2021 Brompton C-Line Explore

[wafter]

Thanks both - appreciate the feedback

If it comes to it I'll consider Marathons but I'm not keen so would rather change my riding habits to address the situation if possible..

Checking the inevitable spreadsheet suggests that of six, five punctures have been on the tow path with one slow puncture indeterminate (I think a thorn so likely picked up on the tow path too). Four of the five definitely occurring on the tow path happened on the east Oxford leg.

I didn't get any in the 2.5 months / 650 miles from starting to ride at the end of June to the middle of September, then it's two in Sep, one in Oct, two in Nov, none in Dec (by this point I'd started avoiding the tow path and going through town) and two in Jan so far; again on the tow path with the bike at around 1400 miles..

So, the most common factors here are winter and the eastern bit of the tow path.. the most appropriate course of action seems to be to avoid this most hazardous section during the winter months, which I'll start doing from next week and see how it goes - shame as it's a pleasant ride


When I lived in Oxford I'd ridden many other bikes on this stretch of tow path with no issues, however probably not for so much cumulative distance or so much in winter as I have on the Brompton. By comparison my road bike has never seen a puncture in in 1800 miles, the tourer only one in in 1500 miles (which was entirely my fault, so not applicable) and the gravel bike about 11 in 4500 miles - again nearly if not all of these coming from off-road excursions where there were a lot more hazards.

 

[Tenkaykev]

The 2Bikes4adventure people have some really useful information.

View: https://www.youtube.com/watch?v=p1i1W6xy8hM&t=641s

 

[wafter]

The 2Bikes4adventure people have some really useful information.

View: https://www.youtube.com/watch?v=p1i1W6xy8hM&t=641s

Thanks

Watched that some time ago; a very informative vid and gives a great, factually-driven overview of what's available but inevitably gives no magic solutions to the problem as inevitably advantages in some areas of tyre performance bring drawbacks in others..

 

[T4tomo]

When I replaced the M+ I have done so with the standard Marathon. not had them long enough to check their puncture resilience, but been running them since I swapped them out in around October last year. I think they're just one rating down from the M+ in Schwalbe's puncture resilience ranking.

I ran the regular marathons on mine and was P free (I had a couple of the standard Brompton tyre that it came with in 2005 so switched to M's when they wore out and stuck to them ever since) ....But I I was just on the mean streets of London & Herts. I think tow paths probably need the M+ hence my earlier post, although @wafter could try regular marathons, they run much better than the M+'s - are they a step up in protection from his marathon racers, or are racers the new "standard" marathon anyway?

 

[wafter]

I ran the regular marathons on mine and was P free (I had a couple of the standard Brompton tyre that it came with in 2005 so switched to M's when they wore out and stuck to them ever since) ....But I I was just on the mean streets of London & Herts. I think tow paths probably need the M+ hence my earlier post, although @wafter could try regular marathons, they run much better than the M+'s - are they a step up in protection from his marathon racers, or are racers the new "standard" marathon anyway?

Thanks. It seems the standard Ms have a thickish synthetic protection strip under the tread, while the M+ has a fatter version of the same. By comparison the racers are essentially "M light" with no thick strip and instead a layer of tougher woven fibres under the tread.. so they give better compliance and rolling resistance at the cost of protection.

I watched a test / review (might have been in the video posted by @Tenkaykev above) showing the load / displacement behaviour of piercing each of these with a small pointy thing (a needle, nail or similar). The Racers initially resist a greater load before pierced, but once that happens it's basically straight through and into the tube.. while those with the protection strip take less peak force to puncture but can suffer much deeper penetraction before a puncture occurs.

While it's generally accepted that the in terms of puncture resistance M+ is better than M which is better than M Racer, I think in some circumstances (such as hitting a thorn or drawing pin than's longer than the M+'s protection layer) you're going to get a puncture regardless. However, they should be a lot more resistive to shorter objects and I think they'd have given a better chance against the fat bit of flint that did for me yesterday..

 

[T4tomo]

However, they should be a lot more resistive to shorter objects and I think they'd have given a better chance against the fat bit of flint that did for me yesterday..

absolutely, and regular inspection and picking out of bits of flint and glass stops them working thru. Its rare a piece of flint instantly punctures, although that one you pictured may well have holed the Titanic.

 

[wafter]

absolutely, and regular inspection and picking out of bits of flint and glass stops them working thru. Its rare a piece of flint instantly punctures, although that one you pictured may well have holed the Titanic.

Indeed - I suspect an M+ or similar would at least have given me a bit more time with the flint. As it stands I doubt the tyre could have withstood many revs with that flint sticking in it - must have gone in to a fair depth as soon as it was picked up in order to stick in the tyre.

I guess this is potentially another danage of riding over loose or uneven stuff (be it gravel, twigs, leaf debris etc) - in that it potentially allows sharp objects like this to sit in an orientation that presents the point upwards, rather than laying flat as it would if you just chucked it on flat ground.

So shocked was I by the little mountain sticking out of my tyre I've kept it for posterity!

 

[Kell]

absolutely, and regular inspection and picking out of bits of flint and glass stops them working thru. Its rare a piece of flint instantly punctures, although that one you pictured may well have holed the Titanic.

I'd absolutely dispute that.

After getting a road bike for the first time in 30 years (since they used to be called Racers) I went out for a ride. I was searching for routes and came across the route maps for an event near me called the Bucks Bumps.

I was intrigued mostly as the start/end point was at my daughter's school which was on our road.

Anyway, there were three routes and I planned on doing the middle one. 54 miles and a lot of climbing.

Not even 10 miles in I had my first puncture. Flint.

2 miles more. Another one. Flint. Different bit.

The thing to point out is that the style of housing in Bucks is brick and flint. So it's everywhere.

These were both tube out and replace punctures for me. Couldn't be bothered with repairing, but I kept the tubes to repair at home.

Then I somehow managed to get a piece of branch go straight through my tyre and tube - making that tube unrepairable anyway. Repaired one of the previously punctured ones. Repaired that, then hit a huge brick on a country lane at about 35mph. Didn't come off, but ruined the second spare tube. Had no more glue. The roads were soaked. I was knackered and pissed off.

Bailed after only doing 34 miles.


View: https://youtu.be/ljnUINbUVMA?si=HW1xic0JcIOgFYIl

 

[wafter]

Today!

Cold but dry ride in already covered in the commute thread so I'll not duplicate it here.

Once at work noted that last week's substantial flint-wound in the tyre had evidently propagated; giving cause for concern.

Ride home was colder and had snow content, but I arrived back at the car with a small measure of satisfaction having overcome the adversity, and had a nice chilled drive back.

Frustrated upon my arrival "home" as the boot latch had evidently failed on the car; forcing me to crawl inside, drop the seats and drag out the contents of the boot (including the bike) through the passenger compartment.. another job for the weekend; then..

Once back flipped the bike, scrubbed the area of flint damage on the front tyre with alcohol and a toothbrush and allowed it to dry. The tyre was then depressurised and a decent blob of superglue bled into the damage before the tyre was compressed radially to force the gash shut and squeeze out the excess glue, which was mopped up.

Left for 30 mins then had 30psi stuffed up it with no ill effects... will probably leave it until the morning to fully harden and bang it up to maybe 60psi. I'm not hugely optimistic, since while cynoacrylate sticks to rubber like sh*t to a blanket it's also stiff and brittle while tyres aren't. So, while it might hold in the interim, I suspect it'll be less enthusiastic after 12000 cycles on the way to work tomorrow.

Will see how it goes - worst case I'll have to write the tyre off after 1400 miles if the bond fails and the split continues to propagate..at least I tried.

 

[ColinJ]

Left for 30 mins then had 30psi stuffed up it with no ill effects... will probably leave it until the morning to fully harden and bang it up to maybe 60psi. I'm not hugely optimistic, since while cynoacrylate sticks to rubber like sh*t to a blanket it's also stiff and brittle while tyres aren't. So, while it might hold in the interim, I suspect it'll be less enthusiastic after 12000 cycles on the way to work tomorrow.

Will see how it goes - worst case I'll have to write the tyre off after 1400 miles if the bond fails and the split continues to propagate..at least I tried.

Take it easy on that repair...!

My tip is - don't superglue significant tyre cuts!

I used superglue when I discovered a cut in my new front tyre just before taking my bike to Spain. I rode the bike for a few days - no problem. Did the big mountain day, including 50 mph descents round tight bends with no barriers and big drop offs from them - no problem. Next morning, before we set off on the day's ride someone pointed at my front wheel. The tyre cut had ripped open and the inner tube was bulging through the hole! (Ex top pro Robert Millar was at the hotel testing bikes and he lent me a front wheel until I could get hold of a new tyre! )

 

[wafter]

Take it easy on that repair...!

Thanks - I suspect the little b*stard won't see the sort of use your tyre did (I only hit more than 20 when I'm trying to bait road-cyclists on the commute ), but I'm well aware that it could easily fail.. After it happened I did patch the tyre from the inside; which should at least prevent the tube violently prolapsing through the tyre if it splits.

The split is along the tyre and right in the middle of the tread so deformation during riding should probably act to push it closed.. however obviously the internal pressure wants to pop it open and I suspect this will probably be its downfall.

So far the split has been relatively slow to propagate.. but I'll definitely be keeping an eye on it.

Thankfully I did manage to pick up a pair of spare Racers for a good price recently; but being super-tight (in both financial and environmental contexts) I'd rather run this one until it's thread-bare if I can!

 

[wafter]

The cut in the tyre looked good this morning and held in the face of inflation to 65psi, however had opened up again by the time I'd got to work 7.5 miles later. Were it in the sidewall I'd have a go at stitching it up, but being right in the middle of the tread it doesn't seem like there's a lot of point.. I guess I'll just have to keep an eye on it and bin it once failure anxiety becomes too much, unless anyone has any other suggestions..?


In more positive news I've been playing "how low can you go" with the tyre pressures; had a situation where the rear felt like it was squirming about somewhat oddly given its pressure was pretty high at 100psi - the issue has largely disappeared now that I've upped the pressure in the front to 65psi.

Mass distribution of the bike is about 33/66% front/rear and I'd considered this a starting point for ascertaining tyre pressures; however evidently this doesn't take into account dynamic loads (such as pedalling and braking) and probably some other stuff I don't understand.

Looking like 65-70psi is optimum for the front, with circa. 100psi in the rear.

 

[Gunk]

Save a search on ebay for replacement tyres, they sometimes pop up for next to nothing. Better than bodging a repair.

 

[wafter]

Save a search on ebay for replacement tyres, they sometimes pop up for next to nothing. Better than bodging a repair.

Thanks - I did just that a while ago and recently scored a couple of new Racers for less than you'd typically pay for a one

Would still rather not waste the one that's on there if I can help it, mind. Will keep an eye on the split and have a go at filling it at the weekend if it's still alive at that point..

 

[wafter]

Little to report... I had another go at repairing the cut in the front tyre at the weekend by filling it with a mixture of rubber powder and vulcanising solution. This seems to have survived the commute in this morning, but time will tell how resileant it is / whether it'll stop the cut from continuing to slowly propagate.

The front tyre continues to leak slowly thanks to its swiss-cheesed tube; I should really take a look / replace it but I'm holding off to see how the tyre repair goes.

The chain got waxed again after only 100 miles or so after getting wet on the first ride out after the last wax, and increasingly squeaking as a result.. as always it's buttery smooth now though - I hope the wet holds off!