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497g now, bike is now rear disc only and commuter use.
i think it´s going to be 630g´ish with new hub dt comps 2x, i hope.
brake is hy/rd with s500 levers on shortest reach so not much brakepower going on on front
I've ordered extralite ultrarear slx (j bend) and ultra front sl2 (also j bend) and pairing them with chinese carbon rims (24mm, claimed ERD 595mm) - i have my reasons for this and am willing to take the gamble.
So looking at the product pages of the two hubs and the ERD of 595 I put these values into the http://www.wheelpro.co.uk/spokecalc/ calculator.
front (i plan to spoke these radially, 28H, unless i should do otherwise?)
C=34 (or should i be using 37mm? makes little difference in spoke calc)
D=34 (ditto for C)
ERD=595 or 597
Offset=0 (all the holes in the rim are in the middle and lined up, this means offset=0 right?)
according to these specifications http://www.extralite.com/Products/UltraFront%20SL2.htm
rear (they say i need to do a 3-cross(??) pattern on drive side as shown in a picture near the bottom on this page) and NDS radially? your opinion?)
ERD=595 or 597
and the specs for the rear hub are http://www.extralite.com/Products/wheel ... %20slx.htm
I just want to make sure I'm putting the right values in the right places.
They insist that I measure the ERD using their method (they call it "spoke hole diameter" (except I couldn't get the rubber bands holding the spokes together, instead I got someone to pull them tight and measured that way but things like fingers in the way i'm not 100% confident in this measure). I actually got an ERD of 597 (573 nipple to nipple then 12x2 for the nipples. spokes were fully screwed in but not poking out). I noticed that this makes a 1mm difference in spoke length in the wheel pro.co.uk calculator. I measured it again without someones fingers in the way and kind of got the same (using their method, measuring to just before the nipple and adding the nipple lengths to get the ERD). 597mm again. Should I go with this?
Whats bothering me is that I am getting different spoke lengths (1mm difference) needed using their method on the rear wheel and wheel pro.co.uk calculator. Here is what I am getting for the following.
front (assuming I will do radial 28H)
- extralite site table: --i've contacted them to ask for this as there is no table, and they say they can provide it--
- wheelpro.co.uk: 282.1 if I use 597 and 281.1 if I use 595
(NDS - radial) - or should i NOT do radial?
- extralite site table: it falls in between 595 and 600, so 597 will be either 282 or 283. They're not clear on this.
- wheelpro.co.uk: 281.9 for 597 and 280.1 for 595
(DS - 3 cross????? they've got pictures of what 32H should be and it looks like 3 cross)
- extralite site table: if 595 then 289-290, if 597 then probably 291
- wheelpro.co.uk: 289.1 for 597, and 288.1 for 595
So mainly you can see there is some differences between ERD of 595 or 597, by about 1mm. I'm thinking that 1mm more isn't going to be as bad as being short 1mm, because if the calculations are even off again (shorter than it should be) I could risk less threading coverage in the nipple to the point it becomes problematic.
I want to order asap so if you can make sense of all this, your opinion would be appreciated. as I mentioned it's my first build with EXPENSIVE hubs and spokes but I figure why not? Don't think I could royally stuff anything up if I just take my time and make sure to do everything right.
I'm also going to order some washers, just read something about this adding to the spoke length, so maybe I could do or do without this if I have problems, but they generally seem like a good idea anyway.
https://dl.dropboxusercontent.com/u/330 ... .00.11.jpg
finished 20h disc front. 656g. brass. alpineIII
am i correct about this? 24h front hub with radial non disc side. when you brake, most the force goes thru 6 spokes, like 70-80%?
When I made my ERD measuring tool (out of two spokes and nipples) I cut and filed the spokes to exactly 250mm and threaded them into the nipples until the ends were flush with the bottom of the slot, not the end of the nipple. It's not too difficult for one person to simultaneously pull both spokes tight and measure the distance between the ends.
I'm not a fan of radial NDS. I have built wheels with that and had wheels built by others. They seem to flex laterally more than wheels built with crossed spokes NDS and on hubs with large countersinks on the spoke holes (i.e. Bitex) they eventually break at the elbows. You can use spoke washers to address that. Same problem exists on radial fronts too, which is why I often use 1x heads in there.
i was going to definitely do radial on the front 28H, because the 28H is even overkill as it is, so i figure it will be fine. extralite seem to expect that you will use radial on the front.
i am going to consider doing 3x for both DS and NDS now. but again, extralite tables are different and they seem to expect radial on the NDS.
edit: ok enough faffing around, i'm now confident of the calculators and the ERD of 597 (measured 3 times now) - now i just need to decide whether to going 3x on NDS. or whether radial will do. @eric. most of what ive read say radial is supposed to actually be laterally stiffer than otherwise.
dtswiss calc=282.3 (they recommend 283 rounded up)
rear DS (3 cross)
dtswiss calc=289.3 (they recommend 290 rounded up)
rear NDS (radial)
dtswiss calc=282.1 (they recommend 282 rounded down)
rear NDS (3 cross)
dtswiss calc= 293.3 (they recommend 294 rounded up)
As for calculators, the wheelpro one has always worked great for me. Spokes within a couple mm should be OK, though I tend to favor rounding down. Nothing worse than running out of threads before the wheel is up to tension.
i think hubs and rims are most important, and a few extra spokes is a very negligible weight addon for piece of mind in durability.
i was going to order 290's where i needed 289's (BHS only do even spoke counts), but add some nipple washers in case they are a little short.
is the truing process going to be easier with both DS/NDS in 3x? if it doesnt matter, even if the NDS radial lacing benefit is very minor i can't see why it would cause any headaches (unless its more difficult to true). the 3x seems like it would be the more involved process. rear spoke lengths different regardless.
sorry to be a pain.
SpoCalc will show you the bracing angle on radial heads in vs heads out.
The amount of tension difference is directly proportional to the bracing angle. More of one means more of the other. Bracing angle is good, tension difference is not. As the builder you get to decide what the balance should be.
That is a lot of spokes. I'm not sure which rims you're using but I found 24mm FarSports tubular rims to be easily as stiff as their 38mm clinchers. I forget your weight but unless you're really large you could go 24h on the front.
Yes, point about heads-out radial having lower bracing angle is a good one. It is mostly for aesthetics, but typically on lower spoke-count wheels; I would just do 3x/3x for sure. Simpler, stronger. I might do 2x in front too if you want stronger wheels (and 28h radial seems less common than 2x), but that is pretty much personal preference.
I would think 24/28 would be sufficient spoke count, but I don't know those rims and certainly 28/32 is gonna be burlier.
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