OzVMX Forum

Marque Remarks => Yamaha => Topic started by: Tahitian_Red on January 22, 2012, 05:46:54 pm

Title: 1975 MX250 Forks
Post by: Tahitian_Red on January 22, 2012, 05:46:54 pm

I have a set of forks from a US 1975 MX250.  I know they are nearly identical to the 74 YZ250 forks and I want to set them up nice.  Any tricks besides Emulators for getting them to work great?

Title: Re: 1975 MX250 Forks
Post by: Davey Crocket on January 22, 2012, 08:20:08 pm

They bend easy, rotate them 1/2 a turn every few meetings, I run 200mls of 15 weight in each leg and thats that.....no tricks....I have noticed over the years quite often when you pull them apart there are 2 different forks...ie springs and bottom legs different.

Title: Re: 1975 MX250 Forks
Post by: Tahitian_Red on January 23, 2012, 05:50:24 am

DC

Thanks for the reply! I'm going to put them on my 75 MX100 (30mm), so bending easy is all relative.  ;D

Title: Re: 1975 MX250 Forks
Post by: Rossvickicampbell on January 23, 2012, 09:56:08 am

I agree with DC - I wish I could find a more "robust" set of eligible forks.  I put emulators in them and these made a noticeable difference.

Title: Re: 1975 MX250 Forks
Post by: Tahitian_Red on January 24, 2012, 03:37:30 am

On a side note, will any 1974-79 front hub work on these forks?

Title: Re: 1975 MX250 Forks
Post by: Freakshow on January 24, 2012, 11:20:29 am

yes all  Yamaha conicals should.  MXA-b, Sc500, YZA-b-c-d, IT - for a long time

Quote from: Rossvickicampbell on January 23, 2012, 09:56:08 am

I wish I could find a more "robust" set of eligible forks.  I put emulators in them and these made a noticeable difference.

i think you need to look to unrobust yourself ROSS - would be the kinda answer.  Those forks were designed for 70kg riders, anymore and yoru asking them to do a lot more work and specs than they were asked to do, so i reckon there doin prity well for a standard pair of 35yr old 34mm forks.  ;)

Title: Re: 1975 MX250 Forks
Post by: IT400C on January 24, 2012, 01:36:33 pm

so what diameter are MX250/400B forks anyway?

Title: Re: 1975 MX250 Forks
Post by: Davey Crocket on January 24, 2012, 01:38:05 pm

34mm

Title: Re: 1975 MX250 Forks
Post by: Rossvickicampbell on January 24, 2012, 01:59:39 pm

Freaky - such a kind person!  Mate - big boned is natural - can't do much to change that  ;D  And I saw 70 kgs once - on the way through!

Title: Re: 1975 MX250 Forks
Post by: IT400C on January 24, 2012, 02:03:09 pm

Quote from: IT400C on January 24, 2012, 01:36:33 pm

so what diameter are MX250/400B forks anyway?

Were they the same as any other Yamaha forks of that era?  i.e. MX360A??

Title: Re: 1975 MX250 Forks
Post by: Freakshow on January 24, 2012, 02:38:17 pm

yes 34mm tubes.....

Title: Re: 1975 MX250 Forks
Post by: Wendell Clark on January 28, 2012, 12:09:12 pm

Quote from: Tahitian_Red on January 23, 2012, 05:50:24 am

DC

Thanks for the reply! I'm going to put them on my 75 MX100 (30mm), so bending easy is all relative.  ;D

Hi Jay,

Building a hunnert? Are you going to make a trip south and ride some of the Tripes races with us?

Wendell Clark

Title: Re: 1975 MX250 Forks
Post by: Slakewell on January 28, 2012, 03:37:40 pm

I thought the forks on YZ A 250 were so good I replaced them with set off a 73 KTM. I did try MX 400B forks for a while which were better. 

Title: Re: 1975 MX250 Forks
Post by: Tahitian_Red on January 28, 2012, 04:06:25 pm

Hi Wendell,

I've always wanted to come down and try Marty's 100cc Revenge, but I figured I better bring an '82 YZ100 instead of bringing a knife (MX100) to a gun fight.
 ;D


Slakewell,

Were the MX400 fork stronger or did they just have better damping?

Title: Re: 1975 MX250 Forks
Post by: Slakewell on January 28, 2012, 04:42:49 pm

Mostly better damping and a little less flex ,thou in deep runts you could still have bars at full lock and be going straight ahead. The Ceranies from the KTM were worlds better thou you have to weld and mill the brake lug on the fork , You should also hone the fork leg after welding.