Front Fork improvements

lgingell
Site Supporter
Site Supporter
Reactions:
Posts: 88
Joined: 13 Sep 2009, 17:56
Bike Owned: CRM 250 AR W
Re: Front Fork improvements

Post by lgingell » 22 Dec 2011, 20:30

you asked what forks fit the crm yokes - wp 43mm usd forks (from bikes like ktm exc) fit directly into crm yokes with no modifications.

the complete ktm front would be needed (brembo brakes and all!)

i have a set to fit, but havnt sorted out a speedo drive yet.

eddie - yes, 15wt oil is too thick but as you will probably know the standard forks "blow through" most of the travel very quickly - the thicker oil helps slow this down slightly but it is a crude fix - improving the shim stack or changing the forks for something better is definetly what i want to do.

the crm is used for daily commute, trails, mx, enduros and hare and hounds

back off road
Super Moderator
Super Moderator
Reactions:
Posts: 1027
Joined: 12 Sep 2010, 10:48
Bike Owned: KTM 200 exc
Location: Derbyshire/Notts border
Re: Front Fork improvements

Post by back off road » 23 Dec 2011, 19:43

easy speedo fix = trail tech no drive needed or even a digital push bike speedo
Im thinking about a bike with more valves than a powervalve

User avatar
BaNZ
New kid on the block
New kid on the block
Reactions:
Posts: 41
Joined: 23 Jun 2011, 13:23
Bike Owned: CRM250-MK2 '93
Location: Vladivostok, Russia
Contact:
Re: Front Fork improvements

Post by BaNZ » 24 Dec 2011, 01:44

[quote="lgingell"]what forks fit the crm yokes - wp 43mm usd forks (from bikes like ktm exc) fit directly into crm yokes with no modifications.[/quote] - someone, please, explain this to me. But CRM fork stanchions 45mm, isn't it?!

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4185
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Re: Front Fork improvements

Post by knackeredMk1 » 24 Dec 2011, 10:27

43mm is the width of the 'slidy' chrome bits.

User avatar
BaNZ
New kid on the block
New kid on the block
Reactions:
Posts: 41
Joined: 23 Jun 2011, 13:23
Bike Owned: CRM250-MK2 '93
Location: Vladivostok, Russia
Contact:
Re: Front Fork improvements

Post by BaNZ » 24 Dec 2011, 16:36

Damn me, knackered, but I can swear, on Mk2 was 45mm! I checked it myself. Don't know about mk3 though.

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4185
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Re: Front Fork improvements

Post by knackeredMk1 » 24 Dec 2011, 17:23

Igingell is saying that WP 43mm forks fit CRMs. Not that CRM forks are 43mm.

User avatar
BaNZ
New kid on the block
New kid on the block
Reactions:
Posts: 41
Joined: 23 Jun 2011, 13:23
Bike Owned: CRM250-MK2 '93
Location: Vladivostok, Russia
Contact:
Re: Front Fork improvements

Post by BaNZ » 25 Dec 2011, 03:07

Ah! So there is difference among manufacturers! Okay.

User avatar
Pie-eyedpiper
Visitor
Visitor
Reactions:
Posts: 98
Joined: 24 Jan 2011, 18:24
Bike Owned: Mk 2
Location: nr Lincoln
Re: Front Fork improvements

Post by Pie-eyedpiper » 03 Jan 2012, 19:39

Fitted CR250 '91 forks to my mk2. They are far firmer, but I might reduce the oil level to soften them up slightly.
What surprised me was the original CRM yokes are slightly larger than the CRs. This made making them fit "fun". But eventually used some 1mm galvanised metal strip to use as a sleeve inside the yokes..

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4185
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Re: Front Fork improvements

Post by knackeredMk1 » 03 Jan 2012, 20:11

I think you might have got the date of manufacture wrong (or the supplier did) :? . The pair of '91 CR250 forks that I got fitted straight into CRM yokes.

User avatar
Pie-eyedpiper
Visitor
Visitor
Reactions:
Posts: 98
Joined: 24 Jan 2011, 18:24
Bike Owned: Mk 2
Location: nr Lincoln
Re: Front Fork improvements

Post by Pie-eyedpiper » 03 Jan 2012, 20:59

[quote="knackeredMk1"]I think you might have got the date of manufacture wrong (or the supplier did) :? . The pair of '91 CR250 forks that I got fitted straight into CRM yokes.[/quote]
Hmmm, maybe they are newer then. They were definately smaller, bit surprising really, I expected to have to get my yokes machined out.

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4185
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Re: Front Fork improvements

Post by knackeredMk1 » 03 Jan 2012, 21:05

Possibly older. What adjusters do they have on :?: .

User avatar
Pie-eyedpiper
Visitor
Visitor
Reactions:
Posts: 98
Joined: 24 Jan 2011, 18:24
Bike Owned: Mk 2
Location: nr Lincoln
Re: Front Fork improvements

Post by Pie-eyedpiper » 03 Jan 2012, 21:22

Turn screw on the top and a large adjuster in the bottom of the fork leg, not sure if screwdriver or socket.

User avatar
knackeredMk1
Super Moderator
Super Moderator
Reactions:
Posts: 4185
Joined: 03 Nov 2006, 17:41
Bike Owned: Modified Mk1
Re: Front Fork improvements

Post by knackeredMk1 » 03 Jan 2012, 22:05

Should be a flat head adjuster inside the large nut on the base of the fork. This is a compression damping adjuster. More clockwise - harder damping.

If it is just a flat head (though it could have been replaced with a crosshead) on the top of the forks then it is likely to be an air pressure relief. The '91 forks should only have these but so did the previous forks.


Post Reply