entrance and exits provide access, i think they can be used, in concert with the foam and some old brake cable and housing, to do the job.

Unfortunately there is no way to access top tube from seat tube. And can't enter via fork either as discussed earlier. So only chance would be to insert thin liner through top tube to enclose the brake cable. Actual brake cable housing is not an option, the housing would not fit inside entry holes. So next step is identify some liner that is wide enough to fit the brake cable but thin enough to fit through the Klein cable entry holes.


But this comes back to my original question, was there supposed to be a cable liner installed for all Kleins like this with integrated brake cable? I just can't see how the road buzz could be avoided without some type of liner.

1. I like stiff. Mostly I climb and the Quantum Pro is a great climbing bike... also descends with great confidence. Never felt harsh on long rides though, including one double century.

2. There was really only one road where the buzzing got annoying, it's a rural road and very coarse pavement; only about a mile long, no biggie but other people commented on the buzzing to me. I'm not sure it was the brake cable - that seems to be kind of suspended in the middle of the top tube, I think it was the shift cables... much closer to the inside wall of the downtube.

3. I ride Vittoria Open Corsa, 23mm, 95-105 psig, sweet like sewups.



This is my regular ride:

so am i right in thinking that there is a bare cable running from the entrance to the exit of the toptube? if so, is there some sort of cable stop at the entrance and exit?

if so i think i would just remove the front cable stop throw some expanding foam in there. work the cable back and forth while it's setting. in essence creating a makeshift sheath around the cable to help prevent it from rattling against the toptube.

replacing a worn out cable could be tricky however. a coat hanger, i suppose, could be one solution, i guess.

Yes, bare cable running from stop to stop, but the cable is more or less in the center of the tube; it enters near the midpoint vertically on one side of the top tube and exits at the midpoint vertically on the other side of the top tube...not in a position to rattle. I don't think it's the brake cable that's buzzing, I think it's the shifter cables.

the shifter cables? i thought we were talking about a toptube rattle. anyway, i don't have a klein anyway, so i'll just bow out.

Upon closer inspection there is noise from both top and down tube. However, the rattle in question is definitely in the top tube. With the bike in the garage on hard surface, pick up the front wheel 1-2cm off the ground and drop it, rattles like a mother f'er towards the front of the top tube. This may be due to the loose debris in the tube more so that just the cable so I doubt that adding liner to the brake cable will solve the problem. But as discussed, since removing the fork is not an option there is no realistic way to clean out any objects that are lodged in the tube.


So although I admire the Klein's appearance and pedigree, in this case the ride quality does not nearly compensate for all of these problems. Be on the look out for a Quantum Pro frame-set on Ebay in the near future.