PSA Planet X tyre inserts

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  • PSA Planet X tyre inserts
  • pedlad
    Member

    Ta, but £37.99’s a bit different just to try out though

    Premier Icon thisisnotaspoon
    Subscriber

    The rebound issue is because they take up air volume in the tyre therefore the pressure increases faster to a given deformation (like volume spacers in your air spring but they are foam so will compress under pressure) If the insert is made from a faster rebounding material this will amplify the affect of the tyre returning to faster and therefore pushes harder against the suspension and increasing the force felt as rebound.

    The squishiness shouldn’t change. As you said “like volume spacers in your air spring but they are foam so will compress under pressure” i.e. nothing like volume spacers. When inflated to 29.4psi it’s volume will be about 1/3 what it was on the outside.

    I suppose if you bottom it out then you’re locally increasing the pressure by reducing the volume of the foam itself locally. Whereas normally the volume of the whole tyre is changing and the pressure increase is relatively low. But you’d only feel that in the last 1/3rd of the ‘travel’ before the rim bottoms out, i.e. the exception rather than the rule.

    Premier Icon chakaping
    Subscriber

    Ta, but £37.99’s a bit different just to try out though

    The Rimpact inserts are really good. If you do smash a rim without one, you’ll look back and think it would have been quite cheap.

    so it seems these are quite large? has anyone tried the size down? i’ve got 2.4s on the fs and 3s on my plus worth getting the size below?

    Well, I have just tried to fit the 27.5+ size into a Specialized Butcher 2.8 on a 35mm internal rim. I have given up for the night. There is no air void at all, and when battle resumes in the morning I am going to have to lube everything up with a film of washing up liquid and hope my fingers have recovered. What a way to spend a Friday night…

    BearBack
    Member

    The Rimpact inserts are really good. If you do smash a rim without one, you’ll look back and think it would have been quite cheap.

    4 rides on my new bike with rimpacts.. 2 dead tires and one broken carbon rim.. not working out well for me
    🙁

    Not riding the same kind of bikes with the anacondas.. but sizing down seems to make sense.

    Round two is a no go. There is no way I am going to get the tyre mounted with the insert inside. I am going to have to trim it.

    Should I trim:
    The inside circumference?
    The outside circumference?
    The sides? (I think this is no)
    Cut a v shaped groove?

    BearBack
    Member

    Yo CL.
    I’ve found (in my limited experience) that the issue getting tires mounted with these things in is that you really struggle to drop the bead into the rim bed.
    I would think shaping the inner circumference to allow the bead to tuck under the insert and into the trough whilst keeping the profile as wide as possible to protect from sidewall pinches would be best. Doing that without a hot wire might be tricky though.
    Removing material from the outer might let you chase the insert around a little to drop that bead, but its still going to be tight when you get to your last few inches of bead as the inserts don’t really stretch a great deal.
    However bearing in mind the early posters feedback on not having an air gap then you will probably want to remove some material off the outer circumference anyway.. so might be worth starting there?
    My 2c

    Cheers Jonny. I might try to rig up a hot wire arrangement. What is the worst that could happen?

    The Vittoria Airliners have a wee void around the rim bed and a void on the outer circumference.

    I’ve got the Rimpact ones. Pretty straightforward fitting provided you inflate and seat the tyre bead first then unseat and remove one bead and insert the liner. Then stuff the tyre bead down the side of the liner.

    That all said, I put a massive dent in the rim on the first ride so not particularly convinced.

    pedlad
    Member

    @Troutwrestler – did you cut them down – have any joy?
    After battling to get the tyres on over the inserts, I’ve failed to get them to seal. Not sure it is the inserts, the tape is old and I may well have punctured it with the heavy handed mounting.

    So I’ve a decision ahead of next week’s trip- new tape but ditch the inserts or try again with the whole lot…..d

    spicer
    Member

    I’ve been running the planet X ones for a while on a 160mm full sus. They seem pretty good. I normally have about 38 psi in the rear so that I can avoid most rim strikes, but I’ve gone to just under 35 and had some pretty hard square edge rock hits (bobming down cadair idris!) and no marks on the rim.

    I suspect if you’re running silly low pressures the foam would make the tyre feel weird- these are a way to get away with a bit less pressure but you can’t be silly. If you’re running too low pressure you’ll just roll your tyre anyway. I don’t notice anything in terms of reduced grip. No problems riding steep wet rooty mini-dh trails. I’ll happily buy again in the future

    Premier Icon K
    Subscriber

    I cut one of mine down in to two (inner and outer) with a thin sharp knife. It cuts really easily just go steady to keep on track with a little bit of a sawing action. I was going to use a hot wire cutter with guide jig but got inpatient and thought I need to make a hole to thread the wire so pushed a the knife through.

    It has worked really well and given a better feel on the front.
    A lot easier to fit the tyre.
    Turned the outer one inside out so the flat is on the outside. That one is a bit loose so next time I take the tyre off I’ll also shorten it a little and zip tie.

    pedlad
    Member

    Cutting it down supports other poster’s ideas of having more air volume….and also making the tyre easier to fit sounds a bonus – tempted to do that….

    I haven’t tried again yet. It might be a couple of weeks until I can get the peace to give it a go.

    FWIW, I think cutting it in half loses too much material. I an tempted to take a slice off equivalent to 1/4 or 1/5 of the total diameter.

    Premier Icon Jordan
    Subscriber

    Thread ressurection.

    @mattbee did you compare the density of the Anacondas with the backer rod? Did there seem to be much difference?

    @Scienceofficer The claimed weight for the Anacondas is 122g per pair. You mentioned in the DIY insert thread that 2M(enough for one 29er) of 50mm backer weighs 110g. This would suggest that the Anacondas are less dense than backer rod. Or could they be a different material?

    Premier Icon mattbee
    Subscriber

    Feel pretty similar  to backer rod to me.

    Have had them fitted for a few months now, not noticed any negative effects. Guess I’ll see how they look when I change back to summer tyres eventually!

    Premier Icon Jordan
    Subscriber
    poah
    Member

    density depends on volume and mass. For the anacondas to be less dense they would have to have a larger volume than the backer rods by about 11%

    Premier Icon Jordan
    Subscriber

    61g vs 110g? Assuming a simillar volume. Actually, just checked and the quoted weight is for 26″ small so not a fair comparison anyway.

    k1100t
    Member

    The the perceived wisdom that these things are better than Backer rod, or are they much of a muchness…?

    The answer to your question Jordan is I don’t know.

    I don’t use backer rod any more, I use rimpact. Backer rod does work, but I found it not especially resistant to cuts at my preferred pressures.

    null

    I was swapping out backer rod every 4 months or so and concluded it needed to be denser than I could find it to be a viable longer term, low faff solution.

    It was much more cut resistant with a skin of gorilla tape, but it peeled off too readily and became more and more of a faff to implement a system that wasn’t any better than some of the cheaper inserts like rimpact.

    Still, it was a cheap thing to try at a time when cost effective alternatives weren’t available like they are now.

    Premier Icon Rubber_Buccaneer
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    I use rimpact. Backer rod does work, but I found it not especially resistant to cuts

    How are you getting on with the Rimpacts?  I like the feel they give but they appear to be a consumable

    Premier Icon Jordan
    Subscriber

    @Scienceofficer Cheers! Cost effectiveness certainly comes into this and yes there are certainly cheaper products on the market these days.

    How are you getting on with the Rimpacts? I like the feel they give but they appear to be a consumable

    All of these inserts are consumables, even Cushcore state that they need to be replaced at some point.

    Backer road is cheap, but requires too much swapping out. I’ve not actually looked at my rimpact. It’s in my hardtail’s rear wheel so it’s unlikely I’ll get to it untill the dry part of summer when speeds go up and ground hardness begins to make my vision blur and I switch to the FS.

    Premier Icon mcnultycop
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    My PX tyre inserts are so tight I can’t let air out of the tyres. Other than that they are great.

    Premier Icon doomanic
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    I had the same issue, but I didn’t use the supplied valves. I just removed the valve core and used an allen key to force the insert away, replaced the core and pumped the tyre up to 25psi on my track pump. Worked for me.

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