bike maintenance: unable to fir tyres onto rim

Everything about building wheels, glueing tubs, etc.
KLabs
Posts: 380
Joined: Wed Dec 01, 2010 4:29 am

by KLabs

Also use talcum powder on the tube ... put the powder in the palm of your hand and run the tube through your hand ensuring the that powder coats the tube. Just to make the tube slipperier.
Also, put a small/tiny amount of air in the tube which should also make it a little more resistant to pinches, because it will have some shape.

thanks KL :)

by Weenie


liam7020
Posts: 774
Joined: Tue Jul 27, 2010 10:04 am

by liam7020

Pull the tyre off the rim and give it a good old stretch. I tend to mount new tyres on to a pair of old wheels to stretch them for a few days prior to fitting them on to carbon wheels. Makes them much easier to mount, saves those f*$kin' pinch flats and negates the temptation to use tyre levers on expensive carbon rims!!!
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"Sometimes you don't need a plan. You just need big balls." Tom Boonen

LionelB
Posts: 1441
Joined: Sun Oct 05, 2008 8:09 pm
Location: Aix en Provence

by LionelB

soapy water.

Or better yet switch to tubular :D

sungod
Posts: 1462
Joined: Fri Dec 24, 2010 9:37 pm
Location: it's raining, it must be uk

by sungod

but the rear.. i already have 2 pinch flats and repaired it with the park patch. and just when it's reaching close to 85psi...it blows...


what blows?

the patch fails?
the tyre comes off the rim and the tube goes bang?

kode54
Posts: 1125
Joined: Tue May 23, 2006 9:39 pm

by kode54

try using veloplugs. i used the red ones on the far sports wheels and they fit fine. allows more clearance to mount tires. i also use a talcum powder so that the tube slides better than getting pinched.
- AX Lightness Vial EVO D + DA9150 + Enve SES 3.4 carbon hubs
- Parlee Altum + DA9150 + Enve SES 4.5 carbon hubs
- Parlee ESX + DA9150 + THM SRM PM + Enve SES 6.7 CK hubs
- Independent Fabrication Ti FLW + DA9100 + Enve 3.4 CK hubs

Beancouter
Posts: 374
Joined: Fri Apr 20, 2012 9:04 pm

by Beancouter

If its any consolation, I have had 2 tubes blow on me - in both cases the bike was sat in the house - scared the cr*p out of one of my mates!!! I am ultra careful on mounting tyres to check for pinches under the bead - i suspect in both cases not careful enough.

For me, The challenge is that the tyres are so tight (particularly new ones), that it is really hard to see if the tube is pinched.

Talc and soap sound like a decent idea. For me, I resorted to using levers to get the tyre on - hand rolling them on seems to makes the chance of a pinch higher as it tends to drag the tyre over the tube.

Afterwards, on the first ride, I was a bit nervous .... However all was fine and they are 'sweet'! They roll brilliantly - the other plus was that the freehub is actually quite quiet.

Persevere ... Defiantly worth it. Now have a set on order for my CX

Beancouter
Posts: 374
Joined: Fri Apr 20, 2012 9:04 pm

by Beancouter

If its any consolation, I have had 2 tubes blow on me - in both cases the bike was sat in the house - scared the cr*p out of one of my mates!!! I am ultra careful on mounting tyres to check for pinches under the bead - i suspect in both cases not careful enough.

For me, The challenge is that the tyres are so tight (particularly new ones), that it is really hard to see if the tube is pinched.

Talc and soap sound like a decent idea. For me, I resorted to using levers to get the tyre on - hand rolling them on seems to makes the chance of a pinch higher as it tends to drag the tyre over the tube.

Afterwards, on the first ride, I was a bit nervous .... However all was fine and they are 'sweet'! They roll brilliantly - the other plus was that the freehub is actually quite quiet.

Persevere ... Defiantly worth it. Now have a set on order for my CX

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prendrefeu
Posts: 8608
Joined: Wed Oct 31, 2007 10:32 pm
Location: Los Feliz, Los Angeles, California
Contact:

by prendrefeu

It isn't the wheels. They're tight, that's for sure. But it's better than having the tire randomly disengage from the bead (ie, Stans Alpha 340).

But, anyway, check for tube placement after mounting the tire fully, before adding any air.
If the tube is visible in any way, you risk a pinch flat.
Exp001 || Other projects in the works.

addictR1
Posts: 1258
Joined: Sun Jun 10, 2012 1:11 am

by addictR1

Thanks all... I stayed up till 2am... The pinch flats are all.at new spots. I already had installed the red veloplugs too. I'll try with new tubes after work and baby powder.

eric
Posts: 2196
Joined: Tue Nov 11, 2003 9:47 pm
Location: Santa Cruz, California, USA
Contact:

by eric

It's a technique (and practice) thing. I haven't pinched a tube during install in many years, but I have installed a lot of tires. Unlike many experienced people I use tire levers to install tires. I make sure the tube is stuffed up into the tire and take very small bites of bead. Like an inch at a time or less if it's really tight. Many people try to lever on too much bead and that's when they start pinching the tube or breaking levers. I use the lever to stuff the tube up into the tire before I mount a section of tire.

When you are getting the last part of the tire on, go around the part that's already mounted and squeeze the beads in to the center of the rim. That part has a smaller diameter. You will get a little more slack.

Once you're done, take 30 seconds and inspect the tire to make sure the tube is not pinched between the tire and rim. Start at the valve stem (so you know when to stop) and push the tire to one side so you can see between it and the rim. You should see rim strip. Do the other side, then rotate the wheel to inspect the next section.

Finally, when I am working on something and it's not going well, I take a break. (But NOT for a beer. I've found that drinking while wrenching is a good way to break stuff.) Going away and coming back later lets you calm down and gives your subconsious time to work on the problem and come up with a different way to try it. That's better than trying the same thing over and over with more swear words each time.

addictR1
Posts: 1258
Joined: Sun Jun 10, 2012 1:11 am

by addictR1

ok.. left work early to come back to the wheel. it's been eating at me all day long! took out the tube.. there's 3 patches i did last night they are all still in tack. decided to inflat that bish and see where the leak is coming from. nothing at all!

put the tube under water to see if there are some minor leaks.. nada..

this is some mystery tube. it's been on my wheels for the past 5-6 yrs.. so i guess it's time to replace anyways. but it's just strange.

picked up some bontrager tubes and will try using that along with everyone's suggestion and technique.

update: thanks to everyone's suggestions and help.. i was able to install the new tube on and took the farsport 38mm out for a spin... man.. it's night and day and i love it!!

metal
Posts: 75
Joined: Mon Sep 10, 2012 2:37 pm

by metal

The best way to install a tyre and tube onto a clincher rim is with the 'back off' method.

- Install half the tyre.
- Slightly pump up the tube. It should be somewhere between a round shape and the flat deflated shape.
- Start at the valve, and install the valve by peeling back the tyre at the valve hole (over the already installed side).
- Pull the tyre carefully back over the tube.
- Push up on the valve to push in comfortably up into the tyre.
- Now put the rest of the tube into the tyre so that it loosely holds the shape of the wheel while sitting in the tyre.
- Now start at the valve hole. Push the tyre bead up and and over and onto the rim.
- Push up again on the valve now to make the tube fully sit under the tyre.
- Now push the tyre lightly down to push the bead under the rim near the valve hole.
- Push a little on each side, and the check to see that you can't see the tube near the valve hole when you try to push the tyre over.
- Extend out by 1/8th of the wheel either side.
- Ensure no tube should be seen at, or either side of the valve when you push the tyre back (the rim strip should become visible, but no tube should be visible.
- Ensure the valve is straight. If it isn't quite, give a pull on the tyre side that will move it across the tiny bit to get it straight. (You may have to do 3 seperate pulls, one at just past the valve, one about 1/3rd of the way around, and one 2/3rds of the way around.
- Now start on one side of the tyre, and push it on, making sure that each push on keeps the tube in the tyre.
- If at some point it doesn't quite sit under it (i.e. is still visible when you push the tyre over to reveal the rim strip), then pull the tyre back off a little with you hands, and keep doing it til you get to the other side.
- Now 'back off' about 1/8th of the tyre with your hands.
- Start on the other side near the valve, pushing the tyre on. Ensure the tube goes in, and under the tyre, and when you push back to reveal the rim strip, no tube is seen.
- Wait til it starts to get a little hard to get the tyre on.
- Make sure all the tube is now fully on the rim, but also under the tyre.
- If you have a little tube showing, and it's starting to get hard, then 'back off' the other side again by about 1/16th of the wheel.
- The tube should now still be under the tyre, but also on the rim.
- 'back off' about 1/8th of the tyre with your hands on this side now.
- Now, you should have all of the tube under the tyre, but also fully on the rim. This is the key to not pinching the tube during installation.
- It's now just a matter of pushing the rest of the tyre on the rim.
- If it's a really tight fit, use a reversed tyre lever or 2 to help. There is still a risk of pinching the tube, but just make sure your careful on lever insertion not to catch the tube. Michelin tyre levers are the best for this.
- Check both sides of the wheel for signs of the tyre being visible when you push the tyre over on the rim base.

If you have done this back off method right, you should never see the tube visible if you have used your hands to finish the tyre install.

If you have used tyre levers, and the tube is slightly visible, you can sometimes just give the tyre a few pushes across, and it will slowly roll up and under the tyre. If the tube doesn't get up and under the tyre, you have to pull half the tyre off, starting from 1/4 wheel from the valve (i.e. a part where there is definately no tube visible.

I tried finding a youtube video on this method, but lo and behold, I couldn't find one. :roll:

But once you have seen someone use this method you will wonder why everybody doesn't do it like this. :thumbup:

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mellowJohnny
Posts: 484
Joined: Thu Aug 16, 2012 12:56 am
Location: YYZ

by mellowJohnny

Had the same issue with a pair of Ksyriums. Ended up running my finger over the seam of factory installed rim tape and noticed a little sharp edge. Seems like they melt the nylon rim tape together which produces a sharp edge. Over time I think this would wear out the tube and blow out.

Also got *really* tired of violent blow-outs - powerful enough to rip about three inches of the tire off the rim. Dangerous.

I'm back on tubs...

Irish
Posts: 787
Joined: Mon Jul 26, 2004 8:57 pm
Location: Ireland

by Irish

Hi Addictr1 , I'm using the same combo (farsports 38 with Pro4) however I'm using veloplugs(red, they're snug) rather than rim tape and have found the fit tight but not impossible, I just had to use a plastic tyre lever to get it over the rim lip for the last 5-7cm, hope this helps.

Svetty
Posts: 476
Joined: Thu Mar 26, 2009 11:06 pm
Location: Yorkshire - God's Own Country

by Svetty

If you think clinchers are hard to mount try new tubeless tyres! I reckon I can get just about any clincher on without levers but needed levers to get the first bead on with Bontrager R3 tubeless and the second bead was an absolute b******d.
I'd definitely suggest gentle warming and soapy water for these. Don't know if the new Schwalbe tubeless will be any easier. ...

by Weenie


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