Finding the correct spring rates

yz_387

Member
Jun 6, 2001
71
0
Anybody know where I can find the correct spring rates for my weight. I used the Race tech websight to get their suggestion, and would like to find another source to see if they match up before spending my hard earned money.
 

Papakeith

COTT Champ Emeritus
Damn Yankees
Aug 31, 2000
6,691
47
RI
Post your information here:).
There are quite a few knowledgeable suspension guru's who lurk and post here.
Just give them the following information:
  1. Your bikes MFG, model, and year
  2. Your weight ( dressed to ride )
  3. Your skill level
  4. The type of terrain you ride (MX, SX, gravel pits, power lines, woods, etc.)
    [/list=1]
 

yz_387

Member
Jun 6, 2001
71
0
Ok, here it is:

2001 yz 250
5' 8" 150lbs
novice (typically run 4th to 8th place in 250C)
MX (conditions very from hardpack to sand)

I probably won't revalve until winter due to lack of funds, but I think finding the right springs would help a lot for this year.

Thanks in advance
 

John Curea

LIFETIME SPONSOR
Feb 29, 2000
177
0
YZ
I would reccomend the following spring rates for MX

Fork .40

Shock 4.5

The stock rates are a little bit on the stiff side for your weight:
Fork 4.3 shock 4.9

Take Care, John
 

robmann

Member
Dec 30, 2000
70
0
yz_387,
front .41, with 8mm preload, oil ht at 95mm
rear 4.6, with 95mm of rider sag

I would agree with KXVET#207 if you were doing woods riding but they are a little light for MX
 

yz_387

Member
Jun 6, 2001
71
0
Thanks for the replies. The Race Tech web sight gave the same answer as KXVET#207, but I am going with the rates that rob mann suggested. They are the same as the stock spring rates from my old '98 yz125 and I still have them so I can make the change without spending a $. I already changed the shock spring and it was a BIG improvement. Tonight I will finish changing the fork springs. Thanks again.
 

robmann

Member
Dec 30, 2000
70
0
Some of the rates that RT suggests are a little light for MX at least that is what I have found. They are much closer on the woods recommendations.
 

yz_387

Member
Jun 6, 2001
71
0
rob mann, thanks again. what exactly is the fork spring preload? Do I need to add a spacer to get the 8mm of preload. I know there is some preload on the springs from the factory, but I have no idea how much. Also, any idea what the weight of the factory oil is? If I need to add oil, I don't want to mix weights, so if I don't know what the weight is, I will have to drain the oil and start from scratch.
 

robmann

Member
Dec 30, 2000
70
0
yz_387,
drop spring in fork with fully compressed, measure from the top of the tube, to top of spring then install the cap measure again from the top of tube to top of spring the difference between them is your preload, the YZ comes stock with 5 to 8mm, you may need to add spacers. In this fork you will have to add them under the spring not on top as it will get in the way of the rubber bottom out system, make sure the washers are just smaller in OD than the ID of the tube and have a larger ID then the plastic spring guild. I would recommend that you dump the stock oil and replace with a 5wt.
 

yz_387

Member
Jun 6, 2001
71
0
Hey rob mann,

I made the changes, but haven't had a chance to ride the bike yet. Since you had so much other info, I was wondering if you had a suggestion as to where to start with the clickers. Thanks.
 

yz_387

Member
Jun 6, 2001
71
0
Thanks for the clicker settings (although I still haven't had a chance to try them). How do you get all this info, do you work at a suspension shop or something? And about that high speed setting of 1, that is a lot more damping than the usual 1.25 to 1.5 that most magazines and such seem to suggest. What will running the high speed compression so tight do?
 

robmann

Member
Dec 30, 2000
70
0
check out my profile, this is the setting that I found worked best for most conditions with the stock valving, remember CA is different than most other areas. try it at both settings and report back as to which you like best.
 
S

Saratoga

Robman: how can you tell someone what springs or changes to make without knowing what the problem is that they are trying to fix? Also, why did you recommend to go heavier on the fork springs but lighter on the shock? In my experience with my 01 YZ 250, a 150lb rider should find the stock springs just right. Maybe change the oil level, clickers, or sag but no need to change the springs. Has your shop done actual testing with the your settings?
 

robmann

Member
Dec 30, 2000
70
0
Saratoga,
I did not recommend stiffer fork and lighter shock you better read the thread again I recommend .41 and 4.6 which are both lighter, it does not matter if they have a problem or not spring rates are weight driven. We not only have done extensive testing on the YZ we also do calculations on weight bias of the bike to help determine the proper spring rate. A 150lb rider will never get the proper sag with stock springs.....
 
S

Saratoga

Robman: Thats right, stock springs are .43s. I was mistaken. I weigh about 205lbs with gear. I installed .46/5.0, stock valving. Bike feels good on a MX track but am wondering if the rebound is too fast even when clickers are turned in most of the way. Do you advise a revalve to fix this or will I learn to live with it? Also, did I install the correct springs for my weight?
 

robmann

Member
Dec 30, 2000
70
0
Saratoga,
Yes I would recommend 5.0 and .46. Here is the problem with running you rebound that stiff is that it will cause the comp to be harsher than it should be. Because the stock rebound needle flows oil in both directions so you will be restriction the bleed on comp. Yes a revalve will help to get you back in the middle of your adjustment range.
 

yz_387

Member
Jun 6, 2001
71
0
For the record, the spring rates that rob mann suggested were definitely a step in the right direction. I haven't had the opportunity to do any real track riding since the change, but from the little bit I have done on the practice track it handles better. Once I get the chance to ride on some real tracks I will report back on which high speed comp setting works better for me. Thanks for the replies.
 

Jeremy Wilkey

Owner, MX-Tech
Jan 28, 2000
1,453
0
Saratoga,
I would suspect that the compression issue is not so much the clicker impacting compression but a packing problem. The rebound orfice at a tight setting offers very little to the shock in terms compression responce. So yes it might be wise to revalve, but I doubt its rebound clicker related compression problem. If you had a early model honda then it would but not on a YZ

Regards,
Jer
 

yz_387

Member
Jun 6, 2001
71
0
hey rob mann,

sorry to keep bothering you, but I was wondering if you could also make a suggestion as to the spring rates for my friend with the same bike ('01 yz 250). He is 185 pounds and is the same skill level as me (around top 5 250 C class). Also, would you recommend different clicker settings for him, or just different spring settings. Thanks in advance.
 

robmann

Member
Dec 30, 2000
70
0
yz_387,
Front, stock springs should be fine, oil ht 95mm, C-9, R-9
Rear, the stock spring is suppose to be a 4.8 but the ones I have tested have been 4.9 which may be a bit stiff would rather see a 4.8 for 185lbs, sag set at 95mm, LSC-9, HSC-1turn, R-9.
 

Pacho

Member
Jun 15, 2001
14
0
'01 CR 250 suspension settings

Hey rob mann, I was wondering if you could also help my with my suspension settings. Here's my info:

'01 CR 250
154 lbs.
5'7
Intermediate??? (top 5 in my country which is comparable to top 5 B class in the US).
100% MX

I'm having trouble setting up my suspension, specially my forks. According to Race-Tech's spring charts, my stock springs are way heavier than what I need and I guess this is the root cause. I want to get this over ASAP but since there's no revalving available in Peru (rebuild only), I'm planning to order the right springs and perhaps one of those MX-Tech or Race Tech valves for my forks. Any suggestions?

Thanks for your help!
 

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