R1 Fork Swap

[MrFreeze5]

This is looking to be a super easy swap on this frame. I am planning on using a 06 R1 front end, but wont have it for a few weeks, but I got my hand on a really cheap 01 front end pieces so i decided to grab them for mock up, and Im sure Ill use them on something. But the stems are the same size, so it doesnt really matter right now. The lower bearing of the R1 is a perfect fit and can be reused. The upper bearing, however is a oddball size 30x47x17. It was hard to track this bearing down, but I believe I have found it to be a pinion bearing in a honda hybrid manual transmission. This bearing is Honda PN 91101-657-014 and available for order here:

http://www.hondapartsnow.com/genuine...1-657-014.html

The only hangup I have encountered so far is the stem is just a hair too short, so I am going to see if I can get maybe a mm or two down total out of the triples. This shouldnt be too hard at all though. The other issue is that the steering stops just barely touch each other, and the frame stop may need to be shaved a little. So Ill probably need to weld a small extension on it to make sure the stops dont slip past each other.
Ill have the fork tubes here soon.

[MrFreeze5]

Ive decided that instead of trying to take material out of the triples to fit the stem, Im just going to make the stem longer. Ill press out the stem tonight. Since the thing is hollow, and pretty thick wall, I am going to have the stem threaded from end to end by a machinist buddy of mine, and then cut it in half at the middle. Thread a piece of all-thread through the entire length of the 2 pieces of stem with a jam nut or threaded spacer in the middle however long I need to extend the stem. Then tighten everything together and youve got a solid, extended stem. Then with the correct upper bearing I found already, the front end is mounted. Nice and simple!

[fredintoon]

Ive decided that instead of trying to take material out of the triples to fit the stem, Im just going to make the stem longer. Ill press out the stem tonight. Since the thing is hollow, and pretty thick wall, I am going to have the stem threaded from end to end by a machinist buddy of mine, and then cut it in half at the middle. Thread a piece of all-thread through the entire length of the 2 pieces of stem with a jam nut or threaded spacer in the middle however long I need to extend the stem. Then tighten everything together and youve got a solid, extended stem. Then with the correct upper bearing I found already, the front end is mounted. Nice and simple!

Hi Mr. Freeze,
seems to me that "simple" would be to have your machinist buddy counterbore the upper tree. Either underneath so the tree drops down over the top jam-nut or on top so the uppermost nut will drop down into the tree.
Gotta make the upper counterbore big enough to fit a thin-wall socket to do up the nut.

[MrFreeze5]

Hi Mr. Freeze,
seems to me that "simple" would be to have your machinist buddy counterbore the upper tree. Either underneath so the tree drops down over the top jam-nut or on top so the uppermost nut will drop down into the tree.
Gotta make the upper counterbore big enough to fit a thin-wall socket to do up the nut.

That was the original thought, but Im going to try the threaded rod method anyway, because then this method will work for swapping a R1 front end onto just about any bike. And also, the thickness of the upper triple tree is pretty narrow right there with a bevel on the underside. Knocking that bevel off would be enough to make it clear, but then the aluminum is getting pretty thin right at the stem nut. I dont think it would be weak enough to cause trouble, but I dont want to risk cracks. If the stem were about 3/4" longer it would work on a FZR and I know a BUNCH of people who would be all over that. I am going to end up using the 01 front end in the pictures on a FZR project and use a threaded spacer to fill the gap between the 2 pieces of stem. And by the time I am done with the stem, it will be a permanent solid unit, probably slathered end to end with loctite red as well. That way, aftermarket triple trees can be used without modification, or if something needs to be replaced due to damage or something. And the final cost really jsut works out to parts+having a foot of aluminum threaded, all thread, a bearing, a few nuts and washers. Thats a pretty simple fork swap thats adjustble to fit.

On the XS, the only spacing needed should be about the size of one maybe two jam nuts tightened together. Cover it in loctite and its a permanent stem.

[MrFreeze5]

If I can find a long enough 14mm tap setup, I dont even need to take this to my machinist. I can cut the stem in half. So if I can find a 14mm tap that can go about 6" deep, Ill do it myself.

[Mathh]

Looking good!

[fredintoon]

If I can find a long enough 14mm tap setup, I dont even need to take this to my machinist. I can cut the stem in half. So if I can find a 14mm tap that can go about 6" deep, Ill do it myself.

You sure that's what you want to do? I'd prefer to weld in a slug.
What size is the square drive on the tap? Put the appropriately sized socket extension on it with it's male end held in the tap wrench to take the tap down to where it has to make it's thread.

[MrFreeze5]

You sure that's what you want to do? I'd prefer to weld in a slug.
What size is the square drive on the tap? Put the appropriately sized socket extension on it with it's male end held in the tap wrench to take the tap down to where it has to make it's thread.

I dont want to do any welding on this and risk warpage and I am confident in the strength of the piece in my head. I could go more complicated with this, but Im trying to figure out something simple yet strong that anyone could do without custom machining or labor. Thats a good idea about the extension though! Ill see what I can find. My tap sets stops at 12mm, so Ill go pick one up tonight.

[xschop]

hmmm

hey freeze, while I'm waiting on that 30x48x15 tapered bearing to arrive from the U.K. and to see if you have found the holy grail from honda, I started thinking about the R1 stem problem.
The BUSA stem also takes the same lower stem bearing as the XS11 (although it is angular contact ball roller)
The Busa stem is plenty long and needs a spacer on top or bottom, this is cool because you can raise or lower the bike front up to 3/4" just by moving the spacer.
What is the R1's lower fork clamp diameter's and Center to Center measurement between the two?
I will mic this extra Busa tree and see if they are the same. Maybe you can just get a Busa stem and mate to the R1 top tree clamp and call it a day....

[MrFreeze5]

Ill check today but I think the offset is different. The R1s should be 54mm at the lower clamp. I wonder if a busa stem could be swapped to a R1 triple? I think, for the average front end swapper, this swap is easier than I am making it, and clearancing the top triple is probably all that is required. But I found this front end also shares a lower bearing with the FZR, and the upper bearing is more plentiful, but its about 3/4" too short. If the busa stem could go into the R1 triple, it might work for a FZR swap(its got a long thin stem). So Im primarily doing this stem modification to make it able to fit both bikes, and to create a method for FZR users to use. Once I get my 06 triple tree, Ill probably just clearance it, but I need that bearing to see exactly how much. But lately Ive got a lot of free time on my hands, so finding a new way to do a fork swap is proving fun

What is the OD of the busa stem where it presses into the lower triple?

[xschop]

xs11 modern fork swap

FREEZIE ASKED.....""""What is the OD of the busa stem where it presses into the lower triple?""""

ANSWER...30mm which is the same as the XS11 so you can reuse your stock LOWER XS11 taper bearing
The top has to be converted to 30x47
30mm for the BUSA tree to fit in the 47mm XS11 neck. This is where people get confused on the swap.

The XS11 steering head stock is 172mm (6.75 inch)
The Busa and R1 lower bearing I.D.s are also a match for the XS11 at 30mm.
I think you mean the R1 lower clamps are 55mm like the Busa, but the top clamp I'm not sure. The Busa top fork clamps are 50mm, maybe the R1 matches I never mic'd one.

The Busa tree stem length is long enough for the swap, but the main reason why I choce the Busa Fork swap was because the stock weight of the Busa is a better match for the XS11 than the R1 forks would be. The stock Busa fork springs are easily up to suspending the heavy XS11. Maybe the newer R1 springs are beefier, IDK....

Here's some real world tech to get the swappers droolin'....
Busa tree stem lengths in (mm) between tapered bearing seats...



Busa Top and Bottom clamps mic'd to (mm) as well....

[MrFreeze5]

I meant the OD of the actual stem itself where it is pressed in the triple. I would think it would be about 17mm like it is at the lower bearing. What Im thinking, is if the stems are the same dia and use the same bearings, but the Busa stem is longer, then the Busa stem in R1 triple with special bearing=FZR forks swap with no machining required. The XS swap is simple so far. I cant wait to get my actual front end in that Im going to use.

The R1 is 54/50mm not 55mm. Yeah the Busa is more suited to the weight, but even though I am bastardizing a bike and making a combination of parts, I am trying to keep it all Yamaha.Plus it helps with keeping spare parts when most of my spares interchange between bikes.

[xschop]

busa stem

As per diagram, the Busa stem O.D. that is permanently pressed into the lower clamp is 30mm....if it were not then the Suzuki engineer needs to be fired because the stem is hollow alloy.

The stem top O.D. that the removable top clamp mates to is 25mm....(center dimension of top clamp portion in pic above)

[MrFreeze5]

As per diagram, the Busa stem O.D. that is permanently pressed into the lower clamp is 30mm....if it were not then the Suzuki engineer needs to be fired because the stem is hollow alloy.

The stem top O.D. that the removable top clamp mates to is 25mm....(center dimension of top clamp portion in pic above)

WOW! Thats significantly larger than the R1! The R1 stem is 17mm at its largest and has a 13mm ID. Those measurments your giving sound like stem bearing ODs.

[81xsproject]

simple yet strong that anyone could do without custom machining or labor

That's what I've been waiting for