Gs750

[layton]

Get longer forks or make dropped yokes.

I am not sure why you would need to raise the front.
Ps the fuel pump should be mounted lower than the lowest part of the tank to self prime

I need to raise it because I have lost 25MM from the wheel swap plus 100MM in fork length so the rake and trail will be all out of wack, plus ground clearance is very minimal now..

[sidecar bob]

I need to raise it because I have lost 25MM from the wheel swap plus 100MM in fork length so the rake and trail will be all out of wack, plus ground clearance is very minimal now..

Rake? That's for the gardening thread
I'd be getting Steve Bridge to pull a couple of degrees out of the chassis geometry to go with the wheels & suspension of that era.
It will fix a heap of problems, as well as raise the front end.
Actually, looking at your workmanship, it's presumptuous of me to assume you can't do that yourself.
I'd also be putting longer shocks in the rear.
I may be able to give you a starting figure for that length if you want it to feel like a modern bike.

[jellywrestler]

very little progress.. Christmas has sucked up all available funds plus house is being reno'd ! But i am looking foward to continuing ASAP, i have a question.. so i need to extend the front ride height by about 50MM i have a few choices get some Honda 954 drop triples or have some fork cap extenders made, would said extenders be "safe"?

im guessing as long as the cap extenders have properly cut threads and are a safe length they will be ok? i could even add a piece of aluminium tube that is a snug fit over the whole leg between the triples.

i have found some online for $400 but that seems ridiculous for what they are, and i have a machinist friend who can make em.

what are your forks like? maybe just get some new 37mm fork tubes, think gs1000g or gs1000l are longest in the suzuki range but pretty easy to do a search on the internaughty to find some that will suit.
try and stick with suzuki as they carry the same internals

[layton]

what are your forks like? maybe just get some new 37mm fork tubes, think gs1000g or gs1000l are longest in the suzuki range but pretty easy to do a search on the internaughty to find some that will suit.
try and stick with suzuki as they carry the same internals

dont quite understand this? i took the original forks off GSX750 forks, and replaced with 93 GSXR 750 USD forks and have lost fork length, so i need to add atleast 50MM for ground clearence for a reasonable price.

[layton]

Rake? That's for the gardening thread
I'd be getting Steve Bridge to pull a couple of degrees out of the chassis geometry to go with the wheels & suspension of that era.
It will fix a heap of problems, as well as raise the front end.
Actually, looking at your workmanship, it's presumptuous of me to assume you can't do that yourself.
I'd also be putting longer shocks in the rear.
I may be able to give you a starting figure for that length if you want it to feel like a modern bike.

wouldn't adding more ride height to the rear make the numbers worse then they are?

Honestly i wouldn't even know where to begin! haha.
i dont expect this thing to handle like a modern bike its really just going to be for shits and giggles. for a first build i will just be happy if i can get it running and ride OK. i need to learn to walk before i can run!

[sidecar bob]

wouldn't adding more ride height to the rear make the numbers worse then they are?

Honestly i wouldn't even know where to begin! haha.
i dont expect this thing to handle like a modern bike its really just going to be for shits and giggles. for a first build i will just be happy if i can get it running and ride OK. i need to learn to walk before i can run!

You can expect it to handle fairly tidy if you follow a few rules. Would be a shame if a bike that cool handled like a tool trolley.
Rear ride height will quicken the steering & help make it feel like the bike you borrowed the front end out of, otherwise it will be a bit of a mismatch of bits unless you tighten the steering angle & raise the arse a bit.
Happy to give you the numbers off my very competitive pre '82 race bike that started with virtually the same chassis you have there & runs 17 inch front & rear.
It's at the very pointy end of what you would want for a road bike.

[Grumph]

It's always a compromise....Our GS1000 postie finished up with geometry nearly identical to a late Triumph Sprint. But that was with OE triples which will have more offset than the USD forks you've used.
The big decider on how it handles is usually trail. With modern 17's, the range is from about 130mm to no less than 95mm. Less than that and it tends to get a tad flighty.
Learn how to measure it, unladen and tied upright will do.

[layton]

It's always a compromise....Our GS1000 postie finished up with geometry nearly identical to a late Triumph Sprint. But that was with OE triples which will have more offset than the USD forks you've used.
The big decider on how it handles is usually trail. With modern 17's, the range is from about 130mm to no less than 95mm. Less than that and it tends to get a tad flighty.
Learn how to measure it, unladen and tied upright will do.

i just measured the trail and came up with about 125MM, now i didnt spend long doing it but its a rough number will have a proper look tonight.

[jellywrestler]

dont quite understand this? i took the original forks off GSX750 forks, and replaced with 93 GSXR 750 USD forks and have lost fork length, so i need to add atleast 50MM for ground clearence for a reasonable price.

oops, 37mm is the old gs750 style from memory, thought you'd mucked around with wheel sizes, whatver it is maybe try and get differnt stanchions?

[husaberg]

dont quite understand this? i took the original forks off GSX750 forks, and replaced with 93 GSXR 750 USD forks and have lost fork length, so i need to add atleast 50MM for ground clearence for a reasonable price.

https://litetek.co/Guide_USD_ForkDatabase.html

	Items in green are either confirmed or obvious, and may link to proof.

Items in white link to credible source
Items in orange are sourced from the official factory service manual, parts book or sales brochure.
Entries in blue are not USD forks
Remaining items in silver are unsubstantiated

• Fork length is from axle centre to top of fork tube, NOT fork cap, when fully extended.
• When replacing the entire front fork assembly only the triple clamp offset, that determines trail, and the fork length needs to be considered.
• When retaining the original wheel, the length, triple clamp offset, brake disc diameter, and brake caliper lateral position needs to be considered. It is usually cheaper to move the discs than create custom triple clamps.
• If custom triple clamps need to be made then the fork centres can be calculated as being equal to twice the FCCM (Fork Centre to Caliper Mount) plus twice the caliper offset plus the the distance between the disc rotor centres.
• As the offset of the triple clamps increases, the trail decreases. This reduces the self-centering effect and makes the steering more responsive and twitchy.
• Steering stem and bearing dimensions are not included nor are axle details. These can be custom machined to suit application.

oops, 37mm is the old gs750 style from memory, thought you'd mucked around with wheel sizes, whatver it is maybe try and get differnt stanchions?

there is streetfighter site that lists different fount ends minly Suzuki

[layton]

Thanks fellas, sidecar bob and gumph have just made me realise that i probably dont need to raise the front and i probably need to raise the rear and build some low profile headers, and make some rearsets i totally didnt want to make headers but i dont have much of a choice. Thats ok though aslong as i have some direction!

[husaberg]

Thanks fellas, sidecar bob and gumph have just made me realise that i probably dont need to raise the front and i probably need to raise the rear and build some low profile headers, and make some rearsets i totally didnt want to make headers but i dont have much of a choice. Thats ok though aslong as i have some direction!

yip use this to figure out what you had and what you will get
https://www.rbracing-rsr.com/rakeandtrail.html

[layton]

You can expect it to handle fairly tidy if you follow a few rules. Would be a shame if a bike that cool handled like a tool trolley.
Rear ride height will quicken the steering & help make it feel like the bike you borrowed the front end out of, otherwise it will be a bit of a mismatch of bits unless you tighten the steering angle & raise the arse a bit.
Happy to give you the numbers off my very competitive pre '82 race bike that started with virtually the same chassis you have there & runs 17 inch front & rear.
It's at the very pointy end of what you would want for a road bike.

Numbers would be awesome, did you get my PM?

[sidecar bob]

Numbers would be awesome, did you get my PM?

Yep, cheers.
The bike is in Melbourne at the mo, we mainly just use it for the Island Classic & Festival of speed in Aus now but I can figure it out from here with a bit of thought.
Unless you want to wait until mid Feb, when I will be with the bike & can give you actual figures that really work very well with top riders on board. (Not me f.f.s)

[layton]

lifted exhaust, i cant possibly get anymore clearance if i tried! theres approx 5 mm between the sump and exhaust! i removed 30MM from the headers and it has raised the exhaust a fair amount it went from 30MM clearance to 100MM its just tacked together at the moment but what a job....! everything moved, because i have made most of the bits around the exhaust it was a total pain to realign, but a plus is the turbo is sitting in a better location

i drank a fair bit out of frustration, kept geting different results everytime i would test fit, then i clicked... it changed the location depending on what header pipe i nipped up first! DOH

but all in all, im happy with how it looks, i like how the package looks more compact.