HPRE

Menu

Members Rides

Modified 350


in
Members Rides

Welcome, Guest. Please login or register.
Did you miss your activation email?
September 15, 2014, 04:03:22 AM

Login with username, password and session length

 

Author Topic: pinch bolt  (Read 1301 times)

jartist

  • Grand Gearhead
  • *****
  • Posts: 761
  • Karma: 0
pinch bolt
« on: October 15, 2011, 08:48:47 PM »
I was changing the tires out on my G5 yesterday and I noticed that the front axle spun freely with the pinch bolt still tight. That's a big chunk of aluminum on the front fork to squeeze with only a 6mm 8.8 grade bolt- a bit optimistic at best to expect from a bitty little bolt!  I drilled it out to 8mm and replaced the bolt with an 8mm 10.6 grade one for 3.5 times more clamping power.  Put it all back together carefully and the improvement is quite noticeable with smoother fork operation and no sticktion at all!

I thought for sure I read of someone else coming at the same conclusion about the pinch bolt on this forum but I couldn't find it so I figured I'd post my findings anyway.
« Last Edit: October 15, 2011, 08:54:25 PM by jartist »

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 4338
  • Karma: 0
  • "But it's a dry heat here in Arizona
Re: pinch bolt
« Reply #1 on: October 15, 2011, 10:12:52 PM »
I don't recall who it was but someone had broken the small bolt several times trying to tighten it enough to cause the fork to actually pinch the axle.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary

Tri750

  • Big Al
  • Grease Monkey
  • ****
  • Posts: 292
  • Karma: 0
Re: pinch bolt
« Reply #2 on: October 15, 2011, 10:48:42 PM »
We started upgrading to an 8mm last year.
With the 6, the speedo drive be able to rotate around and break the speedo cable.
The factory has started using the 8mm as a running change from what ive seen. (not the official word)
'71 BMW R75/5 racer
'73 Kaw Z1 racer
'77 Tri 750 Bonneville
'99 BMW R1100RT
'03 Kaw ZRX1200R

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 4338
  • Karma: 0
  • "But it's a dry heat here in Arizona
Re: pinch bolt
« Reply #3 on: October 15, 2011, 11:19:24 PM »
If they have changed the size it was after the 2011 production began.

My reading on the Indian Team-BPH site indicates that Royal Enfield has started producing front forks without the axle offset that has been a traditional feature of the RE since their first introduction of a telescopic hydraulic fork in 1947.

I haven't seen a picture of the new fork but I assume it will have caps to retain the axle.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary

Ducati Scotty

  • Grand Gearhead
  • *****
  • Posts: 6062
  • Karma: 0
  • 2010 Teal C5
Re: pinch bolt
« Reply #4 on: October 16, 2011, 01:19:41 AM »
We started upgrading to an 8mm last year.
With the 6, the speedo drive be able to rotate around and break the speedo cable.
The factory has started using the 8mm as a running change from what ive seen. (not the official word)

Do you need to drill to fit that?  Sounds like a worthwhile upgrade.

Scott

jartist

  • Grand Gearhead
  • *****
  • Posts: 761
  • Karma: 0
Re: pinch bolt
« Reply #5 on: October 16, 2011, 02:21:34 AM »
I drilled it out with a 5/16" bit from the bottom so I didn't have to remove the fender. Really easy to do.

 I should add that it's really important to understand how the parts fit together. The big nut on the left side bolts the axle to the left fork solidly. That leaves the right fork floating at the axle which is where the pinch bolt comes in to lock down the right fork laterally. My order when assembling is big axle nut medium tight then turn axle with a wrench on the right side to free up the right fork. Then bounce the fork with the bike off the stand to make sure the forks are free and there's no sticktion.  Then fully tighten the big axle nut and pinch bolt and recheck the whole thing for sticktion.

 When the axle is inserted and tightened it hangs up on the right fork and pulls it left which binds up the forks in that they arent parralell. That's why it's important to does all the steps to free up the right side when reassembling.

This process has been posted before but I always have to visualize what's happening. Once I understand it it becomes easy.  Scotty,  your fork tutorial you posted a while back is the gospel on this stuff.
« Last Edit: October 16, 2011, 02:54:24 AM by jartist »

BRADEY

  • Grease Monkey
  • ****
  • Posts: 372
  • Karma: 0
Re: pinch bolt
« Reply #6 on: October 17, 2011, 01:05:53 PM »
here is a picture of the new front forks without the offset. yes RE did it after all these long 60 years  ;D

GlennF

  • Grand Gearhead
  • *****
  • Posts: 885
  • Karma: 0
Re: pinch bolt
« Reply #7 on: October 17, 2011, 01:34:47 PM »
here is a picture of the new front forks without the offset. yes RE did it after all these long 60 years  ;D

wow ... that looks quite odd on an Enfield

t120rbullet

  • Grand Gearhead
  • *****
  • Posts: 1950
  • Karma: 0
Re: pinch bolt
« Reply #8 on: October 17, 2011, 02:48:50 PM »
here is a picture of the new front forks without the offset. yes RE did it after all these long 60 years  ;D


Maybe this is an answer to the rake change they did to the C5 that made it twitchy.
IMHO the old bikes that they made for those 60 odd years handled soooo good. Why would you want to change anything ?
CJ

1999 Enfield 500 Black Deluxe "Silver"
2012 Concours 14 (no name yet)
2013 Royal Star Venture S  "Jelly Roll"

bittercrick

  • Bulleteer
  • ***
  • Posts: 122
  • Karma: 0
  • C-5 Chrome
Re: pinch bolt
« Reply #9 on: October 17, 2011, 03:34:21 PM »
Hey RE if that takes care of the wobbles I want a set.can't wait to hear more on this change.  bittercrick
bikes Triumph 06 T100 - 01 Triumph Adventurer - RE C-5 chrome -78 Honda GL1000-83 Honda CB1100F

Ducati Scotty

  • Grand Gearhead
  • *****
  • Posts: 6062
  • Karma: 0
  • 2010 Teal C5
Re: pinch bolt
« Reply #10 on: October 17, 2011, 04:45:49 PM »
Wouldn't that give you less trail and make it more twitchy?  Unless the headstock angle or csaquette is different.  Remember, the original reason for long forks on choppers was more high speed, straight line stability.

Scott

barenekd

  • Grand Gearhead
  • *****
  • Posts: 5213
  • Karma: 0
Re: pinch bolt
« Reply #11 on: October 17, 2011, 05:15:04 PM »
It gives you more trail. The trail is measured from a line down from the steering head pivot to the ground, paralleling the fork tubes (usually parallels the tube, some forks differ) to the ground. Drop a vertical line to the ground from the axle center and the distance from where the steering axis line and the axle line are on the ground is the trail. Hence, move the axle back increases the trail. Gives a more stability and slower steering.
As for bittercreek's query. It should improve things on the C5.
Bare
2013 Moto Guzzi V7 Racer
2011 Black Classic G5 (RIP)
I refuse to tiptoe through life only to arrive safely at death
http://www.controllineplans.com

Ducati Scotty

  • Grand Gearhead
  • *****
  • Posts: 6062
  • Karma: 0
  • 2010 Teal C5
Re: pinch bolt
« Reply #12 on: October 17, 2011, 06:21:10 PM »
Thanks.  Forgive me, hadn't had enough coffee yet ;)

Scott

Desi Bike

  • Grand Gearhead
  • *****
  • Posts: 845
  • Karma: 1
Re: pinch bolt
« Reply #13 on: October 17, 2011, 06:42:59 PM »
here is a picture of the new front forks without the offset. yes RE did it after all these long 60 years  ;D

Interesting, This is the IDM, I wonder if the Export Version will also have this new fork?
میں نہیں چاہتا کہ ایک اچار
میں صرف اپنی موٹر سائیکل پر سوار کرنا چاہتے ہیں

Arizoni

  • Grand Gearhead
  • *****
  • Posts: 4338
  • Karma: 0
  • "But it's a dry heat here in Arizona
Re: pinch bolt
« Reply #14 on: October 17, 2011, 09:17:04 PM »
From a manufacturing standpoint it wouldn't make sense to have two different configurations in production at the same time.

Parts are least expensive when a lot of them are made without changing the machine setups.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary