Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Tight tires, grind down tight rim to decrease diameter?

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Tight tires, grind down tight rim to decrease diameter?

Old 12-02-19, 06:58 PM
  #1  
Snikerdoodlz
Junior Member
Thread Starter
 
Join Date: Dec 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Tight tires, grind down tight rim to decrease diameter?

My ebike motor's rim is an absolute pain to mount tires on. I know that it's a problem with the rim itself since I've put my exact same tires on another rim with much less effort. Potential DIY defects aside, Is it feasible to grind down my rim to decrease its diameter? I'd rather not spend money on a new rim and service to re-lace my motor.

Edit: The rim in question is the Sun Ringle Rhyno Lite 26x2.00 with 36 holes.
Snikerdoodlz is offline  
Old 12-02-19, 07:09 PM
  #2  
justinschulz9
Junior Member
 
Join Date: Nov 2019
Posts: 8

Bikes: diamondback century 1, cannondale synapse, giant talon, fuji absolute

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked 3 Times in 1 Post
could try a different tire? you should never modify a rim to that degree especially on a bike you are potentially commuting on.
also if the tire is as tight as you say i would recommend getting help from your LBS.
justinschulz9 is offline  
Likes For justinschulz9:
Old 12-02-19, 07:14 PM
  #3  
trailangel
Senior Member
 
trailangel's Avatar
 
Join Date: Feb 2014
Location: Pasadena, CA
Posts: 3,904

Bikes: Schwinn Varsity

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1426 Post(s)
Liked 130 Times in 87 Posts
SNICKERDOODLE is never allow to work on any bike I own.
trailangel is offline  
Old 12-02-19, 07:17 PM
  #4  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 541
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 165 Post(s)
Likes: 0
Liked 40 Times in 25 Posts
Originally Posted by Snikerdoodlz View Post
My ebike motor's rim is an absolute pain to mount tires on. I know that it's a problem with the rim itself since I've put my exact same tires on another rim with much less effort. Potential DIY defects aside, Is it feasible to grind down my rim to decrease its diameter? I'd rather not spend money on a new rim and service to re-lace my motor.

Edit: The rim in question is the Sun Ringle Rhyno Lite 26x2.00 with 36 holes.
no, you can't shave your rim.
Although the center channel of the Rhyno Lite is very shallow, try squeezing the beads together and press them as deep as possible into the center channel on one side of the tire, and then use a tire lever to pry out the tire the opposite side (180 degrees). Once you get a tire lever to pop a small section of a bead out, use a second tire lever to run around the rest of the rim. A rim with a deeper center channel would be easier for removing tires.
tomtomtom123 is offline  
Likes For tomtomtom123:
Old 12-02-19, 07:32 PM
  #5  
HillRider
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 31,744

Bikes: '''96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '12 Surly Pacer, All are 3x8,9 or 10. It is hilly around here!

Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 1252 Post(s)
Likes: 0
Liked 82 Times in 70 Posts
Since this is an ebike and weight isn't a big factor, carry a KoolStop Tire Jack and three really good tire levers with you. Together, they will remove and remount nearly anything.
HillRider is offline  
Likes For HillRider:
Old 12-02-19, 07:33 PM
  #6  
dedhed
SE Wis
 
dedhed's Avatar
 
Join Date: Apr 2005
Location: Milwaukee, WI
Posts: 5,309

Bikes: '68 Raleigh Sprite, '02 Raleigh C500, '84 Raleigh Gran Prix, '91 Trek 400

Mentioned: 17 Post(s)
Tagged: 0 Thread(s)
Quoted: 778 Post(s)
Liked 128 Times in 99 Posts
Get a tire jack. https://www.jensonusa.com/Kool-Stop-...ck-With-Handle
dedhed is offline  
Old 12-02-19, 07:37 PM
  #7  
dsbrantjr
Senior Member
 
dsbrantjr's Avatar
 
Join Date: Sep 2010
Location: Roswell, GA
Posts: 6,567

Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta

Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 798 Post(s)
Likes: 0
Liked 123 Times in 104 Posts
If your rim has a thick cloth tape such as Velox, you could try a thinner tape such as Continental Easy Tape or a layer of filament-reinforced packing tape or Kapton tape. The thinner tape should make tire mounting easier by allowing you to get the bead deeper into the center of the rim channel.

Last edited by dsbrantjr; 12-02-19 at 07:46 PM.
dsbrantjr is offline  
Likes For dsbrantjr:
Old 12-02-19, 08:50 PM
  #8  
3alarmer
******
 
3alarmer's Avatar
 
Join Date: Nov 2010
Location: The Big Tomato
Posts: 17,706

Bikes: old ones

Mentioned: 248 Post(s)
Tagged: 0 Thread(s)
Quoted: 15691 Post(s)
Liked 313 Times in 270 Posts
...along with that bead jack (which is an essential tool for the price), using liquid soap or even talc as a lubricant between the tyre and rim surfaces as you finish that final arc in mounting the tyre helps a great deal more than you might suppose.
3alarmer is offline  
Likes For 3alarmer:
Old 12-03-19, 01:21 PM
  #9  
WizardOfBoz
Generally bewildered
 
WizardOfBoz's Avatar
 
Join Date: Aug 2015
Location: Eastern PA, USA
Posts: 2,286

Bikes: 2014 Trek Domane 6.9, 1999 LeMond Zurich, 1978 Schwinn Superior

Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 840 Post(s)
Liked 103 Times in 80 Posts
Originally Posted by tomtomtom123 View Post
no, you can't shave your rim.
tomtomtom123 is correct. First, the rim mfr did some weight optimization vs strength. Removing metal arbitrarily is going to give you weak rims. On an ebike? Nein danke.

Second, there is no way to do the grinding with sufficient precision, without removing the rim and mounting it on a lathe face plate. Precision metal cutting requires tools and jigs and fixtures that are exceptionally rigid and a spoked bike wheel doesn't qualify.

So, I suspect that you'd end up with an aesthetically unsatisfactory wheel with really uneven grinding marks that would break prematurely.

read tomtomtom123's post: make sure that the wheel beads are in the center well of the rim when you mount the things. I had huge problems with my tires and rims until I remembered this.

Last edited by WizardOfBoz; 12-03-19 at 01:42 PM.
WizardOfBoz is offline  
Old 12-03-19, 01:58 PM
  #10  
ThermionicScott 
hungry
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 19,358

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 81 Post(s)
Tagged: 0 Thread(s)
Quoted: 2447 Post(s)
Liked 349 Times in 254 Posts
These rims (like CR18) are known for having tall sidewalls. A slightly larger OD is one way a rim manufacturer can try to prevent blowoffs without increasing cost, but it leaves much to be desired. Rather than grinding down the rim, thinner rim tape and better technique should do the job.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 12-03-19, 03:06 PM
  #11  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 541
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 165 Post(s)
Likes: 0
Liked 40 Times in 25 Posts
Originally Posted by dsbrantjr View Post
If your rim has a thick cloth tape such as Velox, you could try a thinner tape such as Continental Easy Tape or a layer of filament-reinforced packing tape or Kapton tape. The thinner tape should make tire mounting easier by allowing you to get the bead deeper into the center of the rim channel.
tesa 4289 packing tape is supposedly the same material as some of the other big bike brand adhesive rim tape. I've used this on my 26mm interior width and 32mm exterior width rims. The tape works great and it's very thin, so it should give you some extra space for when removing your tires, when compared to thicker plastic rim bands. I used a 19mm wide tape which fits perfectly into the bottom of the channel of my rims. The adhesive tape doesn't have to extend all the way to the beads (if you're using a tube), it only has to extend a little bit further than the spoke holes, as long as you're careful not to lift the tape when inserting the tire lever. Non adhesive bands usually should extend all the way to the bead to prevent it from shifting and exposing the spoke holes, but the band that I used was getting under the beads and in between the tire and rim, causing inflation problems. I wrapped 3 rounds of tape onto my rim, but you only need 2 rounds. 3M also makes packing tape. You can search Google for alternative tape brands to see what other people use that might be available locally.
tomtomtom123 is offline  
Old 12-03-19, 07:24 PM
  #12  
xiaoman1 
Senior Member
 
xiaoman1's Avatar
 
Join Date: Mar 2014
Location: Weird Coast City of the Angeles
Posts: 2,362

Bikes: Paramounts, PX-10s, Mondias, Motobecane Grand Record, Specialized Allez Carbon, and Nishiki Tri-A

Mentioned: 26 Post(s)
Tagged: 1 Thread(s)
Quoted: 411 Post(s)
Likes: 0
Liked 94 Times in 75 Posts
Originally Posted by trailangel View Post
SNICKERDOODLE is never allow to work on any bike I own.
+infinity
Ben
xiaoman1 is offline  
Old 12-04-19, 12:06 AM
  #13  
Jeff Wills
Insane Bicycle Mechanic
 
Jeff Wills's Avatar
 
Join Date: Mar 2008
Location: other Vancouver
Posts: 9,084
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 476 Post(s)
Liked 57 Times in 43 Posts
Originally Posted by justinschulz9 View Post
could try a different tire? you should never modify a rim to that degree especially on a bike you are potentially commuting on.
also if the tire is as tight as you say i would recommend getting help from your LBS.
This is probably part of the issue. Ebike tires have much heavier sidewalls than standard bike tires. This will make them tougher to install and remove with standard bike tire levers. I would look into the Kool-Stop Tire Jack or perhaps a set of motorcycle tire levers.
__________________
Jeff Wills

Comcast nuked my web page. It will return soon..
Jeff Wills is offline  
Old 12-04-19, 07:45 AM
  #14  
djb
Senior Member
 
Join Date: Jul 2010
Location: Montreal Canada
Posts: 9,412
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1307 Post(s)
Liked 85 Times in 76 Posts
Originally Posted by Snikerdoodlz View Post
My ebike motor's rim is an absolute pain to mount tires on. I know that it's a problem with the rim itself since I've put my exact same tires on another rim with much less effort. Potential DIY defects aside, Is it feasible to grind down my rim to decrease its diameter? I'd rather not spend money on a new rim and service to re-lace my motor.

Edit: The rim in question is the Sun Ringle Rhyno Lite 26x2.00 with 36 holes.
Sniker--whatever you do, don't grind your rim---but DO please watch this excellent video that shows clearly the technique to work with hard rim/tire combinations
oh, and buy some inexpensive PEDROS tire levers, they are usually yellow and come in a pair, and are super super strong.

but the concept in the video is what others have described, and with some old straps, it REALLY makes all the difference

also, at the very end of slipping the last part of bead on, sometimes putting a bit of soap on the lip edge for a the last 5 inches or whatever can help with that last bit slipping over easier--but gaining those precious extra mm's from the technique shown in video is the main help.

djb is offline  
Likes For djb:
Old 12-04-19, 08:44 AM
  #15  
Drew Eckhardt 
Senior Member
 
Drew Eckhardt's Avatar
 
Join Date: Apr 2010
Location: Sunnyvale, CA USA
Posts: 5,777
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 308 Post(s)
Liked 18 Times in 15 Posts
Originally Posted by Snikerdoodlz View Post
My ebike motor's rim is an absolute pain to mount tires on. I know that it's a problem with the rim itself since I've put my exact same tires on another rim with much less effort. Potential DIY defects aside, Is it feasible to grind down my rim to decrease its diameter? I'd rather not spend money on a new rim and service to re-lace my motor.

Edit: The rim in question is the Sun Ringle Rhyno Lite 26x2.00 with 36 holes.
Use two wraps of 1 mil Kapton totaling 0.005" versus 0.020" for typical rim tapes. 16mm (5/8") works well for traditional road rimes, 19mm (3/4") wide.

Combine that with proper technique, starting 180 degrees opposite from the valve, milking the slack around, and finishing at it.

Manufacturers make rims tighter than they used to, perhaps to reduce liability risk from a flat tire rolling off.

Last edited by Drew Eckhardt; 12-04-19 at 08:58 AM.
Drew Eckhardt is offline  
Old 12-04-19, 08:54 AM
  #16  
Drew Eckhardt 
Senior Member
 
Drew Eckhardt's Avatar
 
Join Date: Apr 2010
Location: Sunnyvale, CA USA
Posts: 5,777
Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 308 Post(s)
Liked 18 Times in 15 Posts
Originally Posted by djb View Post
Sniker--whatever you do, don't grind your rim---but DO please watch this excellent video that shows clearly the technique to work with hard rim/tire combinations
oh, and buy some inexpensive PEDROS tire levers, they are usually yellow and come in a pair, and are super super strong.
The video is wrong. It matters where you start, and beginning at the valve is a handicap..

Rims have a shallow depression in the center.

To get the last bit of bead over, you need the rest of it in that depression.

At the valve hole the depression is occupied by the valve stem so that can't happen.

Start 180 degrees opposite the valve. Finish by continuously moving the bead towards the center, maintaining tension, and milking the slack to the end. Flip it with your thumbs or palms.

You don't need straps if you keep tension on the bead all the way around.

This ignores the gains from using a thinner rim tape. Substituting two wraps of 1 mil Kapton for tradiional rim tapes will get you .0.030" of diameter and 3/32" of additional slack.

Together that's the difference between cussing at tools and comfortably mounting tires by hand.

Last edited by Drew Eckhardt; 12-04-19 at 09:04 AM.
Drew Eckhardt is offline  
Old 12-04-19, 09:17 AM
  #17  
djb
Senior Member
 
Join Date: Jul 2010
Location: Montreal Canada
Posts: 9,412
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1307 Post(s)
Liked 85 Times in 76 Posts
Drew, I guess we'll have to agree to disagree. Once I saw the technique in the video, ie to gain those crucial mm's that help at the end, it has helped make things easier for me with difficult rim tire combos.

Getting the tire into the deeper mid part and staying more or less there is what ends up accumulating with that extra slack at the end.

This is my experience anyway.
djb is offline  
Old 12-04-19, 09:34 AM
  #18  
ThermionicScott 
hungry
 
ThermionicScott's Avatar
 
Join Date: Aug 2011
Location: CID
Posts: 19,358

Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers)

Mentioned: 81 Post(s)
Tagged: 0 Thread(s)
Quoted: 2447 Post(s)
Liked 349 Times in 254 Posts
Starting at the valve isn't "wrong" if you're still able to mount the tire without issue. It's just that current thinking has swung toward finishing at the valve since it helps a tiny bit.
__________________
Originally Posted by chandltp View Post
There's no such thing as too far.. just lack of time
Originally Posted by noglider
People in this forum are not typical.
RUSA #7498
ThermionicScott is offline  
Old 12-04-19, 09:47 AM
  #19  
djb
Senior Member
 
Join Date: Jul 2010
Location: Montreal Canada
Posts: 9,412
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1307 Post(s)
Liked 85 Times in 76 Posts
I prefer starting at valve to avoid the forcing the valve if it's at an angle, if some movement has occurred during mounting.
Am I right it wrong? Who knows, it works though for me.
djb is offline  
Old 12-04-19, 09:49 AM
  #20  
'02 nrs
royaloaker
 
'02 nrs's Avatar
 
Join Date: Jan 2010
Location: se MIch.
Posts: 97

Bikes: 1938 claud butler,1983 Basso,teledyne titan,teocali super,nrs,1993 stumpjumper fsr,Paramountain,Paramount Buell,4 banger,Zaskar LE,Colnago Master Ibex MTB,1987ish,.etc....

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 40 Post(s)
Liked 37 Times in 22 Posts
as mentioned above,

a touch of liquid soap+water.done.
'02 nrs is offline  
Old 12-04-19, 06:28 PM
  #21  
Moe Zhoost
Half way there
 
Moe Zhoost's Avatar
 
Join Date: Sep 2015
Location: Durham, NC
Posts: 1,568

Bikes: Many, and the list changes frequently

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 460 Post(s)
Liked 119 Times in 76 Posts
What tires are you using? I have a set of wheels with Rhyno Lite rims and have found it to be a challenge to mount new Kevlar bead tires. I almost never have to use my VAR tire jack but did this time. The tires seem easier to mount now that they're stretched a bit. Follow the excellent advice posted by others above, stay patient, and you'll do fine. Building up your thumb muscles is always useful.
Moe Zhoost is offline  
Old 12-04-19, 08:29 PM
  #22  
Snikerdoodlz
Junior Member
Thread Starter
 
Join Date: Dec 2017
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Moe Zhoost View Post
What tires are you using? I have a set of wheels with Rhyno Lite rims and have found it to be a challenge to mount new Kevlar bead tires. I almost never have to use my VAR tire jack but did this time. The tires seem easier to mount now that they're stretched a bit. Follow the excellent advice posted by others above, stay patient, and you'll do fine. Building up your thumb muscles is always useful.
I'm using Schwalbe Marathon road tires. Those tires are already tighter than usual, so the combination was brutal. I used to use Maxxis Gypsies, which were still unreasonable.

People are saying to guide the bead into the central depression. Does it not do that automatically when you pull on it when flipping tire levers?
Snikerdoodlz is offline  
Old 12-04-19, 08:40 PM
  #23  
tomtomtom123
Senior Member
 
Join Date: Jan 2017
Posts: 541
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 165 Post(s)
Likes: 0
Liked 40 Times in 25 Posts
Originally Posted by Snikerdoodlz View Post
People are saying to guide the bead into the central depression. Does it not do that automatically when you pull on it when flipping tire levers?
Not really. You have to manually press the bead into the center channel on the opposite of the tire lever and also massage the slack from the pressed area towards the lever. If you apply an incredible amount of force to the lever then it may pull the bead into the center, but there is a risk of damaging the rim or tire, and it depends on the shape of the channel and whether it not the rim tape gets in the way. That's why people are recommending thin rim tape for you.

Have you ever seen a YouTube video about how radial deep groove cartridge bearings are assembled? Have you ever wondered how they get the balls in between the 2 rings? It's the same principle as removing a tire from a wheel. By moving 2 concentric rings so that one side is closer together, it increases the gap on the other side.
tomtomtom123 is offline  
Old 12-04-19, 08:42 PM
  #24  
djb
Senior Member
 
Join Date: Jul 2010
Location: Montreal Canada
Posts: 9,412
Mentioned: 27 Post(s)
Tagged: 0 Thread(s)
Quoted: 1307 Post(s)
Liked 85 Times in 76 Posts
Originally Posted by Snikerdoodlz View Post
I'm using Schwalbe Marathon road tires. Those tires are already tighter than usual, so the combination was brutal. I used to use Maxxis Gypsies, which were still unreasonable.

People are saying to guide the bead into the central depression. Does it not do that automatically when you pull on it when flipping tire levers?
as per the video, my experience shows that by pushing the tire into the deeper section, and making sure you keep the tire in the middle as you work your way around, you accumulate a tiny bit more slack as you work your way to the end.
By not doing it, when you use the levers, it doesnt automatically do it ALL around the tire.

my take on this technique is that the difference is small, but by gaining those crucial mm's of extra room, plus maybe some wet on the last bit of rim to help go against the sometimes natural "sticking" of the rim and bead, to help it slide over a smidge easier, plus some good strong levers--all these small details make the difference.

but of course, every tire and rim combo is different, and some people have much stronger hands and fingers than others.
the few times I've encountered a real bugger of tire/rim mixes, it has helped using straps because they physically squish the tire in and keep it in place, it doesnt spring back, but usually I can just use my hands and make sure the tire stays in the middle as I work my way around.
djb is offline  
Old 12-05-19, 06:40 AM
  #25  
stardognine
Turquoise gatherer.
 
stardognine's Avatar
 
Join Date: Jan 2016
Location: Arid Arizona, for now.
Posts: 2,040

Bikes: 1985 Cannondale ST400

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 484 Post(s)
Likes: 0
Liked 83 Times in 72 Posts
This is a good thread. 👍 I recently had a tough situation, while changing my tires & tubes onto different rims. The whole issue was caused by Slime inner tubes, which didn't want to deflate all the way, due to that sealant jamming up the valve stem. 🙄🤔 I finally gave up on one, and used my spare. And couldn't deflate that tube any more, even outside of the tire & rim, to store it in my pannier as a spare. 🙁

Anyways, there's something else to complicate the issue even further. 😁😉 Another good reason to always carry a spare tube or two.
stardognine is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.