For TPU inner bicycle tires, I found out a little over few months ago.
It happened entirely by chance - I read about TPU tires from a comment by Ivan - a fellow cyclist, under a post in one of the cycling groups on Facebook.
I had just received my new set of Continental GP 5000 tires, and the post on Facebook was precisely about a topic that is extremely important for every cyclist - tires. :)
The colleague had posted a picture of two tiny, thin, green inner tubes and explained that he had recently gotten them and hadn't even tested them yet.
Later, another fellow cyclist, Dimitar, strongly recommended these new TPU tires to me in the Facebook chat. He said he had been using them for a year and a half:
https://www.youtube.com/watch?v=o7FX9PsJD9s
- I'm very satisfied with the lightweight inner tubes. Mine are pink, and I've been using them for a year and a half.
- Only one overheated and burst tire due to carbon rims ... but I'm all FOR the inner tubes! :)
- And all three of my bicycles have those tires + 4 spare ones
- Another thing I can share from my experience with these inner tubes is that it's good to add some additional tape on top of the rim tape. My carbon wheels had no issues, but with the aluminum ones on a disc, both tires got punctured near the spokes - one in four places from the spokes. They were very thin punctures that couldn't be felt without testing them in water, but the tires lost pressure.
In the meantime, with Mitko Velchev on Telegram, we started wondering about these new TPU tires... Should we take the risk??? :) ;) :)
- Look, look, one tire weighs 38g, only positive comments - I wrote to Mitaka on Telegram
- Will you order from them? Will they do the job? I'm also wondering. Maybe we can go for the option with 4 pieces; it's more cost-effective?
- Well... they look OK, a colleague from FB recommended them to me and sent a link. I see the comments are good. :)
- Honestly, I'm considering... I think they're perfect for the 1 or 2 spare tires on a long brevet
- Yes, I saw it. Let's wait for him to test them? :)
- I'll take 4 of those tested pink ones in the next few days; think about whether you want them too: https://a.aliexpress.com/_mLvx8C6
- 2 mounted + 2 as spare for long brevets
- Those valves are quite long. :)
- They're perfect when you get carbon rims soon... you can cut the valves with a saw... :) ;) :)
Actually, Dimitar's recommendation from the chat on FB was the last drop in the cup! ... :)
While we were chatting on Telegram with Mitaka about the new TPU tires from AliExpress, we decided to invest in a few of these strange new small and lightweight pink and green TPU tires for testing...
As agreed! :)
I bought 4 pink ones because they were on promotion, together with a patch kit, and Mitko ordered two of the green ones with metal valves.
I specifically ordered 4 pieces and a patch kit for 66 BGN from AliExpress - for almost the same amount, you can order TPU tires from the online store on the Blog here: TPU гуми...
(Immediately after testing the TPU tires, I realized that soon every cyclist will have at least a few of them, both as spare inner tubes in their tool kit and mounted on their bike rims. Consequently, I ordered several hundred TPU tires from China for the online store on the Blog.)
After about 2 weeks, give or take a few days, my 4 tires and Mitko's 2 tires arrived.
We mounted them almost immediately and started active testing.
The small but significant difference in the tests was that in the meantime, by the time I am writing this review, Mitko has ridden over 2500 km with his TPU tires, while for one reason or another, I lagged far behind with almost half the mileage.
The first SERIOUS test of the TPU tires was on the route of the gravel brevet Super Randonnee Mystical Strandja: 600 km with 10,000m elevation gain on almost all the trails in the beautiful Strandja Mountains.
Result: PERFECT impressions and absolutely no problems, and keep in mind that a significant part of the brevet passes through the rough trails in the Strandja Mountains, which are in quite an extreme condition.
After that, Mitaka rode with the tires in the Varna 300 brevet, Isperih 400, and maybe one or two "smaller" brevets of around 200 km... :)
In the meantime, I tested the tires on the roads around me, mainly on the Devetashka Plateau.
In the area of the plateau, there are some quite extreme sections, but for about 500-750 km for both me and Mitko, there were absolutely no problems with the TPU inner tubes.
No punctures or any other defects.
What I noticed for sure is that since I installed the TPU inner tubes, Pip became somehow faster, in contrast to the Continental GP 5000 outer tires I had put on about a month earlier!
There are numerous detailed tests and comparisons specifically showing how the inner tube affects the rolling resistance of the outer tire depending on the surface.
I have always thought, when I came across such information, that these were some marketing nonsense...
How does the inner tube affect the resistance of the outer tire??? ...
BUT YES, it turns out that the TPU inner tube definitely has an impact!
You can read about how and to what extent the inner tube affects resistance to the road in the article here: TPU Inner Tubes Compared to Butyl, Light Butyl, and Latex
Personally, my feeling is that when inflated to 100 psi, my Conti GP 5000 tires with 35g TPU inner tubes became faster.
As I mentioned earlier in this review, almost immediately after testing the TPU tires, I realized that every cyclist will soon have at least a few of these tires as spare inner tubes in their tool bag and also mounted on their bike's rims.
I did extensive research on the topic and connected with wholesale TPU tire traders on Alibaba and ordered several hundred units from China for the online store associated with the blog.
The first batch of TPU tires arrived the other day!
Hooray!!!
Despite the 20% VAT charged by customs in our country + the expensive (but fast) DHL delivery and some minimal markup, I still managed to get a very reasonable heavily discounted price for 1 unit of TPU tire for the blog's store.
I specifically received and tested the pink TPU tires weighing 35g with a black valve measuring 65mm in length.
A 65mm valve is long enough for 50mm carbon rims from EliteWheels that I've been using for a few months now.
(You can read a detailed review of these AWESOME carbon rims here: EliteWheels Carbon Rims - Initial Review)
Later, while reading numerous articles on the topic and watching YouTube reviews, I learned that there are models of much lighter TPU tires.
The most common ones weigh 24 and 28 grams, BUT there are also ULTRA LIGHT TPU tires weighing ATTENTION: only 19 grams! :) :) :)
Yes, you read that correctly: only 19g for one inner tube!
Keep in mind that the 19-gram TPU tires are specifically designed for road bikes with disc brakes only.
Due to the risk of deformation due to increased tire temperature during braking with rim (V-brake) brakes, these 19g tires are intended solely and exclusively for bicycles with disc brakes.
If you are using a bicycle with rim (V-brake) brakes, use TPU tire models weighing 24, 28, or 36 grams.
For gravel and MTB bikes, there are specially designed TPU tires for thicker outer tires, but they have a slightly higher weight of 44 grams, which is still significantly lower than the equivalent classic butyl inner tubes.
Yes, I always thought that classic bicycle inner tubes were made of rubber...
Ha ha ha... it turns out I was wrong. The material used to make all classic inner tubes is called butyl (whatever that means... :) )
Another significant advantage of TPU tires, in addition to their ultra-low weight, durability, and better resistance to punctures compared to classic butyl tires, is that TPU tires are 100% recyclable.
Thermoplastic Polyurethane (TPU), the material used to make TPU tires, is a specially designed type of plastic with specific properties such as strength, stretchability, resistance to UV and other external influences. 
Meanwhile, Thermoplastic Polyurethane (TPU) is very inexpensive and easily recyclable at 100%, and the used and worn-out TPU inner tubes can be easily and affordably recycled to produce either new tubes or completely different products.
On the other hand, classic butyl inner tubes are much more difficult and expensive to recycle, and they are significantly more harmful to the environment as a whole!
So let's continue with the practical tests. Theory and marketing are clear! :)
On May 19, 2023, at 20:00, Mitko Velchev and I started the gravel brevet Super Randonnee Dozen Monasteries: 600 km with 10,000m elevation. 
Both Mitaka and I embarked on this CHALLENGING brevet with one thing in mind... with TPU inner tubes, of course! :) ;) :)
Mitko had two 35-38g TPU tires with metal valves on his rims, but he also carried two classic spare butyl tires because his second order of TPU tires from AliExpress took WAY too long to arrive... :(
I had two 35g tires mounted on Pip's rims, plus two spare tires with the same weight in the tool bag.
These spare tires take up almost no space compared to my old lightweight butyl Conti Race Light tubes weighing 75g...
They can't be compared in terms of weight or size to the classic Decathlon inner tubes weighing 100 grams or more!!! :) 
And for such a CHALLENGING climbing gravel brevet like the SR600 Dozen Monasteries, you should have a MINIMUM of 2 spare tires!
You can easily do the math for the weight saved on the climbs, not to mention the space saved in the saddlebags:
2 tires x 100g mounted on the rims + 2 x 100g spare tires = 400g
2 pcs x 24g TPU tires on the rims + 2 pcs x 24g spares = 96g
You save a total of 304g JUST in weight uphill + you also save a LOT of space in the saddlebags for more halva, lokum, and honey cakes, of which you NEED more uphill... :) ;) :)
And there are MANY uphills on this brevet:
- the first uphill is from Gabrovo to Sokolski Monastery;
- then comes the ascent to the Shipka Pass from the north;
- then the highest pass in the Balkan Mountains: Beklemeto from the south;
- then the ascent through the Bogyo Pass, better known as the Ribaritsa - Shipkovo Pass;
- followed by the super extreme but very beautiful ascent from Teteven to Babintsi! :) ;
- then comes the steep uphill on the main gravel road in the forest to Glozhene Monastery;
- the two short but steep ascents to and from Praveshki Monastery;
- then comes the super steep uphill to Etropole Monastery;
- then the challenging GRAVEL section through Zlatishki Pass... Ohhh! :);
- then the always tough for me personally uphill to Panagyurishte colonies, tough uphill because it always happens that I climb it after 24 hours of riding with a length of 340 km and 6300m of elevation....... ;
- the passage from Strelcha to Koprivshtitsa, probably the MOST BEAUTIFUL pass in Sredna Gora Mountains!;
- there are two more smaller uphill sections after Koprivshtitsa... but by this point, you are at around 8,000m of elevation and every meter uphill becomes harder;
- again, Beklemeto from the south! Yes, the beloved Beklemeto! I love Beklemeto both from the north, where it's steeper, and from the south, where it's even more beautiful!
- two more smaller uphill sections from Troyan to Apriltsi;
- and finally, as a dessert, the organizer of this brevet has left the uphill to Batoshevo Male Monastery...
If you haven't climbed the uphill to Batoshevo Male Monastery after climbing 9,500m of elevation in 40-50 hours, it's high time to try doing it! ...:)
Even fresh and rested, this UPHILL will always be an UPHILL with Capital Letters!
In addition to the climbs, this brevet is known for its beautiful, long, and enjoyable descents, often with poor or even missing pavement.
Both uphill and downhill, reliable and sturdy tires with optimal low weight and super low rolling resistance, while maintaining excellent durability, are a huge plus!
That's why we opted for the Conti GP 5000 external tires paired with ultra-light TPU inner tubes.
Results from this extreme test:
1. With Mitko, everything went smoothly without any problems!
He is currently climbing the bairs as I write this review for the Super Randonnee brevet: Galloping through History
2. I had only one issue with the rear tire, BUT due to what... Ohhh!!! :)
For me, everything on this brevet was "smooth sailing"! :)
I had no problems on the extremely bumpy section from Yablanitsa to Maly Iskar.
I rode that section standing on the pedals because it's almost impossible to sit on the saddle with all the bouncing downhill on the old asphalt with many cracks and protruding stones.
I had no issues on the gravel section uphill through Zlatishki Pass towards Kashana Hut, even though it started pouring rain there for the first time in this brevet, making the stones and the road super wet and slippery.
However, the following highly risky incident occurred after leaving Koprivshtitsa:
The road on the descent towards Sofia from Koprivshtitsa was severely damaged.
They started preparing it for repairs by cutting out large rectangular sections of the asphalt along the length of the road, BUT they did it extremely POORLY and UGLY!
The asphalt was cut to a depth of about one foot with sharp vertical edges on both sides at the entrance and exit of the cut section!!!
It was a horrible and disgusting job!!!
Just before one such cut on the steep downhill, a car behind me decided to pass me with a dirty blast of gas right before one of those sharp and deep cuts.
I slowed down as much as I could and jumped into the hole, hitting the brakes.
On the exit, I made a bunny hop, BUT I didn't realize I was already going at a very low speed...
Accordingly, my front tire successfully went over the trap, but the rear tire shook VIOLENTLY on the edge!
- Horror! My carbon rim is ruined! - that was my first thought.
At the first opportunity, I stopped a little further down, inspected the rim, the tire, everything was luckily perfect!
HURRAY!
I descended about 2 km further down the road and decided to stop for a snack and a short nap on a sunny meadow next to a clear babbling brook... :)
I spent about 45 minutes on that secluded sunny meadow, then I went back on the road and felt that the vibration from behind was unusual and different.
The bike was bouncing heavily... hmmm
Turned out that the rear tire had started deflating.
It didn't fully deflate, BUT the tire was definitely much softer, and the bike was bouncing as if it had springs in the rear... it was the first time I experienced such a strange thing... :)
Clearly, I'll need to change the inner tube!
It's definitely not a puncture, like a classic snake bite, because after that ominous impact from behind, I rode several kilometers downhill, plus I sat on the meadow for at least another 45 minutes, and the tire didn't fully deflate, it was just softer than before.
The replaced tire is currently in my workshop, but I didn't have time and energy yesterday when I got home to check exactly what happened...
My theory is that the valve started leaking after the impact, but the tire itself is intact.
Hopefully, tomorrow I'll be able to carefully inspect it and I'll write a special comment here about what I found out exactly.
EDIT: After hitting the edge, the tire burst, but luckily the valve remained intact. At least the process of patching a TPU tire has been tested :) The only difference when patching a TPU tire is that the area needs to be thoroughly cleaned with an alcohol wipe (included with the patch) for the instant adhesive to adhere well! According to the instructions, the instant adhesive should be left for a minimum of 30 minutes to set before inflating the tire.
Every cloud has a silver lining!
At least now I would be able to capture REAL on-road photos that I need for the instructions in my blog: How to PROPERLY INSTALL TPU INNER TUBE. :)
The removal + installation + pumping the tire with my compact, ultra-light pump until it's as hard as a rock + taking numerous photos of each stage of the process took exactly 30 minutes.
30 minutes for all of that is actually not bad at all!
That means 10-15 minutes for changing the TPU inner tube under normal circumstances without shooting instructional photos and enjoying the sunshine... :)
So, the result for me personally is a documented photo material for the guide How to PROPERLY INSTALL TPU INNER TUBE + one replaced tire, all of this after that ominous impact on the sharp edge of the asphalt.
I personally am extremely grateful to My World for only this!
Final conclusion from the TPU tire test: TPU TIRES ARE SUPER RELIABLE!
In my opinion, and not only mine, soon all of us will have at least a few of them.
Even colleagues with tubeless tires carry at least one spare tire.
Most likely, very soon that will be a TPU tire exactly! :)
The first smaller delivery of TPU tires for the online store in the Blog has already arrived from China and is available!
If you like my writing style, reviews, and travelogues on this Blog, you can support us with the reliable and trustworthy "Pips" by ordering TPU tires from the online store linked here: TPU tires.
The prices are highly competitive, but compared to AliExpress, they are still higher.
There are significant shipping costs with DHL and paid VAT ... but on the other hand, you WON'T have to wait several weeks for delivery from China.
Link to the TPU tires I bought from AliExpress and still enjoy every kilometer with GREAT PLEASURE: https://a.aliexpress.com/_mLvx8C6
Below, I'm sharing a link to an extremely strong and valuable Video review by an Australian on YouTube.
His YouTube channel is highly valuable, and I have been following it for years.
The person is an extremely talented hacker with a sense and provides super valuable information and makes super valuable reviews for the benefit of all other cyclists.
In his video, he describes very well all the pros and cons of TPU inner tubes for bicycles!
P.S. TPU Tires have NO Cons! Only pros! Undeniable FACT :)
