Suspension tuning...

[gareth]

Take those chrome caps off your swingarm and tighten those nuts up like a wheel bearing. Tight-ish.. but not really tight.

That's a quote from the thread below about the top speed of the bikes..

I have read about the "hinge" effect on these heavy bikes if you attempt to push them a bit. I am not sure if I am "pushing" too hard on the bike right now, but there is a sort of a loping up-and-down aspect to the bike when it is being set into a corner at speed. It feels like the front wants to scrub out and the rear wants to do an independent slow-speed, roller-coaster impression. The bike behaves better with a full tank of gas and if I take great care to move my weight to the sweet spot of the bike where the wallowing is minimized. It is still a bit disconcerting. I feel like I am just "holding" the bike a bit away from being in trouble..
Tires are good, SF with special tank, tkat brace, sweeper curves at 55-60mph are where things get interesting..

A quick update on suspension mods would be appreciated. I have read the FAQ's but this was the first time that I had read about swing arm bearing adjustment and wondered if there was something else that I had missed.

Regards,


Gareth.

[T99Ford]

You probably do want to look at the swing arm bearings, wheel bearings, and steering head bearings on your bike if you are having a problem at 60 in sweepers. Mine is lowered a half inch in the front and does not have a fork brace or swingarm brace, and I can take 35-40mph hairpins at 80-85 with the R6's (though I think I sweat more than they do) I have noticed some of the wobble when doing that, but it seems that most of it is rider caused, either me moving wrong, or getting scared and backing out of it. I can go all the way to pipe dragging at those speeds without problems, if I can keep my mind in it. Sweepers I can take at WOT. 60 is pretty slow, and I have not seen much for handling problems at that speed.
I do have the R1 rear single shock, set just right for me, but otherwise everything is stock. I do ride with drag bars, which puts me further forward than the stock bars, and changes the weight also. This is a much more aggressive riding position, and allows for better maneuvering. (The drawback is that it is (arguably) not as comfortable.Those long spindly fork tubes beg for a brace, but I haven't gotten around to it yet. Likewise, I have not heard of wild handling differences (imporvements or otherwise) on the stock bikes by adding a swing arm brace. No one has really posted before and after handling reports with the rear brace. For street riding I have not seen the need so far...but on the souped up ones, there is probably a need.
If you are looking to get serious about suspension tuning, buy a book that outlines suspension operation and theory, and then teaches tuning. There is alot that can be done to customize tuning, and alot depends upon your style of riding. You need to know about the system and what forces cause what problems before you start changing things. There is not a "one size fits all" for suspension. If your bike is OEM stock, you are kind of limited in what you can do. But without getting too involved, you can upgrade your stock suspension alot. Try a search for "R1 shock" to see what quite a few members have done the rear suspensions of their bikes, or "progressive fork springs" for the front end. Member XS Chop even has upgraded his whole front end with good results. The sky is the limit, but alot of upgrade can be done with minimal input.

Good luck!

[thewiz]

Interesting you should mention ...

this T71,

long spindly fork tubes beg for a brace, but I haven't gotten around to it yet

Tkat is missing in action ... I've emailed him several times in the last couple of weeks with no response ... vacation possibly? ... I wonder if he is even still around???

[TopCatGr58]

Hey Wiz,

TKAT posts on the Yahoo groups email/digest system, and I just checked, and his last post was July 15, he didn't say anything about going on vacation, but I wouldn't put it past him!?

Gareth, when you're in low gear going slow, and you crank the throttle, does the rear end of the bike rise up a fair amount?? IF so, then your rear shocks have lost a lot of their dampening affect! My OEM 81SH did that right after I got it home from Japan in '83 when the OEM shocks were NEW! But I wasn't as picky/fancy/knowledgeable of a rider as I am now. When I did my rebuild, my oem shocks were all rusted, so I put on a set of cheapo JCW Monza style/brand shocks, but noticed immediately when I rode the bike that I didn't have the broncing buck type of ride/action under accel that I remembered with the OEM's some 8 years earlier....that's how long it had sat! I've yet to put in a set of Progressive front fork springs, but I did put on a TKAT FB, and the front end definitely felt much more stable..and I had a flimsier setup with 4" over length upper fork tubes! I also pulled apart the steering head, cleaned the races and bearings and repacked, and it's totally smooth, no binding or notching!
T.C.

[psycoreefer]

In addition to what has already been mentioned there is also a upgrade that will give you adjustable damping much like the newer cartridge style forks have. I forget who makes em but if you do a search for cartridge forks I think you'll find a thread a year or so old with links. I haven't tryed it but some day when I'm rich I will......

[b.walker5]

Hey Gareth, you might want to check your steering head adjustment. Loose, or overtightened, bearings can play hell with handling. I'd be checking oil quantity (and quality) in the forks as well, and maybe considering replacing the rear shocks, they dont last forever. I replaced mine a couple of years ago and was staggered by the difference.

[Ivan]

Mine used to feel like it was going to understeer on me when I had the forks set with too much air. Being that i am about three times the weight of the typical Japanese rider, I need more air in the forks than normal, and I finally ended up tweaking the pressure until it just about bottomed out on hard breaking, i.e. throw you over the bars kind of breaking. That really helped me "feel" better in the corners, not sure if it actually accomplished anything or not...

[Shuriken]

It's funny how the things people describe about the XS also apply to the VMax. My VMax wallows and hinges. Front end dives when braking. A wobble starts to develop around 80-90. Spaghetti forks. I don't think Yamaha got it right until the R1...

The 80g I once had did the same thing. I hopped out of a sweeper and rode in the grass for awhile before tipping over due to a bad speed wobble that I had to straighten the bike out of.

I'm going to try some Ricor Intiminators in my stock VMax forks and see what happens. When you look around the net at the reviews, the intiminators can transform handling.

[WMarshy]

A quick update on suspension mods would be appreciated.

Member aussixs11G fit some modern suspension components in his bike from www.bitubo.com You can read about it here if interested, scroll down a little less than half way to read about suspension.

http://www.xs11.com/forum/showthread.php?t=21124