Walter.dreyer

I recently bought a set of used tubular carbon rims (Bontragers). The old glue looks kind of chunky. What should I use to get a clean smooth surface to start with?

BikeWise1

Bontrager says acetone.

ultraman6970

Goo off, mineral spirits works too.

Bianchigirll 

unless the glue is super thick you really don't need to take it all off. the carbon/glue wheels may be a bit different but the new glue usually reactivates the old glue. use a stiff plastice stick ( like the things that come between the forks on new bikes) and knock off the chunky stuff. then athin coat of new glue and you should be OK

cbchess

+1 for goo gone or mineral spirits. And elbow grease.

"I'm not the Glue picker or the Glue pickers son, but I'll pick the glue till the glue pickings done"

Chombi

Depends on how old the glue is. For fairly fresh glue, Mineral spirits and Goo Gone should work (try to avoid Acetone as it is highly flamable, has very bad fumes and can really hurt your skin as it is very harsh), but if you are cleaning old rims with very old, hard glue on it, you can use a Dremel with a rotary copper brush tip and it should come right off without hurting the anodizing on the rim. I cleaned up tubular rims last year that had at least 15 year old, super rock hard glue residue on it, that was more like resin. No chemical and elbow grease I applied on it made a dent. The Dremel though, took it all off in minutes without hurting the dark anodizing on the rims. Just make sure you use the softer copper brush tip.

Chombi

FBinNY 

Don't remove the glue, it's your friend. If there's excess glue along the edges, you can scrape it off with a plastic windshield ice scraper, but that's all I would do.

Built up makes a good tire bed and and acts as a primer for fresh glue. Anyone who's been riding tubulars for more than a few years will tell you that as the glue builds up, older wheels become like old jeans getting better and better (with respect to tire mounting) over time.

If you really think it's too thick, the fastest, easiest way is with a brush wheel on a bench grinder. Use a very light touch and spin the wheel continuously so you don't dig in and gouge the rim. Don't try to remove it all, just clean it a bit.

zacster

I would agree with you for rims in continuous use, but for old rims, or rims with unknown use, I'd want to start fresh. I had a pair of old style tubulars from the early 80s that I cleaned up and reglued. I didn't want to use them the way they were. OTOH, I did use an old tire, a Clement Criterium Seta, as these are made of unobtanium. I get nervous about riding such an old tire so I don't use it very ofter and when I do I just cruise around the park. There's nothing like a silk sew-up.

FBinNY 

I road Clement tipo 6, 250gr Criterium Setas almost exclusively from 1967 - when they cost an outrageous for a bike tire $8.00 - thru the mid 80s when the last of my hoard finally ran out. My favorite tread was Nido Api or beehive. There's still a pair on my Frejus, but I only ride it about once a year (if that).

I try to resist being a Retro Grouch, but I've never since found tires nearly as good. I even used to import tubulars for a number of years, but none were ever as good as a Tipo 6.

zacster

I find the modern clinchers to work better than any of the other tires from back then. Only the silks are better. None of the other sew-ups, and especially not the clinchers, were that great. The first time I rode a GP3000 after not riding for a while it was an eye opener. Consider that a GP4000 costs around $65 (more or less depending where you buy) and that I vaguely recall paying $15 for a Clement and that was a LOT of money for a tire.

Homebrew01

+1 to Criterium Setas and not removing old glue unless there are big chunks or it seems loose & flaky.
I had some Durdoigne (sp?) tubulars years ago thet were very nice too.

FBinNY 

Tires have certainly gotten better, though top quality tubulars are harder to find. But comparisons between tubulars and wired-ons are difficult because more than the tire is involved. the main advantage of tubulars is two-fold and can never be overcome by wired-on tires because it's inherent in the basic design.

1- tubulars are self contained and do not include the rim as part of the pressure vessel. That means no flange to flex, and no added material to support it. For that reason tubular rims can be lighter, and less prone to catastrophic failure resulting from brake track wear.

2- Tubulars ride outside the rim, allowing a higher radial flex zone for a given cross-section. Wired-ons can get pretty close to tubulars in this respect if the rim and wire width are well matched, but that isn't something most riders are very attuned to. Tubulars also allow changes it tire width without the need to worry about rim width, so they're always at peak efficiency.

zacster

I think it is the flex limit (or lack thereof) that made tubulars feel so nice. And on a silk tire, where you have strength and flexibility, you could maneuver in ways that would feel harsh on a clincher or a lesser tubular.

The weight and longevity of the rim were never much of an issue for me. My Easton Ascent rear/Orion Front slightly mismatched pair weigh a lot less than my old style tubulars do. That was one of the things I discovered when I got back into cycling is how light wheels had gotten. I would guess though that an equivalent wheel with a tubular rim would weigh even less still. One thing though, I only have old tubulars and none of them have long stems, so you couldn't go aero back then. Do they make longer stems now?

FBinNY 

There are a few options. You could leave the nut loose and use a valve extender, which is what we used to do when deep rims were new. The only hitch is that you can't let the air out easily.

Now many better tubulars come with two piece valves, so they'll accept an extender on the shank below the valve itself, giving you lots of flexability.

motobecane69

these are carbon rims the op is asking about, i don't think you want to dremel them!

Bianchigirll 

I agree and I am not sure about all the wire or copper brushes, Mineral Spirits and goo gone junk either. the OP is better off asking the manufactureer and providing pics to them if he really thinks the glue is an issue