[darkrai347]

Godd day all,

Im new here and I just want to ask for some advice. Im planning to upgrade my suspension with Race Tech kits. I just want to ask you much spring rate do I choose for the forks and rear shock. I'm 90 kgs give or take add gears lets put it at 95 kgs.

What spring rate do I choose?
Front
Rear

Would love to hear your comments. Thanks all

[Back2-2]

Hello and welcome. Our resident suspension expert JimDirt is going to be away from the site for a short time.If you can hang on a little he will definitely be able to help you. The guy knows suspension in & out.

Thanks,

[darkrai347]

Yes I will definitely wait for his advice because I want to buy Racetech springs and I want to get it right for my weight.

Thank you for your quick response, will wait for his say.

[Back2-2]

While Jim is away you can also you can call Racetech and talk with them. Just an option for you.

[JimDirt]

Godd day all,

Im new here and I just want to ask for some advice. Im planning to upgrade my suspension with Race Tech kits. I just want to ask you much spring rate do I choose for the forks and rear shock. I'm 90 kgs give or take add gears lets put it at 95 kgs.

What spring rate do I choose?
Front
Rear

Would love to hear your comments. Thanks all

Welcome to the site !!

I will be in and out for a bit till I get some pressing family matters taken care of , but first , I need to know what bike (250R/X - 450R/X) ?? , what type of riding are you doing ?? (Trail Riding , MX for pleasure , or Racing MX or Off-Road ,etc.), and what is your skill level ?? (novice/beginner , intermediate , expert , etc.) ...... That all makes a difference when calculating spring rates ,and type of valving you will be doing , like soft/plush for trails or endurocross , as depending on the use , would also affect spring rate etc (I am assuming by your comment about getting Race Tech Kits , that you will be revalving the bike yourself) , were you planning on changing the Pressure Springs as well as the main springs ?? , as one will affect the other slightly ... I have to take care of some things tomorrow during the day , but will return tomorrow evening to check the forum ..... unless you happen to respond tonight , then I will do my best to give you a answer tonight , so you can get on with your project ... but I need answers to my questions first .....

[darkrai347]

Good day JimDirt,

I usually do both trail and on road spirited riding. I would say i an intermediate rider with growing skills. I would be doing my own shocks, I will let my mechanic do it for me. I have a CRF 250L 2018 model. I will also be shifting from knobby tires to supermoto tires as well. Thanks for your idea.

[JimDirt]

Since its a 250L , that does create some issues with the fork springs , The shock rate you will need is a 12.5.kg , for your weight , (198.lbs/90.kg) but the fork will require a 0.57 for your weight , and they are not available from Race Tech ..... however , that does not mean you cannot use another manufacturer's spring for the forks , like Factory Connection , or Eibach , etc. , to see if they have that rate , you could call Race Tech directly and see if they can make up for the spring rate difference with a valving and oil setup that would make the bike work with a lighter (made for a 180.lbs/81.6kg rider) spring , which is the stiffest they offer , and either you or the guy you choose to redo the valving can set it up to their recommendations possibly making the compression stack stiffer to accomodate for the extra weight , the reason I believe it may be done with valving , is because you will unlikely be jumping with the bike , so the adjustment would be to ensure proper handling and front to rear balance rather than for bottoming resistance ... follow ??

So give Race Tech a call first , and see if they can give you some direction for the front spring issue , 1-951-279-6655 (not sure about international dialing) , as I think that will be your only hurdle , once you can either locate a spring , or get a valving stack and oil level that will make up for a lighter spring (you will need to replace your stock springs front and rear due to your weight and the stock spring weight limit) ....

Sorry i could not be of more help , but with a 250R or X you have many more spring options than for the 250L because of the smaller diameter , less adjustable fork they have , so not a lot can be done , but to either try to find the rate I posted , or locate someone who might stock one , or at worst , have springs custom wound ..... Or try to get the valving to make up for it somewhat , which Race Tech can help you with , Basically , if you can keep the bike up in the stroke and not diving into corners and not putting all the weight on the rear wheel while exiting corners where you would also lose steering , I think you will be OK with a lighter rate , as long as a stiffer compression valving setup can keep you in the top part of the stroke longer , and a slower Rebound setup will keep the front from wheeling out of every corner , then in the mid compression stroke can become plusher so the bike transitions into the corner without diving into it making the bike sketchy , I think without needing to worry about what the bike would do jumping , you will be fine ..... Also since you are basically doing a SuperMoto setup , I believe the suspension will have some limiters in it , which will help somewhat as well , as there will be a shorter stroke , so the bike may not be as tippy front to rear as a fully suspended bike would ....... this is all depending on if limiters will be installed of course ...

[darkrai347]

Good day sir thank you alot for answering my quarries about my CRF. What do you mean by limiters on a supermoto setup?

[JimDirt]

Good day sir thank you alot for answering my quarries about my CRF. What do you mean by limiters on a supermoto setup?

Sometimes in bikes set for Supermoto , the suspension is lowered , since you do not need all the travel since any jumping is minimal , so when some bikes are set up for street use with a Supermoto setup , they also do the limiting , similar to a flat track bike , it lowers the center of gravity and makes the bike feel more stable in turns when racing , and some road riding in canyons , etc. , not saying you will want or be doing this , just thought it to be a possibility you were considering it , so I made sure to remind you to mention that to Race Tech or whomever if that was being considered , so you got all the things you wanted/needed to do that type of setup , ,,, that said ... .

Most regular street riders just leave the suspension length stock so they can swap wheels and ride dirt without restrictions , as I am not sure the amount of street versus dirt riding you will be doing , or how serious either will be as far as intensity , as some guys will like to carve canyons , and some just ride street for transportation , so it was just another option to consider or check into , but not mandatory ....

[darkrai347]

Thank you for that additional info sir. I will be doing major street use. No racing, just spirited canyon riding. 80% road 20% trail. Im from the Philippines btw. Any idea how I can reach race tech. Do they have chat supports that I can keep in contact with this matters about front suspension mostly since the spring rate for the rear shock would be just fine with the 12.5kg. BTW im 90 kg now plus all my gear I would already be 100kg give or take 2 or 3 kgs. Will the 12.5kg spring rate for the rear shock be able to compensate for my weight with all the gear. Thank you for answering all this noob questions.

[JimDirt]

Here is Race Techs site , they have different contact methods shown on the right lower part of the page , it shows Twitter , Facebook , etc. , plus their phone number
http://racetech.com/index.aspx

The difference in your weight with gear , you should be able to compensate for with a Sag adjustment , with the correct spring I listed , if it was going to be over 50lbs difference then another spring would be needed , but usually a spring sag can adjust for the added weight of backpacks , etc , so you should be fine with that rate

And I think with mainly street and light trail use , you should be ok with the stiffest spring they have , but as I mentioned , you could contact them directly to see if they could recommend a valve stack that would somewhat compensate for the lack of stiffer spring for your weight ...... because the issue with not having a spring for your weight for the fork , means it has to be compensated for with valving and oil , or possibly a preload washer , to keep it a little stiffer longer when compressing so you do not end up in the wrong part of the stroke all the time , which would make the ride harsher ... , If your using one of their re-valve kits , then they can get you more dialed in then I can with setup , as I am not associated with Race Tech , I just taught myself this stuff , I do not have the experience they do as far as compensating for lack of spring rates , like they would ... Any questions I can answer , I will , but if I am unsure as to how to proceed , I will direct you to them , as I have on some of this , anything I can answer , just keep asking , and I will either answer as best I can , or direct you to someone who can