My test involved going from a bigger tire to a slightly less bigger tire. I was asked in the comments if the Aeron tube, which is rated for anything from a 700 X 32mm to a 700 X 52mm tire would actually work in something even less wide than I tried. This update will cover that use case.
This particular Aeron TPU tube was previously installed in a 700 X 47mm Teravail Cannonball tire. I decided to try the Aeron tube in a 700c X 40mm tire I had laying around. It was an ancient 700 X 40mm Donnelly MSO tire. (Remember those?)
So, following is a pictorial showing how things worked out. I'll have a bit more to say at the end, so check out the images and descriptions and look for further comments below.
 |
| This is the Aeron TPU tube with a minimal amount of air. Just enough to give it some shape. |
Aeron recommends a very minimal amount of air be inflated into the TPU tube to give the tube shape. You do not want to insert a TPU tube with no air in it! Damage could occur rendering the tube worthless or cause a flat while in use.
You can see the residual talcum powder I put on the Cannonball tire's inner casing to allow the TPU and rubber casing to more easily move against each other while installing the tube and inflating it. You can also barely make out the reinforcement around the base of the very long valve stem. I was happy to see this as I've experienced failure of a TPU tube due to the valve stem coming off which wasn't reinforced at its junction with the TPU tube like this one is.
 |
| Here you get some context for how wide the TPU tube from AERON is after being in a 700 X 47mm tire. |
 |
| The 700 x 40mm Donnelly MSO and the Aeron TPU tube installed inside of it. |
 |
| Here you see the side view of the Aeron TPU tube in the Donnelly tire |
The one nit I have regarding these Aeron TPU tubes is that they are trying to be a solution for too many variances in tire size. As an example, you can see above how the TPU is peeking out of the left side of the Donnelly tire. This is due to Aeron's making this tube to be compatible with 650B diameter tires.
That's all well and good, but it makes getting this tube inside a 700c wheel and tire a chore. It also puts the user at risk of pinching the TPU material in a place where a patch probably wouldn't work well. Just make these 700c diameter and IF you feel you are missing sales because 650B exists, make some in that diameter. As far as I am aware, Aeron is the only TPU tube available which does things this way and I feel it is misguided and may cause unwanted issues.
It should be noted that I did not want to use a 40mm tire with this tube so I ended up putting it in the matching Rene Herse tire mentioned in the previous update. I'll be running those wheels and tires as an alternate set for my Salsa Cycles Fargo Gen I. I will also be pitting these against the previously reviewed Rene Herse TPU tubes.
Stay tuned for future updates to this review.
3 comments:
I ran the MSO for years on my Raleigh Fall Guy - it came stock as remained the only viable 700x50 for quite a while. Great tire!
@wp - You are so right! And that bike was also way ahead of the curve as well.
I just installed a pair of the newest Schwalbe Aerothan 17AE tubes. They fit 33-622 to 47-622 (not 650B) and were easy to install. The big improvement is metal valve stems with replaceable cores. Mine have the new Clik cores which I find super convenient, though there's nothing wrong with Presta.
The big issue I've had with TPU tubes is about half of the patches fail. Some failures are obvious, others are slow leaks which get you hours or days later. For that reason I use TPU tubes only in tires with good puncture protection, which partially defeats the TPU benefits of light weight and low rolling resistance.
Post a Comment