|   No tubes experience this weekend....Bontrager Bad!!! | fattirewilly
Jan 6, 2004 8:25 AM | | I couldn't inflat Stan's with the hand pump so I returned home to use the air compressor (20 gal. 150 psi) I got for Christmas. It was a pain with the air compressor, but I quickly learned that the more suds the soapy water has, the better. Think thick shampoo on your head. Once you have enough suds, inflation is very achievable. I did not retry the hand pump and never will based on the effort involved with the compressor.
According to the directions, inflation should be done to 35 to 40 psi and not over because the Kevlar bead may bust. Directions also say wear eye protection while inflating. Once it inflates once, you deflate and add the latex "spooge".
Once the tire inflates with the spooge, you are supposed to seal any small leaks around the sidewall by shaking and rotating the tire such that the latex swishes around inside the tire and covers the leaking area.
Directions say to pay careful attention to the side wall area while sealing. Unfortunately I was no longer wearing the eye protection while paying close attention and the tire bead blew in my face.
It was like having a little 38 cal. going off next to your head and I ended up covered in well...white latex spooge. Note that the tire was only inflated to 15 psi with the compressor and then inflated with a hand pump to 40 psi.
For reference, the bead that broke was on a Bontrager Jones. After swapping to Kenda Klaws front and rear, inflation was successful, and no bead busting issues presented themselves. This is the second instance of a Bontrager tire busting at 40 psi, so beware!!!
Linky here for other Bontrager issue:
RangerJay "Tubeless on your 29er? Who's doing it, and how?" 10/22/03 6:56am |
| how did it ride? feel solid? (nm) | ncj01
Jan 6, 2004 9:14 AM | | |
| how did it ride? feel solid? | fattirewilly
Jan 6, 2004 6:22 PM | | The ride was solid. I got 2 hours in today with no issues. I'm having a difficult time trying to notice the increase in rolling efficency though, so I plan on doing a tubed vs tubeless experiment costing down a long hill. (Yes Cloxi, I read the German test on the weight board)I'm down to 35 psi right now and will try about 32 soon. (I run 40-45 with tubes). The traction is nice. |
| Had you used the Kenda's before? | Miles
Jan 7, 2004 8:14 AM | | Are you comparing the rolling resistance between tubed and tubeless Kendas, or tubeless Kendas and tubed Bontragers? If the latter is the case, it seems like the tubeless must decrease rolling resistance significantly, since a tubed Kenda surely has more rolling resistance than a tubed Bontrager. And can you elaborate on the traction statement? Thanks,
Miles |
| Had you used the Kenda's before? | fattirewilly
Jan 7, 2004 1:39 PM | | Miles-
I previously had the Kenda Klaw rear and the Bontrager up front. I replaced the Bontrager w/ the front specific Kenda. My trails are slow twisty single track so it has been kind of hard to notice the decreased rolling resistance. I "think" I feel it gaining momentum quicker when coasting DH sections, but I wouldn't bet my bike on it. I plan to do a tubeless vs tubed comparison by coasting (no pedaling will eliminate a variable) on a long paved (I think pavement will also eliminate a variable) DH when I get a chance. I plan to measure elapsed time and max speed for several runs under each set up.
I'm running 35 psi right now, (down from 40 tubed). I can feel more traction when standing on a short steep climbs, but it's not as much of an increase as a felt switching from 26" to 29" in general. Running a lower pressure may yet change my opinion, but I'm going to go lower only slowly. Hope that helps. |
| ? | hitekrdnk
Jan 6, 2004 10:33 AM | | Have you ever checked the bead on a UST tire? What does it look like compared to the Bonti or any other Kevlar bead non UST tire? Why does a UST tire weigh about 200g more than a standard Kevlar? Don't blame the tires, it is the fact that you are using it in a non standardized manor. If I was a tire manufacturer I would be adding 100g of warnings on the sidewalls of my tires to warn people that they are not for "tubeless" use.
I have seen an instance of a Kenda bead failure while running with a tube BTW. |
| My take on latex blow-offs (long, but I hope worth reading) | Cloxxki
Jan 6, 2004 12:25 PM | | I think it's better to wait some longer with that 40psi.
I, too, have had a tire (Michelin Mud 622x30mm) blow off, on my face, at 40-50psi. A true traffic stopper at the gas station.
My hand almost broke, I was holding the wheel upright with it. Hurt for days. Funny how there seems to be a short but unmistakable moment of extreme silence jsut before the blow comes...
Perhaps the "pop" sound of the bead seating properly can be replaced with some low-psi riding, I'll probably never ever put my Bontrager over 30-30psi anyway.
I've always though the wet latex and especially soap work as lubricant for the bead to flip over the rim and spew white goo, aimed right at you.
A tire/rim seal that's dried for some days at 20-30psi, to me, seems safer to put at 40psi for pops before examining. UST and regular tires pop too when dry, right?
I wonder what happens if you inflate a soaked in soap UST tire on a loose fitting soapy rim.
Is the Jones' bead really broken? My Michelin tire was still usable with a tube afterwards, no visible damage to be found. Michelin is however notorious for it's loose fitting beads, even 26" beads blow off at times, tubed and all.
I keep preaching a solid buildup of tape or foam underneith the used rimstrip, Eclipse or Stan, to increase the rim's effective tire bead diameter, and more importantly : decrease the difference between rim diameter and tire bead diameter, making for a snug fit where it's harder for the tire to escape from the rim's grip on it without actually *breaking* a bead.
Tires that are a pain to mount on a particular rim are in general real easy to inflate. The tire-rim intersection is already airtight before soap or sealent are being added. I once had a X517 wheel with Eclipse and Fast Fred 2.0 that held air for minutes, aired up with a mini-pump, bone dry. The snug fit of the strip and the strong yet slightly elastic tire bead together made for an airtight seal, the air was escaping from the sidewalls, I'd find after adding latex.
In short, add one or more layers of electrical tape under the Stan's strip to correct for the widish tire bead and/or smallish rim. If the tire becomes a pain to mount, like to the point of requiring tire levers, you've got the right amount of tape/foam on it.
Am I guessing wrong that the Bontrager went on the rim with greater ease than the Kenda? I've been wrong before, and for sure will again!
I hope to race my Jones' with latex next season, I just hope my above tips make it usable that way, I just don't see a worthy alternative for it on dry surface. On hardpack it offers me some 2 mph faster cornering than any 26" soft compound race tire ever did.
Good luck and happy trails!
J |
| My take on latex blow-offs (long, but I hope worth reading) | mv
Jan 6, 2004 3:39 PM | | Cloxx, What do you think of two messages below mentioned tubeless system?
Since the strip fits over the rim the diameter seems larger and blow off risc. |
| My take on latex blow-offs (long, but I hope worth reading) | Cloxxki
Jan 7, 2004 1:49 AM | | Stan's strip and the Stan-copy DIY strip both decrease the rim's effective hook size. The DIY system also makes it less sharp, which could improve pinch flat resistance and indeed increase rim diameter, but.
I think maybe the slipperyness (lack of grip) of rubber over aluminum when soaked in latex is the key problem.
I'm going to sacrifice a Jones tire which I love, do everything like the master says, but leave away the 40psi part. I'm never going to use the setup over 35lb, and if I would manage to get it seated at 25-30psi, why bother bring it to a suicidal initial pressure.
A week after mounting if think I wouldn't have a problem being in the same room as the wheel that's brought to 40psi. Dry latex/soap is day and night with wet latex in terms of (dis)mounting, so I guess the same for tire's likeliness to blow off. |
| My Jones bead sure broke | RangerJay
Jan 6, 2004 5:33 PM | | When my Jones blew, I did just about everything you suggested, Cloxxki. It's a nice tire, but I'd warn you heavily against trying to run it tubeless. So far, we've not seen one report of it being done successfully with that tire. My bead absolutely broke and was placed in the trash with tears in my eyes. After that experience, I won't try tubless with any tire unless someone can report prior success. I don't have the tire budget for such experiments. Anyone ever try a Kevlar bead Motoraptor? I won't be first! |
| Bead is definately busted.... | fattirewilly
Jan 6, 2004 6:45 PM | | and the tire is trashed.
The Bontrager did fit looser on the rim, but it was pumed to about 15 psi, checked for even fit around the rim, slowly hand pumped to 40 psi, checked again for eveness, let alone to sit for 5 min, and then I picked it up and started swishing the latex around. That's when it busted. |
| Nope, never checked a UST tire | fattirewilly
Jan 6, 2004 6:36 PM | | Since it weighs 40% more and costs twice as much, I'll pass. I'm aware of the not using the "regular" tire as intended issue, but it's the curiosity factor, and I guess I should say I never had any issues when using the Bontrager tire tubed.
That said, if I broke a new XC frame going off a 4 ft drop (doable, but not the intended use of the frame) I'd feel the need to post that experience as well and conclude that the particular frame in question couldn't function for my particular use because maybe someone would learn from my mistake. |
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