Author Topic: 2003rm85/85L forks  (Read 109 times)

Offline crfspode54

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2003rm85/85L forks
« on: June 02, 2018, 09:23:37 PM »
I just got given to me a brand new never ridden/never registered 03 Rm85L
The former owner of a San Diego dealer had it stored at his house and never did anything with it, and now I have it.
Anyway, itís the L model with 16/19wheels. My sons on a 14/17 bike.
I want to run 14/17 wheel set up on the L. The swing arm is the same, but the inner fork tubes are different, according to part numbers.
I know thereís a few other differences like seat foam and gearing,

But does anyone know for sure the diff in the forks? Is it tube length or valving? Or what? Any of you suspension gurus know?. My 9 year old is tall enoug for his small wheel, but he would love to rip this old RM.
" ...in dirt we trust...  "

Offline YZed250

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Re: 2003rm85/85L forks
« Reply #1 on: June 04, 2018, 11:44:17 AM »
Lots of links on thumpertalk and other forums discussing the conversion of 14/17 to 16/19 and most of them go into the differences.

Offline Matt Fisher

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Re: 2003rm85/85L forks
« Reply #2 on: June 06, 2018, 09:57:33 PM »
This is on the 05+ bikes, but the older ones are very similar, with the basic design going all the way to something like 1991.

Forks are the same, they just get slid down in the clamp to the top mark when running the bigger wheels. 
Swingarm is longer on the L, which necessitates a stiffer rear spring.  We usually ran the longer swingarm regardless of wheel size.
One tooth less on the countershaft on the L makes up for the larger wheel.  Same seat.

YZ85 wheels will fit if you run the RM wheel spacers.  05+ RM85's have a different sized rear disk (I think it's bigger).
CR80/85 & CRF150R also use the Showa suspension, so some of the parts interchange (I.E. rear springs on the CR are stiffer).

Odd fact- the 05+ transmission fits the older bikes.  The shift drum on the new one fits in a bearing, while the old one fit directly into the case.  Use the new bearing and shift drum for better shifting.

Offline crfspode54

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Re: 2003rm85/85L forks
« Reply #3 on: June 07, 2018, 12:42:38 PM »
Awesome mat Fisher. I actually ran across one of your posts on thumpertalk about it from a few years back. Thanks for the.info tho
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Offline Matt Fisher

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Re: 2003rm85/85L forks
« Reply #4 on: June 12, 2018, 12:40:52 PM »
You're welcome.
My wife says I'm full of it.  I'm sure she means good information.  Right?   :lol: