The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Von datoh on 22.10. 2021 11:01
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Hi helpful people,I'm going to have a go at lacing my rear wheel(a10 plunger crinkle hub) any advice tips appreciated.The good people at the rim company tell me it's an offset of 3mm from the edge of the spline side of the hub to the face of the wheel rim.Suggested using 3mm Packers under the rim and starting the build process like this,my only concern is as you tighten the spokes you lose the offset?,any ideas,it's my first attempt.Thanks in advance Von.
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You move the rim with repect to the hub by loosening the spokes on the side you want to move away from and tightening those on the side you want to move towards. My one attempt at trying this was unsuccessful because I made most corrections by tightening rather than the right balance of tightening vs. loosening. When you're deciding if the spokes are evenly tight you tap them so they ring at about the same tone. I must have been going for too high a tone. The result was bending out the crinkles on my freshly chromed hub. Bought and chromed a replacement hub. Even though a skiiled wheelwright can do this job in a few minutes, taking your time is key. It's very easy to become impatient when making reptitive adjustments on 40 spokes. After the cost of the hub and chrome, decided it was worth letting a pro do it.
Richard L.
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Interesting and satisfying to do. I did a lot of searching before I finally took the plunge. First, I took lots of pictures of the wheel from both sides to see the spoke pattern. Put a flat bar accross the hub and measured the gap at the rim (3 or so places), then repeated on the other side, just to get the feel of the wheel construction.
Patience is important. I used an old swinging arm to hold the wheel after initial lacing.
Hopefully I have attached a couple of guides that I hope will be useful
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one more on handing rims. may be of use
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I appreciate your reply gearbox,but can't open files,well not on mobile anyway what opens it?
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pdf files, use Adobe reader. Its a free download
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Ahh, I see what has happened. I attached links to my NAS storage. I have copied these to my PC and reattached below. Hoope these work.
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Thats not working either. Strange as these seem to attach well enough. I will have to investigate further. Possible to pm me and I will email them to you
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I'll try later when I get home on my laptop to view them this evening.
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Looks like the files automatically download to youe chosen download folder and do not open. Have a look there after clicking on the files.
Fingers crossed
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The files open OK on my Android tablet using the built in pdf reader.
Useful info - thanks.
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Hopefully you have photographed the spoke layout before stripping, When tightening the spokes tighten (slightly) every third spoke. once you have been round a few times all the slack will have been taken up, then you can adjust the offset. once you have got that you need to see to the runout (both ovality? and sideways) Then once you are there its just a case of setting the spoke tension and rechecking everything.
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I prefer to get rid of any ovality and get the hub concentric with the rim first, then go for the initial stage of tightening and then start to set the off-set to where it ought to be.
Getting the off-set spot-on, getting the rim true and tightening the spokes is always a bit of a juggling act but doesn't usually take too long.
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Gearbox ive viewed those files on my laptop very useful information many thanks *smile*
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I'm considering lacing up one of my bare hubs to a well tarnished 19" rim I've had for years, just as a push around. It's a WM2 rim with 40 dimples.
Now here's the teaser. How do you tell if it is a front or rear rim, and do the spoke dimples vary in angle depending on the hub? Parts listing shows there to be a difference in the rims, and rim sellers are always at pains to make sure you have the right rim for the hub. Question is, how do you tell? Any manufacture stamping marks are long gone. Looks as if buying a used rim is also a big gamble in that the application has to be taken on trust.
Swarfy.
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The angle of the spoke dimple holes to vary according to the hub being used. With a half-width hub (ie a very small spoke flange) the dimple holes will be pointing out almost perpendicular to the rim, whereas on the brake side the spoke flange is much larger and the dimple holes will be angled. F & R rims are the same other than the angle of the spoke dimples. You'll probably find that for a 7" or 8" hub the rims would be near enough the same and good enough for a push-around.
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G'day Swarfy.
You'll need to do a bit of detective stuff. If you know for sure what hub you have I'd find as many photos as I could of that complete wheel and blow them up to compare. Full width hubs will have rim nipples at the same angle just a tiny bit different for inner and outer. Single sided hub will have rim nipples at different angles left or right.
30 years ago I drilled the Akront rims on my racer myself *bash*. The angle wasn't quite right so all the spokes (8g 4mm) are bent. But in saying that I haven't had to touch them in all that time (9 years of racing and now on the road).
If it's just to push around I'd buy the correct spokes for your hub and throw'em in.
Cheers
Rex got in first
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Thanks Fellas. I've printed out the links above kindly posted by Gearbox, so yes, time to try old spokes and nipples in the rim and get some handle on the angles. Not so simple as I thought, but not that hard either. As a pusher I'm not too worried about a bow here and there and it will be a good to have a go at wheel building......more a thoughtful pastime rather than a greasy one. Cleaned up the old rim, true to form no identifying marks so it's trial and error for now.
Cheers.
Swarfy.
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Very therapeutic, is wheel building. Don't know that I'd find it that much fun in an unheated workshop in December though... *eek*