cpsqlrwn

Has anybody ever heard of it, and, if so, what are its characteristics, vintage, rider weight limits, etc.

Old Fat Guy

It is mentioned and pictured here:
https://italiancyclingjournal.blogspo...for-frame.html

If you are asking about the recent eBay frame that claimed to be KL, there was no indication of that on the tubing decal. It looked like a generic decal to me.

JohnDThompson 

Light weight tubing for road frames used on smooth surfaces. Read all about it here.

JohnDThompson 

Columbus did not distinguish between their various tube sets on their decals until the late 1980s. KL tubing dates from the late 70s to early 80s and thus would just have the standard decal:



The only way to (non-destructively) determine if it is KL is to weigh the bare frame and see if it is lighter than a comparable SL frame.

vjp

My 86 7-11 bike is built with a KL seat and top tube and an SL downtube. I am out of town right now but I believe the frame is 1720 grams (55cm). It is thin tubing!!

vjp

T-Mar

I never found weighing a bare frame to be a reliable judge of tubeset, unless you've got something in the same size, with the exact same lugs and fittings. After all, we're only talking 1/2 a pound. Another measurable difference is the seat tube inner diameter. Given, the thinner seat tube wall on KL there will be a 0.2mm difference in seat post diameter which is a viable distinction, unless the framebuilder was heavy handed finishing an SL seat tube.

cpsqlrwn

I was only asking because this Pinarello popped up on eBay Sunday night!

https://cgi.ebay.com/PINARELLO-PRESTI...3A2%7C294%3A50

JohnDThompson 

Nice bike. It could well be KL, but it's very hard to be certain without cutting it apart. If you bid on, don't do it because you think it is a KL frame, but because it's a well made and finished frame with good parts.

Old Fat Guy

Yep, That's the one I saw.

cpsqlrwn

Not bidding. Not my size. I just had never heard of KL before.

Bianchigirll 

Hello those are some fabulous frames. lots of great tubes sets you seldom see. I think I only ever saw one MiniMax and maybe a one SPX. too bad everybody has to ride plastic these days.

hackum

Does anyone have any experience riding a KL frame? Do you really need to be under 120 lbs to safely ride it?
I see that early 80s Pinarello Prestige, which was essentially a road bike, was made with KL, so it can't be that fragile.

Road Fan

I didn't see any weight limits in the tubing catalog that was shared. Where do you get that weight limit?

The tubing walls look about the same thickness as Reynolds 753 and 853. I've just gotten a modern frame for cyclotouring and randonneuring made in 969 and 747 tubes and "standard" diameters, and I weigh about 185 atmo. I don't see where the idea of 120 lb is suitable.

If you have a KL frame or access to a set of tubes to be built up, and you are not going to use the frame abusively, I'd say go for it!

repechage

A friend had a pursuit bike built for him with Columbus Record pista tubing. He was about 170 lbs at the time. The advice was train on it to know it, then for Racing only.

teetime

KL tubing was an extremely light weight tube set made for time trialing. It was slightly heavier than Record tubing, made for record attempts on the track, as the name suggests.
https://www.equusbicycle.com/bike/col...olumbuscat.jpg

Just because it has a decal doesn't make it so.

GrayJay

753 and 853 tubesets are made of steel of significantly higher tensile strength that standard columbus "cylex" tubing which is basically just non-HT CrMo. A KL frame would ride very similar to a 753 frame of similar diameter tubes but the lower tensile strength of KL would make it much more prone to cracking from fatigue.

hackum

This source, table 4:
https://www.desperadocycles.com/Lowdown_On_Tubing.html

They actually made a mistake and the 2nd line should be read Columbus KL, not SL. SL is 4th in the table.

hackum

From what I know, KL was used in the early 80s, when Columbus did not denote the tubing type on the decals. They just put their generic sticker. So, I'd be more suspicous of a sticker claiming to be KL.

I am asking all this, because I was looking at a Pinarello Prestige S in a bike shop, and wondering if it would be safe to ride it as an amateur.

repechage

Ride sure, crash no.

hackum

Hm, so basically if you happen to crash, you'd probably total the frame.

PDXaero

Columbus said around the advent of 753 tubing that they would never produce a tubing thinner than .5 to try to instigate that the .3 used in 753 was unreliable.

Road Fan

You're correct about the properties of the 753/853 and the Cyclex, and that the thin Cyclex is more prone to failure than is the 753 or 853, or the OxPlat my Terraferma is made of.

But, I think it's not so clear what the specific conditions are for causing fatigue cracking. I wish someone who can actually compute tubing stresses in real-world usage could weigh in on the likelihood of fatigue failures in different usage profiles. I think all the OP needs to do to preserve his KL frame is ride it on paved, reasonably smooth roads, don't let any rust begin, and don't jump the bike. Slowing over RR crossings and not bunny-hopping them seem to me like good ideas. If the tube stress levels remain in their elastic range, there are no design or build flaws that represent weak points, and no stress risers caused by rusting or sharp dents, it should not fail due to fatigue. Most tales of frame failure involve one or more of these issues developing.

If the fear of fatigue failure in bike frames was completely justified (i.e. "it's gonna happen, no ifs, ands, or buts"), no 753 frames would have survived to this point, nor more especially any KLs. And presumably both Reynolds and Columbus would have been in court many times for selling the old 531 Superlight, the KL, and, for that matter, the superlight Ishiwata. The problem is not that big.

Re: the weight limits, I still wonder what the source of the knowledge is. Yes, Teetime found it at Desperadoe, and we do depend on it as a reference source. But why didn't Columbus place cautions in its tubing catalog, if Columbus actually believes in the limits as stated?

Road Fan

Yes, now that risk I believe. But that isn't fatigue failure.

Road Fan

I'd think you'll be better off buying a modern frame made of something sexy by TruTemper, or a modern Reynolds alloy. TruTemper is still supplying OxPlat in standard and oversize diameters.

But as a recreational road rider, I think that Pinarello would be a hot bike.

teetime

I ride Columbus steel tubing that is .38 in thickness, so either they changed their mind with the advent of new alloys, or you are mistaken.