ADVrider

Go Back   ADVrider > Bikes > GSpot > GS Boxers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-01-2009, 12:59 PM   #1
Zpider OP
Adventurer
 
Joined: Jan 2008
Location: Sweden
Oddometer: 97
21" wheel on a 2007 GSA

Hi

Anyone run a 21" front wheel on a 1200GS without servo (power) brakes?
Some says the ABS will go nuts, some says it work without doing anything. Wunderlich used to market an adapter for their kit, but no longer carry that...
__________________
-----------------------------------------------------------
BMW R1200GS Adv 2008
http://www.weirdperformance.se
Zpider is offline   Reply With Quote
Old 11-01-2009, 02:05 PM   #2
signit98
Nutcase... really!
 
signit98's Avatar
 
Joined: May 2008
Location: Sun Diego, Mexifornia
Oddometer: 802
You are adding 2" in diameter, which will throw the geometry seriously off... I doubt that the added off road ability will make up for that... if you ride offload that much, get a different bike!
__________________
Ralf Wilkowski

Been there - already forgot about it...!

Follow my Journey, pursue insanity:

www.itwasnotme.com
signit98 is offline   Reply With Quote
Old 11-01-2009, 02:20 PM   #3
Zpider OP
Adventurer
 
Joined: Jan 2008
Location: Sweden
Oddometer: 97
Quote:
Originally Posted by signit98
You are adding 2" in diameter, which will throw the geometry seriously off... I doubt that the added off road ability will make up for that... if you ride offload that much, get a different bike!
Well, the question was not really regarding the handling when fitting a 21" wheel, it was about the functionality on the ABS system. I know there are guys who have done this conversion, but did the ABS get a hickup or not?
__________________
-----------------------------------------------------------
BMW R1200GS Adv 2008
http://www.weirdperformance.se
Zpider is offline   Reply With Quote
Old 11-01-2009, 03:01 PM   #4
Boxerlove
Gnarly Adventurer
 
Joined: Jul 2009
Location: IL
Oddometer: 122
There shouldn't be any issues. I have an 05 with a 21" front and servo with abs. The abs works as good as it did with the 19" and didn't throw any lights or codes. I'm not sure about a non servo bike but I don't think it will be a problem. The bike overall rides a lot better with the 21". It rides like the way it should of came from the factory. I'll never go back to a 19"
Boxerlove is offline   Reply With Quote
Old 11-01-2009, 03:23 PM   #5
Russ
.
 
Russ's Avatar
 
Joined: Jul 2007
Location: Sydney Australia
Oddometer: 15,595
I have a 21 from woody's wheel works it has an abs ring fitted that allows the ABS to function correctly,
The wheel has transformed the bikes off-rorad handling


Quote:
Originally Posted by signit98
You are adding 2" in diameter, which will throw the geometry seriously off... I doubt that the added off road ability will make up for that... if you ride offload that much, get a different bike!
signit98 Your reply is ill informed.
Russ is offline   Reply With Quote
Old 11-01-2009, 04:31 PM   #6
Zpider OP
Adventurer
 
Joined: Jan 2008
Location: Sweden
Oddometer: 97
Quote:
Originally Posted by Boxerlove
There shouldn't be any issues. I have an 05 with a 21" front and servo with abs. The abs works as good as it did with the 19" and didn't throw any lights or codes. I'm not sure about a non servo bike but I don't think it will be a problem. The bike overall rides a lot better with the 21". It rides like the way it should of came from the factory. I'll never go back to a 19"
From what i hear the problem comes with models without servobrakes, 2007 and up. Wunderlich used to sell an adapter to make their conversionkit fit on theese models, but now they dont carry that adapter anymore. I have no idea as to what the adapter did, but i think it "fooled" the electronics to think the wheel was the right diameter. I dont want to loose the ABS functionality by going with 21" wheel, so the question is, what would happend if i run without it. And yes, 21" does make a lot of difference.
__________________
-----------------------------------------------------------
BMW R1200GS Adv 2008
http://www.weirdperformance.se
Zpider is offline   Reply With Quote
Old 11-01-2009, 06:21 PM   #7
Russ
.
 
Russ's Avatar
 
Joined: Jul 2007
Location: Sydney Australia
Oddometer: 15,595
Contact Woodys wheel works ask for Woody or Zach they will be able to explain how their ABS ring works, so that the ABS works properly.

woodyswheelworks@gmail.com
Russ is offline   Reply With Quote
Old 11-01-2009, 08:59 PM   #8
signit98
Nutcase... really!
 
signit98's Avatar
 
Joined: May 2008
Location: Sun Diego, Mexifornia
Oddometer: 802
Quote:
Originally Posted by SYDADVGS
signit98 Your reply is ill informed.
No, it is based on facts and geometry... simple stuff engineers look at when designing a bike. If you don't change anything else but just add the 21" front wheel, the bike will turn in much less willingly and get's quirkier in high speed corners... you just lift the front end and change weight distribution.

If you ride more off road than on road, the mod might be useful, but then again... the bike itself is limiting you, compared to even a big orange sail or better a thumper of almost any kind.

If you don't believe me, throw a 17" front into the GS and try it again... you'll be amazed... you have almost a real (albeit heavy) sport bike!

Keep in mind that I ride mostly road stuff and more twisties than anything else... I throw in the odd fire road and in AK was forced to do some stuff I would have questioned on a designated bike down here...

The bike CAN do it... but it's not ideal... a 21" front wheel will not change that by much... adding an 18" rear might help that a tad, though...

This, of course, just expresses my opinion/viewpoint/experience... as it were.
__________________
Ralf Wilkowski

Been there - already forgot about it...!

Follow my Journey, pursue insanity:

www.itwasnotme.com
signit98 is offline   Reply With Quote
Old 11-01-2009, 09:20 PM   #9
Russ
.
 
Russ's Avatar
 
Joined: Jul 2007
Location: Sydney Australia
Oddometer: 15,595
Quote:
Originally Posted by signit98
No, it is based on facts and geometry... simple stuff engineers look at when designing a bike. If you don't change anything else but just add the 21" front wheel, the bike will turn in much less willingly and get's quirkier in high speed corners... you just lift the front end and change weight distribution.

If you ride more off road than on road, the mod might be useful, but then again... the bike itself is limiting you, compared to even a big orange sail or better a thumper of almost any kind.

If you don't believe me, throw a 17" front into the GS and try it again... you'll be amazed... you have almost a real (albeit heavy) sport bike!

Keep in mind that I ride mostly road stuff and more twisties than anything else... I throw in the odd fire road and in AK was forced to do some stuff I would have questioned on a designated bike down here...

The bike CAN do it... but it's not ideal... a 21" front wheel will not change that by much... adding an 18" rear might help that a tad, though...

This, of course, just expresses my opinion/viewpoint/experience... as it were.
Have you ever ridden a GS with a 21" front wheel on the dirt?
If you have you should have noticed a big improvement in the handling particularly in sand or mud.

I presume that this thread about the bigger wheel was because Zpider wanted to use the bigger wheel off road
Russ is offline   Reply With Quote
Old 11-01-2009, 10:57 PM   #10
Boxerlove
Gnarly Adventurer
 
Joined: Jul 2009
Location: IL
Oddometer: 122
+1 just contact woody. That's where I got my wheel from. He will know better then anyone else.

signit98-
Obviously if you mostly ride the twisties you wouldn't care for the huge benefit the 21" front adds off road but is still fun in the turns. I'm a dirt rider and would never consider a 17" front. The 18" rear is nice but then the gearing is too tall so I would prefer the 17" still out back unless there was a lower final drive ratio. I do agree though to get the full benefit of the 21" front you need to have after market suspension to adjust front to rear balance and to your personal settings so not to have the chopper effect. My GS is my do everything bike and it does everything very well.
Boxerlove is offline   Reply With Quote
Old 11-02-2009, 04:49 AM   #11
diabolik37
Push Dumb C***
 
diabolik37's Avatar
 
Joined: Jan 2008
Location: QLD AUS
Oddometer: 912
Quote:
Originally Posted by Zpider
Hi

Anyone run a 21" front wheel on a 1200GS without servo (power) brakes?
Some says the ABS will go nuts, some says it work without doing anything. Wunderlich used to market an adapter for their kit, but no longer carry that...
The ABS job is to prevent your wheels from loocking up. It doesn't really matter if the wheel are not rotating at the same speed. Now if you were asking about traction control, that is another matter and different wheel size would create trouble...
__________________
STOP the Planet! I want to get off!
diabolik37 is offline   Reply With Quote
Old 11-02-2009, 05:17 AM   #12
Zpider OP
Adventurer
 
Joined: Jan 2008
Location: Sweden
Oddometer: 97
That actually makes a lot of sence when thinking of it. As i understand front and back dont really have anything to do with each other regadring the ABS. ASC on the other hand i would believe get confused.
__________________
-----------------------------------------------------------
BMW R1200GS Adv 2008
http://www.weirdperformance.se
Zpider is offline   Reply With Quote
Old 11-02-2009, 08:28 AM   #13
sab
Gnarly Adventurer
 
sab's Avatar
 
Joined: Sep 2008
Location: Seattle
Oddometer: 259
Quote:
Originally Posted by Zpider
That actually makes a lot of sence when thinking of it. As i understand front and back dont really have anything to do with each other regadring the ABS. ASC on the other hand i would believe get confused.
But how would the computer know they are locking up? It would sense one wheel turning slower than the other. I wonder if the fix is a ring plate w/ a different number/spacing of holes to compensate for the increase in wheel diameter?

Seems to me that would trick the computer into thinking all was well...
sab is offline   Reply With Quote
Old 11-02-2009, 04:23 PM   #14
Zpider OP
Adventurer
 
Joined: Jan 2008
Location: Sweden
Oddometer: 97
Quote:
Originally Posted by sab
But how would the computer know they are locking up? It would sense one wheel turning slower than the other. I wonder if the fix is a ring plate w/ a different number/spacing of holes to compensate for the increase in wheel diameter?

Seems to me that would trick the computer into thinking all was well...
I dont think the ABS work by checking that both wheels run at the same speed. It simply check if the wheel is about to stop turning ie locking up regardless on what the other wheel do. I may be wrong here but...
__________________
-----------------------------------------------------------
BMW R1200GS Adv 2008
http://www.weirdperformance.se
Zpider is offline   Reply With Quote
Old 11-02-2009, 06:47 PM   #15
Russ
.
 
Russ's Avatar
 
Joined: Jul 2007
Location: Sydney Australia
Oddometer: 15,595
The traction control is only affected for the first bit travelled if you pull off very fast it kicks in once moving it seems to calculate the wheel rotation and somehow does not activate unless the wheel does slip, I've tried this on dirt don't know how but works but it does.
Russ is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
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 On

Forum Jump


Times are GMT -7.   It's 03:32 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014