Forks

[Crusty Snippets]

My bike Yami is a 79 Special. Has pitted front forks.
Will the forks from a newer 1100 standard fit?
Newer 1100 made 09 80, serial 4W2000199.
Forks are 37mm. The difference is the newer bike has the axle going through the lowers, while my bike has the axle in front of the lowers.
Can get the frame and motor as well. Will assume the steering head angle is different with the newer bike.
Thank you in advance.

Unkle Crusty

[TopCatGr58]

Hey Crusty,

The upper fork tubes ALONE will not work because they are too short for the Special sliders. However, you can put the whole fork assembly on and it will work. Now come the fun part. The Special Triple Tree has the tubes a little closer to the steering neck because of the leading axle design. There will be a change in steering geometry if you just put the standard tubes into the special TT's.

Fredintoon keeps explaining this in the occasional reply, but I keep getting a mental block in being able to remember the affect. IIRC he said they would put Special TT's onto their Standard frames and forks to REDUCE the trail to lighten the steering for their sidecar rigs. Hopefully he'll come along and correct me if I've again gotten it backwards!?

But if my memory is correct, then you will have easier/lighter steering with the standard tubes in your special TT's. The other benefit to this is also getting the better more stable front calipers for the standard forks vs. the wonky slanted speical ones....as well as being able to do the caliper upgrade if you want to(modern dual piston calipers from a HD or such)! You will also want to use the Standards fender, otherwise the rear of the special fender may be too close to the tire? You may also have to swap out the speedo drive unit as well using the one from the standard.

T.C.

[Crusty Snippets]

Forks

Thanks TC.
So I will need to know the length of the forks.
I think it is worth it to get this standard model for the spare parts.
I could put them side by side and study the rake and trail.
The steering on my special is too heavy with the sidecar. Was going to try more air in the front tyre, about 36, and heavier oil in the forks.
I had wondered about making the steering quicker via the less rake plan, and then wondered about high speed without the sidecar. But I should know the answer having ridden a TL250 ( 70's Honda trials bike ) at speed.
I could also get a set of special forks and would have all options covered.

Then I just need to get Yami junior running ( 80s 400 ) so that I have something to ride when working on Yami.

I like the front brake idea, improved brakes would be nice. I need to check to see if the calipers are on the standard, the discs are. Will check next week.

Unkle Crusty

[crazy steve]

Yep, reducing the trail with swapped parts is a good way to get steering effort down with a sidehack. But if running without the hack, the bike will be more prone to 'tank slappers' (something these bikes can do even with the factory geometry) so be careful. Fitting a steering damper is a common fix....

[Crusty Snippets]

Forks

Thanks Steve.
I would rather have heavy steering with the sidecar than tank slappers without it. So will not mix and match. But I can take the complete standard front end, including the triple tree and bolt it on my special. I am assuming that, but it is also a question.
So why have two different front ends?
I like the idea of better brakes as per TC suggestion.
I also need to replace the steering head bearings on Yami.
Unkle Crusty

[DGXSER]

Yes, the frame tube is the same between the Standard and the Special models, so the complete front end is a "bolt in" swap. You do need the complete front end, forks, TTs, brake calipers, and fender.

I think they put the wheel up front on the special models to give the appearance of more rake, another way of taking aim at the V-Twin market.

[crazy steve]

...I think they put the wheel up front on the special models to give the appearance of more rake, another way of taking aim at the V-Twin market.

That's exactly why they did it; trying to get that 'chopper' look.

I'll note that if you do the swap, it's not a total bolt-on... the headlight ears on the Special are longer where they go over the fork tubes, so to use your Special headlight on the standard forks, you'll need to either use the standard ears or shorten your Special units by about 5/8". In either case, you'll need to fabricate a new lower headlight adjustment bracket.

You can get new fork tubes and avoid all this if you want....
http://www.xs11.com/forum/showthread.php?t=38771

[Crusty Snippets]

Forks

Thanks for the extra info Steve.
I will call the new fork place. Will also look around the scrap yard that I was in, for a set of special forks. Then take the works.
The standard has a frame, motor, rear end and front end. It would be nice to have all those spares. Also seat and both fenders. No gas tank or carbs.
I decided the easiest way to have extra fuel is to carry an extra small can of it.
I will have a good look at the front brakes and wheel of the standard as well as the rest of the front end. The forks are straight.

Unkle Crusty

[fredintoon]

Forkswapping

Hi Uncle Crusty,
Special and Standard frames and forks have identical rake and trail so you swap the lot, trees, fender and all.
You can mix'n'match the headlight and ears but you gotta cut stuff to do that and then the parts won't swap back.
You also get the Standard front brake calipers, a definite bonus.
And TC, yes, you got it backwards.
The Standard 'trees reach further forward which puts the fork tubes forward which moves the front axle forwards which lessens the trail.
Standard 'trees with Special fork legs reduces trail.
Special 'trees with Standard fork legs increases trail.
(you might want to try that on your punched-up-the-front Special along with those stretched fork tubes)
Swap the lot, 'trees and all, either way and nothing changes

[TopCatGr58]

Hey Fred,

Thanks for that AGAIN! I have copied your reply into it's own thread and placed it into the Tips Under Construction section, where it will be cleaned/dressed up, perhaps with some graphics and be placed in the appropriate Tech Tip Section:Mods!

Uncle Crusty, I didn't follow the other link to the new forks place, but it's probably Forks By Frank, I got my 4" extended upper tubes from them actually a couple of times, once after my front ender incident that bent my steering neck, but those got rusted badly after sitting outside for 9 years , and so I got new ones again....they've been on since 2000, but properly stored and cared for this time, still no rust!!! They make quality stuff, but they were a bit $$!

T.C.

[motoman]

Actually, the leading front axle was done to improve the corner handling, same as old school moto-x bikes. Having a leading front axle INCREASES the actual down-load at the axle centerline point, putting more load on front wheel resulting in better stability and adhesion.
With the newer bikes having different frame designs, twin-spar etc., this is not necessary, as most all bikes out there today carry axle load directly under fork tubes including moto-x style bikes whether inverted forks or traditional style.
In a nutshell, it was done for handling purposes, not looks.

[fredintoon]

Actually, the leading front axle was done to improve the corner handling, same as old school moto-x bikes. Having a leading front axle INCREASES the actual down-load at the axle centerline point, putting more load on front wheel resulting in better stability and adhesion. - - -
In a nutshell, it was done for handling purposes, not looks.

Hi Moto,
I can't get my head around that theory (I always thought dirt bikes had forward-mounted axles to leave room for those super-long springs) but even if it's true this old cynic reckons it's only an unexpected bonus.
The stylists did it just for looks.

[crazy steve]

hi moto,
i can't get my head around that theory (i always thought dirt bikes had forward-mounted axles to leave room for those super-long springs) but even if it's true this old cynic reckons it's only an unexpected bonus.
The stylists did it just for looks.

+1..... Lolol!

[Crusty Snippets]

Forks

Bought a set of 81 special forks today.
Unkle Crusty