BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
Jwood & co JRC Engineering dealers Jwood & co
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
Posts: 39
Joined: July 2006
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
30 registered members (AngloBike), 247 guests, and 440 spiders.
Key: Admin, Global Mod, Mod
Newest Members
Biscuits, DT 150, DamienE, vietnammotorbike, Lennart Liljedah
10291 Registered Users
Top Posters(30 Days)
Stuart 93
Lannis 66
Mori55 64
Popular Topics(Views)
638,107 mail-order LSR
Forum Statistics
Forums34
Topics67,396
Posts654,359
Members10,291
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate Thread
Jap dampers in brit forks #606389
06/28/15 9:32 am
06/28/15 9:32 am
Joined: Nov 2009
Posts: 626
B
bon Offline OP
BritBike Forum member
bon  Offline OP
BritBike Forum member
B
Joined: Nov 2009
Posts: 626
I have heard of people putting fork dampers from japanese sports bikes in to british forks like the roadholders and others to improve the damping compared to the originals. Anyone here ever done this ?

Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Check out British motorcycles for sale:
British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
Re: Jap dampers in brit forks [Re: bon] #606392
06/28/15 11:10 am
06/28/15 11:10 am
Joined: Jan 2004
Posts: 3,727
ca, us
D
DMadigan Offline
BritBike Forum member
DMadigan  Offline
BritBike Forum member
D
Joined: Jan 2004
Posts: 3,727
ca, us
Any modern Japanese sport bike damper will not fit in these old 34/35mm forks. You might be able to fit period (70's) Japanese dampers such as the XS650 or RD250 which have similar size fork tubes.
Are you talking early damper rod connected to the fork cap or damper stanchion used on OIF forks? The OIF damper is fairly ineffective owing to the slots along the damper tube which basically allows the oil to bypass the damper head.

As the seal in the bottom of the fork tube slides down the damper tube, oil is first pushed up to the top of the damper head but after the slots are positioned above the damper seal the oil goes directly to the chamber underneath the damper head, bypassing it completely.
A new damper tube with the holes and slots removed and the transfer holes put at the bottom so the damper head is always in the circuit.

Re: Jap dampers in brit forks [Re: bon] #606411
06/28/15 1:21 pm
06/28/15 1:21 pm
Joined: Dec 2004
Posts: 9,375
Scotland
kommando Online content
BritBike Forum member
kommando  Online Content
BritBike Forum member
Joined: Dec 2004
Posts: 9,375
Scotland
Modern cartridge inserts can be fitted to roadholders, they need to be the thinner type and even then there will be some turning required.

The Cosentino insets fit directly as they are premodified, but hurt the pocket, there are cheaper but more intensive DIY options.

http://www.accessnorton.com/commando-fork-cartridge-conversion-t21431.html

Re: Jap dampers in brit forks [Re: bon] #606422
06/28/15 3:15 pm
06/28/15 3:15 pm
Joined: Nov 2009
Posts: 626
B
bon Offline OP
BritBike Forum member
bon  Offline OP
BritBike Forum member
B
Joined: Nov 2009
Posts: 626
Yes i believe honda cbr 600 dampers can be turned down and fitted, just wondering if anyone had done it and what was involved.

Re: Jap dampers in brit forks [Re: bon] #607910
07/09/15 6:00 pm
07/09/15 6:00 pm
Joined: Aug 2001
Posts: 3,918
argyll. scotland, uk
gavin eisler Online content
BritBike Forum member
gavin eisler  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 3,918
argyll. scotland, uk
Thats a great link thanks Kommando


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: Jap dampers in brit forks [Re: bon] #609288
07/19/15 4:02 pm
07/19/15 4:02 pm
Joined: May 2011
Posts: 432
england
G
GS DAVE Offline
BritBike Forum member
GS DAVE  Offline
BritBike Forum member
G
Joined: May 2011
Posts: 432
england
The early CBR 600 forks have anti dive valving on one leg this is why I am going to use Honda cb 500 stanchions and damping internals.

Re: Jap dampers in brit forks [Re: bon] #617888
09/17/15 11:46 am
09/17/15 11:46 am
Joined: May 2013
Posts: 743
Overland Missouri
O
old mule Offline
BritBike Forum member
old mule  Offline
BritBike Forum member
O
Joined: May 2013
Posts: 743
Overland Missouri
In some past "Fishtail", the magazine of the Velocette Owners Club, it was told that a certain 70s honda fork leg was only .003 larger than the Velo one, and the article showed installation of those fork tubes on a standard Velo.

Re: Jap dampers in brit forks [Re: old mule] #617892
09/17/15 12:05 pm
09/17/15 12:05 pm
Joined: Jun 2002
Posts: 9,962
Scotland
S
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member
S
Joined: Jun 2002
Posts: 9,962
Scotland
Hi,

Originally Posted By old mule
a certain 70s honda fork leg was only .003 larger than the Velo one,

Velo 1-3/8" o.d., Honda 35 mm. o.d.? Same as Triumph and Japanese stanchions.

Hth.

Regards,

Re: Jap dampers in brit forks [Re: Stuart] #617905
09/17/15 2:17 pm
09/17/15 2:17 pm
Joined: Jan 2004
Posts: 3,727
ca, us
D
DMadigan Offline
BritBike Forum member
DMadigan  Offline
BritBike Forum member
D
Joined: Jan 2004
Posts: 3,727
ca, us
Originally Posted By Stuart

Velo 1-3/8" o.d., Honda 35 mm. o.d.? Same as Triumph and Japanese stanchions.

? OIF stanchion that I measured is 1.3602" (34.549 mm)

Re: Jap dampers in brit forks [Re: DMadigan] #617981
09/18/15 5:37 am
09/18/15 5:37 am
Joined: Jun 2002
Posts: 9,962
Scotland
S
Stuart Online content
BritBike Forum member
Stuart  Online Content
BritBike Forum member
S
Joined: Jun 2002
Posts: 9,962
Scotland
Hi Dave,

Originally Posted By DMadigan
OIF stanchion that I measured is 1.3602"

As that'd be 15 thou. undersize from 1.375" nominal, I'm guessing a working tolerance?

Regards,

Re: Jap dampers in brit forks [Re: Stuart] #618022
09/18/15 1:58 pm
09/18/15 1:58 pm
Joined: May 2011
Posts: 432
england
G
GS DAVE Offline
BritBike Forum member
GS DAVE  Offline
BritBike Forum member
G
Joined: May 2011
Posts: 432
england
Hell of a working tolerance on a ground stanchion I would of thought.
Suzuki GS 550 stanchions are 35 mm, they fit Goldie bottom yokes which are 1 3/8" ( 0.003" ) smaller than 35mm but you have to machine the top diameter down and put the tapers and threads on.

Re: Jap dampers in brit forks [Re: bon] #618064
09/18/15 6:59 pm
09/18/15 6:59 pm
Joined: Jan 2004
Posts: 3,727
ca, us
D
DMadigan Offline
BritBike Forum member
DMadigan  Offline
BritBike Forum member
D
Joined: Jan 2004
Posts: 3,727
ca, us
This was back when England was still on the foot and finger system so presumably they started with a nominal side tube (1-3/8") and ground it down to a convenient dimension that would clean up any dings or slight bends in the material.
A close running clearance (RC4) would have a shaft -0.001 to -0.0016, a medium running shaft fit (RC5) would be -0.002 to -0.003.
-0.015" is off the chart even for a loose fit.
Leak Proof Seals labels the stanchions as 34.60mm.

Re: Jap dampers in brit forks [Re: DMadigan] #619328
09/26/15 8:48 pm
09/26/15 8:48 pm
Joined: Mar 2015
Posts: 31
south ester pa
D
DanDaughenbaugh Offline
BritBike Forum member
DanDaughenbaugh  Offline
BritBike Forum member
D
Joined: Mar 2015
Posts: 31
south ester pa
Ive used the cartridge emulators from Mikes XS turned down 1mm to fit many brit bikes, nice price too!

https://www.mikesxs.net/product/27-1086.html

Re: Jap dampers in brit forks [Re: bon] #643342
03/08/16 1:41 am
03/08/16 1:41 am
Joined: Mar 2011
Posts: 108
Alaska
L
linker48x Offline
BritBike Forum member
linker48x  Offline
BritBike Forum member
L
Joined: Mar 2011
Posts: 108
Alaska
Gil Vaillancourt at Works Performance put CBR600 F3 cartridges in his Premier Manx, the really good blue one, before he passed away. It had the best fork action I ever experienced on a vintage bike, so I put them into the 38mm FZR 600 forks on one of my racers, a Yamaha two stroke F500 bike. My Triumph 750 Sportsman racer has 38mm Marzocchis with a set of custom cartridges Pierre Vaillancourt at Works Performance made for it, and they are really, really excellent too. The F3 forks don't have internal topout springs inside the cartridges, so you have to add them, if your forks don't have topout springs in them already (I cannot remember if Roadholders do or do not). And you need to machine down and rethread the caps, and make the package fit into the internal length you have available, and find springs that will work in the short space these will allow you (or use external springs on the Roadholders). Don't do this if you don't know what you are doing. It is best to send them to Pierre at Works, if he'll do it, he will make them work well.

Re: Jap dampers in brit forks [Re: linker48x] #643691
03/10/16 6:14 pm
03/10/16 6:14 pm
Joined: Jan 2012
Posts: 421
Western NY
P
Pete Suchawreck Offline
BritBike Forum member
Pete Suchawreck  Offline
BritBike Forum member
P
Joined: Jan 2012
Posts: 421
Western NY
See Kommandos post in members bikes about Gavin's project.

Re: Jap dampers in brit forks [Re: bon] #667430
09/12/16 10:56 pm
09/12/16 10:56 pm
Joined: Jul 2016
Posts: 224
Australia
Joolstacho Offline
BritBike Forum member
Joolstacho  Offline
BritBike Forum member
Joined: Jul 2016
Posts: 224
Australia
+1 for Mikes XS cartridge emulators, cheap, effective adjustable damping.

Re: Jap dampers in brit forks [Re: bon] #691482
04/12/17 9:45 pm
04/12/17 9:45 pm
Joined: Apr 2017
Posts: 15
sydney.
T
tank slapper Offline
BritBike Forum member
tank slapper  Offline
BritBike Forum member
T
Joined: Apr 2017
Posts: 15
sydney.
I am going to opt for Japanese forks for my pre unit triumph. The prices you have to pay for pre unit forks now is insane.

Re: Jap dampers in brit forks [Re: bon] #693136
04/26/17 11:41 pm
04/26/17 11:41 pm
Joined: Apr 2017
Posts: 15
sydney.
T
tank slapper Offline
BritBike Forum member
tank slapper  Offline
BritBike Forum member
T
Joined: Apr 2017
Posts: 15
sydney.
Actually, on the subject of forks, could some one tell me the total length of a set of 1957 tiger 110 front forks?

Re: Jap dampers in brit forks [Re: bon] #693195
04/27/17 12:56 pm
04/27/17 12:56 pm
Joined: Apr 2006
Posts: 1,402
New Zealand
J
johnm Offline
BritBike Forum member
johnm  Offline
BritBike Forum member
J
Joined: Apr 2006
Posts: 1,402
New Zealand
The guy who made the Landsdowne dampers for Roadholders sadly died a year or so back.

I understand they can now be purchased here.

http://www.tritonmotorcycleparts.com/297620484

These are a midrange price and not as much as Maxton or Cosentino. I have modern Honda 600 ones in my race Dommie but they took a lot of tuning to get right.

I think getting rid of stiction and preventing twisting under braking is at least as important as the improvement which is possible by going to modern dampers.

Re: Jap dampers in brit forks [Re: bon] #693201
04/27/17 1:49 pm
04/27/17 1:49 pm
Joined: Dec 2004
Posts: 9,375
Scotland
kommando Online content
BritBike Forum member
kommando  Online Content
BritBike Forum member
Joined: Dec 2004
Posts: 9,375
Scotland
The Landsdowne inserts are singe rate dampers, ie its a single hole with an adjuster, one leg for rebound and one leg for compression, they have no facility for digressive damping which has 2 circuits and the circuit used depends on the type of bump you encounter eg you set the Landsdowne for one rate which is a compromise between low speed and high speed damping albeit adjustable between rides. So it cannot be compared to Maxton or Cosentino, they are using the same technology as the Showa's fitted to the CBR600RR with twin circuits hence the difference in price.



Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.6.1.1