It would stump me too. Sounds like you have a good handle on it. Just worried when people suggesting more pressure - the rim is alloy (I assume) so please be careful - we need to look after all fellow motorcyclists.
Given up and ordered Michelins!
When they arrive next week we'll know if it's the tyre or my technique.
BTW. I'll still have this Vee Rubber rear so if anybody gets any ideas feel free to share!
I would be cautious. The tyre should seat at 60psi. That is a lot. Much more and the shock could quite literality destroy either the tyre or the rim. You could easily hurt yourself in the process.
Assuming enough lubrication the tyre should seat properly with or without a tube. Sometimes it takes a few seconds and it can help just to tap (gently) round the tyre with a rubber mallet. Washing up liquid is OK if you don't have tyre soap.
The tyre (& rim) is lubed with Putoline tyre soap, applied generously and was heated with a tyre warmer used for racing motorcycles.
It's been bounced, hit with a mallet and left overnight at 60psi.
I've trimmed the rim tape to ensure the tyre bead isn't binding on that and done my best to get it positioned 'square' before inflation to offer the best chance of the bead getting over the inner rim lip and out to the wall.
I'll also add that before starting I lightly sanded the rim with emery paper to remove any oxidation, then wire brushed and finally gave it a going over with a coarse polishing wheel on the Dremel.
I'm not totally green when it comes to this, but am totally stumped- hence wondering is it just a bad tyre?
The valve core is still in place and I'm using only a foot pump, but as there's a tube I didn't think that'd matter?
(my understanding is that a compressor blows in enough air to force the bead to seal whilst inflating tubeless. Because this is tubed I wouldn't have thought inflation speed/rate mattered?)
After everybody's advice I decided to fit a tubeless tyre on the back with a tube, and because I'm trying to keep costs down I bought...
..Vee Rubber. (I can hear laughter already).
So b**ger me, the rear is tight. I ended up putting it in my race bike tyre warmer and using copious amounts of Putoline tyre lube.
Once on, however, it won't seat.
Probably a quarter of the tyre won't meet the rim wall, it stays in the centre channel. If I deflate and lift the bead out of the channel, it then pulls 'tight' elsewhere and that part of the bead drops into the channel.
Am I doing something wrong or is it my budget Vee Rubber tyre?
Looking at the rim I would be sceptical the tubeless will seal on the corrosion. You can save a bit by using duct tape rather than rim tape - you would need the wide 4" tape for fat MTB on a trials rim, or the proper trials tape (£20 - probably will not seal either).
If you are worried about spokes you might just have to bite the bullet and put a rim on, by which time you are at new wheel stage.
What is the engine like? It is a very hard decision to make but by the sound of it you are very unhappy with the cycle parts and trying to renovate on the cheap? I think you have to decide if you are repairing it to resell or to ride. If the engine is good you might have to come to terms with spending more than you are comfortable with and at least having a basic ride for a year or so. If you want to resell it stop looking for faults to fix - fit a tube and relist it on eBay. Thinking you will ride it for a while then break it seems to me to put you in the position of getting the worst of both outcomes.
Chris, I agree on the sealing and also on the logic.
The bike is rough and with a full rebuild won't be anything but that.
I'm not averse to renovation (my R1 has had a top end rebuild in 2019 and I took the engine out. I also rebuilt the calipers, changed the rad, thermostat, starter relay, rear shock, master cylinder, clip on's and countless other things). I did it because it was fundamentally a good bike and deserved it. (see pic) This Gasgas doesn't!
Plan is to ride it and enter a few trials.
I have road raced and raced motocross, so have intentions of taking it further.
I could cut my losses and sell it, but the engine seems good- starts well, no nasty noises, no smoke etc.
I'm a set of tyres and a few spokes away from having a rideable bike. (fingers crossed)
I have mountain bikes as well and most are now converted to tubeless tyres. You can buy the adhesive tape they use [seals off the spokes] it is very flexible, comes in many widths, and has a very high level of adhesion. After fitting the tyre you have to put some sealer inside to stop any minor leaks. I found a nail in my MTB back tyre the other day when cleaning it and as soon as I took it out the sealer bubbled out of the hole for a couple of minutes and then stopped and hasn't lost any pressure since then after riding for over 10hrs or more, so there system does work.There are plenty of YouTube videos on how to do it and I am pretty sure the sealer would have to be non corrosive as the majority of rims would be alloy. Using this system which won't cost much you will still be able to use the tubeless tyre which is a way better idea than using a tube. I have done this on a couple of mountain bikes as they come 'tubeless ready' that is the tyres are tubeless but they have a tube fitted from the factory.
Cheers Greg
Thanks, Greg.
I'd still need the Morad rim sealing strip as that has valve, or do you advocate fitting a separate valve (like we do in cast wheels) and sealing tape?
Tbh I'm siding with a tube in a tubeless at the moment. It's £20 for a sealing strip and I have neither a compressor not fitting mousse to properly mount a tubeless.
I'm also concerned that more spokes might yet ping and I'll need to replace them, so an adhesive sealing strip would be ruined by me lifting it to replace a spoke.
I ride on a budget by the sound of it similar to yourself. All my modern bikes since taking up the sport again (3 gassers and a evo), have come to me with tubes fitted in a tubeless tyre, and I’ve never had any problems with that set up. They all had rim tapes fitted although I assumed they leaked, but they help protect the tube from damage on the spoke nipples, and also act as grip to stop the tube spinning. Once the tyre is seated properly on the rim with the tube at high pressure, they can be run/ridden down to 3.5psi quite readily, without rim locks. Looking at your rim I might be tempted to apply something like a lacquer or maybe waxoyl to stop it corroding further, as once you ride it in water the area between the tube & rim stays wet forever.
So I’d go with an option 3, tubeless tyre with tube, rim tape but no silicone (no risk of silicone corrosion).
Good luck.
Option 3 sounds good!
I understand running a tube inside the tyre is going to reduce the compliance of the tyre a little, and that I also won't be able to run quite as low pressure but with what I've got it seems the most cost effective solution.
A Waxoyl type product is a good shout.
As for riding, I'm looking forward to getting more involved. I've dabbled with different two wheel sports with & without engines, so hoping there's a bit of crossover.
If you use a silicone sealant be very careful which one you use, some are very acidic an will rapidly corrode the rim. That's how a previous owner trashed the rim on the txt I had.
If you use a tube without a rim lock it seems to be pot luck if you'll get away with it, some have been OK, but in mine it spun and tore the valve off.
Since you're going to the hassle of replacing the spokes it makes sense to replace the rim. It's hard to tell from the photo if that rim is even safe to use.
If you stick with that rim I'd carefully clean where the sealing tape fits and I'd fit a new tape coated in the type of tyre sealant that you put in to prevent flats like gunk or slime. If it goes flat over a day or two then that's fine, as long as it holds long enough for a trial.
I'm only replacing the spokes I have to, which is probably 8 or 9+? (two broken/missing + loose spokes which are seized and can't be tightened).
If I replace rim + full set of spokes I'm looking at c.£200 on a wreck of a bike.
Regrettably I don't have £200 but even if I did, I wouldn't spend it. This is my first trials bike and I need to see how I get on. If I decide to take things further I'd either sell the bike 'as is' or break it for spares.
I need to be pragmatic and given the overall state of the old girl, she just doesn't warrant the kind of money required to make her competition worthy.
I'm ever so grateful for all the help, though, so to recap:
1) Fit a tubeless tyre with a tube.
2) Fit a tubeless tyre, get hold of sealing strip and look to find a low acidity silicone sealant so I don't do any further damage.
If that was mine I wouldn't ride it with that rim due to the loss of strength of the metal where the spokes attach.
It's fairly common to have to replace rims on off-road bikes due to internal corrosion
In principle I agree but in this instance I just don't think it's worth the cost and effort.
When I picked the bike up I could see it was well worn but with eBay I do believe you have to 'suck it and see'. I could see it was rough but that's the game.
I picked it up in December before lockdown and repacked the mid/end silencers, changed plug, air filter & gearbox oil.
Forks are f**ked but have had seals + bushes replaced anyway.
The back wheel had two missing spokes but plenty more loose, and of course they're all seized. Nightly for a week I oiled them with penetrating fluid and took a blowtorch to them. Some freed, most didn't, so I'm £40 into new spokes + nipples.
Guess what I'm saying is I bought a wrong 'un and I'm just throwing money into a pit. I'll do what needs to be done but no more, as it'll only ever be a tired 20yr old bike.
1. Yes, tubeless rear, tubed front. Tubeless front rims were discontinued a long time ago
2. Possibly, they seal normally using a rubber sealing tape around the rim which seals off the spokes to stop air leaking past the spoke heads. Tubes are sometimes fitted as these tapes are a pain to fit and can still leak. Some give up and fit a tube. If the corrosion is bad the tape won't sit correctly and air will escape. If it's really bad be sure that it's not going to fail in some way. Corrosion isn't uncommon on older tubeless rims
3. Tubeless rims need tubeless tyres whether you fit a tube or not. A tube type tyre won't stay on the rim and the bead will drop off. You don't need rim locks with a tube fitted as a tubeless tyre holds itself and won't creep
Woody, thank you so much.
Everything answered and so my best course is to buy a tubeless tyre and run it with a tube.
(The tyre I took off was actually a tube type tyre, so a bit naughty.)
I've cleaned the rim with abrasive brushes and emery cloth but still looks like this:
I'm sorry for asking but I'm a bit lost and usual methods of getting answers aren't working...
I've recently bought a heap of a 2001 250 TXT (eBay, and yes, I should've walked away) and last week removed the cracked, nasty rear tyre.
I couldn't get the bead off on one side so ended up cutting it off.
It was a Barum tyre with innertube, but I thought it odd no rim lock?
So question 1- In 2001 did the TXT have tube front & tubeless rear?
Question 2- the rim is nasty and corroded inside. Could this be a reason for running a tube (because it wasn't sealing well?)
Question 3- if it's a tubeless rim but I choose to run a tube, is it better to buy a tubeless tyre or tubed tyre? Just thinking about rim wall shape.
I think the old tyre had the bead glued on one side to stop rotation (which makes sense if no rim lock) but I'm lost as to whether I should be tubed, tubeless and how to best achieve an outcome?
Hi Guys, the last few weeks I've found myself on this forum almost daily looking for answers so I'm afraid I'm another one who can't offer ANYTHING but needs help!
Background:
My dad rode trials in the 70's (before moving onto Motocross) and has recently restored a '71 Bultaco Sherpa T which he's taken to a few local trials centres.
I've just bought a complete shed of a Gasgas from a typically neglectful owner and I'm finding problems at every turn.
I've got general motorcycle experience but nothing specific to trials so apologise in advance for many stupid questions.
Another Tube/Tubeless Question
in Gas Gas
Posted
Hi Guy,
The rim is old but as clean as I can get it.
It's been rubbed over with emery, wire brushed and Dremel polished with an abrasive.
Any burrs or edges I took back and smoothed.
The tyre not seating occurs at different points around the rim, as opposed to there being one 'problem area'.