SBK triples on Monster?

[BastrdHK]

Will SBK triples fit on my '01 M900....why or why not?  I have 999 forks fitted, but I modified the stock triples to accept them.  Now, I am seeing if need to go aftermarket to upgrade or if SBK triples can be fitted.  Are steering tubes in the frame different?

[Raux]

don't the superbikes have the piece for mounting the steering damper. and isn't the offset different.
i'm just going off when i was thinking about putting SF triples on my Monster

[TAftonomos]

They will fit, but change the geometry.  I looked into using SBK triples on my s4r.  The SBK triples are a different offset than the monster (36mm I believe).  The S4r monster is 30mm offset.  Most of the SBK guys fit 27mm triples on the track.  I was under the impression that fitting the higher offset triples might/would change the handling for the worse, so I had my stockers bored out.

[MotoCreations]

The change in offset changes the "trail figure" part of the front geometry.  Do a Google on the term and do a lot of reading and understand how it affects the handling and do some measurements / calculations before trying.  Some people like the change -- others have crashed. 

Also remember that "trail figure" changes while riding.  If you compress the front forks and extend the rear suspension while under braking -- your head angle changes -vs- stock and thus te "trail figure" is different.  It isn't hard to go "negative" on your trail figure adjustment and let's just say you don't want to be riding the bike when it happens.  Years ago I built various triples with different offsets on my DesmoDevil and got some eye opening lessons to what works and what doesn't.

[Duck-Stew]

They will fit, but change the geometry.  I looked into using SBK triples on my s4r.  The SBK triples are a different offset than the monster (36mm I believe).  The S4r monster is 30mm offset.  Most of the SBK guys fit 27mm triples on the track.  I was under the impression that fitting the higher offset triples might/would change the handling for the worse, so I had my stockers bored out.

NO.  They will not directly fit a 2001 M900.  They will bolt onto a 2002 & up ST framed Monster but the 2001 was the last year of the 888-based frame so the steering head and tube is different.  Also, please read the post above by 'MotoCreations'...he's spot-on.

[TAftonomos]

Sorry, Stu is right.  I thought the years changed in 00. 

Custom stem is probably your option should you go that way.  $100 is normally what they "run".

[BastrdHK]

Responses appreciated guys.  I need a little more clarity on the offset angles.  Monsters have 30mm offset creating a steeper steering angle - less trail, while SBKs have 36mm offset and more trail correct?  Now, is it the top and bottom triple bored for the forks at this increased angle or are the triples mounted on the steering stem at this angle.  Am I way off, and its the angle of the steering head welded to the frame that separates the models?

I have not taken any measurements, and I will because I want to have a reference point.  I am happy with my current geometry as I have raised the rear ride height about 4" and I have 2" of the 999 forks above the triples (which is identical to stock monster fork height) meaning I have reduced trail for desired turn in, but maintained stability. 

I bored my stock top triple out to accept the SBK Showas and switched to clipons.  Now, I want to clean cockpit up and get proper triples without the stock monster handle bar mounts.  If I am going to do the top I want to get rid of the shimmed bottoms as well. 

Reason for the original question?....I am a very cheap bastard and I don't want to drop $500+ on aftermarket triples.

[Raux]

how do the monsters make room for the steering damper mount if the key is there?

also, the offset is the distance from the center of the steering stem diameter center to the center of the fork diameter center. there is no angle. and the top and bottom have to match.

the steering angle for the superbikes is adjustable with an eccentric, the monster is a fixed angle, 24 deg i think.

i'm no expert, but IMO your thinking is all wrong on this right now.

[MotoCreations]

As you realized in that raising the rear and lowering the front you have effectively created a steeper head tube angle.  Keeping the existing triples offset, your "trail figure" was reduced as your offset remained the same.

If you go to a triple with even more offset (30mm to 36mm) -- you will reduce your trail figure even more in your current configuration.

I'd highly recommend doing a few measurements first so you know were you are at currently for a baseline.  Also calculate your minimum "trail" given the front compressed three inches and the rear extended three inches (ie: even steeper head angle)

There is a LOT of politics in regard to rake -vs- offset trail and the relationship between.  (just Google to learn more)

From my personal experiences the following applies:

- the steeper the headtube angle, the more weight you want over the front fork while riding.  Example is a 996 SBK with clipons -- perfect.  But put Monster bars on it and an upright riding position (and keeping the factory offset) -- it will be skittish at times due to change in CG weight distribution.  Thus general rule is the steeper the rake (ie: the more vertical the headtube) -- the more CG (weight) you want on the front wheel.

- a large "trail figure" (ie: Harley) will generally be easy steering at slow speed and be difficult to turn at high speed.  A really small "trail figure" will make slow speed carving incredible nimble -- but make sure you have a steering dampner and nerves of steel at high speed if you should hit a bump.

- "more offset" gives you "less trail"

- it all basically comes down to rider experience and road conditions in which you ride.  The setup that works on a billiard table smooth racetrack can be very different from "real world" riding with many unknowns tossed in and changing road conditions.

Two years ago I rode a customers bike with a custom steeply (@19deg measured static) raked headtube with minimal offset.  It was a LOT of fun to @45mph on tight twisties (very light steering) -- and then it got spooky after that especially under hard braking -- enough so I parked it immediately.  Under hard braking the "trail figure" went negative via later calculations.  Custom triples with less offset would have created a larger "trail figure" and helped correct the problem -- but then steering lock would have been non-existant and the tire already hit the horizontal cylinder under braking -- I gave the bike back to the owner and wiped my hands of it due to liability concerns. (plus poor construction of the bike itself)

[TAftonomos]

\

Two years ago I rode a customers bike with a custom steeply (@19deg measured static) raked headtube with minimal offset.  It was a LOT of fun to @45mph on tight twisties (very light steering) -- and then it got spooky after that especially under hard braking -- enough so I parked it immediately.

Eghads! 

[BastrdHK]

how do the monsters make room for the steering damper mount if the key is there?

I have a friend called Dremel....a little high strung, but handy when all that energy is applied to a task.  With cheap assness in full force, the extent of modification attempted and ingenuity used, are boundless.
 
Thanks for the response Mark.  I did do a little reading, and I am gaining a better understanding of what I am dealing with.  It will sink in a little more once I apply the principles, calculate steering stem angle(rake), confirm 30mm offset on my triples, and find my static trail.

So, if SBKs came with 36mm offset why do the holy swear by 27mm offset?  What is the difference in steering head angle between Monster and SBK?  Is their a magic amount of trail?  

I prefer a weight over the front, agile, light steering bike, and I guess I will keep edging closer to the compromise of high speed stability.  Currently, I am very happy, and I thoroughly test the high speed stability after work each day    I will post up my measurements for all to compare....learnin' is fun!

[junior varsity]

I have a friend called Dremel....a little high strung, but handy when all that energy is applied to a task.  With cheap assness in full force, the extent of modification attempted and ingenuity used, are boundless.
 
Thanks for the response Mark.  I did do a little reading, and I am gaining a better understanding of what I am dealing with.  It will sink in a little more once I apply the principles, calculate steering stem angle(rake), confirm 30mm offset on my triples, and find my static trail.

So, if SBKs came with 36mm offset why do the holy swear by 27mm offset?  What is the difference in steering head angle between Monster and SBK?  Is their a magic amount of trail?  

I prefer a weight over the front, agile, light steering bike, and I guess I will keep edging closer to the compromise of high speed stability.  Currently, I am very happy, and I thoroughly test the high speed stability after work each day    I will post up my measurements for all to compare....learnin' is fun!

Older Monsters had a very quick 26mm or so offset, and newer Monsters are at 30mm. Quick steering and twitchy mid-turn, versus more force to drop in, but very stable once there. A land filled with tradeoffs. No magic number - depends on the rider preference, other geometry settings, and track. A tight corner, technical track with more lower speed corners may require quicker steering than one with higher speed, drawn-out turns that might require more stability.

[Speeddog]

This bears repeating, as I've seen several mix-ups so far in this thread.

More Offset = Less Trail
Less Offset = More Trail

[Drunken Monkey]

Wikimedia to the rescue:



Interesting to note is that Tony Foale (who has probably forgotten more about bike design than I'll ever learn) experimented with designs that had zero rake (i.e. a 90 head angle) but as long as the design continued to have trail built in, it handled okay.

BTW: His site has a nifty little trail calculator that can be downloaded for free

[junior varsity]

Very cool - picture is helpful.

I've also picked up the Sportbike Suspension Tuning book, available here: http://www.amazon.com/Sportbike-Suspension-Tuning-Andrew-Trevitt/dp/1893618455

It goes into some detail that is helpful to many riders looking to improve the way their bike "feels" and ultimately, their lap times (if one was measuring these things - not much need to on my ol' monsta).