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I’m quite impressed by the amount of damage to the FSA seatpost and the fact that I rode it a couple of miles to the station this morning before realising that it was a bit more flexy than usual.
There’s a reason why it did not immediately shatter and impale the inside of your thigh on carbon. Proper carbon manufacturers intersperse the layup of carbon sheets with more flexible materials such as Kevlar and in the case of some manufacturers exotic materials such as flax. This is so when the carbon, which is relatively brittle, breaks, the softer noncarbon material holds everything together while you grind to a halt. This is extremely important when you have fractures around head and down tubes, where a catastrophic sudden snap could send you over the bars at high speed.
I guess it’s up to you whether you like the idea of being impaled on a bit of broken carbon fibre or the idea of a soft, controlled break.
Big vote for the Ottolock
Big vote for the Ottolock here. I purchased a set of three on the Kickstarter. Have used the smallest one as a cafe lock many times, really light, strong and easily carried on the bike or in a pocket. Use the longer ones for multiple bikes, camping kit, bikes on roof racks or towbar racks etc. Can’t fault them.
So, does that mean they’ll come up again at bargain prices through the Sports Pursuit website, and the reduced price will look even better due to the now higher RRP? Some of it is good kit, but I’ve only bought their stuff when hugely discounted. Couldnt justify a purchase at their RRP.You just nailed the SP business model. Never, ever pay any more than half price.
It’s both low and high pressures, at low pressures tyres may burp, but equally at higher pressures you can blow a tyre off the rim, with tubes, the tube will hold it in place. tubess is relying on rim/bead, so the point is lower, hence most gravel/wide road tyres have fairly modest max pressure limits.At a pressure low enough for a road or even CX tyre to burp, you’re talking sub-10psi. Ridiculously-low.
To blow off a rim, you’re talking 70+ PSI with a crap tyre-rim fit – basically too high for decent sizes. Really there’s no point going tubeless with less than 28mm, because it needs to be too hard to maintain less than 15% tyre drop and you loose all the nice supple benefits.
Compass Cycles say their tubeless shouldn’t be run at more than 60psi – as they don’t do less than 35mm in tubeless, that’s a rider-bike weight limit of around 120kg – or in other words, heavy AF. Noting you *can* go harder, but should always go maybe 10-20% PSI higher for a few days to make sure your tyre-rim combo can keep things mounted. The actual pressure limit on the tyres is 75.
Anyway, the point was you don’t *need* a ‘tubeless-specific’ rim.
tyres are the most important, part yes. And lots of folks at least online seem to have success with Converting their rim, this said tubless rims do have (generally) minor shape changes to help keep the tyre in place, seems to still be a bit of a random which rim/tyres will getto and which will not, or at least with out a lot of work. Gravel/bridleways etc will generally require quite a bit more pressure than, CX racing and on the road yet another jump up. At those pressures you’d need to be very sure of your getto rims.er…it’s the reverse, actually there Roger, if I have understood your comment correctly. Having a bead seat ‘barb’ or lip that holds the tyre bead in place is more important at lower pressures, where the tyre is shifting about much more on the rim whilst cornering. This ultimately manifests itslef in ‘burping’, where the tyre bead is pulled away from the rim wall and into the centre channel, thereby opening a gap that allows air to escape. I haven’t had this happen to me in a road or gravel context, ever, nor have I met anyone who has.
Burping happens mostly with very large volume MTB tyres run at single-digit PSI pressures, in extreme off-road situations. Or in low-pressure CX applications where a combination of a tall rim wall and very tight bead mean that once installed, the fit of the bead to rim seat is not that tight. This can be improved by adding layers of tape.
Road/gravel setups – rim width, forces exerted, pressures etc – make burping borderline-impossible to occur. You’d have to be running stupidly-low pressures for it to happen, which would badly-impact handling long before you could put it into a burping scenario.
For road bikes, even new bikes probably don’t have tubless ready rims, my gravel bike doesn’t and it’s a month old..Any rim can be set up tubeless, it’s the tyre that matters. Tubeless yim tape and the right valve. That’s it. My CX bike has early-80’s Mavic Open Pro’s and I raced a season on them tubeless, no bother.
People people, calm down.
People people, calm down.
Road tubeless is sorted. Worst-case to make them seat, is to put a tube in and leave inflated for a day, then remove *just one bead*, swap tube for tubeless vavle, add 50ml of sealant du jour and inflate, worst-case using the likes of the £40 Beto Air Tank. I have dome many, many dozens of setups, and this is the worst-case scenario, all up about 30 minutes, max. The rest is gravy. spend the £40 once and you’re sorted.
Also spend the £32 once on the Stans kit, if you’re worried about getting it right.
In 6 years of riding tubeless exclusively, probalby 15-20,000 miles, on and off-road, on about two dozen bikes, easily twice that in tyres, I have only ever had *one* sidewall cut that sealant couldn’t fix – valve out, tube and tyre boot in, sorted in the same time to do a normal flat. I then superglued a patch in place and rode it quite a few more thousand miles.
I used to go through an inner tube a week riding in Hampshire, with flint, thorns and crap roads – these were GP 4Seasons, properly-inflated, in case you ask. Now I bomb about on and off road with low-pressure tyres and nary a care. I don’t have to patch or replace inner tubes, and I never have to stop in the cold/wet to faff. I have used my tubeless repair kit maybe 5 times in that distance, so once a year, when there’s a tread cut too large to seal. Don’t even need to add air. Plug & play.
If you can’t be arsed, get a shop to set them up for you – should be £50, max for labour.
If you zoom to max, you can see wear on the 22, 25 and 28 cogs, whether it is enough to cause it to skip with a new chain could only be told by actually trying it. I used to get lots of cassettes in the shop that looked okay but acted dreadfully when given a new chain.Chains only ever skip on small gears – like 11-17. Beyond 17, there’s plenty of teeth to wrap on, that ensure the riding up that worn teeth cause doesn’t end in chain skipping forward, not matter the load.
It looks terrible on the shop if you service a bike, put on a new chain and give it a quick test and all looks good, only for the customer to take it out on a big ride, crank it hard on the first big hill and the chain to jump a tooth and send the riders knackers onto the top-tube. This tends to make you say that if the chain is more than just slightly worn, then you need a cassette too.An even half-arsed shop would be able to inspect the cog teeth for wear, and do the brake-on ‘stomp test’ to see if there’s any chain ride-up on the smaller cogs under high load.
I change my chains before I can get the .5 % tooth of a Park chain checker in, if it goes past that then a new cassette goes on.Noting those Park ‘checkers’ are woefully inaccurate, compared to even a cheap metal ruler or £10 set of digital calipers from Screwfix.
Most LBSs aren’t making enough money on a cassette to risk their reputation on blagging bits for the sake of it. Experience tells you you are better off changing cassette and chain if there is any wear on the chain, or leaving them as is. It is a difficult call quite often for a shop.I’d say it’s all over the shop, no pun intended. I’ve seen people sold ceramic-bearing jockey wheels to solve worn-cog chain skip. If they think they can justify it, many shops will sell you anything. Cogsets are hard for the punter to eyeball as worn, so easy pickings and at a reasonably-priced point to make a replacement a do-able thing for most.
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Brian, that looks fine to me.
Brian, that looks fine to me.
Here’s a rule of thumb: for every three chains, replace the cogset. For every two cogsets, replace the chainrings.
You can easily check a chain with a ruler or preferably digital calipers. A new chain measures 127mm for 5 links new. At 127.4, look to replace it. If you go beyond 127.5, you’ve prematurely worn the cogs and will suffer accellerated chain wear.
A decent chain should last you 5,000 miles. Ish. so after 15,000 miles you’re up for a total of 3 chains at £10 each + cogset say £30 – or £0.4p/mile.
Mine just arrived – waiting
Mine just arrived – waiting on the outdry pair as per previous posts.
First ride yesterday, 3-8 degrees C, cloudy. Wow, I’m impressed. Wearing all three layers, fingers were lovely and warm. Dexterity was fine (Ultegra 6800 levers). No bunching or odd feelings in the webbing of fingers etc. Length was perfect for me, using their sizing chart.
DISCLAIMER: I have the shittiest circulation, ever. I’d normally wear a merino liner and a pair of Sealskinz Lobster mitts in these temperatures.
On a road bike there is a seriously limiting curve of ‘return for investment’ on lower pressures and grippiness. Below about 80psi there’s nothing I’ve seen that shows that grip is improved in the real world.If you think an 80PSI tyre grips as well as a correctly-proportioned 50PSI tyre, I don’t think you’re riding in the real world 🙂
Less exhausting: as others have pointed out the 1 or 2 watt saving is both undetectable and ephemerous. On the point of energy efficiency, everything I have seen shows that a higher pressure tyre has lower rolling resistance due to lower hysteresis. However, a larger tyre at the same pressure as a narrower tyre has lower rolling resistance, again due to less hysteresis. That doesn’t follow that a lower pressure, larger tyre is more energy efficient. And again, the improvements are low single digit watts only.Several things here:
1. ‘less exhausting’ means less hysterisis loss because the tyre is suspending the weight of the rider and bike, reducing the vertical movement, muscle vibration and related fatigue. The seminal Bicycle Quarterly article quoted US Army research showing tank drivers suffered significant fatigue due to vibration, that was alleviated by suspending their seats. Anyone who’s been beaten up for a day on a rigid bike over rough roads knows the feeling. This is why bike firms invest millions in vertical compliancy of frames via seat stays, posts etc.
2. Hysterisis loss is the vertical bit. Rolling resistance due to sidewalls flexing isn’t hysterisis loss. It’s rolling resistance, due to heat generated in the flexing tyre carcass.
3. the quantative improvements of a larger tyre at lower pressure, like for like, on a real-world road, are considerably larger than ‘low single-digit watts’. Go ride a bike with a power meter, over a crap road, first on 100psi 23mm and then 50psi 35mm.
I can only think your experience is refering to mtb tyres as you mentioned slime, which is too thick for easily adding via the valve core of a presta valve.Nope. Road tubeless only.
All sealants added either via Milkit valves, or poured direct into the tyre. No sealant can be added through a presta valve, as the gaps inside are way less than 3mm, which is the benchmark for any decent sealant to work up to.
MTB tubeless cannot be used in the same breath as road tubless, the sealants are different, this is my ‘exact’ bugbear with tubeless, when I set out on my tubeless journey, I defaulted to ‘stans’, however it just didn’t work at higher pressures, this is undisputableI’ve run Stans in a road tyre without issue. So have thousands of other folks. Your combination of tyre, pressure and cut size might well have not worked.
Note to all: Let’s kill the
Note to all: Let’s kill the zombie fact that sealants dry out – a number of the newer ones don’t. I’ve had Slime Pro still liquid in tyres a year after installing. I’m more than happy to spend £10 a year topping it up if needed. As a peace-of-mind investment for thousands of miles of flat-free, low rolling-resistance, comfortable cycling, it’s a no-brainer.
Also: It’s a good idea to ‘pre-unpeen’ your valve cores and only install them finger-tight (or carry a tiny core removal tool). So if – IF – sealant clogs the valve core, you can remove the core roadside, remove the brass inner, and clear it out. Otherwise you won’t be able to add air if needed. ‘pre-unpeening’ means holding the core with pliers and undoing the knurled knob with another pair of pliers, so it unscrews fully. Someone needs to make a valve core where this is possible out of the box.
Finally: Behindthebikesheds hates tubeless and won’t be told it works for anyone because (s)he is indeed a cycling ninja with the ability to see through the dark to spot every tiny road imperfection, also rides tyres made of impervious Unobtanium rubber. Also is the luckiest British cyclist alive, and we are all doing it wrong in comparison 🙂
beless, friends who have still have problems, and still need to carry tubes/tyres/patches/levers etc, so I don’t see the point.The point of going tubeless is NOT to remove the need to carry an inner tube or pump, although plenty of people do realise they can now forego carrying these things with only an extremely remote chance of being caught out.
The points are:
1. You will never again have to stop for a flat due to a snakebite or penetrating puncture.
2. You will never again have to pay for or repair a replacement inner tube for 1.
3. You can run lower tyre pressures all the time, meaning every single metre you ride is grippier, more comfortable/less exhausting and more energy-efficient/faster for the same energy input.
Look at the crank-spindle
Look at the crank-spindle interface. The only way to do so is to swap the crank out. I chased a maddening creak for weeks before this was proved the case.