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Raced CX nats in Louisville
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So, this season has been my first go at racing CX. I've done well enough to win a couple of Cat 4 40+ races. Anyways, I was in Louisville racing Nationals Mens 40-49 and the Start went well, I moved from 23rd (callup) to near 10-15th position and then on the first fast winding downhill section, my rear Tubular completely rolls off the rim. Game over! Had to run back to the pits to get another wheel to continue but by that time it was "just finish" mentality. Really disappointed.

So what happened? bad glue job? tires were Glued on around November 9th-10th by local shop and have done about 4 races on them prior to today with no real issue. I did notice a "Hop" in the tire though when I spun it on a stand. I was running 24-25 psi in that tire. I weigh 160#. Conditions were slick hence the lower pressure.

Thanks.
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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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Real bad luck - hard to say what caused the roll off but glueing is the first thing that comes to mind - did your shop have 5 layers of glue including Belgium Tape? That process is what is used by many and on my three sets of CX wheels never had a problem. But great fun to be at Nats eh? Oh and BTW I am a tad lighter but my tires mainly run - depending on track at 19F and 21 B


Next year.... :-)

Graham Wilson
USAT Level III Elite Coach
http://www.thewilsongroup.biz
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Re: Raced CX nats in Louisville [feman] [ In reply to ]
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First guess is glue job as well. Find out or post what method the shop used. Then, for next year, do it yourself 😀. I only trust myself to glue my tubulars.

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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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Just fwiw, that isn't actually low pressure for a CX tire. For a rider of your mass it's actually right about the max I would ever expect to see, as in "start with 25 psi if it's dry/fast, and go down from there." It's pretty common to see pros running in the mid-teens or lower when it's (really) slippery.

IOW, yeah... probably glue job. If you had a hop, tire was probably already part way off.

Custom Studio Manager for Diamondback Bikes.
Coaching and bike fit - http://source-e.net/ Cyclocross blog - https://crosssports.net/
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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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KONO wrote:
So, this season has been my first go at racing CX. I've done well enough to win a couple of Cat 4 40+ races. Anyways, I was in Louisville racing Nationals Mens 40-49 and the Start went well, I moved from 23rd (callup) to near 10-15th position and then on the first fast winding downhill section, my rear Tubular completely rolls off the rim. Game over! Had to run back to the pits to get another wheel to continue but by that time it was "just finish" mentality. Really disappointed.

So what happened? bad glue job? tires were Glued on around November 9th-10th by local shop and have done about 4 races on them prior to today with no real issue. I did notice a "Hop" in the tire though when I spun it on a stand. I was running 24-25 psi in that tire. I weigh 160#. Conditions were slick hence the lower pressure.

Thanks.

That was you huh. . . that stinks. That fast downhill had a fair amount of off-camber and it was putting a lot of horizontal force on the tire. I did a lap at about 20 psi in the morning and it was sliding all over the place. 25 on that course with your weight given the conditions. . . that's about right imo. Yeah, if it rolled within a month, it's a bad glue job. I love my local shops but really solid mechanics are hard to find and it's tough to say who was gluing it and/or how proficient they were. You've got to know the limits of your shop and I sense you just found it. Maybe that shop doesn't glue a lot of tubs? It's best to pull up the cannondale/cyclocrossworld video, learn the tried and true method, and start gluing. You may still roll a tub or two as you figure out how to do it right. . . but it's not all that difficult, just requires time and elbow grease.
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Re: Raced CX nats in Louisville [fredly] [ In reply to ]
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Good to know that it wasn’t the pressure I choose. I still need to play around with that to see what works best.
I will take it back to the shop who glued it and find out what method they used. I’d like for them to re-glue it hopefully at no charge. We’ll see. They do a lot of work for one of the larger CX teams here in the city so I did trust them. Not sure if I should give them another chance or look elsewhere. Feeling a bit less salty about it today. That’s part of racing I guess.
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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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If the tire came off the rim it was the glue job. Lower pressure was a factor (big or small) in the equation but not the only factor. Another issue may be water /dirt penatration. Even the best glue job may have compromised itself by a tire being and staying wet for a prolonged period. If a wheel is ridden in the mud and not cleaned the tire rim interface may be somewhat effected over time.
Off camber will increase the torque in pulling the tire off the rim as the center of the tire moves away from the center of the rim . It is hard to say xxx more psi would have helped or hurt the equation, but it would have changed it. If they were glued on properly, the tire will not come off period. I have had tires glued on that were nearly impossible to get off, but I still visually inspect the tire before every ride. You may still be able to see if there were any gaps or compromises in the gluing process on your wheel.
I have been gluing tires since the 1960s and up until a couple years ago never trusted anyone but myself to glue my tires. We have a local guy who has worked for Geoff Proctor at Worlds a bunch of times that does mine now, he is really good but pricy. I just gave up on going cross wheels, it is way too much work. He uses tape, I have never used tape. I am sure with enough time and layers of glue both ways work. Over the years looking at failures I see a high percentage of problems with the rim surface having some contaminate like oil or solvent on it. Those rims need to be clean clean to get the the glue to stick 100%. Need to see if the base tape ripped apart from the tire as well. Sometimes the base tape is still stuck on the rim and became separated from the tire body.
Sorry to hear it happened in a big race, but higher speeds in races increases the torque on tires. They never seem to roll in practice laps, but 5 min later in the race they roll.
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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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Just agreeing with everyone else, likely culprit = bad glue job. Belgian tape + lotsa glue (there's a good video online from silas anthony, cyclocrossworld mechanic). Can't trust other people to do it right for you.
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Re: Raced CX nats in Louisville [feman] [ In reply to ]
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I've never understood the glue and tape method...if you put a ton of glue on, then tape on top of it...aren't you just negating the glue under the tape (and hence adding unnecessary weight)?
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Re: Raced CX nats in Louisville [AGTC1] [ In reply to ]
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The layers of glue and tape combined help to build up the center channel in the rim. What you are looking to do is create as much smooth, uninterrupted contact between the tire base tape on the rim/glue/tape.

Alex Arman

Strava
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Re: Raced CX nats in Louisville [doublea334] [ In reply to ]
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What he says and add that the new wider rims change the concave profile of the inner rim and should work to the advantage of better sticking over a larger surface area..
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Re: Raced CX nats in Louisville [AGTC1] [ In reply to ]
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I am sure this can be debated for years - but the rationale that was developed in Europe and it appears to work is that with a road tire TPI of say 100 no need for tape= but most tubular CX wheels riders run much lower pressures - mine in general are 19-23 range - so this means the actual rim can and sometimes does make contact - so the tape is more of a mechanical bond to the wheel - I have never had a tire roll off using this method. Hope this helps.

Graham Wilson
USAT Level III Elite Coach
http://www.thewilsongroup.biz
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Re: Raced CX nats in Louisville [KONO] [ In reply to ]
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Tape and glue is good.

Definitely do not fall for the trap of the Effetto Mariposa Carogna tape. Totally worthless. It was fine for a couple races then kept failing. It cleaned up so nicely, though. I really wanted it to work.
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Re: Raced CX nats in Louisville [iamuwere] [ In reply to ]
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iamuwere wrote:
Tape and glue is good.

Definitely do not fall for the trap of the Effetto Mariposa Carogna tape. Totally worthless. It was fine for a couple races then kept failing. It cleaned up so nicely, though. I really wanted it to work.

Tape and glue is good (and I use it), but I have seen enough success in my area with the Carogna tape that I wouldn't call it worthless. Personally, I just wrapped up my 3rd season with PDX tubulars attached to aluminum rims by the same Carogna tape put on in September 2016 (very last minute before Jingle Cross). I had 10 or so races on that wheelset alone this year and at 190+ lbs and low/mid 20 psi, I'm a good candidate for rolling (or burping) tires. Those wheels saw horrible things this year in the CHI CX Cup. I never had enough reason to rip them off and glue them the last few years because they just work. I had a set with the Belgian method and the tires were stuck super tight when I sold them, but that took days and a surprising amount of $$.

I wouldn't hesitate to recommend it for CX to those that want to mount their tires themselves and don't have any background gluing. I don't think there's a shop within an hour of me that I would send anybody to for gluing tires either. It costs a few watts, but it sure beats riding wheels with hops or losing tires entirely.

It's way easier to screw up a glue job than it is with Carogna tape. I said it somewhere else, but the entire Carogna tape process took under 20 minutes for both wheels. Clean the rim with alcohol, cut tape to length, put on rim, pull both edges of tape off slightly, mount tire with a tiny bit of air (so easy to straighten tires with this method), pull edge of tape from underneath, and inflate to max pressure. I raced them a day later. Been racing them ever since.
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Re: Raced CX nats in Louisville [dangle] [ In reply to ]
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My fronts always were fine with Carogna, but the rear rolled two or three times before I gave up on it. Always in significant off camber areas. I think maybe I weight too much at 200lb
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Re: Raced CX nats in Louisville [iamuwere] [ In reply to ]
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iamuwere wrote:
My fronts always were fine with Carogna, but the rear rolled two or three times before I gave up on it. Always in significant off camber areas. I think maybe I weight too much at 200lb

Tape coming off the rim or coming off the tire? Which tires? I have been curious if the base tape on some tires isn't compatible, but that would be the tire coming off the tape and the couple failures I have seen were tape coming off the rim. The tape was wider than the rim in one of those instances.

Those off-cambers or lateral skips on bumpy terrain are exactly what rip rear tires off. Exactly where tubeless woes seem to be as well. I dumped a tubular set to run tubeless for two wheelsets this year. I can't burp a Schwalbe on a Stans rim no matter how hard I try and there's enough volume to get down to 20 or 21 front & 22 or 23 rear (about where I'm smacking the rims too much). Stans rims with WTB or Schwalbe tires have been burp-proof for me and I'm pretty sure the extra volume has been an advantage for a bigger guy like myself. X Ones on Crest rims came out to ~36 mm and seem to have a little extra height than my tubulars as well. I'm just a midpack 3, but it's not for a lack of equipment geekery.
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Re: Raced CX nats in Louisville [dangle] [ In reply to ]
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Tape stayed tight to the rim. It peeled between tire and tape.

Clement MXP tires. New. Cleaned per directions to ensure there was no oil. Seated with pressure and rested for several days in the the correct temperature.

I am down to one set of tubular. Now mostly tubeless and I also like the fatter 35mm tire, although we end up needing muds almost always of late so I have been using the Vittoria Wet (although I am not sure I like them. I want to get a set of BOS Donnely/Clement to try)
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Re: Raced CX nats in Louisville [iamuwere] [ In reply to ]
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iamuwere wrote:
Tape stayed tight to the rim. It peeled between tire and tape.

Clement MXP tires. New. Cleaned per directions to ensure there was no oil. Seated with pressure and rested for several days in the the correct temperature.

Yuck, that stinks. The tape to tire bond is advertised as permanent and the tape to rim side is only semi permanent. Clement/Donnelly tires are one of the combos I have seen a few sets do okay with. I had MXPs on my old set and they were great for mostly dry conditions.
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Re: Raced CX nats in Louisville [dangle] [ In reply to ]
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Chicago has about the mildest courses out there. Not particularly good for testing tires. Pony Shop and Psimet should be very reliable shops for gluing if you don't want to do your own.

If the rim shape matches the tire then belgianing is not necessary. e.g. Major Tom rims match Clements and most others very well. A decent glue job will last seasons. Just check tire adhesion before your race and make sure there is no lift off, and never power wash.

Alloy rims are better than carbon for adhesion.

Reasons for early failure, assuming adequate glue and several layers, are bad prep of rim or tire - presence of contaminants. Another failure mode I've seen is bad glue. Cans of Mastik need to be stirred well - bad things happen when they sit. The matrix distributes unevenly. I've seen a couple of cases of starved joints where the matrix never formed properly due to old or improperly-stirred Mastik. Using tubes is far better.
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Re: Raced CX nats in Louisville [carlosflanders] [ In reply to ]
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Agreed on PSIMET and Pony Shop being the two in the CHI area to check out for gluing tubulars. I'm a bit west of them in Rockford, so they are outside my 'hour' range mentioned above. Some of the CHI courses aren't terribly technical, especially early season. The weather in October and November made for some crappy conditions for wheels just about every race though.

The WI series has some fun courses. I'm partial to the spring ones in Rockford as well.
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Re: Raced CX nats in Louisville [dangle] [ In reply to ]
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Love Wisco racing. Best CX tradition in the Midwest, great courses and hardass racers.

If your rim matches the tire then I think Carogna tape should hold up very well for a season.
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