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offset vs shimsing

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i just wonder what if you change the offset from oem 23mm to lets say 21mm how would the damping change must be much harder feel right ,since there must be more weight on the frontwheel ?? so lighter or harder springs ?? and what about shimsing ??

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i just wonder what if you change the offset from oem 23mm to lets say 21mm how would the damping change must be much harder feel right ,since there must be more weight on the frontwheel ?? so lighter or harder springs ?? and what about shimsing ??

 

 

i went from 20 to 22mm i did not notice a change in suspension operation.

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Hi guys. I'm new on TT but I've been doing suspension stuff off and on for more than 20yrs now. I don't believe that I've ever heard that term. What is shimsing?

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i dont get this .

i have gone one step lower on the shimstack than recomended (had that before ) but the fork seems harder and how the hell can the bike feel stiffer when i have 21mm offset than if i have 23mm offset (yeah got one of those xtrig tripleclamps )

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You are putting more weight on the front , you could preload springs a few mm to hold it up better

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ok so i know theres more weight on the front ,but i should preload the spring a little bit ?? to keep the stroke on the plush side ?? tried today and felt ok when i had 23mm offset and with 21mm offset i let the rebound adjuster out almost all the way (felt like it was packing ) but with preload on the spring wouldnt the spring get to feel stiffer then ??

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and a little more on my setup my weight 97kg  spring rear 5,8 front 0,47 and pressure springs 1,8kg  the settings in the fork are as follow CL 1504 ,CLX 1022,CH46.MV 111004 MVP50 ,#55. RL1003  RLX1012  RH144  thats what i got from the RT dvs search when i put in all info oil wolume 330cc desert  trail riding (swedish enduro )

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The pre load just puts you back to a balanced chassis like you had before

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Let's assume you have a 58" wheelbase, 14732mm.  If you also have a 27 degree head angle, moving the offset from 23 to 21 shortens the wheelbase by 1.78mm, but let's say 2mm just because it doesn't change my point and it's easier.  That makes only a 0.003% change in the wheelbase, and shifts the CG forward such that it adds 0.006% more weight on the front wheel.  On a 250 pound bike that was 50/50, that comes out to just under 4 grams of increased weight at the front end.

 

Frankly, you'd get twice the change out of any typical chain tension adjustment.  I don't think that the redistribution of weight is behind the OP's complaint.

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I respect that you ran those numbers and they could be correct , but less offset makes a noticeable difference on the weight on the front wheel

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Let's assume you have a 58" wheelbase, 14732mm.  If you also have a 27 degree head angle, moving the offset from 23 to 21 shortens the wheelbase by 1.78mm, but let's say 2mm just because it doesn't change my point and it's easier.  That makes only a 0.003% change in the wheelbase, and shifts the CG forward such that it adds 0.006% more weight on the front wheel.  On a 250 pound bike that was 50/50, that comes out to just under 4 grams of increased weight at the front end.

 

Frankly, you'd get twice the change out of any typical chain tension adjustment.  I don't think that the redistribution of weight is behind the OP's complaint.

 

You took the words right out of my mouth. Put each wheel of the bike on a scale with each steering offset and see how much weight shift there is. You will see that Gray is correct in the actual weight shift. The handling difference comes from the change in steering geometry, not the change in weight bias. Changing the offset of the triple clamps by 2mm will not affect the stiffness of your suspension.

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It's not just a bike weight thorough

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ok but then i dont know whats wrong feels really weird at 21mm offset

it says on the printed sheet from RT that front spring preload should be 4mm does that mean adding 4mm on top of the spring or is it the preload that it has from the factory ?? and and putting the front wheel closer to the bike by 2mm i dont think that would affect the steering at all ,but with the triple at 23mm i measured from the radiator to a point on the triple  105mm and with it on 21mm it was 98mm so it put the front wheel more than 2mm closer to the frame at 21mm , dirt rider magazine tested it on the kx450 and they say that the damping curve changed quite a lot ,so some preload may be the answer to it ,as i have more weight on the frontwheel

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It's not just a bike weight thorough

 

Even if you add a 200lb rider to the equation, and assume that the rider stays perfectly still, you have added 8grams or so to the front wheel. If you can notice that then you would be able to notice when you switch brands of handle grips. Definitely not enough of a difference to change springs or valving.

 

The rider's position on the bike is going to have way more of an affect on the weight bias of the bike than the offset of the triple clamps could ever create.

Edited by KJ790

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What about a 200lb rider who is 6 ft tall and leaning far forward and braking hard , the rider and bike weight shift will be far from central, you can get a bike to put 100% of the weight onto the front wheel if the back wheel becomes airborne ( which it does) it's not a static thing and a rider has huge leverage when he stands (that's why a tall rider needs a stiffer fork spring than a short rider if the same weight )

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What about a 200lb rider who is 6 ft tall and leaning far forward and braking hard , the rider and bike weight shift will be far from central, you can get a bike to put 100% of the weight onto the front wheel if the back wheel becomes airborne ( which it does) it's not a static thing and a rider has huge leverage when he stands (that's why a tall rider needs a stiffer fork spring than a short rider if the same weight )

 

This scenario is not affected by changing the offset of the triple clamps by 2mm. That is what I have been saying. If you are doing a front wheelie with 23mm clamps, or with 21mm clamps, the same amount of weight will be on the front wheel. No need to change the springs or valving for a 2mm triple clamp offset change.

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But it does as it puts more weight towards the front in any given situation , if it's a total mass due to leverage of 500lb, and you add 2% extra that's 10 lb more , offset does not alter angles and 8 grammes won't change the handling like a 2 mm offset does , so there is more going on that the static numbers suggest

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