Jump to content
CBR1100XX.org Forum

Project Blackbird


JaBr

Recommended Posts

So I finally did a bit more to the bird at the weekend.

 

Having previously shown the state of the fork legs I bought some replacements, over the last few weeks I have looked at them every time I went into the garage and thought, nope, they'll be fine, not rebuilding them.  I think this was a combination of laziness and fear of the unknown as I've never rebuilt forks before.  Anyway, I decided to go for it, took about an hour working methodically and following the instructions in this video.

 

Ironically, the thing I was most worried about was the cap coming off at 100mph and taking a chunk out of me, looking at the way the forks are constructed I don't think it's even possible with these forks.  Once the cap is released from the stanchion it is still attached to the damping rod of the cartridge by a locked thread and therefore has a very limited amount of travel, all of which would be damped anyway.

 

So anyway, a couple of pictures of the deconstructed forks.  As you can see from the second photo, it's still pretty cramped in my garage.

 

The tube to the left is the one that sits on the lower part of the cartridge.

IMG_4813.thumb.JPEG.b3de0c412696bba030051b749d13ab6d.JPEG

 

Very glad I decided to do this, the oil from the forks is decidedly murky, and one of the oil seals was just starting to weep.  The new stacnhions are reasonably good but do have a couple of small stonechips in them.

 

IMG_4814.thumb.JPEG.8373f1f693e79e42ae7350c33faabe9b.JPEG

Link to comment
Share on other sites

1 hour ago, blackhawkxx said:

So what parts did you replace in your rebuild?

 

I'll be fitting new seals, bushings, and oil of course.  No change to the springs, they seem fine as far as I can tell.  I've been seriously considering the preload caps from Jaws but with all the money spent so far I can't really justify them at the moment.  I do have a 6mm shim ready to go on the rear though, I understand that makes a big difference, one of the things I've found with the bird is that it's way less nimble than my '90 VFR, hopefully the shim improves things.  

 

I have the centre stand and wingrack going off for powder coating next week, I had a bunch of other parts powder coated a while back and want the bike to look tidy, a ratty centre stand next to a newly powder coated side stand just wasn't working for me.

Link to comment
Share on other sites

I've read that using a lighter than stock oil makes them better, but don't remember which was suggested.  There might even be some instructions out there for tuning the valving.  It would be worth checking into that stuff before putting them back together.

Link to comment
Share on other sites

It does not get really warm in your location so I'd strongly suggest lighter fork oil- 7wt. IIRC stock is 10wt. 

Not all suspension oils have been created  equal. I use Maxima blue label or Ohlins products.

Since you got everything out I'd disassemble and lap comp. and rebound valves. Flat piece of glass, start with 600 and finish with something finer. Make sure to use appropriate loctite where needed.

Link to comment
Share on other sites

The XX forks are seriously easy to pull down and work on. Do my own every couple years and like using 7.5 oil. 

Did find out that honda was cheap in the amount of oil they put in from factory. According to the manual and doing it by height I imagine honda shorted me an ounce or so in each fork. 

 

 

Link to comment
Share on other sites

18 hours ago, tomek said:

It does not get really warm in your location so I'd strongly suggest lighter fork oil- 7wt. IIRC stock is 10wt. 

Not all suspension oils have been created  equal. I use Maxima blue label or Ohlins products.

I've already bought the Motul 10w but having done some more research I think 7/7.5 looks like a better plan for me.  About 175lb in weight and like you say our climate is generally cooler.

Link to comment
Share on other sites

2 hours ago, superhawk996 said:

And note that while the number on the bottle 'should' be the end of the story, each brand will have it's own viscosity so it's not as straight forward as one would think.

So does anyone have a list of thick and thin 7.5w of the major brands?

Link to comment
Share on other sites

9 hours ago, blackhawkxx said:

Who knew?

ME😁

 

I didn't want to chose one specific chart/comparison because there's a bunch of them laid out in different ways and each person likes different things, and I didn't want to imply that I have faith in any particular one.

Link to comment
Share on other sites

You already have the forks down.

Unless you are a lightweight, I would look at springs ( 1 kg) and emulators.

I put the Penske cartridge in mine years ago, on a group buy.

I ran 240 lbs full gear at that time. A friend, same size, rides a k1200rs. 

I would bottom out hard on the little bridge on 180 between Suches and Hwy 129.

Not at all on the RS.

Penske cartridge and correct springs make a real difference.

The rear shim helps the bike turn in. 

Doing the front end is worth it.

Cogent Dynamics did the group buy.

They also supplied springs, emulators, and oil suggestions for my SV650. Another undersprung bike.

 

Cogent

Edited by redxxrdr
  • Upvote 1
Link to comment
Share on other sites

3 hours ago, XXitanium said:

Shit, now I have a project.

You won't be disappointed.

You can get the parts for a couple hundred dollars. 

Rick (I think) at Cognet, helped me pick emulator, and spring rates , if I purchased from him.

My little SV had a great improvement, and let me learn a few things.

  • Upvote 1
Link to comment
Share on other sites

On 9/12/2020 at 7:17 AM, redxxrdr said:

You already have the forks down.

Unless you are a lightweight, I would look at springs ( 1 kg) and emulators.

I put the Penske cartridge in mine years ago, on a group buy.

I ran 240 lbs full gear at that time. A friend, same size, rides a k1200rs. 

I would bottom out hard on the little bridge on 180 between Suches and Hwy 129.

Not at all on the RS.

Penske cartridge and correct springs make a real difference.

The rear shim helps the bike turn in. 

Doing the front end is worth it.

Cogent Dynamics did the group buy.

They also supplied springs, emulators, and oil suggestions for my SV650. Another undersprung bike.

 

Cogent

 

I'm currently around 175lbs, usually around 140-145lbs dripping wet and naked, working from home plays havoc with my eating habits hence the increase.  I'm not sure whether that qualifies as lightweight or not :)  I also regularly take a pillion who ranges from 110-140lbs, she'd kill me if she knew I was sharing this 😳.  On top of that we will occasionally be touring with three cases on a wingrack, when all this Covid nonsense is sorted we'll be heading for Provence to experience the lavender fields.

 

At the moment though my finances are unlikely to go much further than a set of springs, I have already put well over £1500 into refurbishing the blackbird and that doesn't include bodywork which is going to need repairing, respraying, and new decals.  I expect I'll be doing the front again in a year or two anyway as 5k is my fork oil change interval.

 

Have to say, the andreani kit looks nice, but 548 euros isn't cheap.

Link to comment
Share on other sites

Your weight might be below the sweet spot that most bikes are suspended for.  Great for you.

I understand finances. I have needed a shock, for almost 20 years. $1000.00 hurts.

Keep posting your progress.  It helps to remind me that the bird ages gracefully, but it does age.

Link to comment
Share on other sites

On 9/14/2020 at 3:18 PM, redxxrdr said:

Your weight might be below the sweet spot that most bikes are suspended for.  Great for you.

I understand finances. I have needed a shock, for almost 20 years. $1000.00 hurts.

Keep posting your progress.  It helps to remind me that the bird ages gracefully, but it does age.

You do know that Race-Tech (and I'm sure several other places) can build the stock shock into a more than adequate performer, right?  Probably $400 tops.  Been awhile since I've priced anything with them.  All I had done was a proper spring and fresh oil.  Made a big difference.  Should have went for the gold valve.

Link to comment
Share on other sites

17 hours ago, jon haney said:

You do know that Race-Tech (and I'm sure several other places) can build the stock shock into a more than adequate performer, right?  Probably $400 tops.  Been awhile since I've priced anything with them.  All I had done was a proper spring and fresh oil.  Made a big difference.  Should have went for the gold valve.

I'm sure they can, and here on the Isle of Man we have plenty of places who have years of race and road setup experience where we can get these things done - at a cost, unfortunately I have some budgeting to do at the minute, a divorce to settle from 2016, and a wedding to pay for in 2022.  We also need a bigger house and additional garages with workshop.  I have another car and bike still to bring to the island from the UK, I'm struggling to do more than you did yourself at the minute, my blackbird is one of 6 vehicles I own and keep roadworthy and legal, 7 if you include the C-Max my Fiancee owns :).

Link to comment
Share on other sites

7 hours ago, blackhawkxx said:

Additional garages with a workshop is important, remember to keep your priorities straight.  😀

Well at the moment we have a single garage that doubles as a bike storage and small workshop, we also have 5 cars and 2 bikes, something's not quite right there 😅

Link to comment
Share on other sites

On 9/18/2020 at 1:12 PM, XXitanium said:

Yep, garage is too small and you need more bikes.

Not disagreeing with you there :) 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

Terms of Use