Rims & tyres - again !

103Alex1

Esteemed Pedelecer
Sep 29, 2012
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Been humming and hawing (for a change :rolleyes:) over tyres and tubes for the Trek conversion (26" MTB).

First - inner tubes

Going to be riding around areas where lane hedges regularly trimmed by the Council leaving blackthorn, hawthorn debris etc. all over the paths which take days to wash away so puncture protection is very important.

Rear eBike rim has a schrader valve hole and I've bought a Protek Max self-healing inner tube for it. So all good.

Front rim is a Bontracer race rim with a Presta valve hole and is tubeless-ready. It has a VERY tight-fitting rubber sealing ring which you have to lever out with a screwdriver to even access the spoke holes. I've broken 3 Presta valves taking tyres off these rims (especially 2.1-2.4 knobbly ones which can be very tight) ... the valves are just too long and fragile to get out of the tyre without the tip breaking off. So ... reluctant to use expensive tubes with those vales on. Longer term it makes sense to change to schrader.

Options are to get a new rim with Schrader hole and build a new front wheel that's easier to work with or to make the existing hole bigger. The rubber sealing ring inside the rim has a moulded rubber section over the Presta hole so not sure how sensible it is to try to make the valve hole bigger :confused:

If I were to convert the front hub to accept Schrader I presume I'd have to drill a bigger hole through the rubber sealing ring and also the metal rim. Any advice on doing this ? I now have a Black & Decker power drill so should be able to use it if I know the right drill bits.

Second - Tyres

I'd like to be able to take this bike off-road as well as riding it on road/gravel and on pretty poorly surfaced tarmac lanes. It's a much more versatile bike for exploring than the Agattu is. Puncture protection is very important and ability to deal with potholes / grip on wet ground also very important.

Have used Marathon Plus Tour tyres on my other bike and they have been great but not subjected it to the sort of conditions I'm planning for this one. These tyres don't seem to come in any versions that are 'hardier' off road for grip on wet ground, mud, rocky paths etc. (which is a real shame).

Guess what I'm looking for is Marathon Plus-type protection on grippier tyres for the off-road use, without these being so knobbly that they're not sensible when I'm riding on road / paved lanes. Regular tyre changes can be a drag (although I've had 3 different sets on my Agattu since October but that was for changing stock tyres to MPs and then to Conti Winters not on account of punctures - both were hard and time-consuming to fit).

The choice of MTB tyres is bewildering and there's no clear "front runner" like there is for MPs. Can anyone with more experience of MTB tyres help me settle on the best compromise ? There are some cracking sales on right now for a few more days so be good to try to take advantage.

Thx. :cool:
 
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GaRRy

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May 18, 2012
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Tamworth

103Alex1

Esteemed Pedelecer
Sep 29, 2012
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Actually ... just some more thoughts .... these come in a 26x1.75 and a 26x2.1 ...

Apart from the weight differential are the 2.1s usually significantly better off-road and significantly worse on-road than the 1.75s ? Bike has 80mm suspension front forks with lockout if that makes any difference. I always think I need to put the same tyres on the front as the back but doesn't have to be that way if there's an advantage to mixing them. Some off-road forum info seems to have people putting a wider tyre on the front.

I currently have Jones AC-X knobblies fitted on the bike (2.2s) which came on the Bontrager rims and they are clearly off-road tyres. Figuring if these could fit (albeit a heck of a job !!!!) the MP MTB 2.1s should fit also ?

The eBike rim is from BMS and was labelled Zhenmeng 26x1.5 before I peeled the label off (the rim actually looks pretty good !). Haven't tried to fit the Jones tyres on it for size yet as it's such a job to get them on and off - but has anyone tried fitting 2.1s to BMS rims ?

Also, do knobblies wear out really fast on tar ? The tyres on the bike when I picked it up 2nd hand were pretty worn down and claimed to have only been used for a year so got me thinking .....
 
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RobF

Esteemed Pedelecer
Sep 22, 2012
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The wider the tyre, the less likely it is to puncture.

Marathon Pluses are hard wearing, so unless you are doing thousands of miles a year on asphalt, there's not much point in worrying about it.

But don't be tempted to run at too high pressure, mountain bike tyres don't like it and it can lead to cracks in the sidewalls.
 

flecc

Member
Oct 25, 2006
53,342
30,694
The off-road Marathon Plus you've looked at above are very knobbly, but there is also the Tour version for combined asphalt and off-road use which will roll more freely:

Marathon Plus Tour
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
2,228
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The wider the tyre, the less likely it is to puncture.

Marathon Pluses are hard wearing, so unless you are doing thousands of miles a year on asphalt, there's not much point in worrying about it.

But don't be tempted to run at too high pressure, mountain bike tyres don't like it and it can lead to cracks in the sidewalls.
Very interesting about the tyre pressure - never knew that. The Jones tyres look cracked on the sidewalls (although not punctured) so maybe that's the reason !

Are there any other advantages to wider tyres than puncture resistance ?

The off-road Marathon Plus you've looked at above are very knobbly, but there is also the Tour version for combined asphalt and off-road use which will roll more freely:

Marathon Plus Tour
That's what I put on my Agattu for non-Winter use but didn't think of them as suitable for anything but the lightest of off-road use in drier ground conditions... they grip tarmac in the wet well (but not superbly) but can see them slipping all over the place on soft muddy ground for example.

Any more thoughts on drilling the rim ?
 

RobF

Esteemed Pedelecer
Sep 22, 2012
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Another point to bear in mind is a bicycle cannot aquaplane.

Thus on a hard unbroken surface, the best grip is from a slick, even in the wet.

The tread on the Marathon Pluses - or any bike tyre - marginally reduces wet grip, but what it does do on something like a Plus Tour is provide grip on hard packed surface with some loose stuff on the top, such as cinder tracks.
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
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So the "knobbles" on knobblies are for dry loose ground and soft ground mainly ? Are any tyres suitable for wet sand or is that just asking for trouble :)
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
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Yes.. the ones on the rear of a tractor :p
.... and funnily enough there is a unique sea tractor just down the road ...

Burgh island sea tractor. Best photos and information of modification.

But that's mainly for when the tide is in and the well-heeled guests of the hotel on the island don't want to get their tootsies wet :) !! :p

Be good to be able to ride across to the pub on the other side - that way I can keep an eye on my bike (and the water level) when I'm "taking refreshments"
 
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RobF

Esteemed Pedelecer
Sep 22, 2012
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I must remember that, next time it happens.

It might skid in any circumstances, but it can not aquaplane.

The tyres - whatever the tread - are way too narrow to build up the necessary bow wave of water.

And in any event, not even Bradley Wiggins could cycle fast enough.
 

103Alex1

Esteemed Pedelecer
Sep 29, 2012
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If I were to convert the front hub to accept Schrader I presume I'd have to drill a bigger hole through the rubber sealing ring and also the metal rim. Any advice on doing this ? I now have a Black & Decker power drill so should be able to use it if I know the right drill bits.
No worries I have found the answer .... according to Sheldon Brown, to enlarge a Presta valve hole to accept schrader valves I need to use a 21/64" drill bit.
 

SRS

Esteemed Pedelecer
Nov 30, 2012
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South Coast
The off-road Marathon Plus you've looked at above are very knobbly, but there is also the Tour version for combined asphalt and off-road use which will roll more freely:

Marathon Plus Tour
flecc, thanks. Did not know that these existed. A compromise on design that I had been searching for.

Just ordered a couple from Evans, hopefully they will perform well both on road and dry trails.