Newbie needing a little advice on tire/tube sizes.

[PeteLittle1970]

Good afternoon. I have very recently (during lockdown) got back into the world of cycling. However when I last cycled I was a fit young 18 yr old whereas now I'm a much less fit (and certainly less young) 51 year old. As such I bought myself an eBike. (Haibike SDURO trekking something something!) I got this in March this year (2021) and it's been great but OH BOY do I get a lot of punctures.

I normally ride on tarmac, shared use bike/pedestrian routes and bridleways. Not exactly what I would consider off road but some of my routes do tend to be more "rural" than "urban" as I commute the 13 miles from Leatherhead to South London. A friend suggested I get better tires and recommended Marathon plus puncture resistant ones and "slime" (? not sure about that last bit yet. Looks and sounds messy!)

but this gets me to the point of my conundrum. I currently have a bike with this array of numbers on the rim

42 - 622 [28 x 1.60 - 700x400)3.5-6.0 bar 50-85 psi

But I CANNOT for love nor money figure out which version I need as NONE of the figures seem to match up.

I looked here
https://www.chainreactioncycles.com/sch ... 93416?gs=1

and they have the 28 inch tires (I assume that's the 28 in my rim sizing above) but the second number is wrong. The closest I can see is a 700x38c (I assume c stands for 100? although that would then be 3800 not 380?) and the 42 -622 stuff just throws more mud into the water and confuses me even more.

I'm probably being really stupid but I can't seem to find any supplier that sells marathon tires with the 400 size or even the 42-622 measurement. There seems to be no set way on describing tire size.

[Vorpal]

Welcome to the forum.
Sheldon Brown explains everything about tyre (or tire!) sizes..

[Jdsk]

What Vorpal says.

+ express them in the ISO format, eg 42-622, and no-one will ever be confused again.

I use Marathon Plus on our tourers, largely because of the puncture resistance, but critics don't like the mass, the rolling resistance, the ride, and the difficulty of fitting them.

Discussion of slime:
viewtopic.php?p=1578003#p1578003

Jonathan

[rareposter]

42 - 622 [28 x 1.60 - 700x400)3.5-6.0 bar 50-85 psi

42 is the width in mm. General rule is that wider tyres are more comfy, can be run at lower pressures and give more grip especially on uneven terrain but they're usually slower than narrower tyres.
Most road (racer type) bike will be about 25-28mm, hybrids and CX bikes about 32-38 and e-bikes (plus a lot of the more extreme gravel bikes) will be around 42-48. Normally the tyre width is dependent on the rim width - if you have a really narrow rim, you can't fit really wide tyres.

622 is the rim size which (confusingly) is 700c. Vast majority of road, CX/gravel and hybrid / touring style bikes are 700c although as mentioned earlier, the rim width will vary - road bikes will have narrower rims than gravel bikes.

3.5 - 6.0 is the pressure in bar
50 - 85 is the pressure in psi
for that combination of tyre & rim. Narrower tyres, you'll need to run higher pressures, wider tyres you can run lower.

Next thing - what is causing the punctures? Is it a spoke poking through the rim bed or is it something cutting through the tyre? Usually, unless the tyre is very worn, a lot of punctures indicates something in the wheel rather than an issue with the tyre. Give it all a very careful check. Schwalbe Marathons are durable and tough but also known for weighing a lot and having a rather harsh ride quality...

[slowster]

The weight of Marathon Plus tyres might not matter much to you on an ebike, and likewise the higher rolling resistance might also be more acceptable. I think the rolling resistance can be improved by pumping the tyres up hard, so that there is less energy loss as a result of the flexing of the thick puncture protection strip, but you will sacrifice some comfort in doing that (probably more so for riding off-road).

The video below features 531colin of this forum showing how to fit the tyres. Note that the demonstration uses an ordinary (non-tubeless) rim. If your bike has tubeless rims, there may only be a relatively narrow and shallow well in the centre of the rim compared with the shelf and well of the rim in the video. If so, that makes it even more essential to follow his advice in the video to get the tyre beads into that well and keep them there.

[thirdcrank]

If you deal with a puncture, either by patching the tube or replacing it, it's vital to establish the cause or it will almost inevitably lead to another .... and another. On modern roads, especially in urban areas it's very easy to pick up a tiny shard of glass which will puncture an inflated tyre but is hard to spot. Search right to the bottom of every cut in the tyre and check the inside too.

[CliveyT]

Search right to the bottom of every cut in the tyre and check the inside too.

But do it carefully- don't just run your finger around the inside of the tyre and hope because if it is a piece of glass that can end up very messily. If you can line up your tyre and inner tube so the hole in the inner tube should be where the offending item is. ( I always line the start of the manufacturers logo with the valve hole so even if things have moved it's easy to line them all back up again)

[ChrisF]

↑ this is the most important thing. If you're getting punctures in both tyres, maybe both have glass embedded.
Another reason my be your tyres arren't pumped up enough and you're getting 'snakebite' holes when the tyre hits a hard stone. If, when you find the puncture, you see two holes next to each other, this is the reason.

[simonhill]

No need to go all the way to M+.

The Marathon Original Greenguard are one of their most puncture proof tyres. Much cheaper and probably better rolling. These are often used by commuters and tourers. Personally, I'm not a fan but have used them on tours where I fear the quality of the roads. (I normally use a much more delicate tyre, the Supreme.)

I think the Greenguards would suit your ebike and your use very well. https://www.spacycles.co.uk/m14b0s142p3 ... uard-HS420

Re sizes, etc all pretty much explained above. The only other variable is the valve type for the (inner) tube. There are 2 sorts (well pretty much so in the UK), presta and schrader (car type). Fit whatever you already have.

EDIT
If you have the basic model of your bike (Trekking 1.0) then it is listed as having these tyres "Schwalbe Road Cruiser 42-622 Valves: Presta valve"
Schwalbe rate 'protection" ie puncture proof of these as 3 out of 7. The Originals are 5 and M+ are 7.

[Darkman]

Search right to the bottom of every cut in the tyre and check the inside too.

But do it carefully- don't just run your finger around the inside of the tyre and hope because if it is a piece of glass that can end up very messily.

I'd add to that; instead of using your finger, use a screwed up bit of kitchen roll or toilet paper - if there's anything even slightly protruding, it will snag on it rather than slicing your finger-end open.

[De Sisti]

What Vorpal says.

+ express them in the ISO format, eg 42-622, and no-one will ever be confused again.

Jonathan

In my case I would disagree. 42-622 doesn't mean anything to me.

[Jdsk]

+ express them in the ISO format, eg 42-622, and no-one will ever be confused again.

In my case I would disagree. 42-622 doesn't mean anything to me.

I'd draw a distinction between not understanding and being confused.

This confusion is a very common topic in this forum. Moving to the ISO format is by far the best way out of the mess. It will require mapping old to new for some people with some tyres, but the same or worse is true for all other approaches.

Jonathan

[PH]

Sorry if it's stating the obvious, but two of the easiest way's to pick up a lot of punctures are:
Riding in the gutter where all the debris gets swept by the motor traffic
Not having the tyres inflated enough causing the tube to be pinched between tyre and rim

There's plenty of other possibilities of course, worn tyres, rubbish tyres, some fault on the rim, something stuck in the tyre, bad patch... but the two above have been the major cause of frequent punctures for riders I've known.

I ride a lot of urban, at least 100 miles a week and about the same again less urban. I have different tyres on different bikes, all Schwalbe - Supreme, Almotion and an older version of Marathon - I had three punctures last year in 9,700 miles and have had two this year in 5,300.

[PH]

But do it carefully- don't just run your finger around the inside of the tyre and hope because if it is a piece of glass that can end up very messily.

I learnt that the hard way and have the scar to prove it! It now makes me wince whenever I see someone do it, though they don't always appreciate the advice...

[mattsccm]

Best way. That way you are more likely to find it. An injury isn't going to be life threatening.