Grnd clearance w/ 17's and 4-1exhaust

[gorbys]

78'GS750 with Sv1000s fork swap and b12 rear swinger. Harris 4-1 exhaust.

I have none. Well okay I have some, about 55mm from the work bench up to the collector as it sits now. Subtract from that whatever sag from me straddling it and I'll probably beach on the first speedbump. So is anyone else with similar mods having issues with ground clearance and did you do anything to help it? 

I guess the obvious alternative is to swap the exhaust for a 4-2-1 but I really like the Harris exhaust even though its brused and battered after my mum falling over countless times  ads to the character of the bike. 

Is it true the gsx1100 engines are taller? I'm putting one in this coming winter, If so how much and does this account to increase ground clearance? 

Another thing I was thinking was making new engine mounts to raise the engine higher up in the frame?

[wraith]

You could get another top yoke weld it under the top yoke you have that will give you some more ground clearance.

Basically the forks you have are to short.

Sorry.

Edited July 17, 2020 by wraith

[gorbys]

Yeah they're shorter than stock probably but not any shorter than other popular conversions like the gsxr and such. So someone must have some experience with this. 

I know the gsx1400 fork stanchions are ca 50mm longer so swapping to a gsx1400 would net me a higher front end but shouldn't the rear shock length be extended as well if you did that? 

[wraith]

I don't know the length of the forks you have on, I've got a set of gsxr1100k RWU forks on my Kat with no clearance problems, think if I remember they are 750mm (ish) for top of fork to centre of spindle (can check that size tomorrow if you want)

If course putting 17" wheels and a more modern front end can reduce the ground clearance but if you only have 50mm clearance you may find the side stand won't work as it will keep the bike to up right.

A full pic of the bike may help so people can see the full stance of the bike and see something you may of mist?

Jacking up the rear won't give that much more clearance at the front but if it's sat to low at the rear that can reduce the front end clearance (don't know why that is it just is lol)

[wraith]

Just got length of the gsxr1100k forks on my kat, they are 730mm I think if I remember correctly that's about the shortest you can go with have big problems with clearance., I've seen someone use tl1000 forks on a gsx et.

The answer will be in these pages somewhere as front end mods are a common thing.

Sorry I can't be of more help.

[mark35gun]

you want ideally gsxr 750/1100 l/m forks they are the longest at 770mm AFAIK, these will give plenty of ground clearance, much less hassle than raising engines? etc 

[gorbys]

Sv1000 forks are 730mm, I know the gsx1400 forks are longer and same diameter so would be a straight swap but hard to find over here as well as the gsxr1100 forks. So this is basically what I have to work with. 

I have a couple of pics here you can see how low the exhaust is. 

[wraith]

Looks nice  can't put my finger on it but something looks odd at the front end? 

Two things you can do as I see it.

1. Using the standard Harris turn it into a flat 4-1 instead of the two headers on top and two on bottom.

2. Find a sv1000 top yoke, cut the center out of it and weld it to the bottom of the top yoke you have, you can then slit your forks through to the welded yoke, that will give you a extra 20-30mm on the length of the fork. This has been do meany times before and you won't need to mess with calipers and discs extra as you may need to do with a gsx1400 swop.

Or to relay help do both numbers 1 and 2  

I know what you are saying about the Harris they do sound awesome 

[Isleoman]

41 minutes ago, wraith said:

Looks nice  can't put my finger on it but something looks odd at the front end? 

Two things you can do as I see it.

1. Using the standard Harris turn it into a flat 4-1 instead of the two headers on top and two on bottom.

2. Find a sv1000 top yoke, cut the center out of it and weld it to the bottom of the top yoke you have, you can then slit your forks through to the welded yoke, that will give you a extra 20-30mm on the length of the fork. This has been do meany times before and you won't need to mess with calipers and discs extra as you may need to do with a gsx1400 swop.

Or to relay help do both numbers 1 and 2  

I know what you are saying about the Harris they do sound awesome 

 

Looks like the springs aren't installed in the forks.  It looks bottomed out.   Should be bigger gap between lower triple tree and bottoms of forks.    

[mark35gun]

i agree with both posts, somethings wrong with the front end, forks look way to short

[gorbys]

I assure you it is exactly as it was when it came off my 2007 Sv1000s. Maybe it looks weird because it doesn't have the brake discs and fender? 

The pictures I have attached is from 4 years ago when I swapped to gsxr's on the SV and put those on this. 

 

[wraith]

This is my gs1000 with sv650 forks,

I will get the length of forks and ground clearance I've got tomorrow 

[gorbys]

19 hours ago, wraith said:

This is my gs1000 with sv650 forks,I will get the length of forks and ground clearance I've got tomorrow 

Thanks. 

On another note I might have measured my forks wrong by a cm, it seems they are 71.5 and not 73cm... 

[wraith]

Forks are 720mm (didn't think they where that size) and I've got 120mm ground clearance.

I have got the rear kicked up by about 30mm but I don't think if I dropped that to a standard height I'd lose that much clearance.

You could always (just to see, experiment) un-bolting your rear shocks end with a jack under the rear part of the frame (cross member under swing arm pivot) and lift the frame up and see what difference you get.

[ccroaker]

great looking project.... love seeing things like this and jealous of the guys with the skills to actually do it..... keep up the good work

[gorbys]

17 hours ago, wraith said:

Forks are 720mm (didn't think they where that size) and I've got 120mm ground clearance.

I have got the rear kicked up by about 30mm but I don't think if I dropped that to a standard height I'd lose that much clearance.

You could always (just to see, experiment) un-bolting your rear shocks end with a jack under the rear part of the frame (cross member under swing arm pivot) and lift the frame up and see what difference you get.

120mm from ground to exhaust that's crazy?! Even if I jacked up my rear I would never get that much 

We'll see how it goes, I did find a 4-1 with a flat collector so I'm thinking about buying it, was a merkin or something like that 

[Niloc]

marving have flat connectors. alternative is to have a drag pipe that wraps alongside the engine. Got a V&H sidewinder on mine.

 

[gorbys]

39 minutes ago, Niloc said:

marving have flat connectors. alternative is to have a drag pipe that wraps alongside the engine. Got a V&H sidewinder on mine.

 

Yes might have been marving! 

I did try jacking up the rear now and 35mm in the rear equated to about 30mm extra ground clearance on the front of the headers. 

So I could always go for 360 or 370mm rear shocks but that would alter the swingarm angle and probably make the chain rub the swingarm constantly wouldn't it? 

[wraith]

You could change the sprockets, bigger rear and a bigger front to give the chain more clearance?

[gs7_11]

Your geometry will be all wrong. You see this a lot with older bikes fitted with 17" wheels.

You need to use forks/wheel with a combination of length, spring rate, sag, yoke offset and rolling diameter that gers close to the original.

[Gixer1460]

3 hours ago, gs7_11 said:

Your geometry will be all wrong. You see this a lot with older bikes fitted with 17" wheels.

You need to use forks/wheel with a combination of length, spring rate, sag, yoke offset and rolling diameter that gers close to the original.

It may be wrong compared to original design but no one uses raked out front ends with 19" dia wheels anymore! My Kawazuki lost about 5 degrees of rake when original forks replaced with GSXR 1100L front end & wheel - and it certainly improved it. So wrong can be right in certain cases!

[gorbys]

I am aware of the geometry changes that swapping forks and suspension often presents. The stock gs is about 27° and I believe I put mine at about 25° to put it in line with the gsx1400 and bandits for a bit more nimble/quicker steering if I remember correctly it's been more than 4 years since I did the swap and since then it's just been stashed away in a corner 

[gs7_11]

Its obvious that you can't change anything on a rolling chassis without affecting 2 conflicting elements, being as they're always a compomise.

My point is, go too far from the original design, and you're on your own. Might work, might not. It surprises me what some people will accept as ok.

[gorbys]

Eww... Just got this reply from a seller. 

"we do not have in-stock, Marving are closed for the whole of August so despatch date would be approx. mid/end of September," 

 

Guess I'm just gonna f'n send it then 

[Poldark]

Would slightly longer forks give the needed ground clearance?  What size fork tubes: 41mm?  A whole bunch of different H-D models ran 41mm Showa forks.  The tubes may be able to swap out with slightly longer ones.  There are plenty of used H-D fork tubes and aftermarket replacement tubes available.   Take a look at "Forks by Frank" in the US.  They've been in business for over 50 years and will make nearly any length fork tubes for nearly any motorcycle model.