Hear me out on this. Proposed "easy" enhancement of tire performance
A request to anyone riding a fat bike, with access to a wider tubular tire.
It may also proof interesting for some 26" and 29" XC setups.
I used to be all into the freakiest of tire setups, intrigued by existing products such as tubulars and tubular clinchers, and the uprise of latex tubless.
I had an idea, originally meant to solve the issue of bead seating (prevent burping) at low tubeless tire pressures.
It consisted of a regular rim, regular tire (although a specific fit would be required), some tire selaent, and, hold on for it...a lightweight road tubular.
The idea was this: you don't use a tub, but a tubular. The tubular would inflated first, to high pressure, to press the tire beads against the rim at say 70psi. The narrow tubular would sit in between the tire hooks, inflation as you know decreases its diameter, causing it to "hug" the rim. I know it's not with a low of concentric pressure, but hey it was my little idea.
So the tire would now be inflated to a ridiculously low pressure, and not be ripped off the rim.
Two interesting side-effects in this setup:
- The tubular would stick out above the rim's outer diameter, and form a cushing in snakebite conditions. Or provide a ride-home aid, again, the beads would stay snug. Commercial products exist to take this role, and this role only.
- The tubular being at higher pressure than the actual tire, makes it relatively unrespensive for volume, it's rigid. It's air volume stolen from the tire.
Now, with rim-tire interfaces improving, I am focussing on the latter side-effect.
Reduced air volume, for a given tire size.
It would a small reduction, say 10% in an XC setup, and might actually prove beneficial in certain conditions. It might increase rebound of a tire, making it more responsive to the surface, and possibly roll quicker. Upon impact, say a drop-off or a curb hidden under the snow, the initial response of the tire would not be affected. However, as the tire is deformed more, per cm of intrusion of the curb, resistance would ramp up quicker, as the smaller volume causes pressure to increase quicker.
And then when the object really gets close to the rim, there is the tubular to take some of the hit at increased pressure. It only kicks in that way when touched by the tire profile.
If someone has a fat bike (I don't have money nor room for it) and say a volumous CX tubular or even the now available larger ~45mm Dugasts, they could stick one in and see how it affects handling.
I only rode a fat bike once, when the Pugsley was new to the scene, and got the idea that one of two things could help: either a piggy bag to increase air volume or dampen pressure increase from impacts, or the opposite: decrease tire air volume.
I'd be VERY grateful if someone could test my little idea. The effect will be most apparent when the tubular's diameter is closer (%) to the tire's.
And, I suppose with a supple tire which you'd like to run at low pressure, but can't deal with the rim hits you'd get, for instance on root infested trails.
You may get away with not drilling an extra valve hole, but it would be easiest.
And I bet it would work with a tube, but tubeless surely would be relatively easy to deal with.
Looking forward to your ideas, but please be civil.
Some one around here already has been working on such a beast. Can't remember who it was though. IIRC, he had some success, and was working on version two or three at this point.
But now I'm interested in the effects of the reduced tire air volume...
So let me get this straight: You bought a fatbike rather than something with smaller, tubeless ready rims and tires and now you trying to justify making the fatbike tires have less volume!?! I understand what you're trying to do, I just don't quite get the justification.
If you addressed me: No, you got it wrong.
Originally Posted by JR Z
- No fat bike in possession ever.
- Technology idea, not necessarily fat bike related.
- Asking for input.
Did your mother raise you to be like this? She must be one proud lady.
Or just reading comprehension? Good luck with that.
Really, I think you're just being a di(k, and need to read the posting guidelines once more.
You asked for responses. It was a fair comment. What is your problem?
Originally Posted by Cloxxki
use these on my mx'er.
wow that is really a great idea, The only problem I see is the shear width apart of the fat tires beads and the weight of the gizmo otherwise sounds similar to what Cloxxi and someone else in another thread was talking about. A small inflatable tube that holds the bead in place.
Originally Posted by kinta
I wonder if something like the old plastic panaracer tubes that you bought in a specific size for your tire might work well. They didn't stretch much and were very light. A 26x 3/4" tube snugged up against each bead in some sort of rim bed would certainly provide enough friction to keep the tire from spinning and enough pressure to hold the bead (I would hope).
And the slide to the level of the 29er forum continues. It's stuff like this that killed the 29er forum, guess who posts there all the time....
Originally Posted by Cloxxki
Just made me realise, I can't remember the last time I looked at the 29er or SS forums.
Originally Posted by pursuiter
So yes, let's keep this place pleasant.
As little bike as possible, as silent as possible.
Latitude: 57º36' Highlands, Scotland
edit: i meant mine, not cloxxis....
@Cloxxki: My appologies for sounding like a di(k, that was not my intention. I all fairness you are posting a "technology idea" in a thread in the "fatbike" forums... My input: at the most basic level, reducing the volume of a tire in order run a lower pressure seems counter-intuitive IMO. HOWEVER, it does sound like you have an idea and, maybe, even a plan and are looking for some sort of outside approval. Since I've never been one to stop people tinkering (as I enjoy it myself) I say, "try and let us know how it worked"
PS "please be civil" (your words not mine)
Cloxxki, couldn't you just test this yourself by running a small cx tubular inside your own mtb tire?
Honestly: I've been out of bikes for many years. I have a singlespeed and a commuter, no tools, and all my old sh[t in a storage unit.
Originally Posted by sean salach
I'm way impressed with tubliss.com
It's exactly what I envisioned way back then. They may have already existed then, dunno, don't care. Just grateful it exists in some capacity.
All one might want for tire compression performance enhancement is a relatively volumous tubliss. A square-ish cross section could either suppose the sidewalss, or leave them alone and still sit low to bare stick out above the rim.