Wednesday, December 29, 2010

All About Compressors

Anyone who has ever worked at a bike shop or even an automotive repair shop knows that one of the coolest tools there is the compressor.   Before tubeless tires, compressors were merely labor saving devices, superfluous to the participant of an activity where you are trying to get some exercise.    I, like all other riders I know, just used a pump to inflate my tires.

Then came tubeless tires, and their finicky inflation requirements.  Some people claim they can fill a tubeless tire with a pump, but I certainly cannot.    At first, I just journeyed to a bike shop or a gas station that had some free air.   Later, I took the intermediate step of purchasing an 11 gallon air tank that I could refill from time to time.

Finally, I broke down and bought an awesome, 10 gallon, 3 horsepower compressor at harbor freight for only $100.    I have since added the 11 gallon tank for 21 total gallons.   Allow me to explain:

What You Need To Know About Compressors

There are two key measures to any compressor, the horsepower and the reserve capacity.   If you merely wish to inflate a tube, you don't need much of either.   You just sit there and wait until it reaches the pressure you desire.   Any $20 roadside inflator will accomplish that.   If you are getting into tubeless, especially road tubeless, such an inflator is worthless.

What you need is a significant amount of horsepower, reserve capacity, or both.    If you have a decent motor in the 1-2 horsepower range or higher, the compressor should inflate your tire with no problem.    If you have a sufficiently large tank of several gallons or more, you can pre-inflate it with enough air to fill inflate your tubeless tire.    This is what I did when I owned a tank, but no compressor.  At the time, I didn't know about Harbor Freight and bought a tank from Home Depot, which cost a third of what a decent compressor was selling for.

Ideally you have both a good motor and a decent tank.  I would say 1-2 horse and 3-5 gallons should be sufficient for almost any tubeless tire inflation.   The only time the horsepower really comes into play is when you have a pinned rim that won't seal quickly.   In that case, you might find yourself running your compressor and shaking the rim for a few minutes, like I did.   Otherwise, it is only a factor in how much time it will take to re-fill the tank.

What Made Me Get A Compressor, And Why I Can't Live Without It Now

I was getting by, filling up my 10 gallon tank at the local gas station from time to time.   Then fall came around and I was about to pay someone $100 to blow out my sprinkler system in my yard. (If you live in a colder climate, you have to do this before winter to prevent the water from freezing and damaging your in-ground sprinkler system.)   About the same time, I realized that I could buy a nice compressor at Harbor Freight for that much, and avoid paying the sprinkler guy the same amount every year.  The ability to rapidly inflate tubeless road bicycle tires was just icing on the cake.

I later realized that the compressor was useful for all sorts of other tasks.    I can drive an impact wrench when I change the wheels on our cars between summer and winter tires (I love the sounds zzzzing!-zing!).  I use compressed air to clean dust out of my computer and keyboard.  Compressed air is also great for drying my bicycle chains after de-greasing.   And of course, I can quickly inflate bicycle tires, car tires, and basketballs.  Nevertheless, I still use a good hand pump with a gauge to achieve the correct pressure on my road bikes.

So take your time and shop around for a decent compressor.   If you check places like Harbor Freight, Craiglist, Amazon, or even your local used tool store, you will probably find one that meets your needs for under $100.   Properly maintained, they should last a lifetime.

Only later will you wonder how you ever got along without one.

Tuesday, December 28, 2010

Tire Review: Hutchinson Atom

At the beginning of last season, I was looking for a road tubeless tire with a bit more performance than the Hutchinson Fusion 3 Tubeless tires I had been using.  So I figured, why not try Hutchinson's top of the line tubeless road tire, the
Hutchinson Atom Tubeless.


Hutchinson lists the Hutchinson Atom Tubeless as a 23c tire.   I beg to differ.  I would say it looks more like a 20 or 21c tire as it is definitely narrower than the Hutchinson Fusion 3 Tubeless, both of which are listed as 23c.    I saw this width issue with the Intensive tire as well.   It was the same width as the Hutchinson Fusion 3 Tubeless, but was listed as a 25c.    Hutchinson really needs to get their act together when it comes to labeling tire widths.

Dimensions aside, the Hutchinson Atom Tubeless gives every indication of being a pure race tire.   It's narrow profile and light weight make it an excellent climbing tire.   I didn't break out the scale, but I have no reason to doubt Hutchinson's claimed weight of 270 grams.   This tire is comparable in weight to a high end clincher and tube combination, but maybe a few grams above after you add sealant.   Keep in mind that an ultra light tube will not give much reliability, while a tubeless tire with sealant will likely run down to the threads without having a flat.

I had only myself to blame for my performance in the local hill climb last spring that I rode with the Hutchinson Atom Tubeless.   Descending was also a bit dicier than on the Hutchinson Fusion 3 Tubeless, as one would expect from the narrower dimensions.   The ride was also a bit more harsh, which again, I attributed to the dimensions more than any difference between the Hutchinson Atom Tubeless and the Hutchinson Fusion 3 Tubeless.   By mid-season, I was looking forward to going back to the Fusion as I was doing more all day rides in the mountains.   The 20 grams per tire saved by choosing the Atoms over the Hutchinson Fusion 3 Tubeless was just not worth it to me for the small, but significant difference in ride comfort.

Who Needs This Tire

In my teens, I jumped at the chance to buy the narrowest, lightest, and fastest tires available for my suburban assaults on the local hills.    This would have been the perfect tire for me then.   If I was a racer looking to achieve maximum  performance with minimal weight in a tubeless tire, I would again select the Hutchinson Atom Tubeless.   Now that I am approaching forty, and I am having fun climbing mountains all day than I do racing, the Hutchinson Atom Tubeless just isn't providing the  level comfort I am looking for.   It is great that Hutchinson is offering a dedicating racing tire, but it forced me to face the fact that I am not really dedicated to racing.    For those who are, but don't want to mess with tubulars, this is the tire for you.

Friday, December 24, 2010

We've Been Slimed!

Today, I am featuring an interview with Bria Di Cicco, brand marketing director for Slime, one of the major players in the tubeless sealant market.

Jason: I was looking through your product offerings on your web site.    The "Slime Pro" product seems specifically designed for tubeless tires, and you even recommend it for road tubeless bicycle tires.  What challenges do you see in dealing with the triple digit pressures encountered in road tubeless that are never seen in automotive, motorcycle, or mountain bike tubeless applications?

Bria: Yes, Slime Pro Tubeless is designed and tested specifically for bicycles with tubeless and conversion set-ups. The biggest challenge sealing high pressure is that our sealant does not dry out when it reaches the punctures, but rather clots in the same way blood clots. Our fibers, binders and clotting agents (Fibro-Seal technology) build-up and intertwine within the puncture and form a plug. When there is a higher pressure forcing against the plug build up the formula has to work extra hard, and our does- sealing punctures effectively at high pressures common in road bikes.

Jason: It must be the cold weather, but lately I have been thinking about the effective operating ranges of different sealants.   Is there an effective operating temperature range for the Slime Pro product?  What is it's freezing point?

Bria: SlimePro Tubeless has an operational temperature of around -20 degrees Celsius (-4 F), making it competitive with other products on the market.

Jason: I have yet to try the Slime Pro product.   How would you contrast the properties of the Slime Pro product versus the regular Slime tube sealant?   How does it compare to your competitor's tubeless sealant products?

Bria:  There is no nasty ammonia smell, rather a pleasant pina colada scent. Our formal contains powerful and rust and corrosion inhibitors, so it is safe for expensive tubeless wheels. It has a competitive lifespan and also works on conversion set-ups.

Jason: One of the challenges I have faced using Stan's sealant is that it dries up every 2-3 months, requiring removal of the dried sealant, and replacement with (expensive) new sealant.   What is your experience with the Slime Pro product?  About how often must it be replenished in a road tubeless tire?    What is the product's shelf life?

Bria: Lifespan is a hard number to pint down as it is so dependant on the average temperature, humidity, tire type and riding style. Slime Pro longevity is on par with other products, and we have also received testimonials that it outlasts many competing products.

Jason: One of the real stumbling blocks with road tubeless technology gaining traction in the market is it's price.    Even on sale, tires sell for $50-$80 each, and it seems like the money saved on tubes is quickly consumed by money spent on sealant.  While this is not a factor for a sponsored racer, it can hit recreational riders hard.    According to your website, Slime Pro retails for $18.99/16 oz. and $49.99/gal (128 oz).   That works out $1.18 per ounce in the 16 oz vs 39 cents per ounce in the gallon size, with no size in between.   I've heard of volume discounts, but why is the 16 oz bottle 3 times the price per ounce of the gallon version?

Bria: Right now our Slime Pro Tubeless is sold only in a 16oz bottle. The Slime Pro formula available in  1 and 5 gallon sizes is our OTR-Over the Road formula for fleet trucks. Although the Slime Pro brand is there, the formulas could not be more different.

Jason: Thanks for clearing that up!

Thursday, December 16, 2010

Part 2 of my interview with Alberto De Gioannini of Effetto Mariposa

 Last week, I posted part one of my interview with Alberto De Gioannini of Effetto Mariposa.    Today, I received his answers to some additional questions:

Jason: Here in Colorado, we can see temperatures below from well below zero to well over 100 degrees Fahrenheit (-18 to 38C).  I noticed it is not too warm this time of year in Bra, Italy either.   Have you discovered the effective operating temperature range of your sealant products?

Alberto: The effective operating temperature is -20/+50°C, that covers 99% of the conditions you might want (dare?) to ride in...

Jason:While your sealant products are well known to cyclists here in the United States, your rim strip may be less commonly seen.   What differences are there between your tubeless rim strip and some of your competitors such as Stans?

Alberto:  My rim strip is a super-strong, fiberglass reinforced adhesive tape. One layer can stand over 8 bar (but I use two layers for road tubeless, for additional safety in the long term use). Compared to other adhesive strips, it's very durable but requires a certain care while putting it in place on the rim.

Jason: What do you see as the future of road tubeless technology.   Do you think it will be a temporary fad, a small niche, or a major challenge to tubulars and standard clinchers?

Alberto: Tubeless in its current incarnation has certain advantages over tube-type (low inflating pressure, lightness, puncture prevention), but these advantages are more relevant/easily achievable for mtb than road applications. The fact you can't use a normal tire and that "hybrid" road-tubeless tires are not there yet (they're just fully "tubeless" tires), means the weight advantage over tube+tire is very narrow (given the same tread thickness, it's hardly there..).

Low inflating pressure for comfort is a good argument, but you can use a lower pressure with your usual tire+tube combo, as pinch-flat or punctures are not that much of an issue on the road (compared to the off-road environment).

What I would like to see is some serious data on reduced rolling resistance for road tubeless over tube type and tubulars: that would be a convincing argument for many people. The weight will eventually go down when more tire manufacturers start working on a road tubeless offering, so I see some good selling arguments coming for road tubeless products in the future.

Wednesday, December 15, 2010

Do Sealants Work In Cold Temperatures?

As the news is dominated by reports of record low temperatures on the East Coast, this seems to be an timely  question; at what point does your sealant freeze and cease to be effective?   To test this, placed a bottle of Stan's sealant into my freezer, which is set to 2 degrees F.   The next day, it was a bit sluggish, but not frozen solid.    My guess is that it's effectiveness would be reduced at this temperature, but entirely gone.

Fortunately, I am not in the habit of cycling at those temperatures, hence the freezer test.   I am confident my sealant will continue to work in the 10-20 degree area  that represents the limits of my personal operating range.

I know that some people, god bless them, regularly go riding in sub-zero temperatures.   The last thing they want on such a ride is a flat.   One interesting thought I had was to dilute the sealant with some alcohol to lower it's freezing point.    Vodka and Stan's anyone?    Heck, the Slime people purposely made their Slime Pro smell like a Pina Colada!  Seriously, I would probably use over the counter rubbing alcohol as it is more concentrated, less expensive, and can be purchased without ID.

I have not yet tried other sealants such as Slime and CaffeLatex in my tires, much less at extreme cold temperatures.   Does anybody out there want to chime in with their experiences with different sealants at different temperatures?

Monday, December 13, 2010

Interview With Alberto De Gioannini of Effetto Mariposa, Part 1

Welcome to the first part of my interview with Alberot Senor De Gioannini, maker of Effetto Mariposa products.    Effetto Mariposa offers one of the leading tubeless tire sealants, the Caffelatex product, and also offers tubeless conversion kits for mountain bikes.  He is also developing a range of road tubeless offerings.

Jason:    Bonjourno Senor De Gioannini,

Now that I have nearly exhausted my knowledge of Italian, thank you for your willingness to contribute to my Go Tubeless Blog about Road Tubeless Technology.

Mountain bike tubeless technology has been around for a long time, while road tubeless is relatively new.  What do you see as the challenges in sealing road tubeless tires as opposed to MTB tires?

Alberto: The main difference between road and mtb tubeless is that you're compelled to use natively tubeless tires on the road, while you can normally convert standard tires to tubeless for mtb (as an extra safety norm, we still recommend to use tubeless or tubeless-ready tires also for mountain bike... but using normal tires on the road is not just a risk, it's looking for disaster). This is due to the main difference #2, the pressure: around 100 psi on the road, around 30 psi for mtb. Wheel conversion is similar and not particularly difficult in both cases (again, the high pressure on the road means you have to pay extra care to your sealing tape).

Jason:    On your website, you do show a couple bikes you have converted to road tubeless with your Caffe Tubeless Conversion Kits.  How have the road    conversions been working for you?

Alberto: No problem at all. Once you figure out how to properly seal the valve hole, the conversion is very reliable.

Jason: I noticed you tried the Hutchinson Fusion 3 as well as the IRC road tubeless tire which is not available in the United States.   Do you have any comment on the IRC offering?

Alberto: The IRC prototypes I've been testing (they're not available in Europe either) were very (I mean VERY) tight to mount and didn't have a carbon bead. Good air-tightness even without sealant, slightly lighter than Fusion 3, a softer compound up front. I'm still using them.

Jason:  The literature on your sealant andyour tubeless conversion kit seems only to specify mountain bike applications.  Do you feel these products are equally suited for road tubeless application?   Are you planning any road specific offerings?

Alberto: Our kit is mtb-specific and is not recommended for road tubeless conversions (we do it at our own risk for testing purposes). A road-specific kit is in the works.

Friday, December 10, 2010

Road Tubeless Maintenance Tip: Don't Let Your Sealant Dry Out

Let's say you have a standard road clincher or tubular tire.   You install the tire, inflate it and ride.   Sure, you might leak some air occasionally, but that is what your pump is for.    Other than that, you maintenance on your tires, barring a puncture, is pretty much taken care of.

This is not the case with tubeless road tires.   I have found that the sealant that I have been using, Stan's will dry up about every 3-6 months.    When healthy, and in the heart of the season, I can put on enough miles on my road bike such that I wear out my tire before the sealant dries up.   In the cold Colorado winters or when I am off the bike due to an injury, my sealant will dry up before I have worn through a tire, typically a Hutchinson Fusion 3.    I simply don't put enough miles on my Hutchinson Intensives to wear through them that quick.

If you have multiple bikes, the problem is worse, as the sealant will dry out periodically long before you wear through your tire.

What Happens When Your Run Out Of Sealant? 

First, your tubeless road tire is more vulnerable to small, puncture flats.   There simply is no sealant to seal the leak.    Worse, I have found that road tubeless tires can suffer from what I call Spontaneous Deflation.    I have seen the bead seal fail when the bicycle is not being ridden.      You can put your bike in your car and drive to work, and by the time you are ready for your after work ride, you have no air pressure!     I even once had my tire deflate, after I topped it off before my ride, while I was getting dressed.

For some reason, I have only seen this with road tubeless tires, not mountain tires.    The only explanation is the higher pressures seen in road tubeless, about triple that of a mountain tire.

How To Maintain Your Sealant

When you install a tubeless tire, keep a log of when you added sealant the last time.   I recommend a small notebook that you keep with your bike tools.   Every three months, deflate the tire and check to see if there is still a small pool of sealant on the bottom.   If there is, estimate that quantity and subtract it from what you normally add.   If there is no sealant puddle in your tire, remove it and clean off any dried sealant before reinstalling it with new sealant.   A dry rag or paper towel is all that should be needed to remove the dried sealant.


I will qualify my advice this way:    I have been using Stan's sealant, so I know it will dry up at this rate.  Your results may vary with other brands of sealants.   I also live in Denver Colorado which is both a mile high and one of the driest places in the country.   It is likely that my sealant will dry out faster than that of someone who lives in a wet climate at sea level such as Portland Oregon.  Nevertheless, the principle holds true.   You should periodically deflate and inspect your tire to ensure sufficient sealant remains to seal the bead and any punctures you may encounter.

Periodic maintenance is a small price to pay for the vastly superior comfort, performance, and reliability that road tubeless tires have to offer.

Wednesday, December 8, 2010

Tire Review: Hutchinson Fusion 3 Tubeless

Hutchinson Fusion 3 700x 23c Tubeless Black

When I first ran road tubeless, back in early 2007, pretty much the only tire on the market was the Hutchinson Fusion 2 Tubeless.    (If there was ever a Fusion 1 Tubeless, I have never heard of it.)  The Fusion line is positioned right in between the narrower Hutchinson Atom Tubeless, and the heavier and more durable Hutchinson Intensive.   I have been riding my Hutchinson Fusion 3 Tubeless since June of 2010, and it is my preferred tire for the kind of riding I do on my road bike.    While the Hutchinson Fusion 2 Tubeless had a different colored center line, to denote a multi-compound tire, the Hutchinson Fusion 3 is all black, despite Hutchinson's designating it as triple compound design.


Mounting a Hutchinson Fusion 3 Tubeless, or any tubeless tire can be a challenge your first time.    The key is to have a good set of tire levers and to use a bit of muscle.   I have gotten to the point where I can hold one part of the rim with my hand and work the last foot of remaining bead with a tire iron inch by inch until the bead snaps into the rim.   After that, I soap up the bead and let my compressor do the work the first time I inflate it to set the bead.    I then deflate the tire, add sealant, and re-inflate.  With a tubeless tire, you leave the tire on the rim until it wears out, never having to mount it again, something I have never done with a standard clincher in 25 years of riding.


The Hutchinson Fusion 3 Tubeless is about the right size for a 23c clincher.   It is slightly wider than the pure racing Hutchinson Atom Tubeless, and just big enough to inspire the confidence I need on a good, switchback descent.   At 290 grams, it is very competitive from a weight standpoint with a decent tube and tire combination.   Sure, you could find an ultra-light tube and tire, but durability would suffer dramatically, and your costs would go up as you puncture your fragile and expensive tubes. 

How I Tested The Fusion 3

As a 180 pound rider on a 15 pound bike, and I generally run 105 psi in the rear and 100 in the front.    I try to minimize my rolling resistance while maintaining a comfortable ride.  I run 2 ounces of Stan's sealant in each tire.  The first time you ride a Hutchinson Fusion 3 Tubeless you will instantly notice a comfort difference compared to a standard clincher

Here in Colorado, I like to climb, and I like to descend.   In the summer, I enjoy all day slogs through the mountains in preparation for epic rides like my annual assault on Mt. Evans or the Triple Bypass.   I find the Hutchinson Fusion 3 Tubeless to be the perfect tire for my needs.   It is more comfortable than any clincher I have ever ridden, and most riders find it to be on par with a tubular.   Unlike a tubular, I need not carry a spare tire with me on my excursions that can be 30 miles from anything resembling a bicycle shop.  In fact, I have yet to use even my spare tube as flats are extremely uncommon.   To put this in perspective, last summer I broke my freewheel, had a part on my pedal fail, lost a chainring bolt, and broke a spoke.  During that time, I had no flats.   In essence, my tires went from being one of the most common causes of a mid-ride maintenance stop, to one of the least likely.


If there a trade-off with the Hutchinson Fusion 3 Tubeless it is durability.    The tire has a relatively soft compound that wears steadily as you pour on the miles.   I did suffer one cut with my Hutchinson Fusion 3 Tubeless, but, with sealant, the tire still held enough air to get me home.   I was later able to patch the tire using Hutchinson Rep'Air Tubeless Repair Kit for Road.   The tire is very vulnerable to wear if you ride on a stationary trainer or on unpaved surfaces.   In order to get more life from my Hutchinson Fusion 3 Tubeless, I am now avoiding the few packed dirt roads that I used to ride occasionally.

As I have put miles on the tires, I have noticed the rear tire wearing faster than the front.   When the rear is finally too worn to ride, I plan on moving the front tire to the rear wheel, and put a new Hutchinson Fusion 3 Tubeless on the front, in order to save money. 


The Hutchinson Fusion 3 Tubeless are my favorite road tubeless tires out there, and they a worthy compliment to my lightest wheelset on my most expensive bike.  They are fast, light, and comfortable enough for an all day ride.   Treat them well and they will serve you faithfully for about 2,000 miles.

Every new technology has a "killer app" that proves it's value, and the Hutchinson Fusion 3 Tubeless is the tire that will make you swear off of tubes for good.

Tuesday, December 7, 2010

Another Two Great Questions About Repairing Tubleless Road Tires

Here are a couple questions in regards to my previous post on fixing tubeless road bike tires.

Question #1:
Thanks for this blog. I'm new to road tubeless but liking it so far. I was wondering if you have tried one of the plug type repair kits like the ones from Panaracer and Innovations. They are meant for MTB tires, but I would think they could do for road as well.
Aren't we all new to road tubeless!   I have not had any experience with these plug type products, at least on a bicycle.    I actually carry the automotive version in my car, which is virtually identical.   They are a great solution when you pick up a nail or a staple.   In those cases, I can remove the nail and plug the tire, but the solution is considered temporary until I get the tire patched at a tire dealer.

As for these plug type repair kits, I don't imagine that I will ever use one for my road tubeless bicycle tires.   I just can't see any advantage over the patch type repair kits.   Certainly the kit from Genuine Innovations (pictured above) is clearly not meant for a roadside repair.  If I am going to remove my tire to fix it at home, I am going to patch it, a solution that has worked for me in the past.

Finally, I find that small punctures are taken care of by sealant, and it is only a larger gash that necessitates a patch.   Such a linear gash does not lend itself to a plug type repair, especially on a bald road tire.

Question #2:
Do you always run sealant? Does it affect the ride quality? Do you think it makes roadside repairs more difficult?

Have you tried any kind besides Stan's?
I do always run sealant.   At first, I only ran about an ounce in order to help inflate the tire.  Now, I am convinced that an extra ounce will go a long way towards sealing any punctures. Consider that a very strong testimonial from this committed weight weenie.  Also, be sure to add about an ounce more every 3 months or so.

I have never noticed any affect on ride quality, nor heard of anyone complain about it, so that is definitely not a factor.   As for roadside repairs, using sufficient sealant will eliminate the need for a roadside repair 99% of the time.   I have worn through or am using currently riding on about a dozen tires, and only once was the sealant not able to completely plug a puncture.     In the one case where the sealant didn't completely fix the problem, the tire still held pressure, just not fully.  

Yes, the sealant contaminated the glue on the patch the first time I attempted a roadside repair.   Now that I know better, if I am ever forced to attempt a roadside repair, I will try extra hard to clean the affected area.   More likely, I will insert a tube and temporary cover (like a dollar bill or a Powerbar wrapper) to the hole between the tire and the tube, and work on the repair at home.

Finally, I have yet to try another brand besides Stan's.   I have read reviews on other products, but so far, it doesn't seem like they do any better than Stan's.   Frankly, I wish they were less expensive, especially their shipping costs, but otherwise I am satisfied with the product.  

Thanks for the questions and feel free to keep them coming.

Monday, December 6, 2010

Question About Patching Road Tubeless Tires

A Reader, TimB, has an excellent question in regards to my post about patching road tubeless tires:
Hi Jason,

I've not yet converted to road tubeless, but am running tubeless on my MTB and have had to patch one big cut.

In your review you say "Rough the surface up" but I've seen advice that the inside of tyres should not be sanded, as the threads are much closer to the inner surface and risk being damaged by abrasion. I've seen advice to use specialist tyre cleaning chemicals, as used in auto shops, but in the end I just rubbed the inside clean, put normal superglue in the cut, and applied a normal inner tube patch to the inside. Seems OK so far!

Does the Hutchinson kit come with sandpaper? I'd be interested to know, to work out what to do with future cuts.
That is an great question.   A little research show that indeed, Hutchinson does not recommend roughing the surface of the tire.    Even though Hutchinson's web site's product page for Rep'Air is predictably short on the this information, Universal Cycles web page for Rep'Air has the goods,  "[Rep'Air] Superglue does not require degreasing or roughing the surface which saves the tire casing threads from damage"

That said, I don't see the point.  The purpose of roughing the surface up is to provide greater surface area and better adhesion between the patch and the tire or tube.   After my first attempt to patch a tubeless tire failed due to lack of adhesion, I felt that I needed to do whatever I could to save my $50 tire on the next attempt.

While I did clean the Stan's sealant off with a rag, I didn't use any automotive grade tire cleaner.   I do like that idea however, and I might pick some up for next time.   I think the key here is that the Rep'Air product apparently uses a "superglue" i.e. Cyanoacrylate, rather than the typical rubber cement that is traditionally found in bicycle tube patch kits.   It is conceivable that superglue type adhesives do not require the surface treatment that other glues do.

Realistically, I have a hart time imagining how rubbing sandpaper on the inside of my thick, tubeless tire is going to damage the threads.   When you consider the large gash in my tire that I was repairing, the last thing I was worried about is a little abrasion to the threads, not that any threads or thread damage was visible.

You will find that that there is a lot of new and evolving techniques out there when it comes to the care and maintenance of road tubeless tires.   From uncertainty flows different approaches that might deviate from manufacturer's recommendations.   As in other area's of cycling, you have to go with the technique that works best for you, without compromising safety of course.  For me, roughing the interior surface seemed a natural way to seal the gash and save the tire, regardless of Hutchinson's recommendations.