Barna's Workshop Top-Tips - Part I

Tubeless Tyres? Revolution or left deflated?

Posted by Philip Cavell

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"Barna is almost certainly the pre-eminent bike-mechanic in Central London"

Tyres - Barna Speaks (quietly)

Every now and then a client will pull me or Jules aside and whisper what has become increasingly accepted and repeated across the capital, even amongst other shops!

"I think that Barna is actually the finest bike-mechanic in Central London"

We know, but we don't talk about it. Anyway, how do you measure these things? If it is by the amount of fine biscuits and wine he is given as gifts, then he is in a class of one.

Barna is Cyclefit's Workshop Manager - he is responsible for all Fire-Station and Store Street bike-building and repairs and leads his little team comprising himself, Ed and Miguel.

Barna is calm and unflappable and never gets stuck. His ability to think/fabricate his way around a knotty problem has become the stuff of local legend.

What follows is Barna's top-tips and ramblings on one the most controversial subjects - Tubeless Tyres! And how to take back control of managing punctures

"His ability to think/fabricate his way around a knotty problem has become the stuff of local legend"


Tubeless, Clincher?


The moment of truth


Plug for Reform custom-moulded saddle

Tyres - The tubeless V's Clincher Debate

Whilst Barna is 'gradually warming' to tubeless technology he retains a note of scepticism based on his understandable cognitive bias of witnessing and resolving all the problems folk have had over the last few years. But the fact remains that 70% of our road clients use tubeless tyres and pretty much 100% for gravel/MTB/Cyclo-X. Tubeless is here to stay and the technology is improving all the time.

The putative advantages of tubeless tyres, centre around two traits:

  1. Superior ride-quality and rolling resistance
  2. Small punctures are shrugged off via liquid silica that freely circulates within the sealed tyre.

The historical challenges include:

  1. Rim/tyre compatibility issues
  2. Big holes tend to not seal - see 'Plug 'n Play below
  3. Home maintenance can be difficult - i.e. getting tyre on and off
  4. Sealant is inherently messy. See Rorschach blot below

Barna's Tubeless Top-Tips

  • Barna prefers a hooked-bead with a thought-through internal profile.
  • With tubeless everything needs to be perfect - rim, rim-tape, valve, sealant, pump (charge or cannister) or there will not be a good seal, ride-quality or puncture resistance.
  • Watch the tyre-pressure - not too low or too high - 60-80psi is a good guide.
  • Barna's preferred sealants are Orange Endurance or Silca
  • Change sealant every three months if you want the re-assurance that a puncture will seal on contact
  • Barna's favourite tubeless tyres are Continental GP5000 and GP5000 AS (All Season)
  • Barna's favourite rims are our own LANDRACE. Why? Hooked bead and great internal profile results in a superior seal to any other rim! His words, not ours.

"The main attraction of tubeless technology has to be that most punctures will self-heal."


Thomas De Gendt has a tubeless moment on UAE Tour


Thank you to cyclingnews for pics

Plug 'n Play - Dealing with Punctures

Beyond the superior ride sensations and reduced rolling resistance of tubeless technology, the main attraction has to be that most punctures will self-heal? And you can safely assume that will be the case if and only if you have followed Barna's top-tips above.

But now and again (consensus amongst high-mileage CF staff is around 2-3 x per year), the hole refuses to re-seal and you are now sitting by the side of the road in a Rorschach puddle of liquid latex. What next?


Dynaplug kit & LANDRACE climbing wheel


and inside the box


Plugged hole

"Barna's favourite rims are LANDRACE. Why? Hooked bead and great internal profile results in a superior seal to any other rim! His words, not ours"


Charge pump - sensitively piloted by Barna


Rorschach or spilled sealant?

What Next?

  • Try partially inflating the tyre and spinning the wheel to get the latex flowing and hole sealed - don't bother if hole is patently too big
  • Find the hole - should be easy with air and brightly coloured silicon frothing out
  • Use a plug to fill the hole - we have found Dynaplug to be the most reliable (pictured)
  • Stand the wheel up and put the repair at the bottom - this will help pool latex around the hole/plug. Leave for a few minutes
  • Pump up to 40psi. Depending upon your rim/tyre combination you may need to use a canister. Jimmy Wilson uses a mini-pump
  • You may need to use the Dynaplug blade to trim the plug
  • Ride for 10-20 minutes before inflating to 60psi
  • If plug doesn't work you will have to put in a tube. Good luck with that.
  • Wash sealant of hands and cycling kit

"Barna's favourite tubeless tyres are Continental GP5000 and GP5000 AS (All Season)"

Cyclefit Folk Tubeless Philosophy

  • Barna (Workshop Manager) - yes for gravel/cyclo-x. Not yet for road but getting there
  • Jules - yes for everywhere, everytime
  • Vaughn (Cyclefitter) - Yes, everywhere as long as tyre is 28c minimum
  • Cathal (Store Street Manager) - Very strong views - best shared in-person. Plans to use tubeless on his gravel bike.
  • Miguel (Store Street Mechanic) - no for road, but yes for gravel/MTB
  • Jimmy (Cyclefitter) - Yes everywhere - with the zealotry of a convert
  • Beth (Store Street) - under review
  • Phil - What's tubeless?

About the author

Philip Cavell, Co-founder

Co-founder, bike fitter and bike designer, author. Phil rides a Seven Axiom XX custom titanium bike and an Airnimal Joey folding bike. He wrote The Midlife Cyclist and enjoys walking his dog, reading, politics and the outdoors. Phil's specialism is working with clients who have complex and frequently chronic issues. Phil is most at home working in a collegiate, multi-disciplinary team, to help clients resolve intricate issues.

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