watchfob

Hey - has anyone had a problem fitting Conti 700c/28 rubber onto a Sun MZ14 rim - I've change many tires in my 40 years on bikes, but I have never run into this problem - it mounts OK with about 8 inches to go & there is no way it will slip over the lip of the rim - have tried inflating/deflating, pulling/pushing, even used the dreaded tire lever [more pinches] - any ideas/tips/tricks - very frustrated!!

Bob Dopolina 

This is something I deal with on a regular basis. Continental has a reputation of tight beads. Here's why:

When tires are made they are made assuming that the rim will fall within the standards set by ETRTO. These standard cover a variety of min/max dimensions relating to the design and construction of the rim itself.

Continental designs their tires so the the bead will fit as snug as possible but will still be able to be installed. They do this because they feel it is the safest way to go.

If the rim is not within ETRTO either by design (this happens) or by mistakes like poorly maintained tooling (this happens with rim designs that have been in production for several model years) then the fit will be a VERY DIFFICULT one. Relating to design: Even though the ETRTO standards are well known within the industry, sometimes a company will deliberately design outside of these standard. There are a few reasons for this I won't go into. Tire makers will also sometimes make this decision. Have you ever had a tire that would just flop onto a rim? Ever worried about it just flopping back off during a corner? This means that either the tire or rim maker is playing fast and loose with the standards.

The guys at Continental don't do this. They design to the minimum tolerance of ETRTO and consequently, there will be tire/rim combinations that require Herculean efforts to install, especially when the tire is new.

Have you tried other tires on this rim? Have you tried spraying the tire bead with soapy water?

Bob Pringle

I use Conti tires exclusively and they are a b?tch to mount initially. The third or fourth time they're a little easier. Here's a tool that really eases that last 8 or 10 inches of bead roll-over:



It's $10 from biketoolsetc.com (good outfit to deal with!)

Regards,
Bob P.

Look486

Same experience with Conti tires on Campagnolo rims, and just as Bob Pringle says, they do ease up with time.

After struggling on the side of the road for 30 minutes to remount a tire after a puncture, I now carry the VAR tire lever system instead of normal levers. Works a treat, and it's only a little larger than the Pedro's levers I was carrying before.

https://www.biketoolsetc.com/index.cg...item_id=VR-425

Gary

hhabca

I have had the same problem with a 28c Cont. 1000 Sport. I spent an afternoon trying to get it on and just got sore hands. This was going on a 20 year old Ambrosio rim, so possibly the rim spec is a bit large.

To get it on I rolled the tire tread over to the other side and kept pulling on the tread, not pushing on the bead, and then as if it acted like a lever or something it just slipped on - I couldn't believe it. Still can't.

Bob Dopolina 

This is the method I use. I turn the wheel around so the section I am trying to roll over the rim is facing AWAY from me. I then wring my hands over the tire and rim. By this I mean I grasp the whole thing (Tire, tube and rim) and pull the tire onto the rim, one hand at a time. It hurts but it works.

operator

I have a bit of a hard time understanding this break in periods for tires where it tire gets supposedley more loose. Are you saying that the bead is actually being pulled out of shape (to a bigger diameter) the longer it's been on a tire?

I've never experienced this, even though i've mounted tight continentals before. But it's hard for me to imagine a wire bead tire actually expanding like this.

edzo

no the bead doesn't change, but the 'thickness of the rubber around the bead edge' compresses and shrinks a wee bit

Bob Dopolina 

If you look at a wire bead - there are a few different windings - they are typically 1 or 2 wires wound or twisted around on themselves. In essence you have a wire that is somewhere in the neighbourhood of 1500cm long (this really varies but as a rough estimate will do). All this has to do is stretch 1 mm over it's entire length to make a significant difference.

You have to also consider that the casing becomes a little more pliable, and the chafer strip becomes a little more compacted and the wire may cut through some of the rubber that had worked it's way between the windings when the tire was cured in the mold. If all of this adds up to a difference of even a single mm that the bead can now stretch, that would be enough to notice.

jjciiijs

Could try going to Specialized. The two I am using on my bike can be completely put on by hand. Sorry guy, but I am having the exact opposit problem.

mrsalty

I had a set of Bontrager tubeless race rims on my Fisher Sugar 2+ MTB.
I was able to mount a Conti gravity wire bead on the rim once successfully (after a marathon session of swearing and throwing things).
I finally took it into the shop where I bought it, and they gave me a credit for the aramid (sp?)bead to upgrade, as the mechanic could not get the tire to seat properly, ever.

My Salsa Delgado Disc 29er rim can be mounted without any tools...............in fact it takes me at least twice as long to mount the tire because you have to hold the entire bead on the rim in order to have it seat properly.

more choices and selection translates to more problems and work arounds.
I still believe we have the long end of the stick on this one with more selection however.

Conti makes good ****.

fatsoforgotso

Yep. I've had the same experience putting 23mm Continental Ultragatorskins on Mavic Cosmic elite rims.
My only help is a sweet pair of Zéfal tire levers that are very rigid and work great.
I still love the Contis, though: no punctures through them in many hundreds of miles and I'm always sure the tires won't pop from the rim despite a higher than recommended pressure.
Lube that tire bead. Lube it up real good.

Bob Dopolina 

UST has been a bit of a problem. There are no ETRTO standards yet so rim makers are experimenting a bit. This makes it hard to get the tire right when the BCD keeps changing (and no-one tells you).

The best I can say here is be patient and it will work itself out in a few years. For now, if you find a combination that works, stick with it.

skycastle

I tried for an hour to fit a Continental wire bead tire without even coming close to getting it on. I filled a container with soapy water and used it to cover the tight areas of the tire and along the rim, as well as the ends of the tire levers. In less than 30 seconds I had the tire on.

Jeff Wills

If by "chafer strip" you mean "rim strip"... I agree. Narrow rims with no valley between the rim sides make it tough to mount the tire because there's no leeway for the bead to move around. Add the thickness of a good rim strip (such as Velox) and mounting can be chore. For 700C and 26" rims, the thin plastic rim strips help a lot. If you're working with some odd-size tire (like me), Velox rim strips are what work, but mounting the tire the first time is a b***h. After inflating the tire the first time, the rim strip compresses onto the rim and subsequent mountings are much easier.

Panthers007

The old thread linked to the VAR Super Tyre Lever - and they are out of stock. But these are absolutely excellent! And very hard to find in the States/Canada. They will get the meanest clincher on the ghastly rim.

Read the directions on the website below:

https://cgi.ebay.com/VAR-Super-Tyre-T...d=p4634.c0.m14

Lightweight and easy to carry.

Sci-Fi

The Var or Kool Stop tire bead jack is what you need for tight fitting/difficult to install tires (esp new tires).
https://www.jensonusa.com/store/produ...e.aspx?sc=FRGL

Either is easy to use.

Retro Grouch 

My trick is to look opposite the last bit of tire bead that you are trying to force onto the rim.

I hold the wheel vertically in front of me with the last bit to be forced on at the bottom. Then I make an effort to pinch the tire beads at the TOP part of the tire together. That's to make sure they don't seat against the bead seat and can drop into the lower center section of the rim. Grab the tire at the two sides and push straight down. That generally gives me enough slack to force the bead onto the rim without having to resort to using a tire lever.

Most of the time, using this method, I can also remove a tire from the rim without using a tire lever.