countalmaviva 

I have a 1986 Schwinn Cimarron and want to build new wheels to make a sturdy commuter, touring, and occasional bikepacking rig. The dropouts are at 128mm (for use with 126mm and 130mm hubs), and I would strongly prefer using my trusty Shimano 8s bar end shifter in index mode. I weigh 140 pounds and tour with about 40 pounds of gear. Looking at Sun Rhyno Lite XL rims.

I've read several threads, including this excellent one: I'm an eight speed girl.

Seems these are options:

1. Spread dropouts - Frame decals says 4130 main tube, fork, and stays. 128 to 135...a bridge too far?
2. 130mm road hub - Few 36h choices? Strong enough for my purpose?
3. Respace - Remove spacer from left side of 135 mm hub and shorten axle. Weakens wheel too much due to increased dish?
4. 7 from 8 - Toss the smallest 11t cog and put 7 cogs from my 8s cassette onto a 7 speed hub to give precise shifting with my 8s shifter. Hmm...

Am I missing any options here? I should mention I have a usable Deore M510 135mm hub in a 700c wheel I can re-purpose.

One quote I love from the thread (referring to 8s on a 126mm hub):

Should I just switch the dang shifter to friction mode and get on with my life?

Bill Kapaun

1. If you spread to 135mm, make sure the fork ends are bent in to be parallel.
You can fudge about 4mm before you'll start having problems eating cones. Mainly the DS cone.

3. Respacing a 135mm to 130 is basically giving you a "road" hub out of a "mountain" hub.
You'll find a couple mm variance in CTF distances amongst hubs of the same "type".
IF you can find the tech docs for your various hub choices, you can try to select a "best" regarding dish.

4.The smallest cog has a built in spacer. You need that type cog, no matter what the tooth count.

140 lbs. isn't very heavy. I had no problem with a 32 Spoke wheel on my hybrid when I weighed 250.
On my "grocery getter" I'll sometimes have a bit over 50 lbs. in my rear baskets. baskets are located about 2/3 BEHIND the axle, so it actually "levers" some of the front weight to the rear.
I used a 36 spoke OC rim for that. Alas, those seem to be disappearing in 36. I was looking for another yesterday and Velocity only had "a few" 32 spoke Synergy's.
That would still be plenty strong for you.
A good build will trump more spokes & crappy build.

countalmaviva 

Thanks for your thoughts, Bill. They're in line with what I'm thinking.

According to Sheldon, a Shimano HG 7s cassette is 31.9mm in total width. Without the smallest cog with built-in spacer, my 8s cassette measures 32.0mm in total width. The separate lockring covers the underlying 13t cog fine. My thinking that, because of the shorter freehub body, a 7s hub would have more favorable C-T-F measurements for a stronger wheel, plus I get the 4.8mm spacing for accurate shifting. Have to make sure the freehub is threaded on the ID to accept the lockring.

I got this idea after reading "8 Of 9 On 7 -- or 9 of 10 on 7."

Maybe I'll just try option 4 and see what happens. Worst case: I put an actual 7s cassette on and deal with fussy indexing from my 8s shifter or switch to friction.

Thanks,
Oliver Henderson

Bill Kapaun

The shorter 7 speed body does give a noticeably better CTF. Some not as good as you would expect.
If you have one of the spoke calculator apps, you can look at the list of various 7 (or other) speed hubs and compare to "similar" 7 speed hubs.
When looking to build a "strong" wheel, a few mm here & there adds up.

Make sure the lock ring has good purchase before hogging it down. I stripped a lock ring & outermost thread of the FH body, pursuing a similar endeavor.
I did an 8 speed transplant to a 7 speed hub. All I had was 7 speed cogs & spacers, so it was try to consistently thin all the 7 speed spacers until I could fit 8 cogs. (I was financially destitute at the time)
Friction can sometimes be seamless.
As I went from 7 to 8 to 9 on my "original experiment", the Deore "Deerhead" with the heavy cast bodies, improved dramatically where I probably hit 95% of my shifts. It was just a matter of ergonomics between my thumb and the shifter.

AnkleWork

You can tinker with the cable anchor on the RD to slightly alter the total actuation ratio. The difference in spacing isn't much and you may be able to get excellent indexing. If you already have the shifter, Rd, and cassette it would be easy to test. Info and pics floating around the internet.

Miele Man

You can respace the the wheel and then adjust the dish so that the rim is centered overthe axle/hub. It's not that hard to do if you take your time .

I've used 7 of 8 cogs without a problem.

7 and 8 speed center to center are so close you should be able to use your 8-speed shifter in index mode. Even better if you do the fine tuning on the middle cog instead of the smallest cog. That minimizes any discrepancy between 7 and 8 speed cassettes.

Cheers

tomtomtom123

Fh-rs300 hub comes in 36h 130mm for $16. Works up to 10 speed. Fh-rs400 is $23 up to 11 speed. But Shimano specs gives 1.4mm less dish on the rs300. Although the rs400 supposed to have more polishing on the cup and cones.
https://productinfo.shimano.com/#/sp...m_Disc%20Brake)

Shimano specs are inaccurate for hubs, so you should check spoke calculator websites, like feespoke
https://kstoerz.com/freespoke/hubs?MfgId=4&OLN=130.0

I chose the rs400 for my current wheels but the NDS spokes are only 44% tension of the drive side spokes according to the calculator set to 5800 which was the closest in dimension. My tension meter says 50 to 60kgf on left and 120 to 140kgf on right.

If freespoke is correct, the r7000 would have been 46%. The 10 speed hubs are somewhere between 51-53%, which is what I got when I built my old wheels.

After building my current wheels and checking again after 200km, the wheel went out of true by around 1mm, but I don't know if that's from normal settling or if the low NDS tension is the culprit. I didn't recheck the wheel again after that so I don't know if there has been any change since then. But I wanted the option to switch to 11 speed in the future and also the supposedly more polished cups and cones.

tomtomtom123

Also, if you look at the old specs table:
https://productinfo.shimano.com/down...CIFICATION.pdf

It says the M510 hub has a dish of 7.6mm on 135mm dropout. So if you were to use a thinner spacer on the NDS to achieve 130mm, you're essentially adding 2.5mm to the dish.

So 7.6 + 2.5 = 10.1mm. The shimano specs is not accurate so you would want to measure your own hub. With this offset, entering estimated dimensions into freespoke gives 43% NDS tension.

freespoke shows dimensions for the M530, which has the same dish to the M510 on the Shimano archive, except a narrower flange to flange distance.
https://productinfo.shimano.com/down...CIFICATION.pdf

However, freespoke gives an 8.3mm dish on the M530. So there is a possibility that if the M510 is really 8.3mm, then 8.3+2.5 = 10.8mm. You'll have really low 40% NDS tension.
https://kstoerz.com/freespoke/hubfil...ort=mfod&DT=19

So if you want a 130mm hub, you might as well buy the cheap $16 RS300 for 10 speed and get a 51-53% NDS tension. Or RS400 $23 or R7000/5800 $40 for 11 speed with 44-46% tension.

Wilfred Laurier

An Ultegra or 105 road hub would have stronger bearing surfaces and better seals than a (also excellent) Deore hub.

countalmaviva 

tomtomtom, thank you for the detailed observations and for recommending FreeSpoke. I hadn't used that particular spoke calculator before, and it's helpful to get me wrapping my brain around this. Regarding "dish," I'll admit I was scratching my head, but I just obtained a copy of Jobst Brandt's book and scanned it. I found this on page 62 of the 3rd edition:

I understood "dish" to refer to the shape of a rear wheel because of its asymmetry, but you're using it in a more specific sense, which I think is the same as the "mid-flange offset" number in FreeSpoke, right? It's essentially the lateral measurement corresponding to the amount of asymmetry in a rear wheel. So, all other things being equal, dish or mid-flange offset determines the NDS and DS tension differential and therefore has a large effect on the strength of the wheel. Yes?

Going by that reasoning, it would seem that, since a 7s freehub body is 4mm shorter than 8,9,10s, it would could also result in lower dish, depending on the spacing of the NDS flange. Can you let me know if I'm understanding this stuff correctly? Ultimately, I want to get my bike on the road, but I definitely dig learning this level of detail.

Bill Kapaun

2*offset is the difference between the 2 CTF flange dimensions.
An 8mm offset would mean there is 16mm difference between them.

tomtomtom123

The tension difference between the left and right spokes is determined by the offset (dish) but also any difference in the flange diameters. Because ultimately it's the angle of the spokes. So sometimes you see hubs that have larger diameter of the right flange to try to increased its angle.
44% tension on the left side compared to 100% on the right side, means that if you had 120kgf on the right, then the left is 53kgf when the rim is centered. Falling below 50kgf is bad. But spoke tension is not uniform. That's why I get 50-60kgf left and 120-140kgf on right. Most manufacturers tell you not to go over 120 or 130kgf, but then some of my left spokes would drop below 50kgf.

That's why 50% is much better, but most 11 speed hubs are 44%. You enter the dimensions in the spoke calculator to get the percentage. Number of spokes and crosses affects the percentage to because it changes the relative angle of the spokes.