919 sloppy cush drive mod - Wrist Twisters
 
Thread Tools Display Modes
post #1 of 6 Old 05-11-2013, 11:17 AM Thread Starter
Tirone
 
Join Date: Feb 2013
Location: London
Posts: 11
Rep Power: 1
 
919 sloppy cush drive mod

I don't know if anyone else has been troubled by sloppy cush drives on their 919 / 900? On my old FZ750, rather than replacing the notoriously poor rubber cushes, I would pack them out with a few 1.2mm aluminium plates, bonded with 467 3M double sided tape (bonded to each of the wheel housing vanes of course), such that a hide mallet would be required for cush drive/sprocket carrier assembly, giving a much smoother drive train. I think I ended up with two or three plates on each vane!

It seems to me that the 919, with it's hefty torque and it's slightly on/off FI throttle response, is in need of a similar mod, as mine is very sloppy after only 10K miles. This time I have used some old adhesive backed 0.6mm Lexan polycarbonate labels I had kicking around, cut to fit (40mm x 60mm), folded and bonded over the wheel hub vanes. I'm hoping they won't creep too much, but they can't go far nor do any damage.

As an aside, my old Yamaha 250LC production racer had so much transmission slack, that it was possible to push start the bike without using the clutch, saving invaluable fractions of a second; the trick was to pull the bike backwards in gear to take up the slack; then on the drop of the flag, one step, leg over and away.... In the days of push start racing (we're talking 25 years ago), this gave me a massive advantage off the line and into the first corner, even against the 350's, which alas didn't often last the race.
Oh the sweet smell of silkolene synthetic drifting down the breeze, as I pick myself out of the gravel at Druids yet again....

Hornet 900 (919) 2003. Leo Vince SBK cans.
lewisham_phil is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 05-11-2013, 12:31 PM
Aquilifer
 
rpcraft's Avatar
 
Join Date: May 2012
Location: Dallas
Posts: 1,128
Rep Power: 1
 
I could be completely mistaken here but I think if you took out the rubbers on the 919, it would mess up your chain and sprockets (and possibly gears) more quickly because of the shock created by the quirky throttle... I mean, the whole purpose of the cush drive is to prevent the components from shock and bang... What would replacing the rubbers with metal do to prevent the sudden on/off shock created by the throttle quirks? I could see on some other bikes it being a bit different, but I know when I try to lug my hornet to any degree if it did not have the cush drive I'd probably eat dirt or break shit.... Now, on my Hawk, I could go cushless all day long, but I don't wanna jerk around with having it converted right now (or just yet). I'm still scrounging money to keep one bike running while rebuilding the other one, lol...

Rob C

88 Blue Hawk (NT650) Project Pics - http://tinyurl.com/clw8h3q
2000 DL650 - Being ridden but make me an offer if interested...
2002 DL1000 V-Strom
rpcraft is offline  
post #3 of 6 Old 05-11-2013, 01:12 PM Thread Starter
Tirone
 
Join Date: Feb 2013
Location: London
Posts: 11
Rep Power: 1
 
Hi Rob, it's good you posted a prompt response, as the thought that people might remove the cush drive rubbers completely, to be replaced by a couple of aluminium shims is rather alarming! No, I was suggesting packing out your current cush drive rubbers to take out any slop that has built up through wear, or is inherent in the original design (I have never had a brand new bike to know if the cush drives are ever a light interference fit from the off). The rubber cushes tend to abrade with wear, and I imagine the wear will be exponential as more slop exacerbates the problem.
Just to re-iterate: Don't remove your cush drive rubbers! Just don't buy new ones: pack the old ones out.

Hornet 900 (919) 2003. Leo Vince SBK cans.
lewisham_phil is offline  
 
post #4 of 6 Old 05-11-2013, 01:44 PM
Aquilifer
 
rpcraft's Avatar
 
Join Date: May 2012
Location: Dallas
Posts: 1,128
Rep Power: 1
 
My bad. I can not say for certain because I have not done them on the Hornet yet but most any other bike I have done the rubbers are more than snug. Are the usually as loose as you reference? I know my Hawk is a SSSA so its a bit different but still, when I replaced rubbers on it they were so tight I had to grease them a tiny bit in order to get it to seat enough to get the thread started to finish compressing the assembly.... Maybe that is just an inherent difference between a standard swingarm bike and a single sider...

Rob C

88 Blue Hawk (NT650) Project Pics - http://tinyurl.com/clw8h3q
2000 DL650 - Being ridden but make me an offer if interested...
2002 DL1000 V-Strom
rpcraft is offline  
post #5 of 6 Old 05-12-2013, 01:46 AM
Imaginifer
 
woodyeee's Avatar
 
Join Date: Mar 2007
Location: united kingdom
Posts: 406
Rep Power: 1
 
I've known guys to pack out the cush drive with an old inner tube, cut up into sections.

http://i121.photobucket.com/albums/o222/woodyeee/IMAG0306.jpg
woodyeee is offline  
post #6 of 6 Old 05-12-2013, 04:09 PM
Aquilifer
 
rpcraft's Avatar
 
Join Date: May 2012
Location: Dallas
Posts: 1,128
Rep Power: 1
 
The first time I took it apart on my Hawk the guy before me had used cut up pieces off a knobby 4 x 4 tire that must have been no longer good for road or offroad use.

Rob C

88 Blue Hawk (NT650) Project Pics - http://tinyurl.com/clw8h3q
2000 DL650 - Being ridden but make me an offer if interested...
2002 DL1000 V-Strom
rpcraft is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Wrist Twisters forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome