Standard forks on a Special?

[Tim Johnson]

is there a picture on here of Dennys bike? would like to get an idea of what it may look like

[TopCatGr58]

Originally posted by Mike Hart
I like it, Tim. Denny Z's standard has special tubes and clip-ons!

From what I've heard, you have to change the clamps. You definitely need to go with calipers from a std if you use std bottoms. So you pretty much need the entire std front end, but use spcl tubes.

Hey there Mike,
Okay, if his(Tim's) SF uppers are rusted, he should be able to replace them with the uppers from the Standard, according to the manual, the spring for the SH is about 4" longer than the Standard, and so I would assume the uppers are also 4" longer than Standard..however...the manual also only differentiates the two types of lowers(SF vs. F), but doesn't state any difference of the uppers, so it may be the internal differences of the lowers and not necessarily the uppers that change the height of the front end and length of springs required, ?!?! That way he can have the lowered look/feel of the Standard, but retain his SF lowers/brakes, lines, fender and leading rake of front wheel due to axle forward mounting!? As he stated, it seems it would depend on how much work he wants to do, just change the uppers, or replace the entire TREE and front end??

As for the difficulty with steering at low speeds, I've experienced that riding a Suzuki Bandit type(650cc) with the short bars, the shorter the width of the handlebars, the shorter the leverage arm and reduced leverage one has when turning the bars....requiring more effort vs. the wider bars. Using the Standard lowers may not provide much increased steerability if still using the narrow handlebars!?!? Okay, my 4 cents worth!

[Mike Hart]

You're covering a lot of ground there TC!

Spring length: if you get progressive springs for an XS, they drop right in a Std, but need a spacer (2.? inches) in the Spcl and XJ. The progressive spring is not long enough for the spcl, but is long enough for the std. Doesn't that seem like the spcl has the longer tube AND lower? I can measure the lowers on both an F and an SF tomorrow and get back on that.

In the meantime, I'll go out on a limb and say that the lowers on the std are shorter (axle at bottom) than the spcl (axle a few inches up the lower).

Bandit 650? On what planet? Maybe a Suzuki SV650 twin? they steer really nice, very flickable. I'm very curious what 'bandit type' is harder to steer than your SH!!! Whatever it was, it must have had some major problem if it was harder to steer than an XS. I mean, XS's steer okay, but the modern jobbies just do it so much better.

Bandit 600/1200 are virtually the same front end-wise. Shorter bars = shorter moment = less distance for more effect. Johnny Yukon has bandit bars on his SF, the bugger steers way easier than with the big bars. So, I completely disagree with your remarks about bar length/steering input, and from personal experience. Yes, you would think more leverage would make it easier, but since you have to move further, and the actual effort is not much different, the subjective feel is that shorter bars steer easier. (How come sport bikes have clip-ons, and the Indian has those 4' wide monsters?)

If he wants clip-on bars, gotta go with some 37mm tube that is long enough to get up through the tree far enough, regardless of which lowers/calipers he uses. I imagine there are many bikes that had 37mm tubes. Hey, the Honda V65 Magna was a tall bike, what size were its tubes?

The std and spcl are more or less the same height at the front. The different feel comes from the diff between center axle std and leading axle spcl. Personally, I find the std to be more responsive to steering input, and it has less trail (more responsive).

Man, I really like your posts, and agree with a lot of what you have said in the past, but on this one, I am finding little to agree with

Okay, if everyone isn't confused enough now, you're not trying hard enough!

[Dennyz]

Standard/Special setup on Vyger.

I am using standard triple clamps with Special tubes, that have Standard shock lowers on them. This provides 3" of fork tube above the top triple clamp. I then attached clip-ons to the protruding fork tubes.

I am using progresive front spring with a 3" spacer.

The triple clamps should be of the same model as the shock lowers to keep the stock XS wheel base and rake.

In lew of the XS's tendancy to have front-end wobble, I would be extremely cautious of sorting up the wheel base (Standard shock lowers on Special triple clamps).

My experience is that both Standard and Specials have the same diameter of fork tube. Specials are 3" longer.

[Mike Hart]

Thanks, Denny.

Y'all listen up, the man knows what he's doing.

Tim, if you want clip-ons, it has been laid out for you:

std clamps, lowers, calipers; spcl tubes, giving you room for the clip-ons to attach.

Let us know what you do!

[Tim Johnson]

Now Denny mentioned not to use the Special Triple clamp with the Std lowers, as this would be a change in angle. But I don’t see any difference in the triple clamps. The angle should not be on the clamps but on the frame head it self. I believe the rack angle is less on the special to give the special the same wheelbase and trail as the STD had. So weather I use the STD or the special clamps on my Special frame I shall have a shorter wheel base and lesser degree of angle.

[Mike Hart]

First off, one rarely (if ever) goes wrong listening to Denny's advice. He has long and extensive experience with both Standards and Specials.

The 78E, 79F, 79SF have the following specs in common:

caster 29.5 degrees
trail 130mm (5.12")
wheelbase 1545mm (60.8")

Downstairs here are an F, an SF, an XJ, and two Bandits. This morning I measured these dimensions:

Fork lower (from dust cap mating surface to bottom of fork):

• F = 15 3/16"
• SF = 15 1/2"

Total fork length (installed w/ front end weight on bikes):

• F = 32"
• SF = 34 1/2"

This clearly shows the tubes to have almost all the extra length, as the lowers are nearly the same.

Here are two pictures - I wasn't able to place the bikes in exactly the same position for the shot, but the parallax favors the SF, and so the difference is even more remarkable looking at them next to each other. The forks on the F are well forward of the steering stem, much more so than the SF.



Also, the clamps sure look different in the fiche drawings, fwiw.

About trail - 5.12" is a lot of trail. 4" is a common length to compromise between high-speed stability and quick steering. Yamaha obviously knew they had to do what they could to improve stability at speed.

And last but not least, one for TC - the quickest steering XS I've ever ridden - note the forks are up in the tree about an inch.

[Stray Bullet]

Originally posted by Tim Johnson
But I don’t see any difference in the triple clamps. The angle should not be on the clamps but on the frame head it self. I believe the rack angle is less on the special to give the special the same wheelbase and trail as the STD had. So weather I use the STD or the special clamps on my Special frame I shall have a shorter wheel base and lesser degree of angle.

tim, you need to listen to yer elders on this. i'm not saying it CAN'T be done, but the fact is, the triple trees ARE different, and the 'rake' IS in the tree and not on the frame.

now you can work from a factual basis, instead of one based on simple belief. best of luck...

[Mike Hart]

One more thought: caster angle mentioned previously (29.5 deg) is rake. Mixing fork lowers w/ clamps from the other model will not change the rake. It will change the wheelbase and trail.

In the second diagram (under the 'Offset' heading) at this site you can imagine that diagram is of a Standard. Now imagine putting the special forks with their leading axle in those trees - you will have increased the wheelbase, and shortened the trail. Putting std forks in spcl clamps would have the opposite effect - shorten wheelbase, increase trail. Both of those methods would result in degrading handling.

Ok, that's it!

[Mike Hart]

Denny's

Tim, finally, a pic of Denny's bike, courtesy of Jim Middlestadt:



Here is a larger version

Bar-end mirrors on clip-ons, R1 muffler, etc etc etc. Niiiiice.

[oldfart]

standard forks on special

I had a 80 special with standard front end,put over 32k on it with no problems what-so-ever,Will

[TopCatGr58]

Originally posted by Mike Hart
You're covering a lot of ground there TC!

SNIPPED

Bandit 650? On what planet? Maybe a Suzuki SV650 twin? they steer really nice, very flickable. I'm very curious what 'bandit type' is harder to steer than your SH!!! Whatever it was, it must have had some major problem if it was harder to steer than an XS. I mean, XS's steer okay, but the modern jobbies just do it so much better.

Bandit 600/1200 are virtually the same front end-wise. Shorter bars = shorter moment = less distance for more effect. Johnny Yukon has bandit bars on his SF, the bugger steers way easier than with the big bars. So, I completely disagree with your remarks about bar length/steering input, and from personal experience. Yes, you would think more leverage would make it easier, but since you have to move further, and the actual effort is not much different, the subjective feel is that shorter bars steer easier. (How come sport bikes have clip-ons, and the Indian has those 4' wide monsters?)

Man, I really like your posts, and agree with a lot of what you have said in the past, but on this one, I am finding little to agree with

Okay, if everyone isn't confused enough now, you're not trying hard enough!

Well, Mike,
Just goes to show what I don't really know!! The "bandit" bike was a Suzuki Crotch rocket styled 600something, lay over the tank PITA style ride....since I only own an XS11 I haven't really kept up with the exact model differences in these racers, so my terminology of calling it a "Bandit" was apparently in error.

And I should have been more explicit in my description of the handling characteristics....yes at speed, it responded decently and just like countersteering, it takes very little input in the bars to direct it. However, at very low speeds, like trying to do a 180 in a parking lot, the front end was much more laborious in my efforts to steer ...and here's where the shorter fulcrum requiring increased presssure to move an object a specific distance came into play that I was eluding to, so in a sense, we're both right!?!?

My other thoughts were along the same lines as Mr "Z"; that since his upper tubes were rusted, he could replace them with the ones from the Special using the Standard tree and lowers, and then just slide the uppers further up in the tree to compensate for the apparent extra length of the Special Upper tubes...God I hope I'm in the correct thread!? As I have mentioned before, I'm "NO" techno-guru, don't have hardly any of the spec's memorized, just trying to keep my beloved beast running, and offering what has worked for me to others with possibly similar problems. Okay, I'll shut up now.

[Mike Hart]

Originally posted by TopCatGr58
My other thoughts were along the same lines as Mr "Z"; that since his upper tubes were rusted, he could replace them with the ones from the Special using the Standard tree and lowers, and then just slide the uppers further up in the tree to compensate for the apparent extra length of the Special Upper tubes..

Yes, exactly right! and that would leave him room to use clip-ons, like he wanted to do in the first place!

Agreement is ours.

[switz1]

I found this thread to be a very good read.Im interested in more "rake" in my 80Special, and have 78E std. parts

[Ken Talbot]

OMG - this thread has been dormant for over five years. It's nice to know that some people actually take time to browse back through the archival material!