Rim size recommendations

[Chuck78]

Steering Geometry info

Steering Geometry info

Here ya go Norm, I use this info all the time when crunching steering geometry numbers based on tire diameters. This also tells you at least the most recommended fit of tire size vs rim width, most manufacturers tell you best fit and alternate acceptable sizes/fitment above and below the best fit.



This Pirelli screenshot is THE ONLY detailed Pirelli info I could find on the net, I think it was only available on the Canadian Pirelli site.


Here's the Avon AM26 Road Rider specs:
http://www.avonmoto.com/products/street-bias/roadrider

note that the Avon tires run wider/taller than any other brand in the same size, so their diameter listing on your original OEM 3.25-19 front is probably going to be taller than the original equipment 1978/1978 front tire was when they advertised the rake and trail specs in magazines.

Bridgestone info, you want the BT45V. The standard H-rated (112mph) BT45V comes mostly in vintage stock sizes, the V-rated (149mph) BT45V comes in sizes for aftermarket wider 18" front and rear rims:

http://www.bridgestone.com/products...rch_size_rim][3]=&c[Item.search_size_rim][4]=

that is only a search listing for 18", so the limited 19" front sizes are excluded from that
here's the 19", basically only choice is stock 3.25-19 or exact same width and darn near exact same height 100/90-19:
http://www.bridgestone.com/products...rch_size_rim][3]=&c[Item.search_size_rim][4]=
You really should upgrade the width to a 110/80-18, gives you ~12mm more tire width but shaves off 13mm in radius, which won't be much of a noticeable difference to the fender clearance up top, but on the bottom you lose another 13mm radius which helps reduce your trail by radius alone and also as a result of dropping that 13mm in front ride height you steepen the rake a slight bit, which also makes the steering more sporty which also reduces the trail spec ever so slightly


Here's the Shinko 230 TourMaster front specs if you go with a 100/90-18 on a 2.15 or 2.50 or 2.75 rim:
http://www.shinkotireusa.com/tire/230-tour-master
and the Shinko SR741 rear specs for 140/70-18
http://www.shinkotireusa.com/tire/sr-740-741-series
Click on the sizes tab, & then click on the individual size selection to expand it to see the fitment/width/diameter info
***I noticed the Shinko SR741 does come in a 150/70-17 if you went 18" front 17" rear rimes. These are phenomenal gripping tires for the price but do wear faster on the rear. Pirelli also offers a 150/70-17. Avon and probably Bridgestone as well. Compare the OEM spec rear diameter to those... going 18" rear will change the gearing and add and little weight, but will quicken the steering additionally, which you will be very pleased with if you can get a steeper rake and slightly shorter front tire that gets your trail down below 4.00" to as low as 3.85". 3.74-3.78" is road rake ace territory and probably needs as steering damper.


I have a hunch that a Battlax BT45V or Road Rider in 140/80-18 may be the best choice with aesthetics in mind - although for total performance, the 140/70-18 and 110/80-18 Pirelli Sport Demon combo will be the best. The 140/70 is a bit low profile (130/70 is too short aesthetically, I won't run one on a big bike) & I always liked the taller look of the 150/70 better, but the chain is darn close to it and makes contact occasionally without offset sprockets. The 140/80 is a hair taller than a 150/70. But no PirellI or Shinko option in 140/80, only RoadRider or Battlax BT45V

 

[Chuck78]

More geometry info

More geometry info

And here is what I use to figure up how the tire and suspension changes affect the rake and trail:

https://www.rbracing-rsr.com/advchoppercalc.html

forgive that it's a Pukely-Davidson chopper website, this calculator does the job well

The rear tire diameter box doesn't do much for some reason. In order to figure in how ride height changes affect the rake and trail due to shorter forks, taller/shorter shocks, taller/shorter tires, I manipulate the "new fork length" data field to give me the figures I want. Not 100% accurate since the forks and shocks are not 90 degrees vertical but darn close enough. Perhaps there is a better online calculator out there besides buying Tony Foale's frame geometry software, but this does the job well enough. For taller than stock rear tire diameter I SUBTRACT the rear tire RADIUS from the "new fork length" field to get the proper manipulation of the adjusted rake. Shorter than stock rear tire I add the radius. Same goes go the front tire and fork height, subtract radius or fork height drop to get the "new fork length" field entry with tire changes added into the rake calculation modifications.

 

[sharpy]

I really am searching for a 2.50x18 front Akront TR rim though. They are hard to find so I may strip the anodizing off of a DID 2.50x18 and polish it instead, as it has a similar slight flanged lip at the bead like the Akront TR.
.

Cant you use a standard GS1000 Rear rim. Pretty dam close to a Akront... Also use 140 X 18 BT45 rear tyre as i found it suits me well. No chicken stips and just using the throttle on a uphill wet road will pick up the front wheel to balance point. Most others just fishtail. Forgive the front tyre, bike has been parked for over 5 yrs

 

[Chuck78]

Sharpy, I think you meant "can" not "can't"
Norm has a GS1000E with 17"/19" mag wheels, not a GS1000C/N with wire spoke wheels. I think a lot of the US GS1000C models still had a 2.15x18 rear but got upgraded to a 2.50. The spoke angle drilled into the rear GS1000C/N alloy rims is not quite right for the substantially smaller diameter GS front hubs angled should really be drilled out oversized to the proper angle and fit with larger spoke nipple to accomodate for the new adjusted hole size.
Also the Akront rims with the lip at the bead are the TR model which are very hard to find these days.
Sharpy, if you have a source for these, PLEASE BY ALL MEANS HELP ME OUT WITH A LINK, as I am really needing an Akront TR 2.50x18 WM4!!! I forgot about the GS1000 stock alloy rear rims looking similar. They are tough to find slso, however!

Thank you for the comparison photo for my purposes, here is what I have in the akront rims, and an old old NOS D.I.D. rim that has a slight lip on the edge unlike the newer the DID rims. The lip did not show up well with the lighting in the photo but can be seen at the bottom portion of the D.I.D. rim, it is bigger than it looks but still slight compared to both sizes in the Akront TR.




You are correct - the rear GS1000 2.50x18 alloy rim is a close match, I will expand my search.

Sorry for the hijack, Norm!! Thanks for dropping me that suggestion Sharpy!

 

[sharpy]

Opps spelling sucks. Sorry. Just rung my contact and seems TR Akronts haven't been made is ages. But we already know that. And there mid $500AU retail for a 4.25 X18 so we sure pay thru the nose. As for a rear rim on front. a redrill to suit 8 gauge spokes/ nipples isn't a hassle over here. Think we should stop. Im sure the original poster is getting confused LOL

 

[storm 64]

Haha, yes it does get confusing, but that's why I asked. In drag racing it was easy. Skinny tire on the front fat tire on the rear. I'm really just wanting spoke wheels for the looks, but if I'm going to do it I might as well do it right. Chuck is really making sence to me about the 18" front.... Hey Mr.Sharpy, I was wondering if you could draw me up a CAD drawing of a hole pattern for drilling GS brake rotors? You draw it I'll machine it��

 

[sharpy]

just the 6 bolt holes. or you talking the slots in the braking area? If its the slots maybe i can use this and mode it to suit the surface area of ure Discs.... https://grabcad.com/library/brake-disc-suzuki-satria-2-tak-1
but looking at them they look huge

 

[sharpy]

Great advice Chuck, I was hoping you'd chime in. I was getting ready to call you. I'm not not sure how the 18 inch front would look under my big chrome fender...

Below is how a 110 X 18 tyre looks on a 19in guard. Thats why i threw the GSX550 esd guard on. Only have to make cutouts for the brake hose brackets to fit.

 

[storm 64]

Baby got some brand new shoes

Baby got some brand new shoes

I got my wheels back from Woody's Wheel Works today. I think they look great and so much lighter! I kind of wish they didn't have the Excel logo on them, but it's good for now. I have to tape them up for tubeless tire application. I have the recommended 3M 4421n sealing tape so we'll see how that goes. I still have to drill my brake rotors, then everything should be ready for assembly ��

 

[Chuck78]

AWESOME!!!

Yeah we just learned how to use my new tire changer Saturday on a stock 77 gs750. I didn't say anything to my buddy who owns the bike, but wow the stock wheels and single disc rotors soooooooooo heavy!!! I had forgotten how heavy they are, I only have some without rotors mounted, and several sets of aftermarket aluminum rim GS wheels here...

 

[Chuck78]

Norm, I had no idea you were looking into tubeless, and at the same time as me at that!

I saw some real nice Out*Ex brand kits from Japan for my DID rims, but wow were they pricey at $130.
I ended up buying 2 different width 15 foot rolls of 3M 4412N Extreme sealing tape, & I read their instructions for it and they recommended using their proprietary 3M adhesion promoter surface primer solution on it, so I decided to try that as well, although cleaning it with acetone would probably have done just as well.

I also went with a NAPA tubeless motorcycle valve stems that directly fit valve stem holes for motorcycle inner tubes, as many tubeless valve stems are larger diameter & far more expensive than a few dollars each.

I was considering taking a two liter soda pop bottle and cutting out 36 small plastic domes to place over the spoke nipples so that I can still tighten them without disturbing the tape. The Outex kit includes some type of stick-on piece onto the tops of the spoke nipples to accomplish the same thing.

The weight savings is definitely nice, but the big advantage for me is that not only is it easier to plug a tire than it is to remove a wheel and inner tube to patch, but all of my aftermarket aluminum rims are safety bead type that are tubeless approved (there are lots and lots of words of caution all over the Internet to not try tubeless on a rim that does not have safety beads). Even if I did try to remove the tube to patch it on the side of the road with tire lever spoons, it would be darn near impossible to break the bead on a safety bead rim without having a bead breaker or shop setup.

I'm not certain if it will work with my Sun Rims, as they are not dimpled rims, so the spoke nipple protrudes substantially up into the center well. My DID rims will definitely take this mod well though, but the only problem I have heard of is on some rims that did not have the welded seam finished off very smoothly. I read several accounts where people could not get it to hold air and it would always leak at the welded seam, because the weld was ground off unevenly.

I have read many accounts of people saying that at least for the Outex kit's tape, it is very necessary to file all of the spoke nipple heads down smooth so that they do not protrude too terribly far, or else the tape will pucker up and will not seal properly. This is why I didn't think that would work on my Sun rims which I generally would like to keep on my primary bike the 77 gs750.

I'm not sure how well this 3M tape will conform to spoke nipple protrusions, so if you do your sooner than mine, please let me know how it works! I can't recall how far the dimples are on the dimpled Excel rims, but I'm sure you will have a much easier time on those than my Sun rims.

 

[Chuck78]

Also, if you decide to do the method with the tape overlapping at to the end, you should start at the top of the rim as it would be mounted on the bike and work your way backwards and down and then up the front, so that the tape will not try to unroll itself from the motion of the wheel spinning. If you watch the Outex install video, they do a non overlap method with the ends of the tape cut at an angle that would be a perpendicular line between the two adjacent spokes to the seam. And then they they put a second layer of tape sideways across that.

From the 3M 4412N datasheet, I even went as far as, not only getting the surface adhesion promoter primer liquid, but also read that there is a 3M adhesive recommended for seams and tight and awkward bends in the tape to make it adhere and seal better.

I also was going to go the route that many dual sporters go, and use 3M Marine sealant ( I saw it at Home Depot I believe, maybe Lowes). I have read of many people just sealing the spoke nipples with that caulking, and bolting in a tubeless valve stem and going with it, but I will probably use that 3M marine sealant to seal the beverage bottle plastic dome caps over the spoke nipples, and then use the 3M 4412N extreme sealing tape

 

[storm 64]

I'm going to see if my local NAPA has the right valve stem and I'll pick up some acetone. If I feel energetic tonight I'll tape it up and mount the tire. I think it will work just fine.

 

[Chuck78]

This is the one. Old photo, I think the part number is similar but longer now (on napaonline.com)

 

[storm 64]

I taped up my spokes. I used 3M 4412n extreme sealing tape. This stuff is amazing! It's like a gooey, thick, very sticky tape with a peel away backing. You just squish the tape into valley of the rim and work it around the spoke nipple. (I should have taken pictures but I never think about it) Then I mounted the tires, taking care not to scratch anything. The rear tire took a little fidgeting to get it to take air, but once it did it slid on the bead with ease. I washed the wheels with soapy water, looking for bubbles. No bubbles NO LEAKS. I have them aired up to 41 psi I'll keep a eye on them.

 

[storm 64]

I finally got my motorcycle on the road today with its new wheels. I just wanted to thank a few people that gave me advice and helped me along the way.Chuck78, Sharpy and others who have chimed in. Oh, and remind me to put Witttom on my ignore list! He's the one that started me thinking about doing this wheel conversion. And offering the wheel hubs for sale. I'm pretty happy with the they came out. I think the drilled rotors add a little extra. When I'm not riding I'll be cleaning spokes☺

 

[Chuck78]

Lookin' sharp, Norm!!!