triple clamp offset

[jack13]

Hello all, I have a question as to what mm offset would be best for flat dessert riding. I have a 2017  crf 450r which I believe to be 22mm. I 'm thinking a 20 would give me better high speed stability . The bike turns great , but ruts and slippery surfaces seem to effect the bike too much. The bike has a scotts damper on it. I had a 08 that I put 07 triple clamps on , and over the same path the 08 tracked with less nervousness. The 08 also used a scotts damper. Both bikes also have a devol lowering link. On jumps both bikes handle the same.

 thanks

[galligar]

20s less high speed ,better turning. You got the damper increase the damping . Had a 96 cr250 with a scotts, in the dez increased the damping ran whoops as hard as you wanted stayed dead straight,zero head shake. 08 had 22s stock, 20s 09-16,22s17-20,. 02-07 24s.

Edited September 30, 2019 by galligar

[jack13]

Thanks galligar, I wasn't sure as I 've read confusing articles on this subject. Seems looking at the technical facts 20mm should be better at high speed concerning  the trail, angle ,  etc.

Many racers say 22mm is more stable at straight line speed.

[galligar]

Push the forks down flush with the clamps. Really with  the scotts who cares what the offset is. High speed dez stuff narrow the sweep and increase the damping . Thats what I did on that 96cr250 ,before I installed the scotts it was scary to run high speed desert stuff after the scotts(correct settings) 5gear pinned.

[Chas_M]

18 hours ago, jack13 said:

Thanks galligar, I wasn't sure as I 've read confusing articles on this subject. Seems looking at the technical facts 20mm should be better at high speed concerning  the trail, angle ,  etc.

Many racers say 22mm is more stable at straight line speed.

Everything else being equal, 20mm would be slightly more stable than 22mm due to 2mm more trail.

[jack13]

Correct Chas M , this is what I read in serval articles , but  some desert racers have said they  feel 22mm is more stable at speed. As galligar said increase scotts damper force and get the same results. I do adjust the damper settings as I ride depending on conditions ,  I'm just trying to get the most of out of the setup.

[Potts228]

On 9/30/2019 at 9:17 AM, jack13 said:

Hello all, I have a question as to what mm offset would be best for flat dessert riding. I have a 2017  crf 450r which I believe to be 22mm. I 'm thinking a 20 would give me better high speed stability . The bike turns great , but ruts and slippery surfaces seem to effect the bike too much. The bike has a scotts damper on it. I had a 08 that I put 07 triple clamps on , and over the same path the 08 tracked with less nervousness. The 08 also used a scotts damper. Both bikes also have a devol lowering link. On jumps both bikes handle the same.

 thanks

Your thinking the wrong way.  24mm offset will give you better stability (in theory).  the 07' CRF450R had a 24mm and the 08' CRF450R had the 22mm.  You will lose turning sharpness when you go to the 24mm.  Run the rear wheel towards the rear of the adjusters (pull the wheel back) to lengthen the wheelbase.  I would start with running the forks fully out (flush with the top of the triple clamps) first and move the rear wheel back.   Also, maybe you need the suspension revalved for desert????  I know the 17' suspension was soft to begin with but I would explore suspension valving and setup before looking for a new triple clamp set. 

   

[turbo dan]

4 minutes ago, Potts228 said:

Your thinking the wrong way.  24mm offset will give you better stability (in theory).  the 07' CRF450R had a 24mm and the 08' CRF450R had the 22mm.  You will lose turning sharpness when you go to the 24mm.  Run the rear wheel towards the rear of the adjusters (pull the wheel back) to lengthen the wheelbase.  I would start with running the forks fully out (flush with the top of the triple clamps) first and move the rear wheel back.   Also, maybe you need the suspension revalved for desert????  I know the 17' suspension was soft to begin with but I would explore suspension valving and setup before looking for a new triple clamp set. 

   

Precisely backwards.  More offset sharpens handling at the expense of stability.  Less offset trades steering response for stability.

I went from a 25mm offset to a 21.5mm offset on my 05 KX.  This is a noticeable difference.  Due to the increased front end traction I could ride the front wheel much more aggressively.  This resulted in much better handling and better stability. 

https://motocrossactionmag.com/ten-things-about-triple-clamp-offset/

[galligar]

Call ride engineering less turns better.Changed my 05 to 22 turned much better vs the24s. Ran 21s on my 13 &15 vs the stock 20s still turned and was more stable in the rough. Get the 20s pull the damper off see for your self what head shake is like.

[Potts228]

21 hours ago, turbo dan said:

Precisely backwards.  More offset sharpens handling at the expense of stability.  Less offset trades steering response for stability.

I went from a 25mm offset to a 21.5mm offset on my 05 KX.  This is a noticeable difference.  Due to the increased front end traction I could ride the front wheel much more aggressively.  This resulted in much better handling and better stability. 

https://motocrossactionmag.com/ten-things-about-triple-clamp-offset/

Read the article again.  On the Honda frame the less offset will give you a nervous but better turning bike.  That's exactly why in 2008 they went from 24mm in 2007 and prior to 22mm to sharpen the turning at the expense of stability.  That's why they added the stabilizer when they went to the 22mm offset.  If they gained stability (which they didn't) then why add the stabilizer?  Actually I can't think of any bike that less offset gives you more stability!!     

 

MXA - "  Less fork offset (20mm as opposed to 22mm) increases trail and, on paper, should make the bike steer slower and improve stability. Yet, for some reason (perhaps the wide number of factors involved in bike handling), less offset often results in a bike that turns sharper and is more accurate."

Edited October 2, 2019 by Potts228

[turbo dan]

Less offset can improve handling because chassis geometry is complex.  Makes no difference which bike, a chassis is a chassis.  The correct amount of offset will vary from bike to bike, though 22mm seems to be a pretty common figure.  More offset will always make a bike turn sharper but that doesn't mean it will handle better.

You are quoting the article out of context.  Read the whole thing, not just the part that you think supports your position:

Quote

How can reduced offset make the bike steer with a much lighter, quicker feel when the science says it should do the opposite? Even though the actual steering geometry is slower-turning and more predictable, increasing trail is also the same thing as moving the engine forward and putting more weight on the front tire. In the end, riders find that clamps with reduced offset steer better, because altogether it gives the bike a more stable feel—but with easier steering and with a front tire that stays more planted.

 

[Potts228]

4 hours ago, turbo dan said:

Less offset can improve handling because chassis geometry is complex.  Makes no difference which bike, a chassis is a chassis.  The correct amount of offset will vary from bike to bike, though 22mm seems to be a pretty common figure.  More offset will always make a bike turn sharper but that doesn't mean it will handle better.

You are quoting the article out of context.  Read the whole thing, not just the part that you think supports your position:

 

All I can say is with 12 years of Baja racing and seven championships , also eight BITD championships, hours of testing with the best in the business, less offset means better steering and LESS stability (more weight on the front wheel) but this weight usually causes a nervous front end (head shake).  We tested less offset starting with XR650Rs and then with the 450X platform starting for us in 07'.  On the 450X platform we tested the 20mm, 22mm and 24mm.  The 20mm caused the front end to turn the best on turn in but knifed too heavily in soft terrain and headshake was very notable.  The 22mm, for us, was the best balance and actually what Honda switched to for production in 09 I believe (450X).  For desert racing I'm very confident I have my facts straight regarding the original post.  A chassis is a chassis yes, there are some good and some not so good but not sure what your point is?  The Honda 2017 Honda 450R is a great chassis for Motocross!  I read the whole article and familiar with it already.  I highlighted a very important point and theory is just that.  So back to the original post... the best option for desert is to leave it stock and drop the fork in the clamps,  Move the rear wheel back and stabilizer.  Going to a 20mm offset will be a mistake!  

                

Edited October 3, 2019 by Potts228

[turbo dan]

There is a just right amount for every bike.  I am running 21.5mm on my 05 KX.  25mm works pretty well on my 03 but that chassis has a much slacker head angle.  I'm getting ready to try a set of 22's on that bike just for kicks.  Pro Circuit had them on clearance.

Too little offset can make the front tire too eager to turn into a lean but this will be somewhat offset by the increased trail.  Beyond a certain point, reducing offset will bear too much weight on the front end which may cause handling issues.  That's part of the geometry package that depends on the bike.  RG3 recommends 20mm for many older Hondas and it may work well with proper setup and suspension valving.  I will say that the best handling bike I have ever ridden was running 22mm offset.  That number seems to be a pretty common choice among many different brands.

[jack13]

Thanks for all the information. I'll try a 20mm, and if I can find a set of 24 mm  I'll try them to see the difference. I have a preload on fork springs of 12 mm. I started with 20mm pre load and worked down to 12 mm. I went with stiffer fork and shock springs and am now back to stock. I may revalve the dampers, but feel for my riding they are acceptable. If I revalve I'll also put in gold valves. Again thanks for the info.

[Potts228]

On 10/3/2019 at 7:26 AM, jack13 said:

Thanks for all the information. I'll try a 20mm, and if I can find a set of 24 mm  I'll try them to see the difference. I have a preload on fork springs of 12 mm. I started with 20mm pre load and worked down to 12 mm. I went with stiffer fork and shock springs and am now back to stock. I may revalve the dampers, but feel for my riding they are acceptable. If I revalve I'll also put in gold valves. Again thanks for the info.

More info to confuse you! ?  https://www.vitalmx.com/forums/Tech-Help-Race-Shop,42/20-mm-offset-on-17-18-or-19-crf-450,1351568

Also... on the BRP web site they make a comment about going from a 20mm offset to 22mm to help handling and stability:  https://www.shopbrp.com/index.php?option=com_mijoshop&route=product/product&manufacturer_id=19&product_id=1445&sort=p.sort_order&order=ASC&page=7&limit=50

 

 

Edited October 5, 2019 by Potts228

[Shawn_Mc]

There is a whole lot of rake/trail confusion in this thread. So much, Im not even going to attempt to iron it out. Rake, Trail, engine placement in the chassis and swing arm pivot location all work together, or against one another and they all change depending on the guy in the seat.

[H4L]

On 10/2/2019 at 12:36 PM, turbo dan said:

Less offset can improve handling because chassis geometry is complex.  Makes no difference which bike, a chassis is a chassis.  The correct amount of offset will vary from bike to bike, though 22mm seems to be a pretty common figure.  More offset will always make a bike turn sharper but that doesn't mean it will handle better.

You are quoting the article out of context.  Read the whole thing, not just the part that you think supports your position:

 

I disagree about “makes no difference which bike,  a chassis is  a chassis.   That’s one of the most ignorant posts I’ve read on this sight in a while.  

[turbo dan]

41 minutes ago, H4L said:

I disagree about “makes no difference which bike,  a chassis is  a chassis.   That’s one of the most ignorant posts I’ve read on this sight in a while.  

You seriously think it matters which color the plastic is?

Ok.

[jack13]

To really stir the pot, I spoke with a Az. native and he's almost as old  as me and he said put a 20mm top clamp on a 22 mm lower clamp. I've never heard of this and would think it would stress the lower clamp  !

Edited October 6, 2019 by jack13
wrong word

[turbo dan]

3 hours ago, jack13 said:

To really stir the pot, I spoke with a Az. native and he's almost as old  as me and he said put a 20mm top clamp on a 22 mm lower clamp. I've never heard of this and would think it would stress the lower clamp  !

It would be very difficult to get the forks in.  The clamp bore would not be square with the fork tubes and the bike would not be safe to ride.

Hopefully he was mistaken.