Ev0lutionz

As per title, which size rim tape do I need to get ? Do I need to get something longer than 19 or shorter ?

JohnDThompson 

You want the tape wide enough to fully cover the spoke holes, but not so wide that it interferes with mounting the tires.

Andrew R Stewart 

Are we to assume a tubed type set up? If so than John's answer is right. Andy

cxwrench

ftfy.

SoSmellyAir

FFWD specifies 25 mm wide rim tape for the 622 x 19C wheels I recently bought. As far as I know, rim tape must be wide enough to be completely pressed into the center channel and reach the side walls.

Andrew R Stewart 

You forgot to specify "for tubeless set ups". When using a tubed system one rarely wants the rim tape under the tire's bead. Andy

SoSmellyAir

FFWD states: Use of 25mm tubeless rim tape is required regardless of standard or tubeless setup.

I was merely describing what I saw with my new wheels, that the rim tape is just wide enough to be applied into the center channel and still reach (but do not go up) the sidewalls. So it does not look like any rim tape would sit between the tire bead and the sidewalls of the rim.

HTupolev

Why?

In my experience, one nearly always wants rim tape under the tire's bead. Most rims are dimensioned for it, and can suffer from sloppy tire fitment otherwise. Tape that only covers the middle can also be prone to lateral crawl; I've been in situations where a rim had to have its tape re-set when repairing a flat, which isn't a huge deal, but it's an easily-avoidable annoyance.

The main situations that come to mind where tape should be excluded from the bead seat shoulder are if you're using single-wall rims (where the tape is intended to be well-contained by a steep-sided center channel) and some rims with no spoke access holes in the tire seating bed (if they're intended to be used with no tape at all).

andrewclaus

Add about 2 mm to the spec inner width, so the tape snugs up against the wall without climbing it.

Lately I've been using tubeless rim tape, two wraps for my high pressure tires. Works great, and makes tire removal easier.

smashndash

I would add 4mm to the inner (hooked) width. So a 19mm rim would need a 23mm tape. You can probably get away with +/- 1mm. The advantage of wall to wall tape for TL is obvious, but it helps with tubes as well because it means the tape is way less likely to get damaged from removing/installing tires.

smd4

For tubed tires I'm with JohnDThompson--I use rim tape just wide enough to cover the spoke holes--nothing more. Velox is the tape I prefer.

hokiefyd 

Tape that extends to both walls of the rim...especially thick tape like Velox...increases the effective bead seat diameter of the rims and most rims I own definitely don't need more in this area -- the tires seat pretty "firmly" on their own! My experience is apparently not universal, but I specifically avoid the bead seat area when fitting rim tape. Not directly related to the original question, but I've gone to using the very thin mylar type adhesive tapes and I do two wraps, covering the spoke holes (of double wall rims) only. I do use Velox with single wall rims, where the spoke nipple ends must be contended with and where the rim has a clear channel for the tape, avoiding walking up the side.

I will say that I'm sure the very thin mylar/tubeless type rim tapes don't increase the bead seat diameter appreciably...my practice of avoiding the bead seat area comes from when I used to use Velox on everything.

HTupolev

That's contrary to my experience. The issue is even seating: the symptom of loose bead seat fit is that it's harder to get tires to mount without twists or hops.

On rims of what type and age? Using cotton tape wall-to-wall can prevent tires from seating on modern rims that were designed with thinner tubeless tape in mind. But that's a poorly-behaved solution, it's far better to just use a correct tape.

On older non-tubeless double-wall rims that were designed for use with cotton tape, a wall-to-wall wrap of cotton tape usually works great. Actually, cotton tape can be more convenient with these rims than tubeless tape, because it can take multiple wraps of tubeless tape to achieve sufficient bead seat shoulder height. The Rhyno Lite rims on my gravel bike have either 3 or 4 layers of tape (can't remember), because any less and the tires simply would not mount without a bit of ripple, no matter how much I massaged them or tried to snap them in place with high pressure; cotton would have been an easier solution.

hokiefyd 

I have a set of double wall Trek Matrix rims from the '90s that are my most difficult to mount tires to. I presumed that it's because they're just a slight smidge larger than my other rims (in terms of bead seat diameter), and the tire doesn't seat evenly around the circumference without a lot of coaxing. I have other rims where the tire seems to simply mount itself...and airs up straight the first time without a lot of air pressure.

The same tires I had trouble mounting before seem to mount easier since I removed the old Velox (which did wrap up towards the rim wall) and replace it with mylar/tubeless rim tape. I chalked this up to reducing the rim diameter as much as I could (especially down in the spoke valley) by using thinner rim tape. My experience is apparently not universal. Studying the theory of what should and should not work best, regardless of anyone's lived experience, is pretty interesting to me.

hokiefyd 

Thinking more about what you're saying HTupolev I see what you're saying -- tires that mount with a hop or sag aren't non-uniform because the bead isn't getting up on the bead seat area itself...they're non-uniform because the bead isn't coaxed to "sit up tall" against the rim hook -- and this is where the extra thickness of something like Velox should help? Interesting... Maybe I need to re-examine what I thought I've learned over the years.

ThermionicScott 

What rims do you have? Without knowing the type, we'll just keep chasing our tails in here.

It's too bad more (non-tubeless) rims weren't made like these Araya 20As. They're double-walled rims, with a shallow 10mm channel for the rim tape. The tape stays put and doesn't interfere with the mounting of the tires at all. They're a joy to use.

jadmt

bumping this up so what size Velox tape would be best on this wheel, 16mm or 22mm? tube type 18.6mm inner width. my gut says 16mm but brain says 22mm.
https://www.velocityusa.com/product/rims/dyad-26

smd4

Did you read anything in this thread? We can't tell you how to do everything. Everyone has different opinions. I run my tape as narrow as possible-just enough to cover the spoke heads and rivets. Others run their tape up the sidewall, for reasons known only to them. What do YOU prefer? Will 16mm tape cover the spoke holes/rivets? I can't see your rim, so I don't know. If it does, that's what I would run. What you do is your choice.

Crankycrank

Ask Velocity. Most mfrs have a recommended size for their rims and would make the choice simple.

jadmt

already tried that.....crickets....that is why I asked here.

Dan Burkhart 

Velocity offers two widths of Velotape and lists the rims each is suitable for on their website.
https://www.velocityusa.com/product/...ries/velotape1

jadmt

thank you

jadmt

Velocity got back to me and recommended 18-20mm wide tape.