Larger diameter axle in RZ forks

General forum on frames, brakes, suspension, wheels and tires

Moderator: rztom

Post Reply
Message
Author
DRC
Posts: 36
Joined: Tue May 12, 2015 4:18 pm
Location: Oshawa, Ontario, Canada

Larger diameter axle in RZ forks

#1 Post by DRC » Sun Jun 17, 2018 12:41 am

I race a CB350 (Sorry about that) and the forks are tweaked.

I have a good set of RZ350 forks and triples that will fit the CB steering head with some bearing and spacing changes and I can get a couple of spacers made to fit the CB wheel between the fork legs (cast rims are not allowed as they are not period correct)

The problem is that the CB wheel has a 15mm axle. I’m wondering if there is enough meat on the Rz forks to have them bored to accept a 15mm axle or should I just use the 12mm with new bearings? I would imagine the 15mm axle would be an improvement

Thanks in Advance

hondaror
Posts: 2828
Joined: Mon Mar 03, 2014 8:44 pm
Location: Alberta, Canada

Re: Larger diameter axle in RZ forks

#2 Post by hondaror » Sun Jun 17, 2018 4:15 am

I would look into getting the right bearings first. Then no modifications or butchery is needed.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

User avatar
Yellow and Black RZ
Posts: 379
Joined: Thu Sep 27, 2007 3:59 pm

Re: Larger diameter axle in RZ forks

#3 Post by Yellow and Black RZ » Wed Feb 13, 2019 6:47 pm

Yes there is plenty of room to open up the axle holes. Radius would be only 1mm which for us Americans is only .040"
'85 RRZ350 - Hacked.

User avatar
OldTZracer
Posts: 240
Joined: Thu Aug 05, 2010 2:21 am
Location: Alberta Canada

Re: Larger diameter axle in RZ forks

#4 Post by OldTZracer » Thu Feb 14, 2019 2:47 am

Just a question - do the tripleclamps have a similar amount of offset? Are you going to end up with a different amount of trail that changes the handling?
"...its a 2-stroke ya twit - Its supposed to smoke..."

evan_calgary
Posts: 1368
Joined: Tue Nov 12, 2013 2:34 am

Re: Larger diameter axle in RZ forks

#5 Post by evan_calgary » Fri Feb 22, 2019 1:25 pm

Bore em out just make sure straight. Should be plenty of material. Larger axle should be improvement. The RZ one is microscopic for an axle.

User avatar
nokturnal
-----
-----
Posts: 2293
Joined: Sun Jan 28, 2007 12:27 pm
Location: Ontario, Canada

Re: Larger diameter axle in RZ forks

#6 Post by nokturnal » Mon Feb 25, 2019 1:13 pm

:smt030 just watch you don't bend the forks with the new super stiff axle...

i would base it on how new the bearings are, myself... will the axle really make that much difference on those forks?
:smt017

evan_calgary
Posts: 1368
Joined: Tue Nov 12, 2013 2:34 am

Re: Larger diameter axle in RZ forks

#7 Post by evan_calgary » Wed Feb 27, 2019 11:54 pm

nokturnal makes a decent point. It is likely marginal improvement with a large axle but i've not done a back to back test. Given the comparable diameter of the tubes to the axle I would not be concerned about bending the forks.

Given the low cost of a proper replacement set of forks of around a hundred bucks your probably best to just find some replacements?

User avatar
nokturnal
-----
-----
Posts: 2293
Joined: Sun Jan 28, 2007 12:27 pm
Location: Ontario, Canada

Re: Larger diameter axle in RZ forks

#8 Post by nokturnal » Thu Feb 28, 2019 9:49 am

evan_calgary wrote: Wed Feb 27, 2019 11:54 pm nokturnal makes a decent point. It is likely marginal improvement with a large axle but i've not done a back to back test. Given the comparable diameter of the tubes to the axle I would not be concerned about bending the forks.
was joking about the forks evan.. :smt033
:smt017

evan_calgary
Posts: 1368
Joined: Tue Nov 12, 2013 2:34 am

Re: Larger diameter axle in RZ forks

#9 Post by evan_calgary » Thu Feb 28, 2019 1:30 pm

My bad!

Post Reply