Building my first wheel - spoke size

[retro-rich]

I've decided I'd like to learn how to build a wheel, most obvious candidate for a new wheel is the Randonneur rebuild I'm currently working on, just the back to start with as have a couple of spare fronts already which will get it on the road.

My main question is this, with a tiagra 130mm rear hub and Rigida Sputnik rim, the spoke sizes come out as left 290.6 and right 288.9

the spokes come in 2mm increments, so do you just go for the next one up? ie 292 and 290?

As per previous threads, my rando for some reason has only 120mm spacing, that along with a possible dink in the chainstay makes me wonder if it's been pranged at some point, think I'm going to get this cold set to 130mm max as 135mm probably too much, hence the tiagra rather than deore. I had some good advice on here when I considered setting another frame a while back. Will do the cold set before laying out for wheel parts in case it goes pear shaped. Talk about doing things backwards, maybe should have tried all this before the respray but never mind.

 

[Jonny69]

I've built about 5 sets of wheels now and my experience is it's difficult to get them right first time. Most annoying is when they are so close but bottom out before they are completely nipped up. I used to hate having a bit of thread on view, but actually there's nothing wrong with that at all, especially because the nipples are not threaded all the way to the bottom. I'd probably go for 290 and 288.

What spoke calculator did you use?

 

[retro-rich]

I've built about 5 sets of wheels now and my experience is it's difficult to get them right first time. Most annoying is when they are so close but bottom out before they are completely nipped up. I used to hate having a bit of thread on view, but actually there's nothing wrong with that at all, especially because the nipples are not threaded all the way to the bottom. I'd probably go for 290 and 288.

What spoke calculator did you use?

Right ok that makes sense, because of course the nipple will cover the ends anyway, and any longer will be poking through the nipple into the rims box section?

i used the spreadsheet downloaded from the sheldon brown site, i did find another online one but it was fiddly and ive lost the link now, but that came within point something of a millimetre on each side.

Ive got myself the book The Art Of Wheelbuilding, I've read it once but going to go through it again to try to soak it up a bit more http://www.amazon.co.uk/Art-Wheelbuildi ... 0964983532

Do you use a tensiometer? seem expensive.

 

[American Friend]

ask Spa, or pop the question on the CTC forum, as it's a very common hub/rim combination that Spa do a lot of, and their wheelbuilder ("Colin 531") regularly posts on the website.

I don't use a spoke tensionmeter thingy, but I just build the occasional wheel for myself. I think you can get the tension pretty even just by plucking the spokes and comparing the sound.

Before doing a rear wheel, I'd try building a front first as it's much easier. A couple of tips I picked up along the way:

- once you have the wheel initially laced up, tighten up all nipples down to a couple of threads showing.
- as you start to tighten up the spokes, work systematically and don't get distracted.
- start truing the wheel before you have done up the spokes really tight.
- back off a 1/4 turn each nipple when the spokes are starting to get really tight to unwind them, especially if using DB spokes.
- take your time, alternating between lateral and radial truing.
- don't go crazy trying to get the tiny annoying bump out of the rim at the joint; some rims are like that.

I'm sure I can think of a few others if I put my mind to it. I find it's a very pleasant contemplative exercise cause I'm not rushed, but I could see how it could drive someone else bonkers.

 

[bm0p700f]

Tomorrow if I remember I can run the spoke lengths for you and post. Whixch Tiagra hub is it as it might maker a difference.

I tend to round up to the next avaialble spoke size.

What ERD and hub measurements are you using in case I get different numbers.

 

[bm0p700f]

Using spoc calc and the Tiagra 4500 hub (the 4600 hub annot be that different) I have flange diameter 45mm, right flange - centre = 20.55mm left flange to centre = 37.55mm.

Changing the hub dimensions by a 1mm or two make sod all difference to spoke length.

I am also assuming you are lacing 3x.

I am using 606mm for the ERD of the Sputnik. What ERD do you have.

From spoc calc and a 36H wheel the lengths L293.5/R291.8mm So use 294 and 292mm.

For a 32H wheel the lengths are L296.2/R294.5mm so use 297 and 295mm. You could use here 296 and 295mm without too much hassle I would think.

Sapim races are available in these lengths but you may want to use a plain gauge spoke like the Sapim Leader on the drive side.

So I do not know how you arrived at your spoke length measurements. Stating the ERD and hub measurements you used and the number of spokes would be a start!

 

[retro-rich]

Thanks for the comments/tips AmFr I'm hoping it would be enjoyable rather than doing my head in, we'll see lol

bm0p': sorry didnt reply earlier

i have the same hub dimensions as you for the 4500, but I got an ERD of 600 http://www.spacycles.co.uk/products.php ... 2b0s116p67 they could be wrong of course

3 cross pattern, 36 spokes

You advise using plain guage on the drive side? was thinking of triple butted all over. Also, the book I read mentions fitting washers, in practice to many people do this?

Above measurements may need to be changed though as having a slight rethink, i have some alex ta19 front wheels in the shed, barely used but with quando hubs. might turn one into a rear and upgrade hub spokes on the other, they are non eyeletted but might be ideal as a first time project and save a couple of quid, need to double check the spoke count though and see if the erd is on the sticker as not online.

If our measurements match based on the erd I was using then it looks like i'm on the right track.

Thanks for the time

 

[bm0p700f]

The ERD that spa publish may or may not be right for the rims you recieve. I have several Sputnik's in stock and the ERD seems to be 606mm. I have measured them previously at 605mm.

I measure by cutting two spokes to 200mm in length and screwing two 12mm nipples onto the spokes up to the bottom of the nipple driver slot. Them simply measure the distane between the ends of the spokes and add 400mm. That give's an ERD of 606mm. Spa may do it a different way and on the CTC forum, Collin, Spa's wheelbuilder says he does not measure ERD anyway. He sizes a rim up next to a referene rim or something like that.

ERD is effective rim dimension. Effective is the important part, there is no right or wrong as such. Doing my way and rounding up put the top of the spoke thread when the wheel is fully tensioned between base of the nipple drive slot and the top of the nipple.

The important thing is measure the rim yourself then order the spokes. Order all at the same time and you may end up with spokes that don't fit.
All it takes is a typo on a sellers website and you can end up ordering the wrong spokes.

You can use tripple butted spokes on your build if you want to. I personally would use Sapim Race 2.0/1.8/2.0mm NDS and for increased stiffness and load bearing capasity Sapim Leader 2.0mm spokes drive side but Sapim Stong 2.3/2.0mm single butted spokes on the drive side would be even better. I tend not to use DT spokes as they are so expensive and I am not sure if they make a more reliable build.

Spoke washers can be used in the hub. They tend to used if there is play in the spoke when seated in the hub flange. The washers redue this play. this sometime occurs with some hub/spoke combinations. With a Shimano hub and Spaim/DT spokes you should not see any play.

Also using washer means on a Tiagra hub and with a Sapim/DT spoke means you will need a slightly longer spoke and you will have bend the spokes at the elbow to get sitting right against the hub.

It is not necessary for your build.

 

[retro-rich]

Ah I see, seems a pain in the neck if buying by mail order to have to order twice, but i see why now you explain it. Although to be fair Spa say they will provide the correct length if all parts ordered from them.

I've had a look at the front spare wheels, no label with erd anyway so will strip one down and measure the way you describe. I did wonder if I could do it by measuring the rim depth and taking it away twice from the outer diameter, but it seems the diameters vary with only the bead seat being consistent on 700c wheels if I've read right.

The rims look in fairly good condition, I've measured the rim wall and am getting on average about 1.5mm, I understand that 1mm is time to change and the old rims that came with the bike are about 1.2 I think. Do the as new thicknesses vary by rim design?

Still trying to get my head round the spoke types and thicknesses, will have another read tomorrow


Thanks again

 

[bm0p700f]

Different rims have different wall thicknesses.

I am not sure how thick the wall of the sputniks are but when they are worn through the a groove appears as Rigida extrude there rims with a hollow tube in side the rim. So when the wall become to thin this hollow space becomes exposed meaning the rim is now worn and in need of replaement. Better I think than a safety line that wear out an disapears.