I’ve got a pair of 25mm Conti GP TT tires and saw some Vittoria latex tubes on sale that are 700 x 19/23c. Will this setup work without removing the whole benefit of using latex tubes?
I’ve got a 40K TT coming up. Myself plus bike will come in at about 213 lbs so I’ll need to run a higher tire pressure than most so I’m wondering if extra leakage will occur due to the extra circumference of the tire and will that be a factor in a ride that lasts a little over an hour.
I use a 23mm Vittoria Latex tube in my 25mm Conti GP TT. No issues.
I run this set up with the 25-28 vittoria tubes. Keep in mind that the 25C GP TTs run wide. They measure at like 27-28mm. I personally wouldn’t do it, but that’s just me. Will it work? Probably.
I’d recommend against it. Latex doesn’t fill spaces well. It might work, but it also might suddenly pop and deflate – most likely sometime soon after you inflate it, but possibly later. You can get the larger ones from probikekit for a good price and, if you don’t have time to wait for them to be shipped from Europe, biketiresdirect will price match and get them to you in a couple days.
Thanks for the feedback gents, much appreciated!
I guess I’ll be changing mine too to the 25mm one. Ordering some now
I use the standard 700x18-23mm tunes with 700x28mm Conti GP4000 II tires- and these tires measure out 31mm.
But I run them down near 65psi and I weight 145 lb.
That said, I think a heavier rider could run them with 25mm tires. It is not like higher pressure makes the tubes fail more easily.
I’ve run my 23mm Latex tubes in my 25 wide tires for years with no issues. This is with the wider HED rims too. I wouldn’t think twice about it.
I routinely run my 20C michelin latex tubes with all kinds of tires from 20 to 25. One of the tubes is 12 years old now. Still works.
I think you’ll be ok.
I found the best latex tubes to be the red challenge ones.
They are 19-28mm
There are a few threads about this. Most people seem to agree that it is no problem. Latex is stretchy. The 25/28 latex tubes seem hard to come by lately so I was researching the same question.
Just an update and a thanks to y’all for your input.
This was my first open 40K TT. The course was flat, only 280 feet of gain per Garmin 920XT.
My bike is a 2015 Felt B14, all stock components except a Profile Design Ozero basebar and T2+ aerobars, both carbon.
I was going to borrow some deeper wheels from a friend but turns out his hub could only do 10 speed and I needed an 11 speed. So stock wheels it was.
But I did install the Conti GP TT tires and the 25mm latex tubes. I was really careful with the tubes but it wasn’t really that difficult. And the TT’s went on a lot easier than the GP 4000S II’s. Either that or I’m getting better at installing new tires.
I pumped up the the recommended limit for the tires (120 psi) and gave 'er a test run of only a few miles the night before.
I’m not in my best bike shape but my goal was to go under an hour. There was some wind but nothing over 10 mph.
i signed up for Masters 50-59.
In another thread around the same time as this one it was mentioned that hydration should not be an issue over this distance if you’re properly hydrated so I followed that advice and removed all bottle cages from the bike.
I don’t have a power meter, don’t go by HR while riding so it was just gut feel.
I went out at 90-95% knowing that 40K is a long way. I was saving the hurt for the last half. It was an out&back and I hit the turnaround at 29:47 and I thought “wow, maybe I can hit my goal”. I felt NO wind on the way out but heading back there it was. It wasn’t a lot but it was there and I felt like I was much slower than going out. I just tried to hold aero as best I could and ground it out.
I came in at 59:52, super happy with that time.
Not sure how much the tires and latex helped but I’m thinking that might have made the different between 59:52 and 60:00.
I finished 3rd in AG, some pretty good riders out there. I would have won the Cat 4 category as the 3 guys on the podium all went just over an hour.
Anyhow thanks again for your input.