cr80/kx80 suspension on xr100?

im finding all these xr 100's on google that have some sick suspension from a kx or cr 80. heres a couple pics for examples

it looks like if you just buy the forks and clamps from the cr80 then it will bolt right up to the xr100 frame. the only thing im not understanding is the shock, the shock on the cr80 is like 1/3 longer than the xr100 shock. does that mean i would have to cut off the stock shock mount, then weld it a couple inches higher to work with the cr80 shock? also can you use the stock xr100 linkage or do you have to put the cr80 linkage on it? i can see in one picture it has the stock swingarm but in the other picture it has the 80 swingarm

im thinking some older cr80 forks like the same year as my xr (1996) would just bolt right into my xr100 clamps right?

The top pic is a CR80/85 fabbed to hold a XR100 motor. It looks like a DMC conversion. I can't tell on the bottom pic if has a TK link or not, but it probably has work done to the stem on the forks.

i was reading a little bit about the stem on the forks situation, what has to be done?

kinda funny i was just going to start a thread on putting a cr85 shock on a 100 i haven't been to concerned about the suspension on my 100's cause i only ride TT and supermoto, and i just cant bring myself to buy a works shock, but i have taken one of them to some real mx tracks in the past and its not real fun riding a pogo stick

ive got both bikes 85/100 and have done some quik measurements , and i think its doable .

my thought is removing the shock tower off the 100 and fabing a new mount to the bottom of the sub frame, ive looked at alot of different options , but all stopped me becuase i coulnt find a replacement spring for my weight, but i saw bbr for one makes a spring for the cr shock , so it looks like my project is a go:thumbsup:

yeah moving the shock mount to the top of the frame/subframe is no big deal at all. the only thing im not sure about is that im a 150lb novice mx rider and i think even the bbr spring will be too soft for me. but again who says i need to ride it as hard as my 250 right. anyways how bout you start the chop shop and see how that goes and if it works for you then im gonna do it!

i just need to check the clearences before i go chopping the stock tower off, and find out its hitting somewhere else , but on a side note the bbr spring is 6.4 that handles a 200 pd rider according to the racetech web site so that spring definatly wont be soft

yeah im 150 so a 150 novice mx should be perfect with the 6.4

so yeah the spring plus the cr front end should go perfect huh.

Keep in mind that the XR80/100 shock linkage ratio is not the same as the CRs80/85. The stock XR spring is about 650lbs= 11kg! The BBR adult spring for the stock XRs shock is 975lbs= about 17.5kg. Also, because of the linkage ratio- the stock XR (shock) have very little throw (about 1.5") the CR80/85 has about 3x that.

Some Food for thought.

AAAhhhh....Gman ,I figured somthing would come up im not that lucky , ive been running a kx front end with good fork springs and a stock rear shock w/bbr spring and like i said ive been pretty happy with them like that ,on TT/supermoto type stuff ,of which i ride 90% of the time, but i wanted to switch one of them over to the cr shock /BBR spring so it would work better on mx .

so explain to me what the differnt ratio linkages would affect? i do have a Tk link on them that raised the rear , basicly i look at it like this , i get to fab on the bike :blah: and spend upto 200 instead of 400 for a works ,on a bike that i already have to much money in .....:thumbsup:

just less travel right?

i believe what hes saying is the linkage arms arent as long as on the cr. which means less travel and a faster stroke (kinda) this is sounding like a lot of trouble now eh

It is tough but the works shock makes the xr swingarm and linkage work.There still isn't a ton of travel, but enough.With cr85 forks shortened to a similar stroke, maybe 7 or 8 inches.Buy the shock(I found mine on ebaay)Find a donor front (wheel and brake) end.The stem is available for around $130 makes it a bolt on deal.

When I ride mine as a flattrack bike I run 16 wheels on both ends.As big mini/woods I use the 17 front/16 back.We have a xr80 I've been wanting to try 14/16 combo on my xr100 .

You prob know but,if your jumping your xr and don't have a frame cradle.Bad things happen!


Saw this in the suspension forum not to long ago.


llength A does almost the same as the length of the rod. it mainly affects progression.

longer means less progression.

length B mainly affects the shock/rear wheel ratio

shorter means the spring/valving has to be stiffer.

This pic in a KXF450, all tho not a CR85 linkage they share the same principles

Notice the TK link (and the XR) linkage length in B.


the raymondguy did you ''have'' to flip the swingarm over to make it fit , or did you do it to make it taller?

That's the CR80 swing arm in the XR frame. The link needs to be flipped to center the shock into the XR frame; swing arm mounts traditionally.

too much is going on

hey ray what year swing arm and shock is that and are you using the xr100 or cr80 linkage?, have you tested it out yet does it ride good?

hey ray what year swing arm and shock is that and are you using the xr100 or cr80 linkage?, have you tested it out yet does it ride good?

Front & rear suspension is 1984 CR80R. The shock is in need of overhaul, but still feels more substantial than the stock 98 XR100 piece. As mentioned earlier in this thread, a frame brace is in order before any serious riding occurs. I haven't had a chance to ride it yet, but it's got to be light years better than stock (on rough stuff, the stock setup actually handles quite well on light trails etc., being so low slung).

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now