Turning brake disc rotors - Stromtrooper Forum : Suzuki V-Strom Motorcycle Forums
Stromtrooper Forum : Suzuki V-Strom Motorcycle Forums
Go Back   Stromtrooper Forum : Suzuki V-Strom Motorcycle Forums > V-Strom Forums > Maintenance, Tech and Farkles. > V-Strom Service and Maintenance Questions and Discussions


V-Strom Service and Maintenance Questions and Discussions Share your service and maintenance information-questions

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-29-2012, 01:05 AM
$tromtrooper
 
Join Date: Aug 2011
Location: Rural north/central Louisiana
Posts: 826
Default Turning brake disc rotors

The Wee is at that point where it needs a thorough maintenance attack. I am starting to feel a slight oscillation in the front disc rotors which also manifests itself by a slight wobble when I let go of the bars at 50mph. Question is, can NAPA turn these rotors just like the automotive discs? I live way out in the country and the nearest town is 11 miles away with a NAPA store that I've used to turn my truck rotors and they did an excellent job. The nearest M/C dealer is over 20 miles away and NAPA charges $10 per disc.
__________________
'92 Honda Z50R
'94 Kawasaki KLX250 modded to 340cc's
'00 Yamaha YZ426F
'94 Yamaha 125 scooter
'05 Vespa E4 scooter
'68 Vespa VBB scooter (restored)
'06 Wee
'03 Honda S2000 roadster
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 08-29-2012, 01:11 AM
greywolf's Avatar
Moderator++
 
Join Date: Jan 2006
Location: Evanston IL
Posts: 29,144
Default

The discs are too thin to turn. It's rare for them to be warped. Warped discs won't cause a wobble when not braking. The steering head bearings, tire wear or tire brand are the usual suspects.
__________________
Pat- 2007 DL650A was ridden to all 48 contiguous states. 2012 DL650A is just getting started.
Nicknames I use to lessen typing, Vee = 2002-2012 DL1000s. Vee2=2014+ DL1000s. Wee = 2004-2011 DL650s. Glee = 2012+ DL650s
See http://www.stromtrooper.com/general-...nicknames.html

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
  #3  
Old 08-29-2012, 10:14 AM
Stromthusiast!
 
Join Date: Aug 2009
Location: Washington, the state
Posts: 5,765
Default

The pressed buttons that hold the rotor to its hub prevent the auto machine shop from securely holding the rotor even if they did try to turn it. And, they probably can't cut the stainless steel rotor--their equipment is made to turn cast iron rotors and drums. If absolutely necessary (because no new rotors were available anywhere), the buttons could be removed, the rotors surface ground by a machine shop, and new buttons installed, but that would cost more than new rotors.

Anyway, the myth that brake judder is caused by warped rotors has been widely debunked:
-Warped- Brake Disc and Other Myths
Brake Judder and Wheel Binding
__________________
To err is human;
to persist in it is diabolical
--Lucius Annaeus Seneca (1-65 AD)


America’s infrastructure is now so wretched that, in some areas, the only people who drive straight are the drunks.
Anyone who is sober swerves to avoid potholes.
--Nicholas Kristof
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
  #4  
Old 08-30-2012, 07:46 PM
Stromthusiast!
Super Trooper!
 
Join Date: May 2012
Location: alabama
Posts: 21
Default

I"M with grey wolf on this. If your rotors were warped, you would only feel it in the brake pedal / lever with braking. I"ve almost bet new front tire and its gone.
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
  #5  
Old 08-31-2012, 04:29 AM
$tromtrooper
 
Join Date: Aug 2011
Location: Rural north/central Louisiana
Posts: 826
Default

I feel no warped sensation from the lever. What I do notice is a slight wobble from the front end if I let go of the bars from the decelleration which puts the weight on the frontend affecting the rake/trail part of the suspension equation. It IS slight. I did a quick check by putting the bike on the center stand and having my friend sit WAY back on the bike to lift the front wheel up so I could free spin it. The front brake shows that at least one of the rotors is not true as the wheel spins freely and then grabs slightly with a high pitched squeal, releases(quiet) and then does it again. When it grabs, it IS slight with the accompaning squeal. It's not a sudden and violent stopping of the wheel. Appears to me that one or both rotors are very slightly warped. Hey, the bike has 40k miles on it. I want the frontend to handle and behave like it should. To be accurate, as long as both hands are on the grips, the frontend is stable and handles with no complaints. It is only if I test the frontend by letting go of the bars at speed, then, there is a VERY SLIGHT wobble. What I have done to this point is to adjust the preload on the forks ALL the way which helped enormously. Before this adjustment, the bike would do a severe frontened dive(under braking) and wobble somewhat violently. No doubt, the front springs are too soft. After that, I adjusted the rear spring preload all the way hard, which aslo helped make the bike more stable. This machine is way undersuspended! I started doing online research and found this to be true. I am an X (too old now) motocrosser with a ton of suspension experience. Brake rotor warpage has never been an issue with MX since we rarely exceed 60mph.
__________________
'92 Honda Z50R
'94 Kawasaki KLX250 modded to 340cc's
'00 Yamaha YZ426F
'94 Yamaha 125 scooter
'05 Vespa E4 scooter
'68 Vespa VBB scooter (restored)
'06 Wee
'03 Honda S2000 roadster
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
  #6  
Old 08-31-2012, 11:09 AM
greywolf's Avatar
Moderator++
 
Join Date: Jan 2006
Location: Evanston IL
Posts: 29,144
Default

Adjusting the preload does not stiffen anything. It only changes the sag or ride height. That can affect rake and trail measurement. Raising the front end will increase rake and trail which provides greater stability at lower speeds. An '06 Wee will be less stable at high speeds with more front end preload though because the fairing design causes aerodynamic lift.

The preload is best set as in The Science and Black Magic of Suspension Setup and the fork tubes raised 10-15 mm to lower the angle of attack through the air. Changing the weak springs if you weigh more than 150lbs makes a big difference. Again, steering head bearings and tires are the usual wobble causes and are commonly experienced.
__________________
Pat- 2007 DL650A was ridden to all 48 contiguous states. 2012 DL650A is just getting started.
Nicknames I use to lessen typing, Vee = 2002-2012 DL1000s. Vee2=2014+ DL1000s. Wee = 2004-2011 DL650s. Glee = 2012+ DL650s
See http://www.stromtrooper.com/general-...nicknames.html

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
  #7  
Old 12-01-2012, 12:19 PM
Noblehops's Avatar
Stromthusiast!
 
Join Date: May 2012
Location: Santa Cruz, CA, USA
Posts: 176
Default You can grind stainelss rotors!

It doesn't sound like a rotor problem is to blame for the OPs troubles, but I thought I'd add this info for others surfing these threads as I was just now:

I was happy to discover this guy a couple of years ago - he has developed a technique for grinding stainless rotors and flywheels and he's done a couple of sets for me by now.

TrueDisk LLC - Motorcycle Brake Rotor Resurfacing and Grinding Services

He's understandably a little shy about going into too much detail into his process, but it's a cousin of 'blanchard' grinding I think, and the rotors are bathed in coolant while he works. Most bike rotors will have a minimum thickness stamped in the carrier if you look closely for it, and if you have 50 thousanths or more to spare then it's worth doing. He charges $45 per rotor plus USPS flat rate shipping at $12 or so. He's a great guy, turns stuff around in just a couple of days. You send him the entire assembly, rotor and carrier.

Some photos of stuff he did for me:

My 1100S:


Before (not so flat):


After (nice and flat)


Upgraded 900F calipers and rotors on my CBX, ground and drilled by Truedisk:


I am about to do a brake overhaul on my Strom and all three rotors will be going out to Tom before I reassemble it. Hope this helps somebody.

Disclosure: When I found him his website was broken. I fixed it for him and he grinds my rotors for me in return. You will see photos of my rotors on his site too.

N.
__________________
--
Nils Menten - Santa Cruz, CA, USA

R1200GS, DL1K3, CBX, DRZ
I have a motorcycle problem.

Last edited by Noblehops; 12-01-2012 at 12:24 PM.
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Sponsored Links
Advertisement
 
Reply

Tags
brake

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 06:20 PM.


Powered by vBulletin® Version 3.8.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.5.2