I am modifying my 1976 Z900 to take a 530 chain and 180/55 rear tyre on a 17" x 5.5" wheel. Can someone please help with chain clearance issues? I have searched through the website and coundn't find an answer.
I've bought a 5/8" offset sprocket from Debben and it looks like I have two potential problems.
1. The chain is going to clear the frame but it looks like it might foul the nuts on the inner end of the footrest mounting studs. How do people deal with this? Does it just clear or should I shorten the studs, lose the locknuts and just use very strong Loctite on the studs?
2. If my calcs are right, then a straight chain run would require that the inner face of the rear sprocket would be about 92mm from the wheel centreline. As a 180 tyre is usually a bit over 180mm wide, this means that the chain will hit the tyre edge. Can I space the sprocket out by 5-10mm so that the chain clears the tyre or will this put too much stress on the chain? Or are my calcs wrong?
Sorry to ask such an anal queston but I am guessing quite a few members have 180 rear tyres and I want to get the chain run sorted before I splash out on a new rear wheel.
many thanks
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Chain clearance for Z900 with 180 rear tyre
Moderators: KeithZ1R, chrisu, paul doran, Taffus
Lose the lock nuts and shorten the threaded portion of the footrest stud,
You will have plenty of tyre clearance with the 530 chain.
What wheel are you using ?
With 5/8 offset front i use zx7/zxr750/zx9 wheels and take 8mm off the sprocket carrier.
Everything lines up and the chain runs around 5mm away from the frame and a 180 tyre.
You will have plenty of tyre clearance with the 530 chain.
What wheel are you using ?
With 5/8 offset front i use zx7/zxr750/zx9 wheels and take 8mm off the sprocket carrier.
Everything lines up and the chain runs around 5mm away from the frame and a 180 tyre.
Thanks for the very helpful answer. I have ordered some new footrest studs, which I will shorten before I fit them. Just as well I ordered new ones as it looks like I will have to butcher the existing ones to get them out.
Haven't chosen the wheels yet. Was thinking of ordering some new CH3 Dymags but I might buy some cheap used wheels from ebay to get the alignment sorted first. Spindles at both ends are 20mm, i.e. thicker than std so wheel choice is proving a bit painful. Front forks are Ohlins intended for a CB1300 and rear arm will be Sculpture. Sculpture say thay can make cailper carrier and spacers if I give them the exact wheel/disc dimensions.
Do you know if the zx7/etc wheels have a 20mm spindle?
Haven't chosen the wheels yet. Was thinking of ordering some new CH3 Dymags but I might buy some cheap used wheels from ebay to get the alignment sorted first. Spindles at both ends are 20mm, i.e. thicker than std so wheel choice is proving a bit painful. Front forks are Ohlins intended for a CB1300 and rear arm will be Sculpture. Sculpture say thay can make cailper carrier and spacers if I give them the exact wheel/disc dimensions.
Do you know if the zx7/etc wheels have a 20mm spindle?
If you put in a wider rear tyre/wheel & off-set the rear sprocket to give some chain/tyre clearence you'd have to fit an off-set front sprocket too, wouldn't you to keep the chain inline ?
The rear wheel obviously needs to remain centered with the frame to keep inline with the front wheel & the rear sprocket & front sprocket also need to remain inline.
I'm not saying it can't be done, but looking at my standard Z900 there doesn't look to be enough room to achieve this. If there is, it's going to be very, very close indeed.
The rear wheel obviously needs to remain centered with the frame to keep inline with the front wheel & the rear sprocket & front sprocket also need to remain inline.
I'm not saying it can't be done, but looking at my standard Z900 there doesn't look to be enough room to achieve this. If there is, it's going to be very, very close indeed.
Have a look at this thread
http://www.z1ownersclub.co.uk/forum/vie ... highlight=
Debbens provided the following info to me,on that link.
Hello KwackerZ1, I have rebuilt my Z1000 rear hub with a 6" rim and a 180x17 Shinko tyre, this rim needs to be offset to allow the chain to clear the tyre and then refit the wheel back into the centre line of the bike by fitting the hub over to one side. to do this you need to fit a wider swing arm and an offset motor sprocket, the 5/8 offset sprocket with a 530 chain gives enough clearance.
The widest rim you can fit without fitting an offset sprocket is 3.5" but this will not fit in the stock swing arm with the chain adjusters pulled forward.
Which ever wheels the first job is to ensure that the front and rear wheels line up, so many we see do not. Once you have the wheels aligned you can run a straight edge (long straight tube will do) off the face of the rear sprocket to see how much the front sprocket needs to be offset, sometimes it is possible to machine the rear sprocket carrier to move the chain line in.
The frame tubes will limit how far you can offset the chain line and therefore how wide you can go with the rear wheel, unless you run the chain on the outside of the frame tubes. The frame tubes are 240mm apart which gives a centre line for the wheel at 120mm, but as you need the width of the chain (non O ring 530 is 23mm) plus at least 1 mm each side for some clearance you need to allow a minimum of 25mm both sides of the tyre.
So with 120mm centreline for the rear wheel minus 25 mm you have a maximum 95mm centre of wheel to the edge of the tyre.
Regards, Steve
http://www.z1ownersclub.co.uk/forum/vie ... highlight=
Debbens provided the following info to me,on that link.
Hello KwackerZ1, I have rebuilt my Z1000 rear hub with a 6" rim and a 180x17 Shinko tyre, this rim needs to be offset to allow the chain to clear the tyre and then refit the wheel back into the centre line of the bike by fitting the hub over to one side. to do this you need to fit a wider swing arm and an offset motor sprocket, the 5/8 offset sprocket with a 530 chain gives enough clearance.
The widest rim you can fit without fitting an offset sprocket is 3.5" but this will not fit in the stock swing arm with the chain adjusters pulled forward.
Which ever wheels the first job is to ensure that the front and rear wheels line up, so many we see do not. Once you have the wheels aligned you can run a straight edge (long straight tube will do) off the face of the rear sprocket to see how much the front sprocket needs to be offset, sometimes it is possible to machine the rear sprocket carrier to move the chain line in.
The frame tubes will limit how far you can offset the chain line and therefore how wide you can go with the rear wheel, unless you run the chain on the outside of the frame tubes. The frame tubes are 240mm apart which gives a centre line for the wheel at 120mm, but as you need the width of the chain (non O ring 530 is 23mm) plus at least 1 mm each side for some clearance you need to allow a minimum of 25mm both sides of the tyre.
So with 120mm centreline for the rear wheel minus 25 mm you have a maximum 95mm centre of wheel to the edge of the tyre.
Regards, Steve
CAT3 wrote:If you put in a wider rear tyre/wheel & off-set the rear sprocket to give some chain/tyre clearence you'd have to fit an off-set front sprocket too, wouldn't you to keep the chain inline ?
The rear wheel obviously needs to remain centered with the frame to keep inline with the front wheel & the rear sprocket & front sprocket also need to remain inline.
I'm not saying it can't be done, but looking at my standard Z900 there doesn't look to be enough room to achieve this. If there is, it's going to be very, very close indeed.
London states he's ordered a 5/8th offset from debben in his first post ?
5/8th is the widest you can go without doing clearance work to the frame.
With a 530 pitch and correctly centered wheels there is around 5mm either side of the chain to frame and tyre.
With a 630 chain it is much tighter at around 1mm to frame and 180 tyre but it doesn't create any issues.
I have run my Z1R like this with 630 pitch for 15 years no problem.
Have a good look around the projects section, there are many examples of this work being done.
CAT3, The 5/8" offset sprocket I referred to is the front sprocket. Debben sell it specifically so people can fit rear wider tyres. You are absolutely right, you have to keep the sprockets inline. The rear will automatically be offset from standard due to the wider rim width. You actually have to inset the rear sprocket with a wider rear rim so the chain runs a bit closer to the tyre to get it to line up with the offset front one.
It will be close but I think there will be room, but only if I get rid of the footpeg stud protrusion.
will post some pics when I have it sorted. I've found some ZX9R wheels on ebay for a reasonable price.
It will be close but I think there will be room, but only if I get rid of the footpeg stud protrusion.
will post some pics when I have it sorted. I've found some ZX9R wheels on ebay for a reasonable price.
Hi,
I have just fitted the gsxr swing arm and wheel to mine with an off set front sprox, it's a 180 rear tyre, when I fitted the chain it did foul the bottom nut of the foot rest, but lines up a treat.
I'm on the hunt for some flat head stainless bolts in the morning. There is a bolt place in Burton which has everything if I find what I want do you want me to pick up 4 for you as well?
I have a set of rear sets from Germany which gets round the rear master cyl, problems and the brake peddle problems. Using the original holes once the old mounts are removed.
I will have the rear sets fitted tomorrow with chain on ect so I will post some good pics for you to have a look at
I have just fitted the gsxr swing arm and wheel to mine with an off set front sprox, it's a 180 rear tyre, when I fitted the chain it did foul the bottom nut of the foot rest, but lines up a treat.
I'm on the hunt for some flat head stainless bolts in the morning. There is a bolt place in Burton which has everything if I find what I want do you want me to pick up 4 for you as well?
I have a set of rear sets from Germany which gets round the rear master cyl, problems and the brake peddle problems. Using the original holes once the old mounts are removed.
I will have the rear sets fitted tomorrow with chain on ect so I will post some good pics for you to have a look at
1973 Z1 and 1976 Z900
Thanks MCZ, if you locate some suitable stainless bolts, then I will definitely take four. Just let me know what I owe you and how to pay.
Just out of curiosity, I measured the chain clearance on my multistrada tonight. The gap between the chain and LH frame casting is 5mm and the chain/tyre gap is 3mm. So 5mm would appear to be ample.
I've got some new rearsets coming as well, they are currently stuck with parcelforce awaiting customs clearance. They use the original mounting points but come with a brembo master cylinder for a rear disc brake.
Just out of curiosity, I measured the chain clearance on my multistrada tonight. The gap between the chain and LH frame casting is 5mm and the chain/tyre gap is 3mm. So 5mm would appear to be ample.
I've got some new rearsets coming as well, they are currently stuck with parcelforce awaiting customs clearance. They use the original mounting points but come with a brembo master cylinder for a rear disc brake.
Mine got here today and I'm off tomorrow, mine came with the master cyl built on as well. No probes with the bolts, they will be stainless, don't worry about the cash for now if I get the right ones we can sort something out.
I will post a pic tomorrow when ihave some that will do the job.
I have about 5mm from tyre and 5 from the frame with a 530 chain. That's with a 180 rear
Cheers Ian
I will post a pic tomorrow when ihave some that will do the job.
I have about 5mm from tyre and 5 from the frame with a 530 chain. That's with a 180 rear
Cheers Ian
1973 Z1 and 1976 Z900
Ok having taken out the foot rest holding pegs and fixed my rear sets with the Allen head bolts which came with them I used some thread lock and they finish flush with the frame near the chain. So as the back section is threaded I don't think I'm going to mess about any more as they tightened up real nice.
The bolt search never got off.
When yours come you will see what I mean, I had to apply a bit of heat to one holding peg only, pics will be up later showing the chain and frame gaps.
Thanks Ian.
The bolt search never got off.
When yours come you will see what I mean, I had to apply a bit of heat to one holding peg only, pics will be up later showing the chain and frame gaps.
Thanks Ian.
1973 Z1 and 1976 Z900
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