Campbell45 Posted March 1, 2010 Share Posted March 1, 2010 Hey guys been awhile since I posted on here. Last time I posted I was thinking of making a bobber build out of it. Now the project has started! I have a friend in Ohio who is building it for me and we are up to the point where we need tires before we get the fender on. I need some help though with tires and conversions. I know the front tire is 18"/3" and the back is 18"/3.5" but we want to use a much bigger back tire. My buddy says to find one with 5-6" tire in the back. I am not sure what to look for at all. You guys think you could help me out? Here are some pictures also. Thanks for the help! Link to comment Share on other sites More sharing options...
BRB Posted March 1, 2010 Share Posted March 1, 2010 Hey guys been awhile since I posted on here. Last time I posted I was thinking of making a bobber build out of it. Now the project has started! I have a friend in Ohio who is building it for me and we are up to the point where we need tires before we get the fender on. I need some help though with tires and conversions. I know the front tire is 18"/3" and the back is 18"/3.5" but we want to use a much bigger back tire. My buddy says to find one with 5-6" tire in the back. I am not sure what to look for at all. You guys think you could help me out? Here are some pictures also. Thanks for the help! There is a limit of tire size according to your rim size and also restrictions for tire size when it comes to chain rub, swing arm dimensions, etc.. If your going to retain the stock rim then you will need to install it and take some measurements. Next you will want to research maximum tire sizes that will fit your rim. Just remember that fitting a very wide tire on a smaller rim might work but will change the profile to the point that the intended performance characteristics of said tire will be compromised which in turn will compromise your handling characteristics. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 1, 2010 Moderator Share Posted March 1, 2010 this should give you the information you want! rim to tyre app chart Link to comment Share on other sites More sharing options...
Campbell45 Posted March 1, 2010 Author Share Posted March 1, 2010 Thanks for the help guys. I think I will go with 130/90*18 for the rear and 110/90*18 for the front. Do you guys think that would be okay? I understand things could rub if were not careful and the performance of the tire could drop if you go too big. how big do you think I could go? Link to comment Share on other sites More sharing options...
BRB Posted March 1, 2010 Share Posted March 1, 2010 Thanks for the help guys. I think I will go with 130/90*18 for the rear and 110/90*18 for the front. Do you guys think that would be okay? I understand things could rub if were not careful and the performance of the tire could drop if you go too big. how big do you think I could go? What size rims? Compare your rim size to Drewpy's chart. Link to comment Share on other sites More sharing options...
Campbell45 Posted March 2, 2010 Author Share Posted March 2, 2010 I did look at it but still confused. My friend wants to to get 5-6" back tire so does that mean I look at the chart for say a 5" back tire? Or am I wrong? Will a 5-6" tire even fit? Everytime I look at the chart I get myself confused Link to comment Share on other sites More sharing options...
BRB Posted March 2, 2010 Share Posted March 2, 2010 I did look at it but still confused. My friend wants to to get 5-6" back tire so does that mean I look at the chart for say a 5" back tire? Or am I wrong? Will a 5-6" tire even fit? Everytime I look at the chart I get myself confused Then you will need a 2.5" rim to fit that tire (130/90)on the rear at minimum according to the chart. Does your rim have any size markings on it? Link to comment Share on other sites More sharing options...
Campbell45 Posted March 2, 2010 Author Share Posted March 2, 2010 Then you will need a 2.5" rim to fit that tire (130/90)on the rear at minimum according to the chart. Does your rim have any size markings on it? the only markings we found were from the tires and that was front: 18"/3.0" and back: 18"/3.5" I know I'm prolly making this alot harder than it actually is im just confused Link to comment Share on other sites More sharing options...
XSwheels Posted March 2, 2010 Share Posted March 2, 2010 My XS360 has a 1.85 rear rim, and I suspect yours is the same. Spooning a 5 or 6 inch tire onto a 1.85 rim is crazy. If you want the fat tire look you have to buy a larger width rim. Do you have a cast or spoked rim? Try a XS650 Special rim,it is a 16 inch cast rim, and is 3.00" wide. This rim would be a perfect size for a 130/90 16 tire. This will give you the fat bobber look. Yamaha uses this rear with a 19" front. Link to comment Share on other sites More sharing options...
Campbell45 Posted March 2, 2010 Author Share Posted March 2, 2010 I just went to a flatout motorsports and asked them about tires. They said I could use a pirelli 180/55/R18 on the back and a 130/90/18 up front. Is this possible? Link to comment Share on other sites More sharing options...
BRB Posted March 2, 2010 Share Posted March 2, 2010 I just went to a flatout motorsports and asked them about tires. They said I could use a pirelli 180/55/R18 on the back and a 130/90/18 up front. Is this possible? Rim specs? Link to comment Share on other sites More sharing options...
Campbell45 Posted March 2, 2010 Author Share Posted March 2, 2010 Rim specs? they are stock xs400 rims. I found a website that gives the stock size of the rims: http://www.bikez.com/motorcycles/yamaha_xs_400_1979.php it says 18"/3" front and 18"/3.75" for the back. So would I be okay using those tires? Link to comment Share on other sites More sharing options...
Runningdog Posted March 2, 2010 Share Posted March 2, 2010 Look closer...Bikez says tire size, not rim size. A 110/90 is about the biggest you'll get on the front (clearance), and maybe 120/90 on the stock rim on the rear...go for the 16" XS650 special rim on the rear, will make the bobber look right. Link to comment Share on other sites More sharing options...
Campbell45 Posted March 2, 2010 Author Share Posted March 2, 2010 Look closer...Bikez says tire size, not rim size. A 110/90 is about the biggest you'll get on the front (clearance), and maybe 120/90 on the stock rim on the rear...go for the 16" XS650 special rim on the rear, will make the bobber look right. dang I was hoping I wouldnt have to but I guess its the best thing to do if I want the bobber look. Thanks for the help everyone! if anyone has a spare rear xs650 16" mag wheel give me a pm. thanks again Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 2, 2010 Moderator Share Posted March 2, 2010 dang I was hoping I wouldnt have to but I guess its the best thing to do if I want the bobber look. Thanks for the help everyone! if anyone has a spare rear xs650 16" mag wheel give me a pm. thanks again look at coker tires if you want bobber http://store.cokertire.com/popular-tire-applications/motorcycle.html Link to comment Share on other sites More sharing options...
Campbell45 Posted March 3, 2010 Author Share Posted March 3, 2010 Do you guys know if the axle, bolt, shims, spacers, and adjuster from the xs400 18" is the same as a 16" xs400 special? Link to comment Share on other sites More sharing options...
Chet Wright Posted March 26, 2010 Share Posted March 26, 2010 Do you guys know if the axle, bolt, shims, spacers, and adjuster from the xs400 18" is the same as a 16" xs400 special? should be. the 650 has different size axles. i want to do the switch myself. you might be able to get smaller bearings to fit in the wheel. if you get it, post up. Link to comment Share on other sites More sharing options...
armyofda12mnkeys Posted March 26, 2010 Share Posted March 26, 2010 look at coker tires if you want bobber http://store.cokertire.com/popular-tire-applications/motorcycle.html wow nice tires... sorry to hijack the thread, what Coker tires would work with a 1978 XS400E cafe style? The rear fender is gone btw... I read the manual saying each tire on that bike is 3.5 (cross-section?) x 18" diameter i think, But most of the tires are all larger than that. (Not sure how to buy tires if anyone can enlighten me lol) Link to comment Share on other sites More sharing options...
bznchris Posted March 26, 2010 Share Posted March 26, 2010 For what it's worth, I have a 120/90 rear tire on my stock xs400 special rim (cast, not spoke). It's exactly 5" wide ... any wider and I would have rubbing issues with the chain and swingarm. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted March 26, 2010 Moderator Share Posted March 26, 2010 For what it's worth, I have a 120/90 rear tire on my stock xs400 special rim (cast, not spoke). It's exactly 5" wide ... any wider and I would have rubbing issues with the chain and swingarm. I have rubbing issues, and the wife thinks its disgusting!!! Link to comment Share on other sites More sharing options...
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