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Mr Popsplayer

  • Thread starter Thread starter miket
  • Start date Start date
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miket

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What is the width of 88 forks Upsidedown forks 11" will be to wide to run es fairing .
 
86-88 forks will fit behind the fairing just fine... I know this, because Im doing it, eventually. Have the forks and whatnot already... just gotta get a few more things together, and get my 750 running right so i have something to ride while i do the swap :)
 
86-88 forks will fit behind the fairing just fine... I know this, because Im doing it, eventually. Have the forks and whatnot already... just gotta get a few more things together, and get my 750 running right so i have something to ride while i do the swap :)
cool:clap:
 
Not so sure about that; Kichigai used GSXR 750 forks (looks like 90-91)on his ESD

http://www.thegsresources.com/_forum/showthread.php?t=118949

He used 750 forks. Which might? Be a bit narrower up top? The forks themselves not the trees. Maybe? And even then he had to spread his fairing stay and use flat head bolts and stuff to get it to work. Plus there are the ground clearance issues with the 750 forks to consider. Etc. For the difference in NOTICEABLE performance gains I think the first gen stuff would probably be more than adequate and a heck of alot easier. You would know tho since you've done it ;)
 
He used 750 forks. Which might? Be a bit narrower up top? The forks themselves not the trees. Maybe? And even then he had to spread his fairing stay and use flat head bolts and stuff to get it to work. Plus there are the ground clearance issues with the 750 forks to consider. Etc. For the difference in NOTICEABLE performance gains I think the first gen stuff would probably be more than adequate and a heck of alot easier. You would know tho since you've done it ;)

I think Katman also uses GSXR750 forks (on a Kat) but with the Honda Drop triple. Going with 4:2:1 that has a reasonably tight fit will make up for any fork clearance issues.

Major complexity with the USD is the ignition and clock mounts and getting 180/55-17 to fit in the back (chain alignment primarily).
 
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I think Katman also uses GSXR750 forks (on a Kat) but with the Honda Drop triple. Going with 4:2:1 that has a reasonably tight fit will make up for any fork clearance issues.

Major complexity with the USD is the ignition and clock mounts and getting 180/55-17 to fit in the back (chain alignment primarily).

Is the wheel on the USD offset from center or the GS front offset from being centered in the forks? I'm trying to visualize how swapping the front end will mess up the rear alignment. I've got some '03 GSXR-1000 forks that are eventually going on mine.
 
Is the wheel on the USD offset from center or the GS front offset from being centered in the forks? I'm trying to visualize how swapping the front end will mess up the rear alignment. I've got some '03 GSXR-1000 forks that are eventually going on mine.

You can't swap the front end and NOT put a matching wheel (radial tire applicable) on the back. Mixing bias ply tires with radial tires, especially radial front and bias rear is dangerous. The offse problem he is talking about comes with the rear wheel set up. GSXR wheels are obviously wider, the hubs are different in depth from GS and you'll need an offset front sprocket to get the chain to line up, not to mention various spacers to get the wheel centered in the swinger in respect to the front end, the chain and the brake.
 
You can't swap the front end and NOT put a matching wheel (radial tire applicable) on the back. Mixing bias ply tires with radial tires, especially radial front and bias rear is dangerous. The offse problem he is talking about comes with the rear wheel set up. GSXR wheels are obviously wider, the hubs are different in depth from GS and you'll need an offset front sprocket to get the chain to line up, not to mention various spacers to get the wheel centered in the swinger in respect to the front end, the chain and the brake.

Outside of the bias/radial issue, what else needs to match up?
 
Is the wheel on the USD offset from center or the GS front offset from being centered in the forks? I'm trying to visualize how swapping the front end will mess up the rear alignment. I've got some '03 GSXR-1000 forks that are eventually going on mine.

USD wheel should be centered. :rolleyes:

I'm just referring to USD forks normally go with the 17" rear wheels and unless you substitute a 17x4.5" rear wheel you will be shoehorning a 17x5.5" (180/55-17) wheel/tire in the rear.

Generally requires much greater care in rear wheel spacing and chain alignment and 1mm is a long way (e.g. 520 chain, some frame grinding, 5/8" offset).

I put a 18x4.5" rear wheel with 170/60-18, 530 chain , 3/8" offset counter spocket and only a single 1" chain side spacer and have nice (4-5mm either side) chain clearance.
 
Outside of the bias/radial issue, what else needs to match up?
Like I said, the chain alignment is crucial. Your rear sprocket must line up with your front. Because the GSXR or later model wheel is WIDER, you will need an offset countershaft sprocket to make this happen. Depending on your chain size, wheel size, etc, you may run into clearance issues. These mods have been documented numerous times on this board, and pretty much just about every concievable model used and everything laid out pretty well. Try a search, you'll get all the answers in detail you could possibly want, and then some ;)
 
You can't swap the front end and NOT put a matching wheel (radial tire applicable) on the back. Mixing bias ply tires with radial tires, especially radial front and bias rear is dangerous. The offse problem he is talking about comes with the rear wheel set up. GSXR wheels are obviously wider, the hubs are different in depth from GS and you'll need an offset front sprocket to get the chain to line up, not to mention various spacers to get the wheel centered in the swinger in respect to the front end, the chain and the brake.

Yea you have to do all that and although alot of people do it you have to be careful in 17x5.5" rear wheel conversions as there is not much room to spare.
 
Like I said, the chain alignment is crucial. Your rear sprocket must line up with your front. Because the GSXR or later model wheel is WIDER, you will need an offset countershaft sprocket to make this happen. Depending on your chain size, wheel size, etc, you may run into clearance issues. These mods have been documented numerous times on this board, and pretty much just about every concievable model used and everything laid out pretty well. Try a search, you'll get all the answers in detail you could possibly want, and then some ;)

Well, seeing as I, personally, have pretty much completed such a swap, I understand how complicated it can be.

I'm just trying to understand why changing the front end to USD forks and the associated wheel requires going to a 180 in the back. If I was running radial tires front and back, could I not run the stock rear end with a tire of equal or wider width than the front and be just fine, or is there some special magic here I am missing?

I'm sorry if my question is lame, I'm just trying to understand why swapping to a 180 out back in order to run new forks in the front is so critical? Or is it?
 
Well, seeing as I, personally, have pretty much completed such a swap, I understand how complicated it can be.

I'm just trying to understand why changing the front end to USD forks and the associated wheel requires going to a 180 in the back. If I was running radial tires front and back, could I not run the stock rear end with a tire of equal or wider width than the front and be just fine, or is there some special magic here I am missing?

I'm sorry if my question is lame, I'm just trying to understand why swapping to a 180 out back in order to run new forks in the front is so critical? Or is it?

I thought you had just done this; I also remember you went 170/55-17 rather than 180/55-17; how much chain clearance did you get (both sides)?

The main problem with a 170 v.s. 180 is the 180's are more prevelant and will probably be a little cheaper in package deals.
 
I thought you had just done this; I also remember you went 170/55-17 rather than 180/55-17; how much chain clearance did you get (both sides)?

The main problem with a 170 v.s. 180 is the 180's are more prevelant and will probably be a little cheaper in package deals.

I haven't finished measuring everything, but it's looking like 2 or 3mm on each side of my 530 chain. I'll have a better number later.

But, my question in this context was why the requirement of a 180 in the back if you put newer USDs up front? I'm just trying to understand the requirements so I don't miss something basic later. Why not put a radial tire that fits on the stock rim and a newer wheel/tire/forks up front? You can stuff up to a 150 on the stock GS1100 rear with minor mods to the brake stay arm no problem, after all...
 
I haven't finished measuring everything, but it's looking like 2 or 3mm on each side of my 530 chain. I'll have a better number later.

But, my question in this context was why the requirement of a 180 in the back if you put newer USDs up front? I'm just trying to understand the requirements so I don't miss something basic later. Why not put a radial tire that fits on the stock rim and a newer wheel/tire/forks up front? You can stuff up to a 150 on the stock GS1100 rear with minor mods to the brake stay arm no problem, after all...
No.. you cant. Not safely anyway. A 150 on a 2.5" rim will pinch like a son of a bitch. Hell a 140 is pushing it pretty hard. I switched to an 1150 3.5" rim to stick a 150 tire on it. If you pinch the tire, the profile and contact patch will become smaller than going with a 130. And you risk it coming apart, sidewall flex and all that. AND.. the GS rims are NOT MADE TO ACCEPT RADIAL TIRES. The rim lip is way to short to support the radial sidewall, and you'll run the risk of that tire coming apart from the rim under stress. This is a BAD bad idea...

It's your bike, and your life, but I would strongly STRONGLY advise against doing what you're suggesting..to ANYONE.
 
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One of the primary objectives of folks going with these mods is to get a hefty rear tire in there, for cosmetic reasons, and perhaps the grip/modern tire selection benefit of radials....it then becomes necessary to change over the fork to match tire selection at both ends, and also get the suspension benefit of a modern fork. No reason you couldn't go with the late model fork and use a 150 radial in back if you choose to do so, and a fat tire look in the back is not that important.

EDIT: Yes, not on the GS rim, obviously!
 
No.. you cant. Not safely anyway. A 150 on a 2.5" rim will pinch like a son of a bitch. Hell a 140 is pushing it pretty hard. I switched to an 1150 3.5" rim to stick a 150 tire on it. If you pinch the tire, the profile and contact patch will become smaller than going with a 130. And you risk it coming apart, sidewall flex and all that. AND.. the GS rims are NOT MADE TO ACCEPT RADIAL TIRES. The rim lip is way to short to support the radial sidewall, and you'll run the risk of that tire coming apart from the rim under stress. This is a BAD bad idea...

It's your bike, and your life, but I would strongly STRONGLY advise doing what you're suggesting..to ANYONE.

Er, I'm just asking the 'why' here, for the sake of the information, and not advising anyone to follow through on anything.

I have a 1100E. I put a radial 150 on the rear 3.5 wide rim with a tube in it, and have run it like that for a while. Here's a photo:



You can click on it for a much larger version, but the rim lip was in the same place on the tire as it was on the bike I took this tire off of, which was a tubeless rim on a '06 V-Strom. Perhaps there is some difference in rim I am unaware of beyond that, but the tire was always solid for the time I had it on.

So, perhaps this was a stupid thing to do, but it sure fit well and the bead set. I only tested it via about 30-40 runs down the drag strip and didn't take it out on the street, though.

Right now I am running a radial 170 on a Bandit 1200 rim, tubeless, and running a radial front tire with a tube on the stock setup, until I can get a newer wheel for the front.


So, really, my question was more of 'what needs to match front and rear, besides radial/bias'.
 
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