Muddymoles mountain biking in the Surrey Hills and Mole Valley

WTB TCS tyres… I don’t get it!

Posted by Matt | May 3, 2019 | 37 comments so far

WTB Nano 700x40c pin leak of Muc-Off in sidewall
This past few months I’ve found myself with more experience of WTB tyres and rims than I’ve had for the last 10 years and… the jury is out!

First some background…

WTB have their own philosophy when it comes to rims and tyres, in particular when it comes to supporting tubeless running. They make specific rim beds which have a slight inner lip, intended to hold the bead in place and they produce tyres with a couple of different sidewall options – a Light option and a Tough option. All this is marketed under the TCS moniker which stands for Tubeless Compatible System.

My experience has been solely relating to the Light casing option of tyres with various WTB rims; three different wheelsets and three pairs of tyres in fact. With the Light casing, the sidewalls are so thin that the tyre flops around all over the place when you are trying to mount the tyres. I’ve managed to get one wheel/tyre to mount with a track pump but the rest have needed the Beto air can in support.

WTB Vigilante 27.5x2.3 on i25 rims

I first came across WTB tyres and rims with my Bird AM Zero build. The donor Pinnacle Iroko came with 25mm rims and WTB Vigilante Light casing tyres, in a Fast Rolling compound. They were a saga all their own but this post is specifically talking about the tubeless aspect of WTB products.

In this respect, they turned out to be troublesome but did eventually seal up after several efforts. I have used Muc Off sealant after reading good things from Guitar Ted and fancying a change from good old fashioned Stans; finding a fur ball in my last set of wheels/tyres that was more like a golf ball convinced me to try something different.

With the pink goo in play, the WTBs proved to need several re-inflations to seal up and leaked small pin pricks of the goo through the sidewalls for an hour or two until they sealed properly. Since then they’ve been good and have not caused me any trouble, but the experience didn’t exactly fill me with confidence.

WTB Vigilante 27.5c2.3 on i25 rims showing tread pattern

My next encounter was with my new Cannondale Topstone gravel bike which came specced with 700x40c WTB Nano tyres on WTB i25 rims. Like the Vigilantes, the Nanos were very floppy off the rim but actually mounted up quite easily with the Beto booster, snapping nicely into place.

The problem has been keeping them sealed. I’ve put extra Muc Off sealant in to try and overcome the fact the tyres deflate after every ride (I’ve managed 160 miles on them so far).

WTB Nano 700x40c tyre with Uberbike purple valves

On each occasion I can see small pin pricks of goo coming through the sidewalls but it’s hard to tell if that’s because the sidewalls are getting cut when I take the gravel bike ‘off-road’ (we’re talking smooth-ish trails here and the Nanos don’t look damaged) or if it’s a problem with a weak, porous construction. I say that because I can see the threads through the tan sidewalls!

Either way, I’ve not had anything like this with any tubeless MTB or road tyre in over 10 years, so it’s extremely disappointing. I just don’t expect to get any punctures riding some pretty rough terrain – that’s the point of tubeless in my mind.

WTB Nano pin leak in sidewall showing Muc-Off sealant

At one point this week, I was re-airing the rear tyre after 17 miles of a mix of tarmac and non-rooty, dusty hardpack trails and could hear air whistling out from somewhere in the in the sidewall. After turning the tyre round the Muc Off sealed it immediately but am I unlucky, or is this just a poor product?

My final experience with WTB tyres and rims was converting my brother-in-laws’ gravel wheelset. It has WTB i19 rims with WTB 700x37c Riddler tyres.

I taped the rims better than I’ve ever achieved before, using two wraps of Hunt’s Black Shield rimtape with brand new tubeless valves. The front tyre went up as expected with the Beto boost, but could I get that tyre to seal?

I put in loads of pink goo and found myself re-airing the tyre 6 times before it finally sealed around the rim and sidewalls. I can tell you, pumping a tyre to 50psi 6 times is annoying and tiring (pardon the pun!).

The rear wheel was impossible to inflate on my own. I could not get it to seat at all – in fact it’s probably the baggiest tyre I’ve ever handled. I needed two extra pairs of hands to pull the sidewall to the rim and someone to dump the air can with 160psi in it to get the beads to seat. Again, pumping the air can to 160psi multiple times quickly gets old too!

Eventually beads seated, lots of goo in and the tyres sealed up after a couple of re-inflations but honestly? I think I’m at the point of saying the WTB TCS system is pretty weak. These tyres too fail to hold air for any sensible time period. I now have no faith in WTB really and am worried about what will happen with a problem on the trail. I won’t go anywhere without a pump and multiple spare tubes at the moment!

WTB Vigilante 27.5x2.3 Boost fork clearance

The shame about the whole thing is that the tyres are actually quite good. I really like the grip and profile of the Vigilantes and the Nanos roll well enough for me to average 17mph on a road only flat-ish commute home, with plenty of supple grip too. The Riddlers also have a nice tread that combines grip with traction by the look of things.

I just don’t feel confident about them. The Tough casing alternative is only available on the Vigilantes and they tend to be over 200g heavier in any case.

I am watching these closely but my patience is wearing thin and I suspect I’ll end up with a different brand fairly soon! I can’t recommend WTB tyres at this point.

My advice is to think carefully before you try WTB Light casing tyres especially with some sealant products like Muc-Off; maybe stick to Stans for the sealant but at this point I don’t even know if that would work.

Filed under Lifestyle, Mutterings in May 2019


About the author

Matt is one of the founding Molefathers of the Muddymoles, and is the designer and main administrator of the website.

Having ridden a 2007 Orange Five for many years then a 2016 YT Industries Jeffsy 29er, he now rocks a Bird Aether 9 and a Pace RC-627.

An early On-One Inbred still lurks in the back of the stable as a reminder of how things have moved on. You can even find him on road bikes - currently a 2019 Cannondale Topstone 105 SE, a much-used 2011 Specialized Secteur and very niche belt drive Trek District 1.

If you've ever wondered how we got into mountain biking and how the MuddyMoles started, well wonder no more.

There are 37 comments on ‘WTB TCS tyres… I don’t get it!’

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  1. Jemster says:

    How frustrating Matt. I haven’t had any experience with WTB tyres.

    It’s bizarre really as back in the day when I opted for tubeless, for grip rather than weight saving (as some folk thought that was the reason behind the mystical tubeless). Tyres that were tubeless ready (in my case Maxxis tyres) were quite heavy and had heavy duty side walls and sealed very well.

    Then ghetto tubeless emerged in various guises using standard tyres that were designed for tubes and lots of sealing tape and sealant eventually stopped the tyres hissing and letting sealent out.
    In my experience that seems to be the case with modern tubeless ready tyres, rather than specific tubeless tyres.

    My personal favourite brand is Maxxis, as they just seem tougher. Specialized grid tyres are also not the best when it comes to sealing and they slowly let the air and sealant escape and also damage easily on the side walls.

    There is certainly a trade off for tough tyres that seal well in being they tend to be quite heavy. They certainly are an advantage though, when tackling rocky or heavily rooted trails IMHO.

  2. Matt says:

    The saga continues. Yesterday I did a 35 mile ride on the Canondale/Nanos and immediately beforehand the front tyre was soft. I pumped it up to 45psi and put 50psi in the rear which was still nicely aired up after a couple of static days.

    After 35 miles with some mild off-road for about three miles, the front remained firm but the rear was softening; three hours later the rear Nano was at 14psi!! I pumped it up, heard air hissing out and turned the tyre to get the sealant to it – that’s the picture you see at the top of this article.

    This morning, it was flat yet again. I aired it up and the hissing started (again), from about 2cm further around the tyre, so I’ve turned the tyre and re-sealed the Nano (again). I just can’t understand how the Muc-Off seals the holes quickly, but they keep occuring in different places, and always on the junction between the tanwall and the black rubber.

    • Tony says:

      Matt – life is too short for leaky tubeless tyres – get some tyres from a different brand!

    • Arren Davey says:

      Hi Matt,
      Did you get any resolution on this? I’m looking to get quite a durable tyre on my Pinnacle Arkose. Currently they have the 45c WTB Riddler that come with the bike (and the associated problems). I’m thinking of Terravail Rutland 42c in the durable bead-to-bead setup but wondered if you had any suggestions? I’m less worried about speed and favour durability (and less flats). They would be filled with Milkit sealant. I’m keen to avoid the same issues I’ve had with WTB Riddler tyres 🙂

  3. Elliot says:

    Just to be annoying the WTB Ranger TCS Fast Rolling Light tyres that came on my Kona Unit last year were dead easy to inflate and had no pin holes in the sidewall. Actually they stood out because I didn’t use the bike for months and months but the tyres stayed up. Used with WTB rims, tape and valves which might have helped.

    I’ve had leaking sidewalls with Specialized before. Schwalbe in particular were odd for having quite thick sidewalls but leaking straight from the factory like a disgruntled employee sat there poking pins through all day.

    I kind of assumed modern tan wall tyres were just coloured over in some way but those do look threadbare. Almost like they’ve done away with one of the outer layers where the colour changes?

    As I may have mentioned before Orange Seal is considerably thicker than Stans. It properly coats the inside of the tyre so might help with this sort of problem. It does dry up sooner, not into a ball, more like it keeps adding layers to the inside of the tyre, so best keep on top of replenishing.

    • Pierson Hotchkiss says:

      Riidler 37 leak through the sidewalls and need to be be pumped everyday or during rides. I got them to ride a 2000+ mile mixed route this summer but will probably throw them out with <200 miles on them. I've always used orange seal but these are just trash. In my mind WTB ripped me off.

      • Matt says:

        I’m glad it’s not just me that has had problems but not impressed that this is happening.

        I’ve gone back to Stans’ sealant (with 38c Specialized tyres now) – 950 miles later, so far, so good. It’s a shame because I like the way the WTBs ride but sealant choice seems critical.

  4. Chris says:

    So frustrating…

    Topstone here too. Around 1k miles on the front WTB tyres. No issues at all on that one.

    On the Rear though, I managed to split it open on a gravel descent (5mm hole). Surprised me as they were new and I ride that route a lot. Needed tubes.

    Then switched rear to Panaracer Gravelking Slick. which is on now (about 500 miles) and holds air fine, but leaked air out of tiny porous holes on the sidewalls for the first annoying days.

    I had to take the wheel off and leave it overnight angled on the worst sidewall leaks. Eventually it held air. (Orange Sealant fwiw.)

    Not sure of the moral of the story. Are there any perfect tyres out there?

    • Matt says:

      Hi Chris, I think my tyres are finally holding air properly. It’s taken a while but I am not seeing significant air loss between rides which is great.

      I do worry about the longevity of the WTB on the Topstone though – your cut on the rear is exactly what I’m worried about but today I took it down some pretty rough tracks and it was fine. Fingers crossed.

      Those Panaracers are on my list of possible replacements though!

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  7. Stephen says:

    Just experienced the same, been riding Mavic UST road tubeless for 2 years and no issues. Took delivery of a gravel bike recently that came with the Mavic Allroad Rims and WTB Nano Tan SW TCS but fitted with tubes.
    Tubes removed before first ride to set up tubeless and 1 of the tyres had pinholes that leaked so fast I could not get the bead to seat. While waiting on the bike retailer sending out a replacement tyre I fitted and ran a couple of Mavic Allroads 40mm for couple of months with no problem
    Decided to swap them out today and surprise surprise the replacement tyre is defective also in the sidewall to crown joint. Really frustrating and no confidence in the tyres at all. I did manage to get it sealed up but when I go out I’ll be taking a tube with me, something I haven’t done for years! Pretty poor show from WTB

    • Matt says:

      It’s crazy isn’t it? I am still hearing of issues with WTB tyres and there’s a definite pattern to it all. I’ve seen it on my tyres and my brother in law has has had the same experience.

      As I’ve mentioned elsewhere, sealant choice seems to be important – I’d say Stans. The Muc off stuff just doesn’t seem to want to seal and in this case with WTB tyres I’ve heard the same with Orange Seal – there’s no point having sealant that doesn’t dry out much if it doesn’t do the job when you need it to.

  8. Martin says:


    had the same experience: Riddler with Muck Off sealant, sidewalls leaked massively. I have a hunch that MuckOff is too thick. Had some issues with a Conti tire as well: very small hole, did not seal, had to enlarge it with a pin to make sealant come through.

  9. Damien Jones says:

    Hi reading the thread with interest – Topstone Carbon 105 with WTBs standard for me.

    I love the tyres and the way they roll so coverted to tubeless with the kit that came with the bike (valves).

    Rim tape – the running end had been fitted up the internal bead on the rim – so corrected that. The tyres sealed against the bead easily using a floor pump

    I used Muc Off – and as above small pinprick leaks in the side walls on both tyres – both flat the next day. 3 days and 20mile per day and they still loose air – although no flat and I have to say improving. We shall see


    • Damo Bird says:

      I’m pleased j came across this thread as I have been aces thing my head for the last 3 days. I have a 2020 Cannondale Topstone Carbon, Ultegra RX. I trashed the riddlers after just 500km. So swapped to WTB nano 40s and took the opportunity to go tubeless. I used stans race sealant around 90ml. Managed to seat the tyre without too much bother. I used soapy water to lubricate the walls and a canister / charger to rapidly inflate. Job done. But – for the first 24 hrs there were loads of bubbles around the tan wall area. I thought it was the detergent bubbling whilst the tyres were kind of figuring themselves out..
      Massive loss of tyre pressure within 24 hrs (45psi down to 30). Now I see many bubbling pin prick sized white foam coming through the tan walls. All around both tyres. They are clearly super porous. I’m
      Hoping the stans sealant will seal them and we will be good.
      Next problem was the bloody Topstone – they shout about the carbon frame having enough clearance for 40mm tyres. What a lie! Width is of but the volume / height of the nanos literally touches the inside of the bottom bracket area. Now I understand why the new Topstone a comer with 650b wheels. Because the frame WONT accommodate 40mm tyres on a 700c.
      Had a bad few days with the bike.

  10. Arren Davey says:

    I have had exactly the same issues with the WTB Riddler 45c that came on my Pinnacle Arkose. I bought the bike in December 2019 and originally I ran them with inner tubes. I was getting puncture after puncture so loved to tubeless. The LBS said they’d ere the worst tyres they’ve had to fit, but they held pressure after 4 attempts and lots of sealant and I was hopeful. Like you mentioned, they run well but tiny nicks in the sidewall do not seal. I’ve ridden 4 or 5 times and get the same issue. The hold pressure when I start but soon go flat soft. Im not sure the PSI but must be about 20-30PSI. I have a picture which is almost identical to yours. I’ve given up with them and I’m looking to get Tervail Rutland durable version. I’ve been so disappointed with WTB tyres and Evans. They are not fit for purpose as I’m only riding farm trails and I’m not quick.

    • Matt says:

      Hi Arren, I solved the problem by switching after 800 miles to Specialized Pathfinders and using Stans fluid! Not had a problem in 2000 miles now.

      In fairness, a mate has Riddlers and they work fine with Stans too. It seems the combination of Muc-Off + maybe the tyres had been sitting in a warehouse for ages doesn’t play nice (Nanos are old these days).

      The downside of the Pathfinders are low tread (fine, but not for mud), a bit narrow (38c) and sidewalls a little stiff. But at 32psi, they haven’t been a problem in terms of reliability. You can get them as 42C BTW.

      Hope that helps, I’ll try and review them properly when I get a chance.

  11. chris says:

    same problem. Tried and tried with different sealant, finally gave up. I work in a bike shop so I called the distributor and to their credit they sent a new Riddler. Only problem is that it also leaked.
    Now running with tubes but will not buy again.
    Also, buy yourself a real compressor. Great for inflating and also cleaning your bike. Worth the cost.

    • Matt says:

      Compressor? Pop… Boom!!

      Yes, mate has granted me the use of one on occasion but generally now the Beto air can works pretty well.

      I’ve given up on Muc Off – its not worked in several scenarios now. But WTB now have SG2 tyres with better air retention I’m told – that might help perhaps.

  12. Tom Brewerton says:

    I’m so glad I’ve found this blog. I have the same problem with my rear maxxis tyres. Another rider on the trail suggested something and I think it makes sense.
    The muc off sealant is the problem. The sealant isn’t plugging the pin prick holes in the sidewall.
    I’m going back to stans sealant on the riders suggestion and seeing if that works.
    It’s frustrating as I made a point of checking the pressures were high every ride but even when new I often had to add air pressure.

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  14. Doc Perry says:

    I have a set of WTB Raddler gravel tires that I have been running on my Hunt gravel wheelset. I started having to pump up the rear tire every morning because it was losing around 10-15 pounds overnight and then I started seeing Stan’s sealant coming out of pin holes on the side walls. Not sure what I’m going to do about this in the middle of my ride I can feel the tire swimming around on the rim as well as bottoming out when I come off a drop, so I’m looking for a new tire sorry WTB but this is just too much maintenance on a day-to-day basis.

  15. Peater says:

    Got a new bike that came with Nanos in 40c. Nice fast rolling, good grip off road. Then did the tubeless conversion and exactly the same problem as above. Bubbly pin pricks in the sidewall where sealant weeps out.

    It sealed, I rode it, but when I washed the bike down afterwards, I seemed to dislodge/scrape off whatever latex was holding the seal from the outside and it started spitting out again until the tyre was flat. I have patched it from the inside and await to see if it will let me down again. Very disappointing.

    Also, a friend bought some ‘Byway’ tyres on my suggestion a few months ago and he had a complete failure where the sidewall pulled away from the bead profile.

  16. Scott Gould says:

    I have been unable to get my byways to hold air They loose half of their air pressure in the first hour of riding regardless of terrain. I have added more Stans with no luck. I think I am going to pitch them before I get stuck out on a long ride. I don’t recommend them .

  17. Ed says:

    Exactly the same issues here. Running WTB Venture 700cx50mm
    I googled to see if anyone else had any issues and found this.
    Struggled like anything to get the beads to seat (never struggled with MTB tires)
    Then every now any then I get a pinhole appear in the tan walls. Come to my bike after a few hours and I’ve lost 20psi, top them up and pppsssst pin hole in the side wall, spin the tire and it seals again.

    Think I’ll go back to tubes on this bike until the tires need replacing.

  18. Mark Smith says:

    Running 32mm WTB Expanse tyres over the summer and having serious sidewall and puncture issues. Expect a little sealant to bleed
    but these are small holes that just won’t seal. Have reverted back to tubes but now have a traditional puncture! Will be swapping them for another brand as soon as possible .

  19. Gordon says:

    I have the same issue with WTB riddler tyres and muc off sealant leaking sidewalls losing pressure overnight. I would like to know if this is just an issue with the tan wall tyres. Just about to swap out to a third set of tyres in about 300 miles as my Topsone 2 came with non TCS Nano tyres, should have spotted that at the time. I’m going to try another brand

  20. Jeff says:

    It’s funny coming across this post, as I just took my rear wheel to my local shop this weekend to see if they could figure out why it wasn’t holding air. (fwiw, the front one holds air with no problem)
    Basically the tech told me that WTB is aware of the issue and that when those little beads form out the outside of the wheel, not to pull them off, as I did. I honestly didn’t realize they were little bits of sealant coming through the sidewall, considering the vast majority of my riding was on tarmac. He said that he was told by WTB to seat the tire, put in sealant, inflate to max psi, and ride it around to spread the sealant. That should do the trick even with the little beads on the outside of the tire. Not the most reassuring fix tbh, so I imagine I’ll be looking at new tires soon.

  21. Bogdan says:

    Unfortunately. Nano SG2 doesn’t solve poor puncture resistance. After two weeks of ride – got centerline puncture just on gravel road and problem with the sealing after all. I use milkit which works perfectly with any other tyres. Probably now will try anthing else than WTB. Pity, as performance of Nano is really impressive.

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  23. Jeffrey Lewis says:

    I just bought this tyre as it had great tread pattern for where i ride. Packed small gravel/sand. Wish I’d never bothered! Seated easily enough with just a track pump on Fulcrum 3 wheels but proceeded to deflate. 2hr into ride i have to inflate again. Limped home on 12psi. After scrubbing with soap water(thinking i may have a damaged valve) i see a ton of bubbles coming from every part of the sidewalls. I used more MucOff pink silicon and ran it around sidewalls, has helped but still deflating. Im thinking of writing them off as i have zero confidence in them for an “longer” ride and certainly none for any events. Really dissappointing.

  24. Chris says:

    Just stumbled on this discussion as I have fitted new 37c Riddler tyres and noticed loss of pressure in one tyre due to multiple pinholes in tan sidewall. Stan’s seems to be slowly solving the problem but it has been very frustrating. It’s like the sealing layer of the tyre is missing or defective over a wide enough area that the liquid sealant either can’t plug it or takes a long time. Should point out that I bought these because I had previously run the Riddler 45s for several years with no problems at all. Great tyre profile, pity about the QC

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