M750 Front-end Geometry Question

[carbmon]

Please pardon if I should have found this info via search

I have an '01 Carbed M750 (see signature block).  I know that in '02 the steering stem / triple clamps changed at least insofar as the stem and head-tube diameter:

up through 2001 steering head bearing = 26mm ID, 52mm OD
2002+ steering head bearing = 35mm ID, 55mm OD

The OEM bearing type also changed from roller in the 2001 to ball in the 2002+, but that is of no consequence for my interest.

I'd like to know the head-tube angle (RAKE) and steering stem-to-fork tube dimension (OFFSET) for 2001 and prior vs 2002+

Thanks!
 

[junior varsity]

Pre-02:25mm offset, 02-On: 30mm offset

SBKs: 36mm offset

[Düb Lüv]

bookmarked. thanks

[junior varsity]

if i recall, its a 24 degree steering angle

[ducpainter]

if i recall, its a 24 degree steering angle

Sure...

with stock tires, ride height, and no rider.

[junior varsity]

haha, true

[The Mad King Pepe']

Question for the knowledgeable here: if I had a SBK front end (forks, triple and clip-ons, 65mm caliper spacing, 25mm front axle) that I wanted to put on my 2001 M750 would changing the steering head bearing work for me?

I know that would change the steering geometry and that I would need to get different springs. I'm just wondering if I can get away without modifying my current triples, especially if I'm going to use clip-ons. As for a bearing source, www.accuratebearing.com should have them, any other suggestions?

[caperix]

The SBK tripples use a 36mm fork offset, that will greatly reduce the trail on the bike making it unstable.  If you realy dont want to modify the triples I would look into the japanesse bike forks as some of them use the same 54mm/50mm forks as the monster.  They are far from a direct replacement though. 

[junior varsity]

Your local dealer, SpeedyMoto has tapered bearings, All Balls for bearings. Not sure if the outer diameter is the same, I do know the shaft size is very different on the triples (inner bearing diameter)

[The Mad King Pepe']

The SBK tripples use a 36mm fork offset, that will greatly reduce the trail on the bike making it unstable.  If you realy dont want to modify the triples I would look into the japanesse bike forks as some of them use the same 54mm/50mm forks as the monster.  They are far from a direct replacement though. 

I used to think that more offset = more stability so I'm surprised to see it's the exact opposite.

So it's more rake = more stability (to a certain point), while more offset = less stability.

This image from Wikipedia helped me understand things better:


The drawing references bicycles so the offset is near the wheel axle, while on our bikes it's at the triples, however the effect is the same: increasing the offset (aka the rake) decreases the trail and stability.

Your local dealer, SpeedyMoto has tapered bearings, All Balls for bearings.

Not even close to them (I wish), but thanks for the info!

[junior varsity]

think of offset as: the distance between the pivot and the wheel is greater, so a small change of input at the bar, has a bigger effect on the bike.

36mm makes the bike very tipsy.