What is the Correct Method to Measure Spokes

[gregwils]

I am trying to get an accurate measurement of my existing spokes. The spoke is off the wheel, so there is no problem working with it. My question has to do with the angle at the hub end of the spoke. Do you measure it and add it to the spoke (as if the spoke were entirely straight)? Do you ignore it and measure the straight portion (probably not likely)? Or is there some other way to approach this? Thanks.

Greg
66 Monza Jr

[gregwils]

I think I found my answer assuming everyone does it this way. L = length So, the correct answer is only measure point in the bend where it connects with the hub. Does anyone know if this is an industry standard? Thanks.



http://www.central-wheel.co.uk/spokes/spokes.html

[amartina75]

[quote="gregwils"]I think I found my answer assuming everyone does it this way. L = length So, the correct answer is only measure point in the bend where it connects with the hub. Does anyone know if this is an industry standard? Thanks.

yes i believe that is the industry standard for measuring spokes. if you want to be sure Ducati did it like that here are some measurements you can check
I am assuming you are working with your monza jr.
from the tech page on Motoscrubs the monza jr parts manual lists the spoke measurements as
front 16" rim 3mm x 135 mm
rear 16" rim 3mm x 140mm

also for a 250,350,450

18"front 3.5x151
19"front 3.5x162
18" rear 3.5x155

also it really isn't that important to have an exact measurement 2mm plus or minus will mean nothing when you come to build your wheels. you will likely need to grind down the spokes that protrude through the nipples so they do not puncture your tube.

[gregwils]

Excellent, thanks. Yes, my front spokes measured 134, so I think I am good on the stock length. Are you sure about the 18" wheels using 151? I would actually like to upgrade to 17" wheels from the stock 16's. I calculated that I would need an additional 16mm in length or 150, but if the 18" wheel uses 151, I am too long. I would think splitting the difference - 142mm would be correct for the front.

Thanks again, very helpful information.

[gregwils]

I forgot to account for the dimple and raised center portion of the rim in my calculation. I am good with 142mm spoke for a 17" rim. Thanks.

[Jon Pegler]

Mototrans 160's use 17'' rims as standard.
Spoke length is 140mm according to the parts book.

Jon

[amartina75]

the larger bikes, 250-450's have bigger hubs then the monza jr. so the spoke length for them doesn't relate to what you are working with. i mentioned the measurment for them because i was unsure of what you were working on.
if there was a mototrans bike that used the same hubs as a monza jr and had 17" rims then the spoke length would be correct for you also.
i don't know anything about that because i do not have any of those parts books.
where are you thinking about getting spokes anyway? if you have someone make them for you like Buchanan's they will figure the length for you.
i think i saw a post on here once where someone restored a monza jr or bronco and they used 17" rims. you should try finding that old post. i was a very nice bike and well done. i think the owner was talking about taking it to Barber's.
hope that helps

[amartina75]

search "barber" 5th post down Ducati 160
you should PM DesmoDog and ask him about his wheels/spokes

[gregwils]

Thanks. I have exchanged e-mails with Craig (Desmo) in the past. I will most likely buy my spokes from Buchanan's. I am going to use a set of Radaelli rims, Buchanan's didn't have anything at that price point. I checked around on spoke prices and they are reasonable. If they will also help me calculate the correct length, then hands down I will go with them. Thanks again for your thoughts.