mitchibob
Über Member
- Location
- Treorchy, Wales
Seems that for 10 quid, you just get and post us a review. Only concerns would be more landfill.
Zefal vs Lezyne pump
- Thread starter ExBrit
- Start date
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Seems that for 10 quid, you just get and post us a review. Only concerns would be more landfill.
Fastpedaller
Senior Member
I bought one last week - Better than their previous £10 steel pump (which is good anyway). The new chuck is better, having an 'unscrew and reverse' rather than the 'automatic double end'. IMHO well worth the £10 and I'm confident it won't fall apart like the plastic ones. The only issue I found is the gauge (I never rely on a pump gauge anyway) reads about 10PSI above both my electronic gauge and old-style pencil gauge.
berlinonaut
Veteran
- Location
- Berlin Germany
Possibly use the search function of the forum or at least post pictures or specs of the pump in question.
In this thread you find a discussion about a track pump that was avail. at Lidl and it's up- and downsides:
https://www.cyclechat.net/threads/r...-pump-for-brompton.278808/page-2#post-6792170 As the linked thread is named "Recommendations for floor pump for Brompton" while this one here is named "Zefal vs Lezyne pump" your question would even be on-topic there.
Kell
Veteran
- Location
- High Wycombe/London
Well, I had to use mine this morning as I got a puncture in the front.
the little tread that folds out was useful - as is the handle that folds out to give a little more purchase.
the little tread that folds out was useful - as is the handle that folds out to give a little more purchase.
Profpointy
Legendary Member
More likely he's got narrowwr tyres. On 25mm or whatever tyres you're going to want well over 100psi plus. On a more mountain bike or hybrid width wheel it's going to be more like the 70psi you mention.
berlinonaut
Veteran
- Location
- Berlin Germany
As visible in the thread they are both using the same tire on a Brompton and are talking about this tire: Conti Contact Urban in ETRO349, nominal width 35mm. No reason to speculate. How do you come to the idea "narrow tires" would be involved?
Profpointy
Legendary Member
Didn't spot the brompton reference.
mitchibob
Über Member
- Location
- Treorchy, Wales
No, I'm talking about road bike, hunt carbon aero rims with 28mm tyres, run tubeless. They advise max of 90psi for 105kg rider. 70psi is perfect for me. 100psi is really a thing of the past on road with most recent research into rolling resistance, etc. 100psi+ is for indoor velodrome boards. On a brompton, even with the fastest tyres, pumping them up over 100psi, on a rough road surface, they'll roll worse, and give you a less comfortable ride.
Even World Tour Pro teams aren't running those sort of pressures in road races (especially the likes of Paris Roubaix).
I'll caveat with the fact that the likes of Marathons on Brommie have smaller window between rolling nicely and rolling like treacle when pressure too low. Kojaks probably need boards to make them really fast, otherwise, at high pressure, they can be as bad as any of them. The schwalbe ones, seem to have a sweet spot I didn't find, yet. The Contis, just seem to roll well over a reasonable range of pressures.
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berlinonaut
Veteran
- Location
- Berlin Germany
This is in my eyes oversimplification and possibly misunderstanding to the point where the conclusions get clearly wrong.
A wider tire has - at the same pressure - better rolling resistance than a slick tire but the aerodynamics are worse. At the same time high pressure causes a lower rolling resistance as a low pressure. And then a small tire has bigger rolling resistance than a big tire but better aerodynamics.
Aerodynamics come into play massively more and more above 25 kph. A too high pressure causes on a not totally flat ground a lower adaptivity to the tiny obstacles on the road and thus makes you slower. This all together is why Alex Moulton went for high pressure small tires on a suspended bike frame and won - in the sixties. So this not at all new.
But: A wider tire is heavier, a typical slick tire has thin sidewalls and thus needs high pressure for stability, with low pressure it rolls catastrophically. This is the case with the Kojak in ETRO 349 - rolls best at 7+ bars, at i.e. 4 bars it is a total dog. In i.e. ETRO 507 it runs happily and comfy with 3,5 bars.
A wider tire can typically not stand very high pressures well.
Traditionall racing bikes had tires of 23-25mm width running at very high pressures. Today, somewhat wider tires are used but those still are only like 28mm wide. And they are running on high pressure, just not as very high as before. On a Brompton the slickest tires are 32mm (Kojak) and 28mm (Strozzapreti). The widest one is the Scorcher at 40mm. And indeed: The Scorcher runs fast (and very comfy) at only 4,5 bars. On bigger wheels, i.e. a 55mm Big Apple in ETRO 406 runs happily at 3-4 bars and will hop like a mad bunny if you pump it too massively. A Marathon+ in 700cc/ETRO 622 will run faster at 6 bars than at lower pressure - just that it is very uncomfy.
You should not ignore that all the research that has been done has been done on 700cc tires, leaving out the specialities of smaller wheels. The Kojak used to be the fastest tire on the Brompton - but in bigger wheel sizes it was considered to be a slow tire. How that? For one the specialities of the smaller wheels and second there were simply more (and faster) tires available in those sizes than in ETRO349.
The Conti Urban seems to outperform the Kojak on the Brompton: As fast or faster, more puncture resistant and, being wider, needing less pressure. But still: depending from the surface more pressure will make it faster.
What the racing guys recently realized and sell as hot shoot is basically what Alex Moulton knew and used 65 years ago and what every maker of tires knows (as well as the handful of people that dived seriously into the field of rolling resistance on bike wheels). Now they claim to have invented it (which is total bullshit as others had talked about that for decades already) and other others repeat that message even more shortened, generalized and oversimplified until it gets simply factually wrong.
I.e. Schwalbe have a pretty well thought and illustrated article on the topic on their webpage for ages already:
https://www.schwalbe.com/technik-faq/rollwiderstand/
The one thing that is new: Progess in materials opened possibilties that were not there before. Wider wheels have become trendy. With disc brakes they are easier to use on race bikes. The rim industry is happy for their carbon wheels not having to withstand the high pressures. And the manufacturers are happy to sell new bikes to the victims following the trend, believing that they have to have it.
Your claim is really a massive oversimplifaction in a very complex area.
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mitchibob
Über Member
- Location
- Treorchy, Wales
Thanks for detailed answer. Definitely I oversimplified based on personal experience more than anything. Although, I do have some power data to compare efforts vs tyre set up as well, although, too lazy to switch tyres and stuff on the same day to compare in identical conditions. Plus, where I live, identical conditions don't necessarily last long.
I was certainly old-school, putting as much pressure into tyres as they could bare for a long while. Used to use 22mm tyres on a tandem many years ago, pumped to their limit. Didn't have power meters and bike computers in those days, but we thought they were cool and fast. After many years without riding, but renting Brommie, after the marathons lost a little pressure, felt like riding through treacle, so used track pump at work to get back to 100psi. Pretty much used that with most tyres I'd tried on my own brommies, for years, even with the sluggish rough road, energy sapping, descents.
But after switching to tubeless on road bike during lockdown, started to enjoy lower pressures for speed, grip and comfort, and realised, brommie conties run pretty well at those pressures too. And when you think about it, surely with smaller wheel, you'd want slightly lower pressure than you'd want with equivalent 700c with clinchers (when the hell did that word become a thing?) to take the bumps in the road better?
Aero hardly comes into it on brommie unless you get aero rims, and still, come on... it's the scary TT bars that I'm not even going to try with my brommie, unless I can get a couple laps at Maindy, to get any slight chance of me being aero (will make excuse that they don't quite fit anyway... I didn't try... just guessing.. don't want to try... scare me occasionally on road bike ... even with free watts ... see what happened to Chris Froome and Egan Bernal?).
Wider tyres are not necessarily less aero, depending on the width of the rim they're attached to, and the aero-ness of the rim. Aero rims are getting wider. Let's face, it's the rider not the tyres/rims that make biggest aero impact, and having fast rolling, wider, more comfortable, controllable tyres/rims seems to be becoming more the norm. At some point, world tour will be running the same size tyres us brommie riders have been running all along, and trying to do skinny tyres for a brommie without there being a track series was just a mistake.
I guess, making a tyre that can take a large amount of pressure is important, but running it at that pressure isn't the point. Certainly, I want the margin of error. Hookless rims suggest much lower maximums that we used to try and stuff into the tyres of borrow bikes at HHV in late eighties. But those Geoffrey Butler track bikes must've had 30mm at least tyres on them, not slick at all (HHV surface wasn't brilliant then), but damn, they felt so fast.
My over-simplification is, those contis don't half roll well for brommie at variety of pressures and I'm not going to jinx myself anymore than that!
Also, in simple tests, with power meter, didn't get much different with tubolitos vs butyl, but tubolitos are more of a pain to get pump off (also don't really colour match the bike), but WAY smaller/lighter as a spare. Didn't help me in last year's UHC, but that was down to lack of appropriate training.
berlinonaut
Veteran
- Location
- Berlin Germany
In theory what you'd want is a pantour hub. In practice, they were not totally convincing and went out of business a long time ago. They have been available for the Brommi - you can find an archived version of their website here.
mitchibob
Über Member
- Location
- Treorchy, Wales
Maybe, but surely there's a weight penalty on the climbs. Think this hub is solving a problem that can be fixed with appropriate tyre pressures for the rider.