F4i questions - Wrist Twisters
 
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post #1 of 36 Old 12-05-2013, 08:28 PM Thread Starter
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F4i questions

I've been bitten by the suspension bug lately, and am working to build up a pair of F4i forks (resurrecting them...more on that at a later date).

Question 1: I have a pair of G2-R compression gold valves that I had bought for the 919 forks that I now won't be using in them. Can they be used in the F4i forks? They appear to be the right size, but didn't know if they would be applicable since the forks have a low speed compression adjustment anyway.

Question 2: I've read where McRomo mentions modification of the top-out spring. I assume this is to bring the forks to the same length as the 919 forks? If this is a worthwhile mod, do you simply cut the spring?

Question 3: The tube protectors on my F4i forks are directed somewhat outwards instead of being directly in-line with the direction of the wheel. Is this normal, or have they maybe just been twisted to the side?

Sorry if these are noob'ish questions. I've tried to search and get the answers, but these still remain.

Thanks for any help!

Stu

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #2 of 36 Old 12-05-2013, 09:11 PM Thread Starter
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Nevermind on #1. Right size, wrong attachment method. Oh well.

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post #3 of 36 Old 12-05-2013, 09:55 PM
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No idea on #2.

#3 - Yes, they are pointed outward compared to the straight point of the stockers. You can loosen them & then point them straight as I did. They just wont be flush with the mounting tabs but they will stay put. Mine hasn't moved a mm since i put them that way 2000 miles ago.

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post #4 of 36 Old 12-05-2013, 09:59 PM
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Originally Posted by Superdog View Post

Question 3: The tube protectors on my F4i forks are directed somewhat outwards instead of being directly in-line with the direction of the wheel. Is this normal, or have they maybe just been twisted to the side?
The fork protector has a raised key on the inner diameter that aligns it with slot in the F4i lower & yes they point outboard a touch from the factory.

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post #5 of 36 Old 12-05-2013, 10:01 PM
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Originally Posted by arshishb View Post
No idea on #2.
Same here ..... I just changed the springs, spacer, seals and oil then bolted them up.

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post #6 of 36 Old 12-06-2013, 05:09 AM Thread Starter
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Thanks guys! Paging McRomo for more info on the top-out spring mod!

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #7 of 36 Old 12-06-2013, 05:37 PM Thread Starter
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Bump!

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post #8 of 36 Old 12-07-2013, 09:49 AM
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The revised top out does a few things.
1
It effectively lengthens the forks, the change was about 5 mm, not as much as revised topout can yield in other forks. 919s on the track gain from taller chassis height.
2
It alters the effective spring rate towards the end of extension travel, as well as reducing the travel zone where a blended top out/support spring rate exists. Theories abound on this, and it could be a book length topic very easily.

So overall, in simple terms, one gets more fork length, and a very linear ride height adjustment characterisitic.
Buy a revised top out spring that is wire sized and coiled for the application, don't butcher a stock spring.
If one is serious about doing a full build of 4Fi forks, it's on the work order, that's for sure, revised top out that is.
Superdog, is this an adequate response for you ?

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post #9 of 36 Old 12-07-2013, 10:51 AM Thread Starter
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Thanks! That helps some. I'd seen you mention revising it in older threads, but couldn't find any specifics (eg, cutting it or completely replacing it). Based on the above, I assume it depends on my specific setup. Do you have any recommended sites or reading? This isn't a must-do for me, but since I've got these torn down anyway, I'm trying to do what I can to improve them (within reason!).

I appreciate your input.

Stu

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #10 of 36 Old 12-14-2013, 08:42 AM Thread Starter
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Another question. The stock low speed compression adjuster needle isn't very tapered... Is there an aftermarket unit (I've seen Traxxion mentioned, but can't find any) that might offer better tunability, or does it not really matter? Probably doesn't matter for my current level of riding, but if I came across a reasonably priced option I might go for it.

Stu

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post #11 of 36 Old 12-14-2013, 09:47 AM
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Quote:
Originally Posted by Superdog View Post
Another question. The stock low speed compression adjuster needle isn't very tapered... Is there an aftermarket unit (I've seen Traxxion mentioned, but can't find any) that might offer better tunability, or does it not really matter? Probably doesn't matter for my current level of riding, but if I came across a reasonably priced option I might go for it.

Stu
The factory low speed adjustment screw is a poser piece, plain and simple.
You don't need to be a racer to get benefit from a nicely tuned setup.
If one is respringing and changing the damping force curves of a F4i based fork set, why do all that and leave in the crap adjuster ? The F4i rebound needle is fine as is, keeping in mind in needs to be turned in a bit more than the 919 needle does, for equivalent damping force.
Go to Traxxion directly.
I don't have the part number.
Ask for Compression Needle for F4i.
Around $ 40 for this.
I also suggest a buffer kit, which keeps the springs better centred and reduces tube rub and your fork oil lasts longer as it won't get contaminated at the same rate by the rubbings. "Fork Spring Buffer Kit 11 mm " Around $ 20 for this.
Traxxion will also have revised top out springs. Guess price is $ 10 ? Stupid cheap for sure.
Traxxion will sell directly to you.

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post #12 of 36 Old 12-14-2013, 10:07 AM
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Do you have any recommended sites or reading?



Stu
Following is s copy and paste out of an old thread, with a slight edit re David Moss, plus adding in Vittore Cossalter.

FOR SUSPENSION RELATED READING AND BROWSING
• Andrew Trevitt’s book Sportbike Suspension Tuning is good.
• Lee Parks’s book Total Control (High Performance Street Riding Techniques) has some good content on suspension in various chapters and has a pretty good diagnostics guide in Chapter 15 Suspension Setup. Also see Chapter 18 Chassis Tuning.
• Kevin Cameron’s book Sportbike Performance Handbook 2nd Edition has some good content. This is not a book for you if you want a diagnostics chart, but if you want a deeper understanding of suspension science, it has some excellent content.
• Traxxion (Max McAllistair) has an excellent booklet you can still get called Suspension for Mortals. You won’t find it in a library, so can only buy it from Traxxion. It’s cheap and worth every penny. They superceded the booklet with a 2 DVD set that is really a school session that was recorded. I have them and they are good, but unless you really want to get into it, they are probably more in depth than you want. I believe there are still some booklets left at Traxxion, but they may all be gone by now. If so, too bad, personally I think the booklet with the DVDs makes for a really good combination.
• David Moss’s work is pretty good overall, but be very careful of little snippets out of YouTube segments that can be misleading. For example, there's a short clip that shows how he does a rude and crude quickie setup for track day groups showing up clueless or with whacko settings. But this is NOT at all his clean sheet/do it right approach to front ride height. Another one of his front ride height segments is remiss in that it does not fully present the overall spring rate effect with long top out springs, and how dramatic a change there is when one revises the top out. Overall, good info, but be careful. David is Catalyst Reaction Suspension Tuning. (also see OnTheThrottle.TV) He has two DVDs out, one is An Introduction to Sportbike Suspension(2 DVD set), the other is Twiddling Knobs – Suspension Tuning for Sport Bikes. These are focused primarily on track useage, but have some very good content for street use. David’s work is the only info I have found that has anything on reading tires (in the An Intro’ to ..), some of which you can get for free of his website Feel The Track! Catalyst Reaction Suspension Tuning. Said website has lots of good and free info for downloading.
• Tony Foale’s book Motorcycling Handling and Chassis Design is not a book, it is a textbook. Few will want or be able to use the content. It’s a really good book though, and has some interesting history in it.
Vittore Cossalter's Motorcycle Dynamics 2nd Edition is another serious textbook, same comments hold as for Tony Foale's textbook.
• I have all of the Keith Code (California Superbike School) Twist of The Wrist Books, and none of them are what I would call suspension referral text worth looking at from that point of view alone. The Twist of the Wrist II DVD has a sort of suspension section and it is very very weak. Keith’s work is good on the overall and riding, but forget it on suspension, and note that he does not pretend that his books are suspension guides. They are riding guides, as is the latest DVD.

I have no websites to suggest, but some very interesting insights can be learned from www shimrestackor.com

I have not looked at Traxxion or RaceTech in ages, but if they are like they were a couple of years ago, they are not educational sites at all.

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post #13 of 36 Old 12-14-2013, 12:56 PM Thread Starter
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Awesome, thanks so much for the info!

For those wondering, I know I could probably send these someplace and have them tuned better than what I'll ever need. I'm using this as my fix for my non riding season (I _could_ ride, but haven't geared up for the cooler temps and the rain :P ), and to try to understand how the suspension works and the effects of different changes.

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post #14 of 36 Old 12-17-2013, 09:48 PM Thread Starter
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top out spring

After doing some research, I'm wondering if the top out spring change is related to making it more like the setup in a USD fork; I can't find replacements for the stock-type top out. It seems like it should work, because the damper rod assembly looks essentially the same. In the USD fork, the top out spring goes inside the damper cylinder, whereas in the F4i (conventional) fork it attaches to the outside of the cylinder, and interacts with the fork tube directly. See below from a 2005 CBR600RR fork (USD):



Pic taken from Peter Verdone's site, as it was the best example I could find.

I need to take some measurements to find the position of the rebound piston when the fork is at full extension to see if this concept would work for an F4i fork.

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post #15 of 36 Old 03-03-2014, 07:26 PM Thread Starter
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Franken-forks?

Rather than start a new thread, I'll continue where I left off a couple of months ago. I had a second thread where I'd mentioned putting GSXR valving into the F4i. My plans have (tentatively) changed again!

I bought a pair of damaged (only slightly bent) '07 CBR1000RR forks on ebay for what I thought was a great price, just to get more pieces to play with What I found when I opened them up has intrigued me, and in doing more reading, I see that overall they are pretty good forks. They even are spec'd for the same amount of travel as the 919. Even though they are USD forks, it looks like a lot of the internals could work just fine in a standard fork, specifically my F4is that I'm getting ready to reassemble.



This is where I need the suspension gurus to chime in, and also need some advice. I'm seriously considering using the 1000RR damper tube in the F4i forks. They are both 20mm units, and fasten in exactly the same way.

1000RR top, F4i bottom


I would use the damper rod and rebound adjuster from the F4i, so that the overall length is correct.

For the oil lock, I'll re-install the F4i part, since the 1000RR lock can't function with the setup I'm proposing.

I would use the valves/shim stacks from the 1000RR.

The springs I have for the F4i are .95 kg/mm; stock 1000RR is 1.0 kg/mm, so pretty close.

I will be using an updated low-speed compression needle from Traxxion. Traxxion needle is on the left, 1000RR middle, F4i on the right:


Is this overkill? Probably, but since I have the parts, why not?

Is this a smart thing to do? I think the concept is sound, and I don't know why the performance would be any worse than using RC51 forks
Might even be quite comparable!

That said, here is where I need some input.

1. Is this just completely stupid?
2. Probaby for Zaq, since I know from reading many threads that you opened up your RC51 forks: Do you think the topout spring needs to be modified? The one in the 1000RR cartridge is pretty long, but there are those that praise a long topout.


Appreciate any feedback; good or bad.

*gets his fire-retardant suit out of the closet*


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post #16 of 36 Old 03-03-2014, 09:06 PM Thread Starter
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1000RR valves/shim stack

Just FYI, I tore them apart to see how they were built up.



It's got a mid-speed compression stack instead of a check-valve on the rebound valve.

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post #17 of 36 Old 03-04-2014, 03:39 PM Thread Starter
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No comments? Maybe I'm onto something!

CBR1000F4iRR forks! I may do a test fit tonight.

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #18 of 36 Old 03-04-2014, 04:23 PM
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Why not put the 1000RR pistons/vavles and shims in the F4i forks?
Just check and see if the longer tube is needed and there are no interference issues.

I have a couple of sets of RC51 forks and there internals are not that much different and need to be reworked also.

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post #19 of 36 Old 03-04-2014, 04:41 PM
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No comments? Maybe I'm onto something!

CBR1000F4iRR forks! I may do a test fit tonight.
Man you are breaking new ground here ...... I am far from a suspension guru, but I like your style and can appreciate your drive. Keep it up and good luck!

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post #20 of 36 Old 03-04-2014, 05:42 PM
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Quote:
Originally Posted by Superdog View Post
Thanks guys! Paging McRomo for more info on the top-out spring mod!
not going to go into details but offer the following:
USD forks are completely different design that f4i. Forget about top out springs on f4i forks, do not touch them.
DO NOT use anything but f4i cartriges in f4i forks. RC51 showa valves are the same as your f4i ones (obviously shim stack is different) And there is nothing wrong with showa f4i valves, period. A little polishing of the valve face will do it (2000 grid on a flat glass surface. Just a little without removing any material)
Traxxion comp. is pretty cool although won't make a lot of difference. It will offer better adjustment curve though. (if it matches up).
When you decide on the spring rate, post it. I'l give you a few ideas on the shim stack

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post #21 of 36 Old 03-04-2014, 06:26 PM Thread Starter
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Quote:
Originally Posted by Hondad View Post
Why not put the 1000RR pistons/vavles and shims in the F4i forks?
Just check and see if the longer tube is needed and there are no interference issues.

I have a couple of sets of RC51 forks and there internals are not that much different and need to be reworked also.
That was my initial thinking. You're right, the longer tube is not needed, but I've done a little (not extensive yet) reading on the longer top-out springs, which I could have if I went with the longer tubes. I admit, though, that I haven't physically put them together yet to check everything, but I don't see anything glaring that says it wouldn't work.

Quote:
Originally Posted by zaq123 View Post
not going to go into details but offer the following:
USD forks are completely different design that f4i. Forget about top out springs on f4i forks, do not touch them.
DO NOT use anything but f4i cartriges in f4i forks. RC51 showa valves are the same as your f4i ones (obviously shim stack is different) And there is nothing wrong with showa f4i valves, period. A little polishing of the valve face will do it (2000 grid on a flat glass surface. Just a little without removing any material)
Traxxion comp. is pretty cool although won't make a lot of difference. It will offer better adjustment curve though. (if it matches up).
When you decide on the spring rate, post it. I'l give you a few ideas on the shim stack
Just to be clear, my thought was to use the RR tube with its longer topout intact. Other than being longer, and having an internal topout vs. an external topout spring, the overall design of the tube is the same as the f4i.

To help me understand better, is your concern primarily in that the f4i wouldn't work well with the longer topout? If that's the case, I can't argue; I was thinking it could be an improvement if I can get the preload set right, but one unknown is any problems I might run into with fork re-assembly due to needing more preload. Figuring the correct preload would probably be a task in itself.

Also, the effect on fork length isn't lost on me. My plan was to experiment on one fork to see what the overall length ended up, and move back to the f4i tube if things just wouldn't spec out right.

Not trying to argue; just trying to better understand specific concerns. This is the kind of feedback I was wanting

Fork springs are new Racetech 0.95 kg/mm.



Edit: So this is what the RC51 has? On the left?

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post #22 of 36 Old 03-04-2014, 06:52 PM
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Quote:
Originally Posted by Superdog View Post
That was my initial thinking. You're right, the longer tube is not needed, but I've done a little (not extensive yet) reading on the longer top-out springs, which I could have if I went with the longer tubes. I admit, though, that I haven't physically put them together yet to check everything, but I don't see anything glaring that says it wouldn't work. Just to be clear, my thought was to use the RR tube with its longer topout intact. Other than being longer, and having an internal topout vs. an external topout spring, the overall design of the tube is the same as the f4i. To help me understand better, is your concern primarily in that the f4i wouldn't work well with the longer topout? If that's the case, I can't argue; I was thinking it could be an improvement if I can get the preload set right, but one unknown is any problems I might run into with fork re-assembly due to needing more preload. Figuring the correct preload would probably be a task in itself. Also, the effect on fork length isn't lost on me. My plan was to experiment on one fork to see what the overall length ended up, and move back to the f4i tube if things just wouldn't spec out right. Not trying to argue; just trying to better understand specific concerns. This is the kind of feedback I was wanting Fork springs are new Racetech 0.95 kg/mm. Edit: So this is what the RC51 has? On the left?
. Yes. Cbr is an open design valve, strictly based on shim stack to control the damping. Same as RT gold valve concept. RC, f4i , Ohlins, 919 have a combination of valve porting and shim stack. As far as other things go and swapping cartridges..... What exactly are you trying to achieve ? Don't get it. What's your goal? An experiment or to improve your f4i setup? To experiment - go ahead. Don't forget to post your results. To improve f4i setup - you are going in the wrong direction with those cbr cartridge assemblies.

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post #23 of 36 Old 03-04-2014, 07:17 PM Thread Starter
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Quote:
Originally Posted by zaq123 View Post
. Yes. Cbr is an open design valve, strictly based on shim stack to control the damping. Same as RT gold valve concept. RC, f4i , Ohlins, 919 have a combination of valve porting and shim stack. As far as other things go and swapping cartridges..... What exactly are you trying to achieve ? Don't get it. What's your goal? An experiment or to improve your f4i setup? To experiment - go ahead. Don't forget to post your results. To improve f4i setup - you are going in the wrong direction with those cbr cartridge assemblies.
Primarily experiment, and to learn in the process. Also an effort to see if it's possible to improve on the f4i fork. Will I need more than the f4i can provide as-is? No. But this is interesting to me. I didn't buy the RR forks with this in mind; I only bought them for the shims because that was the cheapest way for me to get shim material

When I saw the undamaged internals, this idea started formulating...not so much as 'this will be better because it's from an RR', but more of 'this looks like it would fit; I wonder how they would work' kind of thing.

And as I said earlier, the long topout has me intrigued. What are your thoughts on that subject? Is it primarily a benefit on the track, and very little for normal road riding?

In the end, I will want these to work well for my riding, which is primarily road riding and hitting the twisties when I can. I do anticipate some track days in the future, but that won't be the focus. When it's all said and done, if I do use the RR parts, it may be a short-lived experiment. I could very likely end up back at using the f4i valves, and I'm fine with that. On that vein, I would very much appreciate your thoughts on shim stacks for those.

If nothing else, I have plenty of shims to play with now

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post #24 of 36 Old 03-04-2014, 07:43 PM
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Add 17 to the rebound and maybe 14 to the comp, to free up that last 15.

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post #25 of 36 Old 03-04-2014, 08:17 PM Thread Starter
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Awesome; truly appreciate your input.

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post #26 of 36 Old 03-05-2014, 03:56 AM
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If you like front end being really firm, you can use that 8.7 shim instead of f4i's 8 to firm the whole stack through its entire stroke range. Both reb and comp. If you use your 9er as a mile muncher, I would not do that though. If you run it on the track here and there, different story.

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post #27 of 36 Old 03-09-2014, 02:09 PM
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If you are game I would go with the 1000rr pistons and shims, in the F4i cartridge, since the springs are very close. You will really like the mid valve. I used a 110 spring preload spacer though that might not be of any help since are springs could be different in lenght. 140mm oil level with 7.5 wt Silkolene RSF Pro oil.

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post #28 of 36 Old 03-10-2014, 10:58 AM Thread Starter
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Definitely one of the things I'm considering. It'd be neat to have access to a fork dyno to try some different things and see the changes in response. Not going to happen, but would be interesting.

I think I'm about settled on my approach, good or bad. Will start a new thread when I get started. Probably next week.

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post #29 of 36 Old 03-10-2014, 11:59 AM Thread Starter
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Oops, double post.

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post #30 of 36 Old 03-20-2014, 07:57 PM Thread Starter
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They live again!

Got them back together last night!

Used the proper damper tubes. I figured out the problem with trying to use those from the CBR forks; I'd need a fork cap that separates the length of the damper rod from the preload adjuster. Had I set them up like I was thinking, getting the preload right would've been a nightmare. I'm keeping an eye out for those special caps, just in case they exist

Anyway, I used the CBR compression and rebound valves/stacks, just to try them out In reading, I found several places that mentioned that the rebound damping on the CBR forks was a little weak, so I added a 17x0.1 shim to firm it up a little.

0.95 kg/mm Racetech springs, 15mm installed preload, and 5w Maxima racing fork oil. I hope to get them installed this weekend; I still need to make some brackets for my front fender like Ian used to make.

Here they are, minus the tube protectors






Is it strange that most people powdercoat to make their bikes unique, and I had these forks done to make them look more like stock?

The olive-gold-gray-green (whatever that color is!) of the f4i just didn't go with my red bike.

I have the f4i valves/shim stacks waiting to be installed if I decide this setup just doesn't work for me.


Edit: Here's a before pic of the tubes before powdercoating

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #31 of 36 Old 03-26-2014, 08:33 PM Thread Starter
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Finally installed! Man, I'm slow...

Finished the install last night. Probably doesn't make much sense to say much about the install, since it's pretty much a direct swap, but I'll give you pics anyway :P

For no particular reason at all :gump:, I decided I wanted to keep it looking stock. This means color (already mentioned) and re-using the stock fender. Since Ian is out of his F4i brackets, I bent some of my own. Didn't get them exactly how I was envisioning, but they look okay, and the fender is solid.





I cut the tabs on the fork tube protectors so I could rotate them straight forward to look like the stockers too.

One thing I'm considering, probably a waste of money, is getting the 919 fork caps so that I can get that 'touch of blue' back

Does anyone know if they are identical to the F4i caps? I need to pull one off and look. If so, they aren't too expensive. Kind of silly, but I like how the blue offsets the top of the fork


Anyway....

Took it out for a spin this evening, and I'm really liking them so far. I'll admit, though, that a lot of the difference is probably due to having proper springs and good oil. The ride was firm, but not overly so, and felt well planted. I need to get more time and some different road conditions to play with the settings, but my initial impression is that this is a good baseline for me to start from.

I installed the forks with 6mm of tube above the top triple, on the assumption that the higher spring rate would raise the front end a little, plus it has always turned a little wide so have been needing to do this anyway. So far, that seems to have worked well too. Turn-in is greatly improved, without feeling twitchy. It's much more willing to fall into a turn, and seems more predictable through the course of the turn than it used to.

Again, these are initial impressions from someone who doesn't ride nearly as much as he'd like to, so take them for what they are worth. What I hope to do someday is have it set up by someone who really knows what they are doing to help me know what a good setup (well, as good as this one can get) should feel like.

I'm really looking forward to getting a lot more seat time and trying to dial this thing in.

In case you are wondering how the rear shock is going to affect this, I have a confession.....

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'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #32 of 36 Old 03-26-2014, 10:29 PM
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Nice. The gold valves have made a stunning difference. Love em.

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post #33 of 36 Old 03-27-2014, 05:38 AM Thread Starter
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Quote:
Originally Posted by NZspokes View Post
Nice. The gold valves have made a stunning difference. Love em.
Glad to hear that!

'96 DR650, '01 SV650, '10 Aprilia Tuono 1000R
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post #34 of 36 Old 03-27-2014, 10:32 AM
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Nice. The gold valves have made a stunning difference. Love em.
Redone front and rear suspension on the 919 is nothing short of transformational.

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post #35 of 36 Old 03-05-2019, 11:36 AM
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Originally Posted by mcromo44 View Post
Following is s copy and paste out of an old thread, with a slight edit re David Moss, plus adding in Vittore Cossalter.

FOR SUSPENSION RELATED READING AND BROWSING
• Andrew Trevitt’s book Sportbike Suspension Tuning is good.
• Lee Parks’s book Total Control (High Performance Street Riding Techniques) has some good content on suspension in various chapters and has a pretty good diagnostics guide in Chapter 15 Suspension Setup. Also see Chapter 18 Chassis Tuning.
• Kevin Cameron’s book Sportbike Performance Handbook 2nd Edition has some good content. This is not a book for you if you want a diagnostics chart, but if you want a deeper understanding of suspension science, it has some excellent content.
• Traxxion (Max McAllistair) has an excellent booklet you can still get called Suspension for Mortals. You won’t find it in a library, so can only buy it from Traxxion. It’s cheap and worth every penny. They superceded the booklet with a 2 DVD set that is really a school session that was recorded. I have them and they are good, but unless you really want to get into it, they are probably more in depth than you want. I believe there are still some booklets left at Traxxion, but they may all be gone by now. If so, too bad, personally I think the booklet with the DVDs makes for a really good combination.
• David Moss’s work is pretty good overall, but be very careful of little snippets out of YouTube segments that can be misleading. For example, there's a short clip that shows how he does a rude and crude quickie setup for track day groups showing up clueless or with whacko settings. But this is NOT at all his clean sheet/do it right approach to front ride height. Another one of his front ride height segments is remiss in that it does not fully present the overall spring rate effect with long top out springs, and how dramatic a change there is when one revises the top out. Overall, good info, but be careful. David is Catalyst Reaction Suspension Tuning. (also see OnTheThrottle.TV) He has two DVDs out, one is An Introduction to Sportbike Suspension(2 DVD set), the other is Twiddling Knobs – Suspension Tuning for Sport Bikes. These are focused primarily on track useage, but have some very good content for street use. David’s work is the only info I have found that has anything on reading tires (in the An Intro’ to ..), some of which you can get for free of his website Feel The Track! Catalyst Reaction Suspension Tuning. Said website has lots of good and free info for downloading.
• Tony Foale’s book Motorcycling Handling and Chassis Design is not a book, it is a textbook. Few will want or be able to use the content. It’s a really good book though, and has some interesting history in it.
*Vittore Cossalter's Motorcycle Dynamics 2nd Edition is another serious textbook, same comments hold as for Tony Foale's textbook.
• I have all of the Keith Code (California Superbike School) Twist of The Wrist Books, and none of them are what I would call suspension referral text worth looking at from that point of view alone. The Twist of the Wrist II DVD has a sort of suspension section and it is very very weak. Keith’s work is good on the overall and riding, but forget it on suspension, and note that he does not pretend that his books are suspension guides. They are riding guides, as is the latest DVD.

I have no websites to suggest, but some very interesting insights can be learned from www shimrestackor.com

I have not looked at Traxxion or RaceTech in ages, but if they are like they were a couple of years ago, they are not educational sites at all.
More for KarlJay and anyone else interested.
Essentially a bit of an update re David Moss and adding in Vittore Cossalter.

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post #36 of 36 Old 03-06-2019, 08:39 AM
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Thread starter Superdog's thread addition of today:

Since one of my threads was resurrected regarding suspension, I feel obliged to provide a little input.
FWIW, after monkeying around with my forks, I tend to agree with Sniper's comment above, with a caveat: if you have not changed your fork oil, start there. While in there anyway, go ahead and install the proper springs for your weight. Ride the bike like this for a while and see if you feel there are still deficits. If there are, you have some options. Cheaper is to go with a set of valves (Ohlins or Racetech to name a couple), or spend a little more and take/send to a pro.

Don't get me wrong; I liked the way my forks came out, but I didn't try new oil/springs in my stock forks and so didn't have a basis for comparison.

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