Hi guys,

Started to get a little annoyed with the number of punctures i’m getting on one of my bikes now on the rear wheel, every time I go out I end up getting at least one…

It’s been a mix of pinches and normal pinhole punctures. I’ve completely cleaned the inside of the tire (there was a bit of dust from trailside fixes) and there isn’t anything sticking through, I use a Schwalbe Nobby Nic 2.25 (the one that has sidewall protection e.t.c), running at about 40psi (in the wet which isn’t fun), on a Giant s-xc 2 wheel (i think it’s the same as a dt swiss wheel but not sure which). I weigh about 65kg, so at the pressure i’m running i really shouldn’t be pinching that much…

I’m inclined to think it’s something to do with the bike as I can’t remember the last time i got a puncture on my other mtb. Both bikes are hardtails. I have noticed a couple of tiny nicks on the rim, but they seem to be outside the bead so no direct contact with the inner tube. I haven’t been clever enough to check tubes to see if punctures occur in the same place, normally when they happen I’m on the trail with light failing so i just whack a new tube in.

Bike’s a Whyte 829 if they’re known to puncture a lot – can’t see how though…

Any advice?

Thanks

Go tubeless?

Easier said than done, don’t like these wheels so waiting to get some hope hoops, but need the money first haha. Would it be easy enough to convert these wheels to tubeless?

No idea but stans, valves and tape don’t cost much to try…

You should know when you get a pinch puncture. You hit something hard and there’s a clang or a bang followedd by a loud hiss.

If this is happening then you tyres are too soft or you are too clumsy. And 40psi should be plenty. Otherwise, check your rim tape, and check recent hedge trimming activity.

ignore double post

I strongly doubt you’re pinch flatting with 40psi and your weight.

I agree that tubeless is the answer, otherwise if your tubes have removable valve cores then adding some sealant to them will help you out.

The best advice I can give is for you to buy the following:

Two rolls of black electrical tape – £3
A litre of Stan’s or Joe’s – £10
Two Specialized tubeless valves – £8

Roll the tape around the inside of the rim, making sure that spoke holes are covered and that the tape seats all the way to the edges of the rim bed. No need to be sparing.

Punch a hope in the tape over the valve hole, insert valves and tighten valve lockrings with pliers to ensure a complete seal

Remove valve cores, seat tyres, inflate and wait for the “pop”. 40psi ought to do it.

Deflate tyres, add 100-150ml of sealant and valve cores, reseat tyres and inflate.

If this is happening then you tyres are too soft or you are too clumsy.

I strongly doubt you’re pinch flatting with 40psi and your weight.

He’s riding Nobby Nics the most puncture-prone tyres I’ve ever used including the notorious Mountain Kings.

My experience was exactly the same as yours, op. They would puncture if you waved a fork at them. The guys I ride with were a little embarassed for me when I threw my bike into the undergrowth and started kicking it in frustration…

I gave mine to my BiL to use for his road commute with the warning that they would puncture before he left his drive. They still hang in his garage.

The only time I didn’t pinch puncture them was when I put them up to over 50psi when, not surprisingly, they lost any semblance of grip.

Simply an awful product and I assume that anyone who recommends them is living in some fantasy world made of pillows, duckfeathers and soft down.

Chuck ’em, buy decent tyres.

just go tubeless

wrap those rims in electrical tape, put some tubeless tape on top, punch a teeny hole and insert tubeless valves. Get some decent Specialized 2-bliss tires (I found my Schwalbe tires dire with sealant) and chuck a couple of cups of Stan’s sealant in there before inflating

I’ve put the same setup on my Giant XTC Advanced 29’er and no issues since instalation

I would use Gorilla tape, not electrical tape as suggested, still only about 3 quid per roll and available at homebase or b&q in 1 inch wide roll. Much better in my experience than stans tape.

@fizik

I’ve been installing tubeless setups for 10+ years for myself and too many customers to mention

electrical tape is great to actually make the rim bed airtight, but it will quickly deform under inflation (into the spoke holes), and allow sealant to leak into the rim bed.

This is why I then install a good tubeless tape like Roval on top of the electrical tape. All the Giant MTB’s and many of the road bikes will come with a similar width blue tubeless tape. Stan’s tape is simply rebadged 3M adhesive tape.

I will degrease the rim with Isopropyl alcohol before installing electrical tape, and do the same before putting tubeless tape on top of electrical tape.

The trick with the valve is to put a tiny hole in your layers of tape using a small spike, when you insert the value it then expands the hole and won’t allow a leak between the tape/valve

Tubeless is absolutely the way forward though. One puncture in what, 6 years?

Sorry I meant dont bother with electrical tape or Stans type tape. Gorilla is enough on its own, I usually use two layers.. job done. Its pliable enough, strong, cheap, doesn’t leak and bloody sticky, whats not to like?

I use the dedicated rim strips though…

Are you using a 29 specific pump? Although superficially similar to 26 and 27.5 pumps (there’s not enough difference to these to cause an issue) 29er pumps pump the air at a slightly higher density to compensate for the higher volume of the larger wheel. Not using the correct pump can lead to the described symptoms.
HtH.

Repeated punctures pushed me to trying ghetto tubeless with split tubes. I wouldn’t go back, as the secondary benefits of lighter weight and better grip were really noticeable.

I’m sure I’ve read that the Giant own-brand rims are pretty easy to tubeless. Gorilla tape is cheap and works well (if you never plan on taking it off). The “to-go” rolls were the perfect size for the last wheels I did.

Thanks for all the advice guys, i’ll try going tubeless as soon as i can – £21 is grand for all the kit needed but i don’t think my tires themselves are tubeless – at least another £30 for one of the 2-bliss suggested…

PJM1974 (or anyone else reading lol), you suggested putting sealant into a removeable core – i use the continental inner tubes so i should be able to do this – is it just the same technique as tubeless i.e. empty into the tube and spinspinspin?

but i don’t think my tires themselves are tubeless

Doesn’t matter. It’ll still work, just won’t seal as readily and you’ll need to keep topping it up for a few rides. I ran non tubeless tyres tubeless for years.

Non tubeless can work fine. Depends how porous the sidewalls are and how good the bead is and/or rim profile for keeping it seated. Generally though just use a lot of sealant. Three cups full of Stans does me (of the red cup that comes with Stans). Top it up if you shake the wheel and can’t hear it sloshing.

I’ve only just finally had a tyre give up tubeless after years of running. It’s got loads of holes in it but just kept sealing. Sidewall tear fixed with a patch inside. It’s just had too much finally and won’t keep inflated. Only got a supply of old tyres so stuck an old one on for now that was used with tubes before, and on pumping it up it turns out it’s got loads of holes! . Soon enough the sealant sorted it out though. 😀

Tubeless kit – all you really need is the sealant. You can make the rim tape (http://www.pinkbike.com/news/Tech-Tuesday-Gorilla-Tape-Tubeless-Conversion.html). Valves you can ghetto out of old inner tubes. Though ones with removable cores are more useful.

If you’ve got access to a compressor then seating tyres is easier, but otherwise you may be lucky with a track pump and removable valves. Tubeless Ready tyres do seem to seat better this way.

Otherwise, I use CO2 cartridges to seat.

p.s. Fairy liquid also handy 😉 (other brands are available). Soapy water around the tyre bead basically before trying to seat the tyre. Helps keep the air in as you do it.

change your rear tyre. i had no end of punctures with nobby nic’s and schwables as a whole seem more delicate than many tyres. i can’t imagine a NN is much fun on loose pack or wet rock & roots at that pressure

but yes, as others have said, your long term solution is tubeless.

I had a similar problem last year with a particular tyre. Turned out I’d stretched/damaged the bead/casing of the tyre.

I’m guessing it allowed the tube to move inside causing it to puncture every time I used it. Binned tyre. Been fine ever since using the same tube and rim.

I’ve successfully set up Giant rims tubeless with Gorilla tape, alos with non tubeless tyres. Worked fine but I did need to use a coke bottle compressor.

If you want any info then let me know.

Si

Of course a 29er will get more punctures than a smaller wheel – there’s more outside diameter in touch with the ground 🙄

Tubeless, 1 puncture per hour during the hour I tried it, wouldn’t reseal, wont be trying again any time soon.

To the OP are you sure there isn’t a very slow leak softening the tyre until you pinch? Try inflating then leaving for a day and measuring pressure again?

Another possibility is a sharp edge to the valve hole in the rim which causes a leak at the base of the valve, but you often get away with these with the bike stood still, they don’t start leaking until the bike is moving.

As other have said with your weight you really shouldn’t be pinching at 40psi even on Nics, no matter how many rocks. I’m a 90kg bad bike handling monster and I only run 30 even in rocky places, probably 15 in muddy winter slop if there are few rocks around. If it’s always the rear you’re flatting are you too far back on the bike?

Tubeless, 1 puncture per hour during the hour I tried it, wouldn’t reseal, wont be trying again any time soon.

Given everyone else’s endorsement, it’s very obvious you did something wrong surely?

So you were still during the learning/set up phase?

I used to get about 1 puncture a year running tubeless. Two riders, both riding pretty much daily and pretty much all year round. Neither of us particularly hang about. (Don’t get tubeless punctures any more as i am currently off the bike…..)

On the flip side. The one Nobby Nic puncture i had destroyed the tyre (it was one of the Evo tyres) went up first time, no leaks. Hit a root a bit funny (and quite hard) and split the carcass, right in the middle of the tread.

Yes, I know other people report better experiences, but that phase was just so bad I’m not up for trying again soon. Bit of a faff to deal with trailside and much more of a faff getting that same tyre to reseal second time. Maybe I’m just tight and don’t want to have to throw a tyre away because it’s not in tip top condition.

Also I don’t think any amount of practice setting up tubless would prevent a rock ripping a hole in the tyre?

But a rock will rip a tubed tyre as well. So you’re no further ahead.
Tubeless and sealant just eliminates those annoying punctures that don’t trash tyre or tube.

Maybe I’m just tight and don’t want to have to throw a tyre away because it’s not in tip top condition.

You don’t. Really, it’s worth keeping trying, the benefits are huge.

I’ve pretty managed to get everything i’ve got to go tubeless. Even old and (allegedly) impossible tyres (Conti supersonics).

It’s well worth the effort.

The Contis stayed on there until they were almost completely bald!

Brand new bike. Brand new tyres. Nobbly Nics and puncture first ride.*

I have had 2 punctures in th previous five years of riding tubeless.

Today I went tubeless on the new bike. I will post next time I get a flat.

*tyres also feel like they have no traction but I was riding in wet slippy mud so I will hold back before totally condemning Tom as the hoops of shite they currently appear to be

tyres also feel like they have no traction but I was riding in wet slippy mud

I found that they felt less confident on rocky, gravelly stuff than on soily tracks. 😉