Was at the Irish National champs today, and unfortunately punctured with very little of the last lap to go and had to retire which was gutting as I was doing reasonably well.

So a few questions for the racers and tubless set up whizz kids.

I have been using Stans Crest rims with a set of regular Kenda Nevegals on them and had them sealed fine and dandy. Have ridden them for about half a dozen races on them now, and while they arent fast rolling like the super quick XC tires I liked the extra wee bit of safety grip they have been giving me.

Something punctured the sidewall today, but the hole is tiny, like a fat pin hole. Why did the sealant not seal it up? I am using JRA wheel milk in it. I took the wheel out after walking to the car and pumped it up and sloshed sealant inside round the wound but it was just blowing the sealant out in wee bubbles. Is it just bad luck? DO I need to change sealant?

And anyone that races – Is there anything you can do about this midrace usually other than fight to get a tube in or something? Can you get anything that blows air and sealant into the tire in some form of Cannister?

And as I think I now need a new tire… Recommend me something to go on these crest rims. I may as well try something faster rolling now. Maxxis crossmark on the back? What on t he front?

Personally, having gone tubeless with conventional Kenda Nevegals in the past, I would recommend pretty much any tyre over a normal Kenda for converting tubeless. They are a nightmare as the sidewalls are so weak and porous. I’d be willing to bet that yours didn’t seal cos there wasn’t much sidewall left for it to seal.

Personally, change your tyre/s. Still stick with the Crests, and Stans Sealant (or maybe if you don’t mind spending the money, go caffe latex as it foams, though adding a bit of washing up liquid to stans has the same effect), but go for a more suitable tyre. I’m not an XC racer, so not best placed to give advice, but from what I see and hear, the Evolution versions of the Schwalbe Nobby Nic and Racing Ralph seem pretty much universally loved by XC racers, and the Racing Ralph is a pretty fast rolling tyre out back too.

Just out of interest why did you retire if there was only a short way to go? Why not shoulder the bike n run?

And as I think I now need a new tire… Recommend me something to go on these crest rims. I may as well try something faster rolling now. Maxxis crossmark on the back? What on t he front?

Racing Ralph front and back – work very well tubeless with sealant too (though I’m sure njee will be along shortly to recommend Rocket Rons – having had bad experiences with very light tyres I’ve always been wary of those, preferring to stick with the added security of Ralphs or NNs).

Just out of interest why did you retire if there was only a short way to go? Why not shoulder the bike n run?

+1

Also, try some conti tyres maybe, race kings/speed kings whatever. Much lighter, much faster. And conti tyres seem to fit really well, last well, seal well, and stay inflated. I like stans sealant, but there might not be a lot in it.

Posting a DNF because of a puncture is a bit unnecessary IMO. Sometimes the sealant doesn’t fix the hole and you simply have to put an inner tube in there. If you practice doing this it shouldn’t take you more than a few minutes, especially if you are using CO2 cannisters, and finishing two minutes down is better than DNFing.

tubeless repair kit is quick if you can see where the puncture is. Sticky string stuff poked through the offend ing hole, pump tyre up and ride. Done

Sod doing that in a race!

You can get Innovations ‘Seal n Flate’ or Hutchinson Rep’Air which both contain co2 and sealant, they’re a bit hit and miss though IME.

Just out of interest why did you retire if there was only a short way to go? Why not shoulder the bike n run?

+1

IMO Wheel Milk isn’t any good at sealing punctures, dries out too fast if nothing else. Switch to Stan’s, no need to add washing up liquid.

When racing either carry a tube, or just co2 and trust it’ll work! If it’s an important race I carry a tube, although I’ve not used it in about 6 years.

Re tyres I use Schwalbe, Rons mainly, Ralphs if it’s rocky, Freds if it’s dry and not remotely technical and no one’s sneezed on the course.

Cheers for the feedback guys.
I hadn’t considered the tire wall having an effect on resealing. They were quite porous when originally setting them up but they sealed ok after a few minutes of heaving sloshing.

I retired because I was averaging 21 minutes a lap. Where I punctured I had about 5 minutes left to ride on the last lap, but it was a flat out section and the fastest bit on the course. Took about 15minutes to walk it as the crow flies. I did start running in my delerious state but when i realised where i was I knew it was pointless. There were no league points available as it was the national championships.

I never bring anything out with me to fix punctures usually, as in a 3 lap race unless you puncture right at the start its over for you IMO?

But it was a little daft I think in a 4 lapper yesterday. Especially with that kit that cruzheckler posted. I could have used that and a C02 and been back on the bike in a couple of minutes. Ah well. Its a learning curve

As for tires, a lot of guys seem to race on the racing ralph/nobby nic combo so I assume they must be decent. But the lack of knobblies on them concerns me. Im used to a more aggresive tire and just accepting the slight drag. Are they really grippy enough? Most of my races seem to be on foresty loamy singletrack.

I may give them a lash as On One still have some of their cheap ones.

Evolution versions?

Stick in a tube has to be the answer in a race.
Or this:
http://www.winstanleysbikes.co.uk/product/22764/Geax_Pit_Stop_Tyre_Inflate__Repair_Aerosol_Kit_Pair

I’ve used it once (someone else’s bike) comes out like shaving foam and got them home.

I would stick a tube in, but most tires are pretty tight on crest rims and a bit of a pain to get on and off while under pressure? Maybe I should do some emergency tube insertion training over the winter! May save me in the future.

Do those aerosol things actually work? The tubeless repair kit above seems to work well judging by reviews about the net

Time-wise the aerosol thing would be the quickest. It would have got you round the end of your last lap anyway. Whether it would be any good if you punctured on the 1st lap, I’m not sure!

Next slowest repair would be the outside tubeless kit – not 100% reliable.

Then changing a tube, which would be the most secure repair, but yes, would take the longest.

Maxxis or Hutchinson UST tyres have the best puncture resistance IME.

Kenda Nevegals

For XC racing? 😯 Switch to Racing Ralphs and save 5 mins a lap!

I have some Nevegals run tubeless and they seal ok eventually and stay sealed. No flippin way I’d run them in an XC race though!

I also use Stan’s sealant – it has small fibres in it apparently unlike the others. I once ran over a piece of glass and put in a hole big enough to spray sealant all over the place, all up the downtube. Before I had the chance to stop I noticed it slowing, and it’d sealed within about 20 yards.

I’d lost some sealant though so when the same thing happened AGAIN about 5 miles down the road I had to put a tube in 🙂

I carry a couple of spare tubes and CO2, but then I’m doing very long races, where it’s well worth stopping to add a tube. Have only used the CO2 to top up a slow puncture in recent times (that was due to forgetting to top up on sealant which had dried up – using wheel milk which sealed it when I added some more, so interested in comments on that vs Stans).

I find punctures with tubeless are rare enough for me not to bother with anything on XC races. If I puncture I’ll lose so many places that I find there’s no point in plodding on for a crap time. It’s not like it’s a marathon or an Iron Man where just finishing is a goal, for me.

I find punctures with tubeless are rare enough for me not to bother with anything on XC races. If I puncture I’ll lose so many places that I find there’s no point in plodding on for a crap time. It’s not like it’s a marathon or an Iron Man where just finishing is a goal, for me.

Thats my thinking. These are hour and a half style races. Flat out until you choke on your puke and then keep going. But It was gutting not to finish at the same time.

Ok – So its Nevegals off. Going to order a Nobby nic 2.25 evolution for the front and a 2.25 racing ralph evolution for the rear and a bottle of stans sealant… and that wee external repair kit too taped under my saddle.

I’ll give these insanely non grippy looking tires a lash.

Go RR front and rear if it’s dry, NNs front and rear if it’s wet, imo.

RRs are really fast and dead grippy in all but gloop, I have 2.0s and I love them.. the XC bike is so fast like that 🙂

Just carry a tube and CO2, I changed a rear flat in under 3 minutes in one race and im hamfisted. When events cost a lot to enter let alone the fuel to get there and back, a small weight sacrifice for basic spares inc chain tool/power link, multi tool and tube/co2 is well worth it

Plus you can then spend the next week boring your friends by telling them where you would have finished had you not had a mechanical 😀

Been using the newer ‘pacestar’ compound Rocket Rons for a while & they’re great. Fast, grippy & they’re now ‘tubeless ready’ which seems to be an excellent compromise between the standard & UST ones – they seal first time & the sidewalls aren’t too flimsy.

i carry a tube and co2, sealant is hit/miss. i consider an xc race over with a puncture, but you still need to get back to your car. in a long event a few minutes doesn’t matter. i’ve punctured twice this year, at the dalby dare (about xc race length) the race was spoiled at 10@kirroughtree it was a nuisance but made no difference to the result.

If it’s an important race I’d always rather get back in, David Fletcher won the U23 Nat Champs last year despite a flat. Oli Beckingsale got 2nd in 2008 despite one too. Learn to change them quickly. With co2 it needn’t take more than 90 seconds to get back on. Yes you may not win, but I’d far sooner finish than walk back to the car.

Ok in this instance you may have lost 5 minutes, but that was the difference between a result and a waste of money and a day!

If it’s an important race I’d always rather get back in, David Fletcher won the U23 Nat Champs last year despite a flat. Oli Beckingsale got 2nd in 2008 despite one too. Learn to change them quickly. With co2 it needn’t take more than 90 seconds to get back on. Yes you may not win, but I’d far sooner finish than walk back to the car.

Ok in this instance you may have lost 5 minutes, but that was the difference between a result and a waste of money and a day!

Point taken!
Even if I had have lost 5 minutes I still wouldnt have come last I dont think.
Plus it was a pain in the ass walking back. I’ll see what I can cram into a wee saddle bag for the next one. CO2 + a skinny light tube and/or that tubeless kit.

I think If i put CO2 in though i have to let it out and replace with regular air later though or else it reacts with the latex? Or did i dream that?

In my experience, just use some stans sealant rather than wheel milk and you’ll be fine…

CO2 can freeze the sealant, but it’s not a big enough issue to worry about IMO. It also leaks fairly quickly, so the next time I use the bike the tyre’s gone flat again, again though not really a problem.

Kenda tyres? You’re brave. All the ones I have came with warning stickers about the sealant de-laminating the tyres. Having experienced the result of this recently I’ll stick to Maxxis and save my hearing/heart/face.

I don’t believe in those crazy aerosol things, or even CO2, too many witnessed and personal bad experiences with them. I carry a tube and a £3.99 short plastic pump. 2 minutes gets the tube in there and inflated. I’ve won races after puncturing, there’s little excuse in my mind for a DNF when it’s a puncture.

Practice, practice, practice. Buy some Schwalbe Marathon Plus and practice getting those on and off the rim fast, you’ll make your fingers bleed at first, but you will become very good at getting normal tyres off nearly instantly.

The ‘proper’ UST Racing Ralphs don’t seem unduly heavy to me, and the slight extra toughness seems worth the trade off. Still put sealant in of course. Bargain at on-one prices too!

More than 200g per tyre heavier. Rather you than me.

mboy – Member

Personally, having gone tubeless with conventional Kenda Nevegals in the past, I would recommend pretty much any tyre over a normal Kenda for converting tubeless. They are a nightmare as the sidewalls are so weak and porous.

They’re the easiest non-tubeless-ready tyres IME, seal up first time most times and go onto the beads easily but firmly.

I would stick a tube in, but most tires are pretty tight on crest rims and a bit of a pain to get on and off while under pressure?

Oh god, yes. Trying to get anything off a Crest, then fit a tube, then get the tyre back into the centre channel, then get the pressure high enough to get it seated right, all in the middle of the race?! Not sure I’d be up to it, anyway…

my experiance is that you can’t beat combination of Maxxis tyres with Stans sealant on Stans rims – they seem to work easily every time.

yes Schwalbe are very nice but also rather $ expensive to run and I think you get great tyres from Maxxis for a fair price….

Kenda are a right royal arse to setup and always end up with the same problem as you have experianced. Kenda need inner tubes, period.

as for puncture fixing during a race then yes I carry a large Co2 canister and it works great (i.e. never yet had a mid race puncture in 5 yrs of racing and enduro events!)

MisterT – Member

Kenda are a right royal arse to setup and always end up with the same problem as you have experianced. Kenda need inner tubes, period.

2 years of tubeless on 3 bikes, maybe 12 different kendas (mostly Nevegals, few small blocks and an excavator), never a single problem with any of them. Now Conti were a pain in the arris.

Sometimes the sealant doesn’t fix the hole and you simply have to put an inner tube in there. If you practice doing this it shouldn’t take you more than a few minutes, especially if you are using CO2 cannisters, and finishing two minutes down is better than DNFing.

IME Once a tyre has been tubeless its got that many ‘intrusions’ that you have to be so careful to check that odds-on you’ll puncture the tube straigh away.

My experience of Nevegals is that they came readymade with sidewall-holes…

interesting thread, i really rate tubeless but have had 2 tubeless punctures now during races. Both were muddy nightmares on the first i failed to use the weldite strips but luckily i did also carry a tube and managed to get it in covered in mud and crap and made it to the finish! silly me though as it took me forever and i probably could have ran it quicker!
2nd time i got a v shape stone cut in my tyre and the weldite thing wouldnt plug it 100% with all the mud and no sealant left and i wasted 2x co2 inflating for it to go down again. unfortunately i was somewhere in teh middle of the course and no idea how to shortcut back and faced the humiliation of walking my bike back to the finish, took about 15 mins.. lol but i did not come last!

so in conclusion, carry a spare, but beware getting the ust valve out can be tricky if you over tighten the nut! done that too!

weldite strips wont work in muddy wet conditions, especially when your impatient and wanting to get straight back into things and sealant is low.

and its not all tears, ive managed to use ust plugs like weldite at night on sdw but prefer tubes but it gets messy..

tubeless are great with thorns though.. (BR above raises a valid point regarding thorns tubeless and tubes though)