I never would use 12GA spokes on this hub. They probably have drilled out the holes to make the large spokes fit.
No modification to hub to make spokes fit. I dont completly support the spoke size with this hub. But the new custom stong hub will have a high flange drilled for proper use with motorcycle rim so i can add more tension.
I've built up a number of those. They are very heavy, but not nearly the strongest rims. The main functional problem with them (besides not accepting rim brakes) is that they're drilled for 10ga spokes so they can't stay tight. They impose constant maintenance to keep the spokes done up. They're basically 1890s tech. Superior to wagon wheels maybe, but we can do better.
I understand that this may be a pretty dumb question, but is is possible to use a pattern here every fourth rim hole is skipped in order to lace a 36 hole hub to a 48 hole rim ... and still have a solid, stable and strong assembly? With symmetrical skipping of one hole, it seems like it might work well.Chalo wrote: ↑Jun 22, 2018 1:07 pm
The pedicab manufacturer I work for has a new run of custom 48 hole, 64mm wide double walled and eyeleted rims in production. Those should be the undisputed king of the mountain among high strength bicycle rims. Since pedicabs are standardized on 48 hole hubs, there are no plans for us to make 36 hole rims that would work easily with hub motors. But for mid drives, there will be a new and formidable option.
It's usually good to do that--to go from a too-large size that goes slack too easy (or breaks the rim trying to tension them enough) down to a smaller thinner size that can stretch and be tensioned correctly without damaging the rim.
It'd work, and for most uses it'd be perfectly ok. I suspect it'd be less than perfect on an application like the pedicabs, or my piano-hauling trailer (but even on that, it'd probably work fine).
I reckon it could be done with as few as two different lengths of spoke per side. I laced my 32 hole Rohloff hub (drilled with extra holes for a total of 56) to a 48 hole rim when I first built it up. That took two different spoke lengths in a crow's foot pattern.wturber wrote: ↑Jun 22, 2018 5:49 pmI understand that this may be a pretty dumb question, but is is possible to use a pattern here every fourth rim hole is skipped in order to lace a 36 hole hub to a 48 hole rim ... and still have a solid, stable and strong assembly? With symmetrical skipping of one hole, it seems like it might work well.
I used to do that with my Brompton because it came with a 28 hole Sturmey and I didn't want to special order the 28 hole rims. I replaced about a rim a year from brake wear - on an industrial road with lots of construction grit. It was easy to lace and true, it just looked really weird. The straightest run spokes poked thru the nipples a bit, and the longest runs were a bit short, but I just put enough tape inside. I don't remember having to tighten up often, nor breaking any spokes. But I'm light and the Brommie has rear suspension. Also since the Sturmey doesn't have a gear cluster, there is no dish.
OK. Then no real advantage then. Was just thinking that other aspects of the wheel design might make it worth the trouble.
Where and when does a spoke break? (nl)
Normally just before the bend (this is fairly standard after many years use)
The rim has been damaged - even the smallest dent can be the cause;
The use of non-compatible components;
Irregular tension on the spokes;
A gap exists in the spoke-nipple alignment;
Is it possible to replace 1 or 2 spokes or do you have to replace all the spokes and re-spoke the wheel? If you do not re-spoke the wheel, the replaced spokes will have to be very tightly tensioned if the wheel is to be round and true.
Do not forget when the first spoke breaks, all the other spokes suddenly have a different tension pattern! Also the rim structure goes out of line.
If you only replace 1 or 2 spokes, you can expect these or the spokes next to them to break again. It is best to re-spoke the entire wheel and to replace the hub just in case the hub holes are damaged. It is possible to re-use the hub by mounting the spokes in the opposite direction (i.e. not in the direction of the ovalisation of the hub holes).
The spoke head breaks off (this is unusual)
Bad positioning of the head in the hub (e.g. a slant position puts all the pressure on one side of the bottom of the spoke head. As a result the head snaps off, the so-called "bottle cap effect").
The hub flange is too thick and is not suited to the length of the spoke bend (i.e. all the pressure is on the head, which will be excessively stressed and rip off).
If the wrong cross pattern is chosen, e.g. cross 4 on large flange hubs, the spoke bend can rub against the adjacent spoke head. This should be avoided.
The spoke thread breaks in the nipple
This often occurs as a result of nipple/rim and spoke mis-alignment.
If spokes are used which are too long, new threads in the nipple will be made. Under heavy pressure the spoke threads will be stressed too greatly.
Spokes which are too short may also break at the spoke thread.
When the thinner middle section breaks (on single or double butted spokes)
Any object striking a moving wheel causes damage (sometimes only visible with a magnifying glass or microscope).
Top quality manufacture will safeguard against damage. Lower standard processes will produce an inferior quality. SAPIM draws wire in such way that no change in molecular material structure occurs. The spoke does not twist much when it is built into a wheel.
Aerodynamic, elliptical spokes, such as the SAPIM CX-Ray spoke, are best fitted with a special CX-Ray key.
This will prevent the spokes from twisting during lacing and centring.