Thorn Cycles Forum
Technical => Wheels, Tyres and Brakes => Topic started by: ourclarioncall on April 06, 2021, 08:46:36 pm
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I see on Thorn bikes or touring bikes in general , presta valves is most combo
I really dislike these with a passion and have never had a good experience with them . I had my bike drilled out for schrader vslves which I’ve never had a problem using with pumps or at garages
Maybe I’ve just got unlucky , had poor quality pumps, or poor quality valves/tubes
How does everyone get on with them ?
I’m reluctant willing to give them another go if there’s some good reasons or his experience
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I've had no significant problems with either type. Presta valves tend to be used with narrower rims. The valves on the Schwalbe Presta tubes have removable cores which are useful for either replacing a leaky core or for squirting in some sealant (my first line of defence against puncture problems). I also keep a stock of these Presta - Schrader adaptors https://www.ebay.co.uk/itm/5-Piece-Brass-Presta-Valve-Schrader-Adaptor-Bicycle-Mountain-Bike-Tire-Tube-Pump/372706940175 so that I know that any pump can be used with a Presta valve while the pump on the bike is a Lezyne which has a reversible hose which fits Presta at one end and Schrader at the other.
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Presta only for me since 1976. Very pleased with them, never a failure, easy to pump in my experience and airtight on all 13 of my 15 current bikes, the exceptions being a 1938 gentleman's bike and my 1970 U-frame folder. I prefer the smaller hole in the rim and rim tape and you can choose the valve length to match your rim (important if you use aero-section rims).
I generally store a Presta-to-Schraeder adapter on my rear wheel's Presta tube valve and cap it with a Schrader valve cap in the unlikely event I need to use a pump with Schraeder-only head (in case my primary or secondary pump fail*). The o-ringed alu adapter and plastic cap keep dirt out and the whole combo weighs 1.7g, not much for peace of mind.
Might be an option if you want some of the advantages of both valves in one.
Best,
Dan.
*Pumps can fail and have for me on occasion, so I carry a spare mini-pump in my kit for emergencies. Nice when you are more than 50km away from a traveled road or highway. An old Zefal HP failed when I pumped too vigorously and dislodged the rubber ball that served as a check valve under the head. A simple repair at home with a very long screwdriver to undo the head from inside but not so handy at 3,000+m on a mountainside. Another time, I placed my old Silca frame-fit pump to one side as I was removing the rear wheel. The bike started to topple, I moved forward to steady it an stepped square on the plastic barrel, cracking it in two. Fortunately my partner had his own pump but it would have been about very bad thing if I'd been alone. My favorite backup pump is a Crank Bros PowerPump that fits in a jersey pocket or underseat tool bag. It takes about 700 strokes to fully fill a 26x2.0 tire to proper pressure but is reliable, has a high volume/high pressure switch and beats co2 cartridges for repeated use without weighing any more).
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I think it is useful to have only 1 sort. Not sure there is any great advantage in one or the other, but I feel that Presta are easier to inflate with a small pump on tour - no proof though.
As I have a preference for Presta valves I converted all the family bikes that arrived with other types (mainly Schrader, but in the past there have been one or two with the old Dunlop valves) to Presta.
I do still have a dedicated Schrader large-volume stirrup pump. This is used for the only two rolling objects I possess that still have Schrader valves - my wheelbarrow and a hand chariot for moving furniture around. I don't own a motor vehicle, but the Schrader pump does get used occasionally for visitor's motor vehicles and hire vehicles, though I generally use a fuel station compressed airline for the latter.
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I drilled out my rims for Schrader although I'd been riding with presets with adapter on the valves for a while. High pressure tyres are easier to pump at a garage or from the electric pump many cars now have instead of a spare tyre. No need to sweat with a mini pump getting 6 bar on your marathons when you have the power.
The only problems I have had with Schrader is when I ran with repair gloop in self sealing tubes which can cause the valves to leak slowly if it gets in around valve seal.j
Both systems work well in my experience. I personally prefer the convenience of the free air at garages without pfaffing with adapters. But decent quality tubes with either system should offer similar reliability.
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What’s the best pumps to get ?
I guess knowing what pressure your tyres are at is pretty important, which would invite a pump with some sort of guage/dial ? Not sure how accurate they are tho
And for those who just use non fancy pumps , I think you can get some sort of gadget to put on your valve to tell exactly what pressure your at ? Again... how accurate?
Also in Thorn literature there was a warning against using garage type pumps
Also I heard that the readings on those garage pumps (digital) are not super accurate either. Can’t remember the reason. Something about the pressure hitting your target then dropping or something
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Does anyone know if schrader leak air faster than presta? Or vice versa?
I just regular pumping of tyres could be part of a maintenance routine to make sure your tyres are always close to where you want them
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Unless there is something wrong with the valve, both should be about equal in terms of leaking. A presta valve uses a little captive screw-down nut/bobble and internal gasket to make a firm seal while a Schraeder valve uses a spring with a little internal gasket.
One caution for presta valves with removable cores: Sometimes the core can work a little loose and become a mysterious source for air loss. Easy to tighten with a small adjustable or purpose built wrench if it happens and that's usually the end of the problem.
I've found the greater source of air is the tube itself and the material it is made from. Latex tubes are lighter and some feel a difference in ride quality, but they require more frequent airing-up tham butyrate rubber.
A long time ago when I was more frequently driving a car with small wheels at racing speeds, I experienced a gradual pressure loss. In this case, the Schraeder valve core springs were weak. I replaced the cores with ones having stronger springs intended for motorcycle racing and had no leaks thereafter. I still have the specialist tool that not only included the core remover/installer but also a die for the cap threads and a tap for the core threads.
I used to use tubular (sew up) tires -- Clement Criteria Setas were my go-to -- and repairs were...tedious: Unglued the tire, pull the tape, cut the stitching without causing more punctures and hope you found the right spot. Patch, stuff, resew, reglue the tape, then spread fresh contact cement on tire and rim, wait for it to dry, then hope you got it seated straight the first time. Orders of magnitude more difficult in the rain than clinchers if you weren't carrying a spare. ::)
Best,
Dan.
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My preference is for Presta valves, and indeed on my wife's non-Thorn bike, originally fitted with Schraeders, I now have presta valved tubes in.
On narrower tyres, as on the 700 - 28 on my Audax, most decent quality tyres are Presta, and in my experience, they tend to leak less ( may be a reflection of Schwalbe quality of course) and easier to overcome initial pump resistance. My 'workshop' pump has an analogue gauge, and I keep pretty closely to pressures as in Thorn's guide, which have suited my riding and the roads I ride on well. Day rides and weekends, I just have a lightweight pump, no gauge, in case of punctures - on a 4 week tour I did a few years ago I took a cheap light gauge from Halfords, a UK motor/cycle chain store, which I reckoned was accurate enough.
Yes, I have had the Presta core come out, but I check them periodically, and newer tyres seem to have them secured??
Lewis
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Maybe I’ve just got unlucky , had poor quality pumps, or poor quality valves/tubes
How does everyone get on with them ?
The only time I've had any issue with them, or seen anyone else having one, it's been due to the pump, or it's misuse, rather than the tube, usually bending the pin. The popular mini track style pump, like the Topeak Morph series, pretty much eliminates this, there's no strain on the pin, though with those that use a screw on head you have to be sure the valve core is tight if it's a removable one. I've seen as many issues with Schrader, though that's usually also misuse, like letting them fill with muck by not using the cap. In engineering terms, they're both very simple, though using air pressure rather than a spring to keep them closed is simpler.
My favourite tubes, Schwalbe Extralight, are only available in Presta, I haven't looked at all tubes but I suspect that may be the case with many of the better ones.
I have a Presta to Schrader adapter in my touring toolkit and some of my rims also came drilled for Schrader with a grommet for Presta, and like most pumps mine can do either, plenty of options there, I haven't needed any of them.
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in the past there have been one or two with the old Dunlop valves
The last bikes I bought with Dunlop valves were c1990; they were given away to an LBS in return for future advice (in the form of letting me handle his tools so I could decide which to buy) in 2002 when I decided I could do better importing my own bikes and my electronic Smover all-automatic Trek arrived requiring complete reengineering to fit me which in return required a lot of space around it. Those two bikes, a Raleigh and a Peugeot, were instruments of torture straight out of the Inquisition anyway, but they went mainly because of the odd valve. It was the point at which I standardised on Presta, though there's still a Schrader adapter on each of my bikes just in case I (or more likely a pedalpal) require the air at the petrol station.
At first I felt that the Presta valves were a bit small-appearing on my fave 60mm Big Apples, in which like PH I prefer the Schwalbe Extraleich tubes Type 19A which come only with Presta valves, but of course I've long since become accustomed to the relative proportions.
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I look on a pressure gauge as being an option that's useful for guidance (I have this one https://www.sjscycles.co.uk/inner-tubes/schwalbe-airmax-pro-digital-pressure-gauge-for-presta-valves-only/ while the footpump I keep in the garage has an analogue gauge) and not essential. Each rider has their own preference for comfortable pressures. In my experience a tyre which is too hard means I feel every little stone in the road surfacing while if the tyre is too soft then the bike feels draggy. I do a quick pressure test before I go out on a ride: Lift each end of the bike in turn a few inches and let it drop. The wheel should bounce a little. If it doesn't bounce then more air is needed. The digital gauge tells me that my comfortable pressure is around 32 psi for 50mm tyres.
When it is time to top up I usually use the foot pump and put the pressure a bit high and then use the digital gauge to guide how much air to let out. Note that a pressure gauge on a pump is reading the pressure on the pump side of the valve. The pressure in the tube may be lower.
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I have been employed by others and myself all of my working life until retirement.
My final occupation was as a qualified ADI driving Instructor.
Prior to this (after hard work) I was a Garage Manager. The rules regarding cycle tyres and filling station pumps is this.
Do not use a filling station/garage pump on your cycle tyres. It is dangerous.
That is it. Full stop.
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Easy to tighten with a small adjustable or purpose built wrench if it happens and that's usually the end of the problem.
By accident or design, I don't know which, the lower part of a chain tool usually fits the flats on a core. I say usually, because I haven't tried them all, or all chain tools, my chain tools fit all those I've tried.
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I’ve never had any problems with pumping schrader valve bike tyres at a garage , nor ever heard of anyone else ....
But I suppose that doesn’t mean it can’t happen , and I’m willing to change my actions if it is wiser /safer . Hmm 🤔
Here’s a random internet story
“ Sonic BOOM!
I fixed the 700 x 40 tire’s sealing issue with a new rim strip. I next wanted to make 100% sure the tire would stay on the rim. I inflated it to 60 and let it sit and it was fine. No air loss and no signs of the tire creeping off the rim.
The tire had a maximum pressure of 75psi printed right on it. I know riders experiment with tire pressure and that pumps can be wildly inaccurate. So, I decided that I should test the tire at 90psi.
The instant the number “90” appeared on the pump’s digital gauge, the tire blew off the rim. The explosion was unlike any tire blowout I’ve experienced before. It didn’t knock me down, but I was rendered completely deaf and stunned, just standing there trying to regain my senses.”
Full story https://www.roadbikerider.com/overinflation-explosion-a-cautionary-tale-about-very-wide-tires/
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JohnR
I like the little bounce trick, helpful to give an idea of where the pressure is at
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I’ve never had any problems with pumping schrader valve bike tyres at a garage , nor ever heard of anyone else ....
But I suppose that doesn’t mean it can’t happen , and I’m willing to change my actions if it is wiser /safer . Hmm 🤔
Depends on the pump and how you use it, an old fashioned airline with a gauge and trigger is fine if used with care. The more modern automatic type are harder to use, they're not set to constantly monitor the pressure, instead they: add volume>pause>measure>continue. The volume between pauses is far too much for a bike tyre, it's delivered at a speed that you might not be able to regulate it and although there's a safety cut off, your tyre might have popped first.
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“ As Bikeradar is probably already aware of, the industry de facto-standard is the analog Meiser Accugage, available in different measurement ranges (0-15/30/160 psi.) Leaving the Accugage out of this test, even for reference, is pretty ignorant.”
A few other guages available
https://www.bikeradar.com/advice/buyers-guides/best-tyre-pressure-gauges/
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However you inflate, don't forget to only finger tighten the locking ring against the rim.
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What’s the best pumps to get ?
I guess knowing what pressure your tyres are at is pretty important, which would invite a pump with some sort of guage/dial ? Not sure how accurate they are tho
And for those who just use non fancy pumps , I think you can get some sort of gadget to put on your valve to tell exactly what pressure your at ? Again... how accurate?
Also in Thorn literature there was a warning against using garage type pumps
Also I heard that the readings on those garage pumps (digital) are not super accurate either. Can’t remember the reason. Something about the pressure hitting your target then dropping or something
I bought this same pump last year in Lidl that you might have in UK this week if you are still lucky
https://www.hotukdeals.com/deals/lidl-bicycle-floor-pump-ps799-3697250
It is not great for tours due to size. I have a mini telescopic pump for emergencies on commute, and a Zefal from Halfords for longer tours that is less armwork. But this floor pump is way better than my old electric compressor pump, and gets you inflated without much effort or working up a sweat. In Germany it came with 3 year guarantee. Presumable same for UK.
Adapters for presta was included.
I know there are warnings on forecourts for only use on cars. I still prefer to top up my air there as the most effortless way. It is easy to exceed the limit and blow your tube, but most are still free to use in Germany- unlike the pay to use ones I see mostly in the UK. I use with caution, with little squirts of air. On forecourts where you only set the PSI/BAR, I avoid as I am too nervous it might overinflate then be programmed to let air out to the set level- which is my experience when I do my car there.
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What’s the best pumps to get ?
The best on-bike pump I know is the Topeak Peak DX, the first full-size series, about 250mm/10in long, which I carry in its supplied clip under the water bottle. This was one of the gifts in the big box of "welcome to the family" tools and spares and accessories that came with one of my German bikes. These Germans are obsessives, who have everything tested by professional destroyers, who also certified the Topeak Peak DX. I don't know if you can still get it or if, like everything else, its successors have been cheapened, but mine worked fast enough the half dozen times I've used it. It's a pain to hold on the valve though, and if I were choosing for myself, I'd select something with a flexible tube so that the operator has more choice in his stance.
I think it is a shame that a peg for a full-size frame pump is no longer automatically fitted to quality frames. The best hand pump short of the SKS Rennkompressor I ever owned (and may still -- the trick is to find it...) was a Zefal HP, light enough, reliable as the day is long, rebuildable, a pleasure to use, available in four lengths to suit any bike with a peg in the right place. On a touring or utility bike you can still mount one with Bodge <tm> fasteners under the top tube or rack if you choose the length right, and the shortest HP fits a large bag or perhaps even a very large jersey pocket. Extra trivia point: There are also those, even in this thread, who believe the original Silica frame pump was as good as the Zefal HP.
The best garage (floor) pump I know is the SKS Rennkompressor which looks like a leftover from the Bauhaus -- because it is. It is also very easy and convenient to use and infinitely rebuildable because SKS keeps all the parts in stock; of the many heads optionally available, I like the modern one with the Presta and Schrader fitting in the same head: you push it on, you flip the lever, and you pump away. If you see an orange pump on the TdF that looks like the mechanic inherited it from his grandfather, he may well have, or the team manager may have ordered a dozen new ones last week to equip all the vans because the fancy modern trash the sponsors wanted him to use broke too often. The SKS Rennkompressor is the standard pump for decades already of serious racers whose livelihood depends on it. Lesser pumps come and go but an SKS Rennkompressor lasts forever. We have two with enough spares to keep them going half a century or so. When people I suspect of being careless with or entirely negligent of their bike preparation come to ride with me, even though I carry the Topeak Peak DX in its clip under my water bottle, I shove the Big Orange in the pannier basket for pumping up their inevitable flat tyres; it is usually faster to pump their tubes every few miles to the nearest LBS than to wait while amateurs try to patch a tyre and inevitably fail. (On those occasions I'm sometimes envious of the fellow who announced on another forum, "We give the guy with the flat two minutes to fix it, then we're gone." But the express policy of my rides into the maze of lanes is, "Everyone who leaves with us returns with us." A regular who has few flats as I, but even less patience, was once heard to mutter when I mentioned the policy to a blow-in who wanted to speed ahead, "Maybe you should change it to the policy of the US Marines: we bring all the bodies home.")
Because it is hard for me to bend over the bike for long, I also have an electric pump (Lipo, intended for car boots) but I cannot recommend it: heavy (battery included!), loud enough to hurt your ears and for the neighbours to wonder if roadworks have started outside, and slow, and with an inaccurate dial plus a cutout which makes me deeply uneasy; I use the Rennkompressor instead and gain a glow of virtue for a craftsman job. For the same money as the electric pump you can get a lovely HP, including carriage.
There's an iPhone on my bike to fix the few flats I get. I find it far less stressful to call for transport than trying to fix a flat in the rain. Mmmm, actually, punctures in Ireland are always accompanied by a hailstorm -- the rain follows only to keep you miserable when you're already sore from the hail. Since I switched over exclusively to Schwalbe's banded tyres in the Marathon family (Plus and Big Apple are both Marathons!), I've had no more than a flat every seven years or so, and in every instance traceable to something I did that I shouldn't've, like ride at 50kph through a pothole, or take a shortcut through a building site when it started raining.
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The best garage (floor) pump I know is the SKS Rennkompressor which looks like a leftover from the Bauhaus
I second this pump. It is brilliant but of course slightly costly.
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Hedge trimmings are among the bigger puncture hazards. The flail mowers used these days often scatter sharp bits of wood over the roads and, if the hedge is a thorn (nothing to do with the bike seller) hedge then the risk is even greater. If the puncture is fairly slow then I tend to add air and continue. However, 50mm tyres need a lot of pumping but then they are holding a lot of air so tend to deflate gently and are also rideable down to about 15 psi.