Front Wheel Spacing vs Triple Clamp Spacing

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Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Front Wheel Spacing vs Triple Clamp Spacing

#1 Post by Hooligan » Tue Oct 14, 2014 1:51 am

Something has been bothering for a while, every time I torque up the front wheel on my LC. There is a fair bit of space between the forks and the wheel spacers. This means the fork bottoms are being pulled in (pigeon toed) quite a bit when the axle is tight.

This didn't seem to present so much of a problem until I added a fork brace. After that the forks had noticeable sticksion. My theory was the fork bottoms where being pulled in at enough of an angle to create a fair bit of friction on the moving parts.

So, I decided something needed to be done about this problem. I loosened everything up, including the brake calipers to allow the forks to find their own spacing as dictated by the triple clamps. Then I slide the wheel to one side and measured the space between the spacer and the inside of the fork leg. It came to a yawning .150" gap.

I dug around in my scraps bin and found a nice bit of stainless steel round bar with the correct OD. A drill bit produced the correct ID to fit the axle and I parted off two .075" thick washers/spacers.

A spacer was inserted into each side of the front wheel spacers to keep everything centred and the axle was torqued up. Now the forks were correctly spaced, they slid up and down properly with no sticktion.

However the extra spacers created three problems. The fork brace bolt pattern was not wide enough to allow the brace to be bolted back together. The middle section went up on the mill and had its bolt holes elongated slightly to compensate.

The extra width between the fork legs has caused the axle nut to cover the cotter pin hole so currently there is no secondary protection against the axle nut coming loose. Properly torqued that should never happen but I will have to fiddle with it a bit to see if this can be solved.

The last problem was that the extra spacing between the fork legs caused the brake calipers to be offset. At first I thought the pistons would simply compensate for the difference but there was some excess friction created in the brake setup. This was easily compensated for by adding a ca .070" thick washer between the caliper and its mount.

In the end this all required a bit of fiddling around with some small bits and a few custom made parts but I now have forks that slide smoothly without binding .... which was likely to create elevated wear and tear on generally non-replaceable parts.

I'm not sure if the RZ suffers from this same issue. I will have a look at my 90 the next time I have the front wheel off.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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nikfubar
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#2 Post by nikfubar » Tue Oct 14, 2014 6:39 am

Sounds to me like there's something wrong with your yokes (triple trees) to cure one problem you created 3 more, if the axle is now too short there must have been a problem elsewhere.
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RuZty
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#3 Post by RuZty » Tue Oct 14, 2014 7:19 am

Without the calipers rotate the fork lowers 180 degrees (maybe one at a time) and see if the situation changes. At least this way you can narrow it down to one leg or the triple.

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nikfubar
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#4 Post by nikfubar » Tue Oct 14, 2014 7:39 am

Yeah good call most likely bent stantion
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two-stroke-brit
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#5 Post by two-stroke-brit » Tue Oct 14, 2014 8:20 am

to resolve the cotter pin hole alignment issue you can make a thicker washer to go under the castellated nut ,
whatever the degree is needed to line up it up,will be a % of the thread pitch added onto the washer thickness.
unless its now disappearing below the slots in the nut .
but it sounds like maybe other issues are at play here.
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Front Wheel Spacing vs Triple Clamp Spacing

#6 Post by Hooligan » Tue Oct 14, 2014 11:23 am

The problem is the axle hole is now under the nut. I will prob just shave down the nut a bit and elongate the hole a bit till the pin will fit.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Front Wheel Spacing vs Triple Clamp Spacing

#7 Post by Hooligan » Tue Oct 14, 2014 11:24 am

I'm fairly certain neither of the stantions is bent but that is worth checking.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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2smoke
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#8 Post by 2smoke » Tue Oct 14, 2014 2:47 pm

Maybe play in the fork bushings?
I would leave the fork brace loose above the lowers.
Then install the forks and wheel as you used to, check for binding, then if none, bring the fork brace down and see if it is forcing anything.
Colin
79 RD400F Daytona Special
81 RD350LC
89 TDR250
75 Kawasaki H1 500
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hondaror
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Re: Front Wheel Spacing vs Triple Clamp Spacing

#9 Post by hondaror » Wed Oct 15, 2014 10:47 pm

I have to agree with Peter on this one. My LC forks pulled in an awful lot at the axle. I never liked it, but never did anything about it. Good work Peter!
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

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