Fork Swap question

[fchan]

I've got my very 1st project swapping the front and rear end off a Katana Popup with a 92 GSXR750W. The katana popup stock fork is 820mm in length but the GSXR750W fork length is approx. 73.5mm. This however will probably screw up the geometry of the front end.

So my question is are there any USD fork that is at least 790mm in length? Or with the current GSXR750W USD fork I have, what can be done to have it extended to at least 790mm?

For those of you have this experience and knowledge, please help.

Cheers

[bladehunter]

This might have some info and ideas

http://www.suzuki-katana.com/

[Gitzy]

I'm assuming you mean a 92 GSXR750N first of the water cooled?? A GSXR750W is a 1998 SRAD Model.. anyhoo skipping over the minor details you could have a stepped top yoke made by.. say EXBEN.. and that would solve your problem.. I think the longest of the USD'S belonged to the 90/91 ish GSXR1100 don't quote me.. you could try and source a set of them??

[bladehunter]

Shame OSS has been down lotsa cool info there

[Gitzy]

Not sure where measurements are taken from on this chart.. but it seems GSXR1100 93-95 are the longest but it also appears they are wider on lower clamp??

http://img843.imageshack.us/img843/656/oldschoolforks.jpg

[Gitzy]

Here are some examples of step down top yokes to take shorter fork legs, if your too not familiar with the setup..

http://img24.imageshack.us/img24/3082/1269674570.jpg

http://img337.imageshack.us/img337/2354/1269639308.jpg

http://img651.imageshack.us/img651/1298/stepdownyoke.jpg

[fchan]

quote:Originally posted by bladehunter

This might have some info and ideas

http://www.suzuki-katana.com/


I know Rob but he does the 1100 & 750s katana. Last year he started the 1100 Katana turbo project but haven't heard from him since. Might email him tonight. Cheers.

[Gitzy]

Orrrrrrrr..................

You could buy some fork leg extensions for USD's.. I didn't know they existed.. now I do..

http://www.billetbikebits.com/shop/index.php?main_page=product_info&cPath=1_16&products_id=86

[fchan]

quote:Originally posted by Gitzy

I'm assuming you mean a 92 GSXR750N first of the water cooled?? A GSXR750W is a 1998 SRAD Model.. anyhoo skipping over the minor details you could have a stepped top yoke made by.. say EXBEN.. and that would solve your problem.. I think the longest of the USD'S belonged to the 90/91 ish GSXR1100 don't quote me.. you could try and source a set of them??


It is actually a 'W'. Might contact EXBEN if all else fail.

[bladehunter]

hahaha Gitzy I was just looking at that myself.

[Gitzy]

Aaah pas de touché.. its actually a WN..

1990 - L
1991 - M
1992 - WN
1993 - WP
1994 - WR
1995 - S
1996 - T
1997 - V
1998 - W
1999 - X

[fchan]

I was actually thinking of either the fork extension or the stepped top york.

Anyway a bloke in UK and myself have the same idea of swapping our katana popup with the GSXR750W complete front and rear end. The bloke in UK had started his project and I will soon be starting mine as well due to the topend is undergoing a make-over with Wiesco 816 kit. Currently looking for a pair of camshaft and will have the engine respray, frame powercoated. Here's some pictures of my little kat now....Damn cannot upload photos at the moment? It show 'Currently Unavailable'.

[bladehunter]

Didn't they used to call fork extensions "Widow Makers" ?

No chance of getting longer tubes made ? Or does that not work with USDs ?

[fchan]

quote:Originally posted by bladehunter

Didn't they used to call fork extensions "Widow Makers" ?

No chance of getting longer tubes made ? Or does that not work with USDs ?


I don't know anyone in Sydney make longer inner tube to suit the fork? Do you? My concern is the nearly 3" or 80mm length difference.

Unfortuantely the forum currently cannot upload any photos to show you guys the transformation of the kat :(

[Fight_fan]

Jst chuck em in n run really aggressive geometry! ;)

[fchan]

Here's the bike that Peter in UK and myself coincident have the same idea in the first place. Peter had started to put it together.
http://img695.imageshack.us/img695/4134/popupconcept.jpg[/URL]

At the end of the day mine will probably be spray with matt black, frame will be in black colour to make it a stealth bike look. There will be two identical stealth bike......one in UK and the other in Oz

Any comments, suuggestion, advice? All are welcome.

cheers.

:D

[Gixxer_rat85]

Fork extensions scare me. Blokes used to use `em in the golden age of choppers (you know, before all the posers got involved :) ). If the join is any more than 1-1/4" below the top yoke they would split the tube at the thread!! Not sure if USD front ends would cope better but You`d be better getting extended tubes made or go with one of those super-trick looking drop down top yokes...
Just my 2 bob`s worth.
Wheels Down, shiny side up!

[fchan]

I'm wondering if it is possible to lengthen the fork tube or any other solution to have the fork lengthen by up to 50mm so when braking hard the fairing will not hit the front mudguard. Anyone know who make fork tube in Sydney?

[fchan]

quote:Originally posted by Gitzy

Not sure where measurements are taken from on this chart.. but it seems GSXR1100 93-95 are the longest but it also appears they are wider on lower clamp??

http://img843.imageshack.us/img843/656/oldschoolforks.jpg


Hi Gitzy, have you got the full list of the chart? Cheers.

[bladehunter]

Might be an idea to contact this mob, they are in england ,at around 80 quid per for leg at std length that seems not too bad. They claim to be able to do custom lengths.
Postage could be around the, I dunno $100 mark.


http://www.allbikeengineering.co.uk/html/forks.html

[Gitzy]

Nope sorry mate the list was chopped when I found it..