180 Rear Tyre on a GS1000

[GarinRogers]

Hi all new to the forum and after some advise re rear wheel size for a GS1000

Whats required to fit a 180 tyre, what offset front sprocket is required and would the frame need modding to clear the chain, I'm planning on wide spoke wheels so want to go 5.5 inch rear rim

Cheers in advance

 

[alexl]

There's a good build thread by Strangeways covering a big tyre fitted in a GS1000 on the old skool proboards site. Search the builds section, he did a GSX and a GS 1000. 

[johnr]

what swingarm are you planning to use? i ran a 180 on the back of my katana and it went in the standard kat arm.

[CockneyRick]

Got a 180 in mine, & i had to use a Busa rim as the hub is narrower than the other options.

Also i spaced out the front sprocket as a cheaper option than an offset. 

It has a JMC arm in so had to turn down the carrier a bit & use shortened sprocket bolts & 1/2 nuts too. But that may all be down to the JMC?

[berty]

I did this on my 1100et , 1100et swinging arm (ali) standard, bandit 12 rear wheel , et carrier, 170 tyre, offset sprocket and 530 chain / rear sprocket,, dropped calliper down to bottom ( b6 calliper) , bespoke dog bone made up  to act as calliper stay which goes from calliper up to lower shock mount.  no frame mods required . not sure if gs frame is same as et but sure someone here can confirm that.

pm if you wish

will post a pic shortly.

 

 

[berty]

Won't let me post pic - file to big . ????

[johnr]

well im not sure about the frame, but the gs1000 and 1100et swingarms are interchangable.

Edited July 16, 2015 by johnr

[CockneyRick]

I did this on my 1100et , 1100et swinging arm (ali) standard, bandit 12 rear wheel , et carrier, 170 tyre, offset sprocket and 530 chain / rear sprocket,, dropped calliper down to bottom ( b6 calliper) , bespoke dog bone made up  to act as calliper stay which goes from calliper up to lower shock mount.  no frame mods required . not sure if gs frame is same as et but sure someone here can confirm that.

pm if you wish

will post a pic shortly.

 

 

Also did the USD caliper & torque arm. I went down to 520 chain & also did it on the EFE too, plenty of strength in good make chains these days.

[CockneyRick]

[GarinRogers]

Cheers for all the info, I've got a metmachex deep brace swingarm and have been running a 160 rear tyre on spoked 4.5  Rims was thinking of going 180 on a 5.5 Rim if there is clearance for the chain

Going for 17x 3.5 on the front down from its current 18x2.75  

[berty]

with the 530 chain,9mm offset front sprocket and a 180 tyre, it  left me with about 4mm clear to tyre wasn't very comfortable with such  a small tolerance,so opted for the 170 and Avon av60 tyre. laser adjusted chain so dead straight .

any further out on the front sprocket would mean frame rub and chain off line - imho.

tyre sizes are not always spot on depending on make.

I found this article very usefull

http://www.gsx1100.com/site4/tips/offset_sprocket.php

 

[CockneyRick]

Caliper mount.

Edited July 19, 2015 by CockneyRick
update

[kiwi]

Like Rick iv'e gone down to a 520 chain on me Katana and it gives  more clearance, 

A good quality 520 chain is plenty sufficient you must remember they have been developed for todays powersports bikes.

[bigyellowthing]

I found that a 520 chain and debben offset drive sprocket makes 180 possible. 170 is easier though. Bandit swing arms are easier to fit than gsxr types (wider at pivot) but jac and metmachex make bespoke, braced alternatives.

i found it difficult to get a clear chain run and keep the wheels aligned. 

Shock mounts are an issue too. Shocks like to work without shear forces created by being moved outwards to clear the chain. 

There are some talented people on here than can give advice and help. Anything is possible!

[richardgs1000]

im in the process of fitting rf900 arm in 1978 gs 750 fits quite easy and will take gsxr1100 w rear wheel and 180 Tyre  I run srad 600 rear end on my kat with 180 tyre and was much more of a pain

[wraith]

I did a 180 rear on a GS1000 using a GSXR750wr swing arm and putting a 520 chain and sprockets on had no problems, you can bring the chain in a bit by using a gsx1100f or gs500 sprocket carrier on the gsxr rear wheel (slingshot wheel that is)