I said on Sunday that I was going to do a post about my tire coming off the rim on Saturday in Houston. I’m not sure were I want to go with it. I guess I want some advise. I barely did anything wrong. I’m putting barely here because I should of been more concerned when I peeled off the new Specialized tire that I’d just glued on the Friday before and it came off the rim pretty easily, taking virtually all the glue off with it.
I originally thought that it was the Belgium rim tape I was using, maybe it was too old, but then I realized that the tape was stuck to the tire pretty darn good.
So now the chronological order of things. This is pretty much how I always glue tires onto carbon rims. Two weeks ago I took a new Shimano wheel and glued on a new Specialized cross tire. I put a layer of 3M Fast Tack on the rim (use only 08031) and then another layer a couple hours later before I put the Belgium rim tape on. I let that dry while putting a layer of Vittoria Mastik One on the rim strip of the tire.
I let both of those dry and then used the Masik One on the Belgium tape once again and mounted the tire. I would normally use Fast Tack here too, but there is this rumor out there that the solvents in Fast Tack dissolve the adhesives that hold the rim strip onto the tire itself. I’ve never noticed this on good tires. I always wear the tires out before the rim strips have a chance to get loose I guess. (And my old mechanic from Levis, Calvin Jones, from Park Tools now, keeps sending me nasty little notes reminding me of the way of the Jedi mechanic.)
So, that is what I did. Then I raced the tire in Austin and it seemed to work good. But, then I got the shipment of new FMB custom tires from Europe and decided to mount one of those on the wheel. So I got prepared to spend 10 minutes getting the tire off. To my surprise, pleasant one at that, it came off with just a little stiff thumb action. And the rim was nearly clean. I think I was so happy that I didn’t have to get a screw driver under the tire to peel it off, I kind of just overlooked the issue of it not being stuck on well enough for my liking.
Then I glued the FMB tire on the same way, except I didn’t use any Fast Tack at all this time. Only Vittoria glue. The reason is, according to this chart, Vittoria Mastik One is the best glue. But, maybe it’s only the best glue for non carbon rims, I don’t know, because when I looked at my wheel after the race in Houston and peeled the tire off the rest of the way, there wasn’t much, if any glue left on the rim once again.
Now my high rent, FMB custom tire has the Belgium rim tape stuck onto the rim strip, along with a bunch of pine needles and dirt. I just ordered a can and a bunch of tubes of the Continental Carbon specific rim glue. I’m not sure why other than a guy at the race in Texas said he was using it with stellar results. I guess I did it because I don’t have an explanation of why my tire failed to stay on the rim. I’ve been gluing tubular tires on carbon rims ever since they started making them and have never had a problem. I don’t use the rim tape on road tires, just cyclocross tires that I’m riding at such low pressures. (Too low, it seems, sometimes.)
Tonight I took some 80 grit sand paper and scuffed up my rim pretty good and put on two more layers of Vittoria glue. I’m going to try to put the FMB tire back onto the rim once again, while waiting for the Continental glue to show up in the mail. I used solvent to get most all of the stuff stuck into the Belgium tape. Tomorrow I’m going to try to reattach it once again. I’ll let you know how that goes.
But in the mean time, Calvin or whoever else thinks they are experts, or not experts, at this process, let me know your thoughts on the subject. It is kind of scary, I pretty much rely on my tires to be stuck to the rim at all times.
Everything I thought I needed to keep tubular tires on carbon rims.
I ran into some issues about a year/two ago with some Enve composites rims. I glued tires onto three different sets of Enve 65 rims, and when the (road & track) tires came back off (for whatever reason) I noticed they were taking most of the “rim glue” with them onto the tire’s base tape. My normal procedure was one coat of Vittoria Mastik onto the rim, fully cured, before the assembly coats (one on the tire, one on the rim, assemble). So it was no lack of glue being used and I had not had issues with other rims having similar behavior.
I pinged Enve about it and they told me that their new rims may have a bit of residual mold release left on them, and to clean them with acetone and a scotchbrite pad before doing any glue coats. That seemed to work with other new Enve rims I have glued since. I imagine roughing them up with sandpaper may also have a similar effect.
If these are new or newer rims then something to look into is heat dissipation. Maybe you can get the rim manufacturer to put you in touch with someone with a technical background in composite materials.
Ask a lot of questions about how the carbon rims are built, how the layers are bonded together etc, until you are totally satisfied that it is not rim.
I’m new to tubulars at the shop I work for. This is my secomd season of gluing our teammates wheels up. I start with cleaning the rim. Ill scrape dried old glue off with t tire lever or a flat head. I cleqn it with acetone then. We only use conti glue for every wheel and/or tire combo. My first coats for tire and rim are thin. Then i just keep adding until the thickness is how I like it. I usually first thin coat plus three more for both rim and tire. No belgium tape. Ive never had a team mate roll a tire I glued yet in two years and I can still remove them without destroying the tires
I had that same issue w some easton carbon wheels and Victoria road tires. It was like the carbon didn’t absorb any of the glue (masik one I think) I stripped the rim down rim bare and got the sand paper out. Sanded it down and wiped it clean w rubbing alcohol. Put a layer of glue on and let it sit over night. Then preceded to glue the way I usually do. For cx tires I don’t use any Belgian tape, just additional layers of glue to build the rim up to something that resembles a flattish surface.
That being said I’m no pro mechanic but I havent had any problems as of yet. Well except getting the tires off at the end of the season. Hope this helps Steve.
I third the acetone and scotchbrite.
1. scotchbrite
2. wiping the rim seat with the acetone and a clean cloth.
3. two thin glue layers on the rim and maybe two on the tire. I want a level adhesive surface. Glued rims may need more.
4. one more layer of glue and mount while the glue is a little wet. The wet part is likely superstition on my part.
At step 3, you should be able to test if the glue is bonding by scraping at it after it’s set.
Might you have inflated the tire too much during the curing process? Sometimes, especially on narrower rims or those with a deeper rim/tire interface, the tire can become separated from the rim when inflated for curing, leaving only the edges attached and severely compromising the integrity of the adhesive. It sounds like you’ve been avoiding this with the Belgian tape, but it may have just not worked out this time around.
At any rate, my technique: Vittoria Masik One, three layers on the rim, two on the tire, with 24hours of dry time between each. Pretty standard, but has not caused a problem.
If epoxy is cured w/ medium or fast cure hardner, it leaves behind a thin film called blush, which has to be removed before you can glue tires. Mold release can also be left behind, but it wipes off easier than blush. The key to getting a good bond on carbon is exactly what others have said already–acetone and scotchbrite. Don’t worry about scratching the surface of the rim bed, you won’t hurt anything w/ a scotchbrite pad (or >220 grit sandpaper). One poss. explanation for why it hasn’t been a problem in the past is that market pressures (increased volume, decreased prices) may be encouraging manufacturers to use faster cures, but this is pure speculation.
I don’t know if it’ll help, Steve, but I’ve found that, like mixing beer and well drinks can be risky – so can mixing sew-up adhesives/tapes. My best guess is that something in the make-up of the tape or glues didn’t agree with each other and spoiled the bonding power. I think if you just use one type of sew-up glue, you’ll be better off. I have been using Conti regular glue on my Neuvation carbon wheels and Conti and Vittoria tires – not for cross; for road. I agree that roughing the rims and then cleaning them with acetone is key to a good glue job too. Putting on several thin coats of glue and letting them dry works best is my experience. I have heard many stories of FastTack causing issues so I never use it. I stick with the stuff from the tire makers, like Conti or Vittoria. Hope this helps keep those tires on! Love your blog.
Jim Langley http://www.jimlangley.net
Sounds like cure time combined with low pressure (and that sideways hop) may have been your issue. I’ve certainly raced on wheels that have been glued in less time but ideally the process takes 2 days allowing each layer to cure fully before mounting.
Cool Blog.
Steve- Not sure how deep your rim bed is. You might already know this, but if the base tape isn’t making full contact down in the rim bed, that pretty much means the glue job is only getting it’s strength from the outter portitions of the bed.
Dugast recommends cutting down an old base tape and gluing that in down in the “v” of the rim bed to take up that void.
As a test-Maybe take on of your unglued tubulars, pumped inside out,and see how the basetape matches up in the rim bed
Don’t we already know why the tire came off the rim? Because the glue didn’t adhere to the carbon? So I think Steve should focus first on the glue/carbon interface, not the tire/rim interface. I’ve worked with epoxies for over 20 years. Don’t discount blush, it doesn’t wipe off easily and it will inhibit bonding. The faster the cure, the worse the blush. It doesn’t take much to inhibit the bond. Just make sure there’s no oily feel, no shininess, no part of the rim bed that isn’t ‘scratched up’. Then remove the dust w/ acetone or alcohol. If you do this and still have problems, look at your gluing technique. If you haven’t done this, don’t re-evaluate gluing techniques just yet.
Don’t underestimate how much glue those FMB pure cotton casings will soak up on the first go around. Maybe treat them a couple of extra times the first use.
Guys-I agree with everything above. It must be some substance on the rim because it was two different tires. I’ve glued literally thousands of sew ups on and have never had a problem. But, it doesn’t take much to get spooked here.
I remember when Tim Johnson, Todd and even Jonathan Paige were rolling tires right and left. I couldn’t understand why. I rolled a Dugast off the rim strip once, that that is my extent of rolling tires.
I glued the FMB tire back onto the rim this morning. We’ll see how well it adheres after the scuffing and cleaning.
Interesting video from Tejas and the failure. Didn’t seem Steve had some much speed at the corner, and just hopped the rear a bit. Must have been enough impact to get it off the rim, but still to me surprising. Would be interesting to know if the rim there still had good glue, or did the glue lift clean. The statement of “dirt and pine needles” indicates there was still glue, yes?
There needs to be more back up from the industry here, and it is just not forthcoming. There have been some new glues being tested, but it is the entire system that needs a review. Tire diameter, seam stitching, base tape material, rim width, rim radius, rim surface, glue type, and of course technique all need to work together.
Look at most other industries, and you will not see this type of adhesion used in areas where you must replace components (tires) often. But, having said this, tubulars are a great ride.
“Tire diameter, seam stitching, base tape material, rim width, rim radius, rim surface, glue type, and of course technique all need to work together.”
^ ^
this atmo.
also – why is CF so popular for ‘cross? it seems to me that there’s an inherent liability in trying to ensure a tubular stays on a rim no matter who glues it. what with different pressures needed at every turn, off cambers to beat the band, wet weather, and human error, i see the material as a recipe for disaster. we’re a dedicated metal rim team if for no other reasons that the gluing of tires to aluminum rims has a long and proven track record. plus, the cost of the parts is a fraction of what a set of tech CF hoops are. who can put so much into training, traveling, and the sport in general and then enter a race only to roll a tubular. what’s the upside? i don’t expect to change anyone’s mind, but would love to know why someone buys a really expensive set of wheels and some tubulars and then hops on with no guarantee that it will stay on the rim.
hey – have a nice day, huh.
Just a thought. Toss the old school tubulars in the trash and get some clinchers. Tubulars suck.
Fast Tack is an automotive adhesive. Hexane and rubber are it’s base. It has a low shear stength. Not really made for the shear and peel force’s of a bicycle tire. I suspect the tape would leach much of the hexane into it. Carbon is made with adhesive ,it’s surface not easily glued to without cleaning(acetone) and roughing it up a bit. FastTack works better with aluminum . Conti seems to have the best bond in all conditions without the Bel. tape. I would use Mastik or Conti in layers as you know. One other thing I’ve noticed , cold temps.(this time or year) cause adhesive to setup to quickly and the bond not as good. Are you sure it’s not those barriers you jump ? Good luck.
Conti Carbon glue differs from reg conti glue, in that, it is built to withstand the higher breaking temps assoc. w/ carbon (just like CF specific brake pad). Bike radar and KU Glue guru Howat recommends using it, and has found it be just as good as reg. conti glue (although he has not test it add high temps). The same article goes on to say, that CX does create high breaking temps and therefore CX does not require CF specific glue. (http://www.bikeradar.com/gear/category/components/tubular-adhesive/product/review-continental-carbon-rim-cement-44556/)
I use a technique recommended here, http://www.bikeradar.com/gear/article/workshop-gluing-tubular-tyres-for-cyclo-cross-28099/. Basically, three layers on rim and tire (w/ 24 hr cure btwn) and one last fresh on the rim. The trick is: rolling the tire (almost totally deflated) on a broom stick immediately after it is mounted.
For CX, I also wrap a racket strap around the tire (partially inflated) as the glue dries- pressing the tire onto the rim.
That said, tubies roll sometimes. They’re still worth every penny and all the time invested.
I know some people swear by the Belgium tape method for cyclocross, but I’ve never met another mechanic who uses it or recommends it. I think using the same glue, not Fast Tack, for every layer is important too. The process isn’t hard, two layers on rim, two layers on tire, allow proper cure between layers, then one final layer on rim, allow to get tacky, then mount the tire. I allow three days for each wheel for proper cure between layers. I’ve never had a tire roll in 18 years of wrenching.
I agree with Tyson. Steve, I was the one who saw you in the parking lot Saturday after the rolled tire. If you’re gonna keep with the Belgian method use the same glues throughout. I’m using the carbon specific on road and new cx tubies as it doesn’t sound like the new formula is compatible with either the standard conti or vittoria glues. Good on you for toughing it out. My 12 yr old was proud as hell for you and finished 3rd the next day in the 10-14 division.
Steve, My 2 cents. i used to run shimano wheels as well and i quit when i couldn’t shake the same problem. I figured the belgium tame was the answer but in reality the gluing surface on the rim isn’t holding the glue very well, then your tire is ruined with a layer af tape on it that rots out in a few months. I tried sanding, green pad, acetone,… it just isn’t a good gluing surface. Glue a tire on a set of Zipp wheels, no belguim tape and no special gluing process and you will be amazed the difference, you will rip the base tape from your tire trying to get a tire off. Zipp uses a special kevlar type layer on the braking surface and the gluing surface that makes a huge difference. I love shimano wheels but they really need to address this on their tubies. BTW throw that tape in the garbage, it is just going to ruin your tires!
It will be interesting to see how tubulars play out with MTB XC racing. The rims are a bit wider, so the bed of contact is better. There will be no rim heat from braking, and there will be an absence of lateral loads from hard cornering at speed. However, sideways hops and lateral impacts, much like CX, will still be a threat. At Champery this year it seemed to me the field had a big increase in tubular use. I would also suspect that having 2 tech pits per lap influences this decision, but that is a different thread.
– Cleaning and roughing up the rim is important.
– I have found your 08031 to work very well. better than anything else I’ve tried. The fact that you didn’t use it the 2nd time probably contributed. I’d suggest using ONLY FastTack 08031
– I build up a couple of thin layers on new rims, even a third on new carbon
– FasTack not mixing with rim tape,.. that was true when it first came out in late 70’s, but AFAIK all tire manufacturers made a correction by mid-80’s
– I’ve used additional rim tape, but as mentioned it made a mess of the tubular when it was changed. The foam ones (Tufo) adds some energy-absorbing sponginess, so there’s a trade-off.
– C-X tires too large a diamante for the rim? – quite possibly, and even if it was allowed to stick without much pressure, it’s still trying to tear off in the middle when it’s inflated. perhaps that’s where the Belgian tape comes in,.. reduced the depth of the curve in the rim.
– good luck
Update. I scuffed up the rim with emory cloth and then cleaned it with acetone. Then I put 2 layers of Mastik One on and then remounted the tire. It is stuck on pretty good now. The Belgian rim tape was stuck onto the FMB tire, so it got all gooey again, as usual. But, it is stuck on good.
I guess the rim must have had some substance on it that made the glue not want to adhere the first couple times around.
I had a road tire mounted on the wheel previously, so this is kind of weird. I know a road tire doesn’t get the same sort of stress that a low pressure cross tire gets, but rolling a road tire is much different that popping a cross tire off.