Aftermarket shock shaft length - Discuss Aftermarket shock shaft length on CBRXX, the ultimate on-line community for Honda motorcyclists. Read it in Suspension / Tires / Wheels / Brakes. (Discussion of Honda CBR 1100 XX Super Blackbird Forks, Shocks, Chains, Sprockets, Tires, Wheels, and Brakes.)

SSUXX · 12-15-2006, 9:48 AM

I passed on the Ohlins group buy but decided to pick up a Wilburs instead (I haven't ordered yet). What do you guys suggest as far as shaft length? Is there a preferred length? The 6mm shim is popular, should I order a longer shock than stock?
Thanks in advance.

OZDave · 12-15-2006, 10:59 AM

I ordered the 5mm longer shock and don't need the shim. The rear wheel just clears the ground on the center stand (with new tyres). I'd recommend 5mm. 6mm is great for handling but can cause problems with the center stand. I also had to extend the side stand.

SSUXX · 12-15-2006, 11:17 AM

I've been riding long enough to know that tire profiles change the geometry of any bike. I installed BTO14's and the front end of the bike rides much higher resulting in much slower steering and heavier handling. I was never happy with these tires but the grip is good enough to wear through them. No problem. I bring this up not to discuss tires (Please god no

) but I think many times (And especially regarding newer riders) tires are judged by how they change the geometry of the bike rather than the feel they offer. Sharper steering is viewed as an improvement yielded by installing a "Better tire". What does this have to do with shock shaft length? I wonder how often the 6mm shim fix and a longer shock shaft worsens the feel and balance of the bike? If you switch from brand A tire to brand B tire, technically handling issues could arise just from the tires having different profiles and different sizes. This is why i'm wondering if the stock length is the way to avoid having handling issues in the future.

PJNXX · 12-15-2006, 12:38 PM

IMHO, don't shim and keep the stock shock length. The Honda engineers got paid big money to design the bike with the correct geometry for it's intended purpose. It's not a racer replica, so why mess with it? The higher you raise the rear end, the more unstable the bike will be at higher speeds.

SSUXX · 12-15-2006, 12:48 PM

Quote:

Originally Posted by PJNXX

IMHO, don't shim and keep the stock shock length. The Honda engineers got paid big money to design the bike with the correct geometry for it's intended purpose. It's not a racer replica, so why mess with it? The higher you raise the rear end, the more unstable the bike will be at higher speeds.

That's certainly one way to look at it but I think the XX would benefit from raising the rear. Alot of bikes would.

OZDave · 12-15-2006, 10:45 PM

Most of the guys have done the mod around here and it definitely does not affect stability at speed. I believe the standard ride height is overly conservative. The improvement is very noticable.

lois · 12-15-2006, 10:56 PM

Quote:

Originally Posted by SSUXX

That's certainly one way to look at it but I think the XX would benefit from raising the rear. Alot of bikes would.

I think the Honda people took a midline approach when they set the rear ride height of the XX.

IMHO, the bird is set up for fairly good handling, as well as fairly good top end stability. However, that being said, this set up does not suite everyones riding style and could, if desired, be changed to suite.

As for tires, I could not agree more that different tires change the dynamics of a bike.

How many times have I heard " wow...I put new tires on my bike, and man, does it ever turn in quicker" I say, sure it does, but why?

Is it because it's a different brand or stlye of tire than they had before with different dynamics....or is it simply because the old tire ( front and rear) were squared off and had lost their " tippyness" ?

I have tried lots of differnt tires on the bird over the years , found what works for me, and stay with that brand/style. I have also lifed my bird 6mm and love it that way, cause it works for me.

So hey...

Play with your bike, find what works for you.....or, if you like her the way she came out of the box....then thats good too. : )

testrider · 12-16-2006, 2:09 AM

Quote:

Originally Posted by PJNXX

IMHO, don't shim and keep the stock shock length. The Honda engineers got paid big money to design the bike with the correct geometry for it's intended purpose. It's not a racer replica, so why mess with it? The higher you raise the rear end, the more unstable the bike will be at higher speeds.

Yes, I agree. At least it wasn't for me. I added the 6mm shim a year ago. It did turn in faster but:

- the rear now is higher and therefore put more weight on my wrists when riding
- the rear is higher => more wind blast to my helmet
- I'm sliding to the tank
- Depending on the wind and speed, the steering gets nervous and easier to get headshake with my Givi

I just removed the shim to go back to stock.

12-15-2006, 10:59 AM	#2
OZDave Join Date: Oct 16 2006 Location: Brisbane, Australia Posts: 808	Re: Aftermarket shock shaft length I ordered the 5mm longer shock and don't need the shim. The rear wheel just clears the ground on the center stand (with new tyres). I'd recommend 5mm. 6mm is great for handling but can cause problems with the center stand. I also had to extend the side stand. __________________ Just because I'm paranoid doesn't mean people aren't out to get me!

12-15-2006, 12:38 PM	#4
PJNXX Moderator Join Date: Nov 12 2006 Location: Medford, NY Age: 40 Posts: 1,905	IMHO, don't shim and keep the stock shock length. The Honda engineers got paid big money to design the bike with the correct geometry for it's intended purpose. It's not a racer replica, so why mess with it? The higher you raise the rear end, the more unstable the bike will be at higher speeds. __________________ -Paul

12-15-2006, 10:45 PM	#6
OZDave Join Date: Oct 16 2006 Location: Brisbane, Australia Posts: 808	Re: Aftermarket shock shaft length Most of the guys have done the mod around here and it definitely does not affect stability at speed. I believe the standard ride height is overly conservative. The improvement is very noticable. __________________ Just because I'm paranoid doesn't mean people aren't out to get me!

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Rear shock preload and ride height question	testrider	Suspension / Tires / Wheels / Brakes	8	05-17-2008 12:28 PM
FS.........Aftermarket Wheels	BDAZXX	For Sale / Wanted	2	12-31-2006 11:24 AM
Blackbird Mega-Sale: WILBERS #641 Rear Shock - SOLD!!!	Warchild	For Sale / Wanted	0	11-14-2006 11:11 PM

12-15-2006, 11:17 AM	#3
SSUXX Join Date: Nov 07 2006 Location: LI, NY Posts: 72	I've been riding long enough to know that tire profiles change the geometry of any bike. I installed BTO14's and the front end of the bike rides much higher resulting in much slower steering and heavier handling. I was never happy with these tires but the grip is good enough to wear through them. No problem. I bring this up not to discuss tires (Please god no ) but I think many times (And especially regarding newer riders) tires are judged by how they change the geometry of the bike rather than the feel they offer. Sharper steering is viewed as an improvement yielded by installing a "Better tire". What does this have to do with shock shaft length? I wonder how often the 6mm shim fix and a longer shock shaft worsens the feel and balance of the bike? If you switch from brand A tire to brand B tire, technically handling issues could arise just from the tires having different profiles and different sizes. This is why i'm wondering if the stock length is the way to avoid having handling issues in the future.