smokinjoe73

Saw this on ebay & just had to point it out. Not sure whats going on over in bloody old england but apparently they have this. Could this have that much effect?
http://cgi.ebay.com/HONDA-VTR1000-VT...dZp1638Q2em122

Tweety

Yes... It makes a difference... But paying for that is bogus... get some washers...

1 mm at the shock means a lot more at the wheel as the shock linkage comes into play... 1mm at the front of the swing is a lot more at the end...

SlowHAWK

I run a 4mm shim, and it works pretty well... I tried 6mm at first, and was shocked how high the rear was afterward. I used a piece of 1" wide aluminum strip/bar from Home Depot that I cut a slot into with a drill and a dremel. It looks like the letter "u" afterward.... this helps in that you don't have to truly remove the upper portion of the shock from the frame, just lift he bike from the oil pan, loosen the shock nut a few turns, slide it in under the frame, then re-tighten.

J.

Hawkrider

This has been around for quite a long time. This is on my website:

Truckinduc

Or you just adjust the overall length of your fox twin clicker

slot

Depending on your height, they may leave you on your tippie toe's, old chum !!

What o, tally ho, old boy, chocks away !

Had one on my spitfire !!

JamieDaugherty

It's approximately 3:1 ratio on most bikes, including the the VTR. That means 1mm of increase in shock length (or shim thickness) would equal 3mm of ride height increase. Just in case you were wondering....

Tweety

I think my calculation was that it came to 2.6... But my maths is rusty... so I could be of by a bit... or measurements are off...

nuhawk

Greg, is this why after you reworked the forks that we installed 10mm into the triples? We are getting our steering fine tuned but it could still use a little more turn-in. I feel it a little but Chas feels it a lot because he rides harder than I do. The last time we talked I told him I thought raising the rear was the answer not dropping further into the triples.

A fork stabilizer won’t hurt either.

Thanks for the ratio, Jamie! You too Tweety! 1mm or 1.5mm could do the trick.

I have been all over this bike’s suspension and I appreciate how much 1 mm is and the difference it can make. We are getting very close.

Track day May 10.

Jerry tells me all the major tire companies are doing promotions this month. With the economy the way it is, I got a feeling the tire specials are going to last well into the season.

nath981

I just used some fender washers(shaped like the diagram above-i.e., slotted circle). You can get them at an auto store. Just losen the nut on top of the shock(directly behind tank) and slip however many you want in and tighten-five minute job.

The nice thing about using the fender washers is that you can add/subtract to suit, and they cost nothing. I just did this mod and have inserted four washers, which is approx. 6mm. Between the rear height increment and race tech springs at OEM height in the triple clamps, the bike is sitting up high enough that I had to shim my sidestand 3/4" to get the bike to stand safely. Also am now on the ***** of my feet instead of flat foot while still.

I just rode it for the first time tonight and it's definately going to take some getting used to. Feels less stable like as in steering stabilizer needed maybe? and also seems rougher in the rear. I couldn't get into it too well because of too much winter debris on the roads plus water.

nathan

RCVTR

I think I stated a while back that I had increased my shock length by 10 mm. This was not the case. It was 5mm.

I'm increasing the shock length on the RC by 4mm, or about 12 mm at the rear wheel.

nath981

Increasing the shock length is probably the right way. I shimmed the shock 6mm and it seems more harsh than before. I don't understand. I have preload set at softest position. It's almost like I have increased preload with the shims?

JamieDaugherty

Shimming the upper mount is exactly the same thing as a longer shock. Something else must have changed, but I don't know what that would be.

RCVTR

I agree.

I wonder if it is bound at the top mount. The rubber bushing at the top of the shock allows a small angular adjustment by twisting the rubber in the bushing.

You might try loosening the cross bolt that attaches the shock to the bracket, to allow the bushing to relax to the new shock angle caused from adding the shim.

This is a common problem with kids that lower their Hondas and Acuras. The bushings get bound up and eventually tear.

nath981

okay! I see what you mean and I never would have thought of that. I took all the bolts loose from the bottom linkages and lubed but never considered the top bushing. out of sight out of mind I guess.
thanks, nathan

Hawkrider

+1

Hawkrider

Doug,

The raising of the forks in the triples only compensates for the increased front ride height due to the stiffer springs. You might be able to eek out another 5mm but you are jeapardizing cornering clearance on the front header on right turns. I tried 15mm before. Didn't quite work out the way I wanted it to, particularly at turn one VIR (What was that sound? And why did I just go wide?).

You're best off raising the rear and/or getting the aftermarket shock.

Hawkrider

Nathan,

Raising the rear that much may get you into trouble, especially if your rear preload is too high. Set sag in rear for as close to 25-30mm as possible while sitting on the bike.

You are correct in your assessment on the instability. Fork damping can affect the way the bike handles too. Since you added the fork springs did you get a revalve? If not, take out some rear ride height until you get your forks fixed. PM me if interested.

nath981

Thanks for submitting this suggestion. It must have been bound. The rear feels back to normal now. I should have known something was amiss when I was trying to adjust the rebound buy pushing down on the seat and it was more lifeless than normal.

thanks again, Nathan

nath981

I have shimmed 6mm rear and RT springs/spacer to OEM length and at OEM triple clamp position. I was leaning toward what most suggest, i.e., dropping front 10mm or so. Trinc(Tim) suggests a geometry of 24.9 degrees rake, 97.0mm trail. I wonder how this compares with OEM geometry since I found it to be rock stable in terms of high speed stability and hard turns on smooth roads.
Anyway, I'm going to try to measure my geometry to see what it is now as soon a as i figure how best to do this with home made measuring devices.

nath981

[QUOTE=Hawkrider;200885]Nathan,

Raising the rear that much may get you into trouble, especially if your rear preload is too high. Set sag in rear for as close to 25-30mm as possible while sitting on the bike.

You are correct in your assessment on the instability. Fork damping can affect the way the bike handles too. Since you added the fork springs did you get a revalve? If not, take out some rear ride height until you get your forks fixed. PM me if interested.[/QUOTEG]

Just noticed your post. Got the rear sorted out as well as possible for it's inherent limitations. Upper bushing bound i thought, but today discovered the real culprit while adjusting chain. I noticed the nut(bolt on muffler tab and front peg which I rotated a few degrees clockwise for more rearset position) rubbing hard on the swingarm to the point of making a groove in it because I put the fabricated tab on the inside intead of the ouside of the grommeted arm, dah! anyway, it's cool now.

Relative to the front fork revalve,no I haven't. I didn't take the forks off the bike but modified the end of the damping/rebound rod and drilled 1mm hole(cartridge tube) according to Stuart Ablett's VTR pages. Are you familiar with his(actually, Roger at Revolution Racing) mods? Haven't had the weather down hear as you know(aren't you a couple three hours north in New York?) to properly eval the front end. I can say that I think something is amiss because there seems to be some problem relative to the rod sticking a bit, especially if I crank the compression down. I put in 7.5 wt oil @ 15oz., 2oz under OEM. I guess I'll find out soon enough, but I'm not optimistic.

thanks, Nathan

Hawkrider

Hmm, well for a start we don't have compression damping adjustability on our forks - preload and rebound only. Preload is the large 14mm doohickey with the lines machined on it. The rebound damping is the flat headed screw.

Yes, I'm north of Albany, west of Saratoga Springs.

I'm familiar with the Ditchfield mods. Personally, I think it's a band-aid and doesn't really address the problem. If you're tearing the forks down that much already, why not just revalve? That's the real answer.

Rod sticking? Which rod?

nath981

I guess I have confused compression with preload. I thought compressing the spring meant increasing compression and that these terms were synonomous. "Oh lord, I apologize for this...." What your saying then is that some forks have another ajustment that increases compression separate from compressing the spring. How does this work? does it compress somehow using fork oil?

The rod I'm referring to is the one that is attached to the preload/rebound cap and has a point with two protrousions/wings that look like they're supposed to keep the point from entering an orifice at the lower part of the fork. I followed the instructions on ablett's vtr site(Ditchfield's) and ground the wings off and drilled the specified the 1mm hole. The rebound aduster doesn't turn freely like it did pre-mod. It used to turn about 3 turns I believe, and now only turns about one turn and seems to bind and turns the preload adjuster withit. Maybe the locknut holding the cap/rod is not at the best height-I just ran the locknut to the lowest position (bottom of threads) and screwed the preload adjuster all the way down and then tightened the locknut against it.

The bike seems okay based on a short testride between snowstorms, but I don't think the front-rear geometry is optimum. I'll have to find the stock front height and then add 3/4" to it(6mm shim raised the rear 3/4")to get back to the relative OEM front-rear geometry which actually worked well except for being too soft in the front.

I drove a semi (long haul) for twenty years and have been up in your area a few times. Seems like I got off I-90(maybe Glen Falls?) well before Albany, went North and then east to Saratoga Springs, possibly on the way to Vermont. I did run across New York State through the Adirondacs once or twice too. Nice riding country up there, huh.

thanks for the insights, Nathan

Tweety

It seems there is a need to clarify some terminology...

The preload (big fiddly **** on VTR forks, big collar on shock) sets the tension of the spring, and this is a fine-tune to what you set up internally with the stiffer spring and spacer which is calculated and set according to your weight...

The compression (not adjustable on stock VTR) is a fine-tune to the valve inside controlling oilflow on the compression stroke...

Rebound (small fiddly ****, both on forks and shock) is similarly a fine-tune of the valve that controls oilflow once the fork rebounds on the de-compression stroke...

These two characteristics are in stock form matched to the stock spring... If you change the spring, they become miss-matched... Small changes are ok, big one's are not a good option... It usually ends up with either pogo stick characteristics or squishy to soft settings...

The internal valving can be setup by a pro like hawkrider for your weight... Me, I managed a decent setup for myself by trial-error and it took me several attempts... But I had an experienced suspension guy to ask for help...

Tweety

BTW you keep referring to having your bike setup like stock by measuing heigth on it...

I can tell you from experience it won't work like that... If you set it up with the same external measurements... ie the forks with the small groove for a locking ring at the top of the clip-ons... and such... Then you have the stock setup... And you have added 6mm to the rear... But it's still NOT the same...

In terms of geometry on the bike it's a whole new setup... because with the stock components you have a softer spring, which means the spring compresses by the weight of the bike alone a lot more than now... And the same when your weight is on it... So the geometric setup of the stock might be stock... but it won't be the same with you on it... and certainly not after changing the spring...

The reason I'm saying this is that you are starting backwards... Aproach it fresh from another angle instead and it becomes a lot less complicated...

Start be setting sag... Static and rider sag... That's how much the bike compresses from it's own weight and from your weight... Set both front and rear... Once that is done you have a baseline...

Then you remove temporarily the rear spacer and using the numbers given above you set up the front as stock in terms of geometry ie rake and trail... For that you need nothing more than a piece of sting with a weight, a ruler and a way of measuing an angle (can't remember the word in english) the string gives you a straight line down to have as a base for measuring the angle and trail...

Then take that baseline setup and add the rear spacer back for a bit quicker stearing... And start fiddling with +/- a couple of mm in front to get it to where it feels comfortable... And with a good setup of the internal components for your weight it migth only take one mm to transform the handling... So at that point any concerns about getting th front too low is unnecessary...

nath981

[QUOTE=Tweety;201414]BTW you keep referring to having your bike setup like stock by measuing heigth on it...

I am trying to emulate the stock attitude because it felt very stable at full lean, except for scraping feelers/boots prematurely. Anyway, I have 85kg RT springs and 6mm on the rear. i know the rear raised about 3/4" because that's what I had to shim the sidestand to get it to sit right, however i do not know how much the front height changed since I installed RT springs. if I was smart, I would have measured ground clearance at the front and rear before changes.

there was some thread I saw where someone measured ground clearance but i can't find it. the specs on greg's site say 5.3", but at what place is that measured?

thanks, Nathan

Tweety

That's actually what I'm talking about... The stock attitude is actually described by those two numbers... Rake and trail... They describe the angle of the fork and how far forward the front wheel is... Look here for a good description on what they actually mean... http://en.wikipedia.org/wiki/Rake_and_trail

If you change anything those numbers change... raise the rear and they change as the angle of the fork compared to the vertical plane changes as the bike is tilted more forward... move the fork legs up or down and it changes again...

Nope... the rear wasn't raised 3/4"... The center was raised part of that by the shim and part by the stiffer front springs... That means it was raised an unknown amount front and rear and not equal... And that is what makes it very hard to get back to "normal"...

If you get back to stock rear ride height temporarily and get the rake and trail to OEM spec with your current springs you are as close to stock spec as you ever going to get... And you have the same ground clearance when on the stand, and better than before with you on the bike, courtesy of the stiffer springs...

And that my friend is your starting point... Then if you add height in the rear the bike becomes less stable but quicker... same with reducing front height... But the rear shim increases ground clearance and the lowered front reduces it... So a rear shim is a better start, if you need more use a little in both ends and you have close to stock ground clearance...

Tweety

What actually happens when you put in new springs for a heavier rider is that the fork legs effectively become longer when in rest (or less compressed by the bikes own weight)... The behavior with the rider on the bike becomes better, but if the fork legs are left in the same position as stock the bike sits higher up front (think chopper)

The rake and trail is affected and makes the bike more stable (large trail) and slower to turn... lowering the fork legs to have the same rake/trail as stock puts you back at square one... Now trow in a raised rear and you have effectively raised both front and rear... Unfortunately an unknown amount... And also affected the rake/trail but unknown in what direction (but probably more rake and more stable bike)...

Tweety

BTW... Stock rake and trail on the VTR is the numbers trinc gave you... 24.9 degrees rake, 97.0 mm trail... It's in the service manual specs...

nath981

The reason i figured that the 6mm translated to 3/4" at the wheel is that raising the forks that much allows the bike to rest normally on the sidestand.

what I have measured so far is:

trail=102mm vs stock spec=97mm. I haven't figured out how I'm going to measure rake yet, but i will.

Wheelbase is reduced from the OEM 56.3" to 56"(520chain/sprocket-1f,+2r).

Free sag is 25mm front, 5mm rear(haven't got help to get rider sag yet).

thanks, Nathan