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-   -   As experienced 50-plussers, does spoke length matter? (https://www.bikeforums.net/fifty-plus-50/351389-experienced-50-plussers-does-spoke-length-matter.html)

SaiKaiTai 10-10-07 09:43 AM

The ongoing saga. I rechecked with Bontrager and they flatly state that the front and rears are the same length -263mm, non-disc side and 261mm, disc side- yet I absolutely, dead certain measure a front at 292mm plus or minus. So, either my ruler is nuts or Bontrager is. I clarified with them that I have a 700c wheel. So... do I believe them and order 261mm and 262mm or do I believe my ruler and my eyes and order 292's? This is pretty insane

Terrierman 10-10-07 11:24 AM

Quote:

Originally Posted by SaiKaiTai (Post 5427920)
The ongoing saga. I rechecked with Bontrager and they flatly state that the front and rears are the same length -263mm, non-disc side and 261mm, disc side- yet I absolutely, dead certain measure a front at 292mm plus or minus. So, either my ruler is nuts or Bontrager is. I clarified with them that I have a 700c wheel. So... do I believe them and order 261mm and 262mm or do I believe my ruler and my eyes and order 292's? This is pretty insane

You let the fellow who is going to build the wheels for you worry about that. At least that's what I would do. :D

SaiKaiTai 10-10-07 11:34 AM

Quote:

Originally Posted by Terrierman (Post 5428648)
You let the fellow who is going to build the wheels for you worry about that. At least that's what I would do. :D

Well, yeah, I should, you're right
But, for some reason, I just can't shake the desire to take a whack at it myself.
Then, if I can't get anyone to give me accurate, consistent lengths and I don't really have to tools to measure the hub so I can calculate it myself, maybe I *am* nuts for even thinking about it.
I do know the rim has an ERD of 604mm. It says so right on the rim :D

TwoShort 10-10-07 11:52 AM

You know the ERD of your rim.
Measure the diameter of the hub (to the spoke holes).
Measure the the positions of the flanges/lock nuts such that you know how far from center the flanges are.
Know how many spokes you're going to use, and in what pattern.

Now Google "spoke length calculator" and be done.

Anyone telling you what you need without all of the above information is guessing. (maybe well, maybe not) There's no need to guess; it's just simple measurements and some trig, and the trig exists as code online.


As for not having the right tools, your best guess with a tape measure will be fine. But I would reccommend a proper truing stand for actually building the wheels.

SaiKaiTai 10-10-07 01:49 PM

Quote:

Originally Posted by TwoShort (Post 5428846)
You know the ERD of your rim.
Measure the diameter of the hub (to the spoke holes).
Measure the the positions of the flanges/lock nuts such that you know how far from center the flanges are.
Know how many spokes you're going to use, and in what pattern.

Now Google "spoke length calculator" and be done.

Anyone telling you what you need without all of the above information is guessing. (maybe well, maybe not) There's no need to guess; it's just simple measurements and some trig, and the trig exists as code online.


As for not having the right tools, your best guess with a tape measure will be fine. But I would reccommend a proper truing stand for actually building the wheels.

I see my reply to this got lost in the last DB crash.

Why would you think I haven't already "Googled spoke length calculator"? More than once.
I've looked at Sheldon Brown's site on the subject as well.

I don't know about your tape measure but mine measures in inches.
Every calculator I've found online -and there are a LOT of 'em, from ridiculously simple to hideously complex- works in mm. Sure I could convert inches to mm but why add an unnecessary degree of uncertainty?

TwoShort 10-10-07 02:25 PM

Quote:

Originally Posted by SaiKaiTai (Post 5429138)
Why would you think I haven't already "Googled spoke length calculator"? More than once.
I've looked at Sheldon Brown's site on the subject as well.

I don't know about your tape measure but mine measures in inches.
Every calculator I've found online -and there are a LOT of 'em, from ridiculously simple to hideously complex- works in mm. Sure I could convert inches to mm but why add an unnecessary degree of uncertainty?

I only meant to be complete, not to imply you couldn't find the calculator. Google or a calculator will also convert 16ths of an inch to mm with more precision than your measurements will have in the first place. My point was that you want to work from actual measurements of your hub & rim, but don't be too concerned about extreme precision. The first time I built wheels, I broke out the calipers, and did everything to some crazy number of decimal places... and then the shop helpfully rounded up to the next multiple of 4mm. If you're in the more typical spoke length range, they'll stock them to every 2mm, but in any case you've got a pretty significant range of acceptable sizes; and only the error in your measurement of hub diameter will have much impact. Get that to within a couple mm, add a mm to the final spoke length and you'll be fine.

maddmaxx 10-10-07 02:50 PM

SKT, I suspect that your rims are Bontrager Select Disc. If the model of hub is written on the hub somewhere then I have a spreadsheet that will give me the data. For example if the rim is "Bontrager select" then ERD is 604.1..........If the hub is "Bontrager select disc" then the flange diameter is 58mm, the left flange is 34.4 from centerline and the right flange is 20.4 from centerline. For this example only, the spokes would be 293 left and 289 right.

We already know the rim erd but I need to know what hub is in play here to be certain.

SaiKaiTai 10-10-07 02:52 PM

That's cool, TooShort... I sound a lot crustier than I really am.
You provided a lot of good info here... I have a little more piece of mind now.
I'm pretty confident I can get things to within a couple of mm.
I actually find mm a LOT easier to read than 1/16ths of an inch. Those little marks get really tiny :lol:

SaiKaiTai 10-10-07 03:00 PM

Maxx, that is cool!.
The rim is labeled Ranger, fwiw, but yeah, it's actually labeled with the ERD. How nice... I wish the hub was, too. And speaking of "hub", it's listed as a SuperStock Disc, which is fine except every SuperStock Disc I've seen says it's got 28H. Mine has 32H so who knows what it really is? But seeing how my front spokes are 292mm (maybe 293mm, sure), then your figure of 293mm/289mmm sounds pretty reasonable.
I wish I brought in the rough hub dimensions I took last night, I won't trust my memory at this point.

clancy98 10-10-07 03:06 PM

you can get a tape measure in cm and mm. I got one at the depot.

maddmaxx 10-10-07 03:26 PM

Your in luck, there is an obscure Bontrager Hub manual on the internet somewhere. (I got the data but lost the web address)

Final calculations are..............................survey says

front left 291.8mm.............front right 292.7 292 both sides was close enough

rear left 292.8mm..............rear right 291.5 293 and 291 sounds right. Bontrager help desk seems to that the details right except for the 6 vs 9 typeo.

Now you can do it yourself and have fun.......:D

SaiKaiTai 10-10-07 04:29 PM

Cool beans, daddy :D
Thanks MM...


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