I’m curious about the AFM testing of the 2 Veloflex Record tubulars. 2nd down on the list is a VF record 19mm width properly glued. About 10 down from their is a VF Record 20 mm Jens used properly glued. One question is the difference between 19 mm and 20mm. Does VF make both or is the 19 mm actually measured vs whats printed on the sidewall. Other than that is the difference found attributed to measurement error, different glue procedure, something else.
Styrrell
I’ll take the liberty of answering for Al since I asked him about the tire width discrepancy a while ago. Originally, he just used the size marked on the sidewall when he first started testing (remember, he just started off doing this on a lark–I don’t think he planned on his testing becoming the internet sensation that it’s become).
Later, he started actually measuring the tires. As far as the VF’s, none of the Record Tubulars have actually measured 20mm, at least that I’ve seen. They seem to be between 18.4 or so to 19mm.
As far as the difference in Crr, it’s most likely dependent on the gluing procedure, which counts for a lot.
I’ll take the liberty of answering for Al since I asked him about the tire width discrepancy a while ago. Originally, he just used the size marked on the sidewall when he first started testing (remember, he just started off doing this on a lark–I don’t think he planned on his testing becoming the internet sensation that it’s become).
Later, he started actually measuring the tires. As far as the VF’s, none of the Record Tubulars have actually measured 20mm, at least that I’ve seen. They seem to be between 18.4 or so to 19mm.
As far as the difference in Crr, it’s most likely dependent on the gluing procedure, which counts for a lot.
Sir Roady has is exactly right. The VF Record Tubular that tested very well was a new tire sent to me by Nico glued using Mastik 1 with 3 coats on the rim and 2 coats on the tire (total of ~ 2 tubes per wheel). The tire measured 19.1 mm with 120 psig. I didn’t measure the VF Record from Jens - also don’t know exactly how that tire was glued which can make a difference.
As Roady points out I got started just trying to determine how fast my original Zipp tubular tires on the 999 set which I had just invested in were after hearing that clinchers were overall faster. Jens and I exchanged some wheels and tires soon after to try and combine our data sets. That didn’t work out but more data was made available.
Thanks,
And thanks for making all of this data available, it seems like a lot of work. One last question, Any opinion on continental vs Vittoria glue? I believe both are clear, I always assumed they were interchangeable.
Styrrell
Thanks,
And thanks for making all of this data available, it seems like a lot of work. One last question, Any opinion on continental vs Vittoria glue? I believe both are clear, I always assumed they were interchangeable.
Styrrell
Thanks - a bit of work but spread out over a few years not too bad plus I get the jump on any fast tires which can be a liability at times if you were to look at my new tire shelf. I’ve used both which are both clear but haven’t done any real comparative testing of the 2 glues. Mastik 1 is ~ 10% stronge per the KU tests and seems to dry faster so it’s a little trickier to use. The original Zipp tubulars that I had were glued by Christopher Kautz using Conti using a one coat on the rim and one on the tire however this was over ~ 2 coats of old (~ 2 months) glue on the rim (the Zipps replaced the original Tufo S33 Specials). My gut feeling is that Conti would be fine as long as there is enough glue to make a “complete” surface bond but I’ve switched to Mastik 1. I only do TT’s so don’t have to worry about replacing a tire in the middle of a race - if I flat it’s over and I wait for a wheel or the broom wagon.
Roady may be able to add to this.
Have you done any testing on the Veloflex Carbon tubular tire?
Yes he has. For the complete list go to Biketech review and look for tire roller testing or something similar.
Styrrell
Wow! The Carbon tire is way down the list.
I wonder why it is so much slower than the Record.
For the most part, the important things for a fast tire is latex tube, very little tread, very thin casing. Not sure about the carbon but the record has a pretty thin tread and casing. Also a lot of the older testing of tubulars was done with minimal glue. Turns out a lot of glue helps a lot. Make sure you aren’t looking at a listing for a lightly glued carbon. Also look at the watts column. Quite a few tires get grouped together, meaning the carbon could be 20 tires below another, but the actula speed difference may be pretty minimal.
Styrrell
except for the Record, none of their tires (including the clinchers) seem very fast. I’m not sure why that is, except maybe the tread extends down too far over the sidewall, or the tread compound itself is really stiff??
Also, their earlier tubulars used to use a ‘butylized latex tube’, coated w/butyl to reduce air loss. I don’t know if they still do that, but if so, I’m guessing that doesn’t help.
Does anyone know who makes the Bontrager tubular tires?
Maybe Vittoria?
dunno about bontrager, but the zipps are made by vittoria AFAIK, which is why they perform that well. the older models were made by tufo though, right?
i have an important question about the “properly glued” method: it’s recommended to use 3 coats on the rim (2 base layers + 1 to actually glue the tire to the rim, that is, the final layer you let dry for about 5 min?) and 2 on the tire.
does the 3-layer procedure only apply for new rims or also for previously glued rims that already have a base layer? do you remove any old glue on the rim before glueing a new pair of tires?
Does anyone know who makes the Bontrager tubular tires?
Maybe Vittoria?
Having owned and held in my hand the Bontragers, and also the Specialized S-Works “Open Tubular” tires, I would be VERY surprised if they were NOT made by Vittoria. The casing material is IDENTICAL to the 290 TPI Vittoria casing 
For the most part, the important things for a fast tire is latex tube, very little tread, very thin casing. Not sure about the carbon but the record has a pretty thin tread and casing. Also a lot of the older testing of tubulars was done with minimal glue. Turns out a lot of glue helps a lot. Make sure you aren’t looking at a listing for a lightly glued carbon. Also look at the watts column. Quite a few tires get grouped together, meaning the carbon could be 20 tires below another, but the actula speed difference may be pretty minimal.
Styrrell
The Carbon I tested was on a friend’s wheel and was glued by a shop mechanic using Continental glue IIRC - I labelled it as properly glued. There is some history on it down at the bottom of the list - we were trying to see how aging of the glue would improve the Crr. OT but I happened to get hold of a “Hutchinson” tubular used by Astana in the TOC last year. Took it over to show the same friend - he said that he had one of those as well and pointed to the same VF Carbon - it was very similar. Astana is now using the Bontrager RXXXL tubular which is again very similar in look. I did test the “Hutchinson” which wasn’t that good. I tested the RXXL but with light glue. It didn’t roll as well as the RXL Pro also with light glue. I have another RXXL and plan to test that soon. Based on the RXL Pro test data the Crr of a properly glued tubular will improve by ~ 0.0003 compared to a lightly glued tire. I screwed up with the light gluing - was trying to achieve a thin and hard glue layer based on the “understanding” that the reason tubies didn’t roll as well was a soft/compliant glue layer which resulted in additional hysteresis. Using Mastik 1 however it is more important to achieve as complete a bond over the entire tire bed area - that is the critical parameter. Tom has a way of putting this much more concisely.
dunno about bontrager, but the zipps are made by vittoria AFAIK, which is why they perform that well. the older models were made by tufo though, right?
i have an important question about the “properly glued” method: it’s recommended to use 3 coats on the rim (2 base layers + 1 to actually glue the tire to the rim, that is, the final layer you let dry for about 5 min?) and 2 on the tire.
does the 3-layer procedure only apply for new rims or also for previously glued rims that already have a base layer? do you remove any old glue on the rim before glueing a new pair of tires?
What Tom said on the Bontragers - the Theorem of Least Surprise also works well here.
Actually I’ve just finished some tests on gluing over old glue. The first tire was installed with 3 coats on the rim and 2 on the tire - Mastik 1. Long story but to duplicate a pro tour team process after removing the first tire (20 - 30 minutes with resultant blisetered/now calloused thumbs) I filled in the spaces on the rim where the glue had pulled off with new glue (also removed any loose material) and also put one coat on the new tire. Dried for ~ 24 hours - then applied one additional coat on the rim and installed the new tire. Different tires of the same model but the Crr was the same within my day to day repeatability range estimate. I think you can do this 5 - 6 times with no effect on Crr but I can’t really prove it because different model tires were tested subsequently. In all tests the tires were definitely well glued - difficult to remove.