I've got about 200km so far, refined the jetting and calculated the fuel mileage commuting to work, which isn't very realistic for mixed off-road riding. About 8L/100km so could likely make my 300km goal with the new tank but depends on the ride.
You’ve got me beat, I had clocked 175kms by my ride into work April, 13th, but at home time my rear tire was completely flat. I attempted to put air in it but I could heat it leaving as fast as it was entering. I got a ride home from a coworker and brought the bike home with truck next day, replaced the rear tube on the weekend, and have been waiting for my next chance to ride since. My tube had a total valve stem failure, it separated from the body of the tube. I installed the tube wrong about 5-6,000 kms ago, so I’m just glad it failed at a convenient time and I’ve learned my lesson. Good practice for when I need to spoon on a new set of tires later in the summer
Yes, spooning tires is definitely a game of finesse. I've made plenty of mistakes, usually pinch holes. I use 3 spoons and got some longer ones for replacing tires at home because I found the short packable ones harder to keep from prying too far and pinching.
Gahhhhh, I must have cursed gas in my tank, or something as equally logical. Got my new tube installed 3 weeks ago, weather was poop since. Rode 24kms to work today, and only 18kms home. Flat rear tire, valve stem sheared off the tube. Was cruising at 70 when it went flat. Parked in a friendly driveway, buddy gave me a ride home, returned with truck ramp for the second time this year. What might I be doing wrong? This $40 tube got me roughly 40kms. My first tube (installed wrong) got me 5-6,000kms.
Did you back off the stem nut so the stem could move a bit? Is there a rim lock? Talc in the tire? I would say, torque caused the tire to slip on the rim and it caused the stem to shear off.
Thanks for the discussion points @Chef. I did not back off the stem nut. Still pretty snug in its current state. Should it be loosened? No rim locks, never had one before, but I’m adding a pair to my shopping cart currently. Looks like my rim is pre-drilled for 2, but plastic caps plugging the holes. Yes talc in the tire to prevent chaffing. And the rim strip was fully intact too. I used a little bead lube to install the tire in April, rode my first 24 kms to work rather tamely to prevent spinning on the rim. I’m inclined to agree with you on the torque theory. Hoping I don’t find sharp debris inside the tire when i disassemble.
I don't run rim locks on this bike only because I use it so much on the road and I found they make the tire wear out of round, I also don't use much lube on the bead though (and run ~25psi). I definitely think the stem being tight is part of the problem especially if the tube isn't perfectly aligned before you seat the bead it probably has a lot of tension on the stem.
Offroad bikes, you shouldn’t have that stem locked down. Some back it off to the valve stem cap. Some half way. Two nuts are used as a lock nut so the nut doesn’t turn back down to the rim. Two rimlocks will help to keep the tire more in balance and keep the tire in place on the rim if you are hard on the throttle/brakes. Talc helps to let the tube slip in the tire. Some slime in the tire can help with the balance too.
Bead lube is not a good idea if you haven't got a rim lock. Without the rimlock, air pressure is the only thing holding the bead to the rim. Anything that reduces friction between the bead and the rim can cause trouble. I don't use the nuts on the valve stem at all. Easy to see if the stem is tilting before it gets completely ripped away. I only use bead lube to grease up the inside of the tire and the outside of the tube. I put the tube into the tire then mount them as an assembly, wiping off any bead lube that gets on the bead area. I used to use talc as an assembly lube, but you still get bits of rubber crumble inside the tire by the time the tire is worn out. I expect the bead lube will let the tube move enough to avoid pinch flats. I only ride offroad with reduced tire pressures (and a rimlock). If I rode onroad, I'd use two rimlocks or balance the tire/rim combo with weights.
Thanks fellas, I see a few errors in my ways. The valve stem jam nuts, will allow the next tube to float. Bead lube, will do without next time. Tire pressure, I was running around 15psi, but my gauge isnt too accurate down that low….so I will get a better gauge to ensure my set pressure. Rim locks, still torn here. I don’t want to bother with balancing my tire, nor do I wanna wear it out funny. Think I’ll try the above remedies before travelling this route. Long story short…Tire pressure, bead lube, heavy throttle use.
Put my new tube in yesterday, ensuring I didnt repeat errors. No bead lube, 22psi, valve stem jam nuts up high with the valve stem cap. While the tire was off I also used a wire wheel to clean up the bead of the rim, making the “grippies” seem to be more raised (as not filled with gunk). rode my 25kms to work this morning with no drama, gonna take an extended route home, maybe about 50-60 kms total.
Did 150km tour around my neck of the woods, no tire drama. Ive officially purged the “cursed gas” from the tank. Rode Terra Nova, a bunch of the North-South roads between Hwy 9 (Orangeville) & CR 9 (Creemore). Only 1st line and Garden of Eden had water on them, but overall pretty dry. i put a paint mark on the rim and tire, and the rim did spin slightly. I think the bead of the tire is getting weak, its been mounted and dismounted at least 5 times now, and has at least 5,000kms on it. If the tube goes again, I’ll replace the tire at the same time.
Soon to be gearing up for 2024! My only tasks are to BUY new tires, and spoon them on. Gonna re-up on the MT21s. Then book in another set for spring 2026. I reviewed my last couple posts, and to fill in the gaps of 2023, My tire troubles didn’t end in May. In august I had the front tube gain a pin hole that leaked too quickly for comfort to make the ride home from work. Turned out I missed a “QC OK” sticker on the inside of my MT21 when i mounted it the first time…that lil sticker chaffed a pin hole in the tube. I patched it and has been fine since. Fast forward to September and the glorious riding weather had me making excuses to detour and extend my commute. Sept 30th ended my season abruptly with a painful lowside going around a gravel 90* left…front tire washed out. It had almost washed a couple times during the previous tank of gas. Lessons learned? Don’t be cheap with safety. My MT21 were AMAZING for 2 seasons, trying to push a 3rd was stupid, then quite painful. (I’ve said for years that Sometimes stupidity should hurt). It was Almost 2-months before i could cough or sneeze without wincing (or whining, grunting, complaining…you get the idea). I did manage to pick myself up and ride another 30kms of back roads and no winter maintenance to get home. If you’re gonna be dumb, you gotta be tough. Cheers to a new season! Good luck everybody!
This is the best tire change instructions I have ever come across. See Lyndon Poskitt video on tire repair / install : Cheers
Just re-watched, I'm gearing up for a front tube change. I've ridden 200 kms this year, most of which was for my M-license road test. I rode another couple hours and parked it for a week, came out to a dead flat front tire. Hope you've all geared up for spring!
Pin hole. 4 years ago when i put that tube into a new tire, i failed to remove a "QC OK" sticker from inside the tire. That chaffed a few holes into the tube. I patched all but one, which took 3 years to start leaking. Anyways, it's in the trail spares bin now.
