mystery front axle shaft

[theDQG]

Hi all,

First timer in this forum asking for some help.

Please see photo attached- the upper axle shaft in the picture is from a xs650, is the lower one in the picture from a xs400? Dimensions are 7/16" in dia (14mm) and 8 1/2" wide (216 mm).

Thanks in advance.

 

[xschris]

In my pic bottom one is for a disc mag wheel and the top is for a drum spoke wheel. Also 15mm thickness.

 

[theDQG]

In my pic bottom one is for a disc mag wheel and the top is for a drum spoke wheel. Also 15mm thickness.

Thanks, I guess the diameter is right for an xs400, but why is mine only 8 1/2" (more like 8 9/16") where yours is wider than 9"?

I should clarify that my axle shaft came with a front brake drum, so it's definitely early '70's, or earlier- did the axle length change when Yamaha stopped using the brake drum?

 

[xschris]

The sohc xs400 used drums right up till 82. You stated yours is 14mm thick when the xs400 used a 15mm axle. Post a pic of the wheel yours came from. Drum and mag front wheel axles use different lengths.

 

[theDQG]

Here you go:

 

[xschris]

Yamaha used that type of drum break from the 60's till the 80's. That rim is not from a xs400. So that axle don't fit you bike is your question.

 

[theDQG]

Yamaha used that type of drum break from the 60's till the 80's. That rim is not from a xs400. So that axle don't fit you bike is your question.

That drum brake is laced to an akron rim and is going to be mounted on my xs650 project. What I want to do is make sure the drum is really from an xs400 then I'll get xs400 forks and triple tree clamps and use that.

 

[xschris]

Not sure using a 33mm fork and brake setup from a xs400 will work on a much heavier bike as the xs650 or be safe. But that's up to you. Hard to tell for sure what it's off of, but I do know the xs400 uses a 15mm axle. Another thing to measure is the gap for the fork brake stay. The xs400 uses a 17mm gap.

 

[theDQG]

Not sure using a 33mm fork and brake setup from a xs400 will work on a much heavier bike as the xs650 or be safe. But that's up to you. Hard to tell for sure what it's off of, but I do know the xs400 uses a 15mm axle. Another thing to measure is the gap for the fork brake stay. The xs400 uses a 17mm gap.

View attachment 30505

I finally found a MM ruler and measured what you told me to measure, and the axle is indeed 15mm and the gap is also 17mm so it's in fact a xs400 brake drum. Thanks for helping out.

Yes, I'm aware I'm putting it on a bigger and heavier bike, but it's a very stripped down cafe racer, so that should hopefully balance things out.

Again, thank you.

 

[theDQG]

Got xs400 forks and TT clamps on the way to me. Could someone point me to where I could find a blowup diagram of the front end (brake drum) to make sure everything is accounted for?

 

[theDQG]

I think I found it here:

http://www.boats.net/parts/search/Yamaha/Motorcycle/1980/XS400G/FRONT WHEEL/parts.html

Were all the front drum brake setup the same across the xs400 models? I.e., it doesn't matter that this is for a XS400G?

 

[spectra]

I think I found it here:

http://www.boats.net/parts/search/Yamaha/Motorcycle/1980/XS400G/FRONT WHEEL/parts.html

Were all the front drum brake setup the same across the xs400 models? I.e., it doesn't matter that this is for a XS400G?

I think they all use the same diagram as Partzilla looks the same.

http://www.partzilla.com/parts/search/Yamaha/Motorcycle/1981/XS400+-+XS400H/FRONT+WHEEL/parts.html