Richbiker

I could use some advice from someone who's built up tandem wheels that stayed together.
I've built a lot of wheels over the past several years, but the ones that I've built for my own tandem (and for a friend's tandem) seem to have issues with frequent spoke breakages on the back wheel.

At first I chalked this up to using disc brakes and cheap spokes on my tandem. So I switched the spokes to DT Swiss Alpine, with much thicker elbows. Then I read on this forum, that those spokes like to break also because they are so stiff, they lack elasticity (I think that was a post by TandemGeek). My wheels are 700c, built up with 36 spokes using a 3 cross lace. I also had some of those Alpine spokes break too, without a lot of miles on them.

So I have some friends who I built up a tandem for. They are pretty short, so we had to go with a 26" wheel size, using Mavic Rims and Phil Wood tandem hubs. I also built those up using 36 spokes, but this time used DT Swiss Competition double butted spokes. They've been experiencing a lot of broken spokes on the back wheel also.

So I'm doing something wrong, but I don't know what. I don't use a tensionometer--I check the spokes by feel, and when the wheel rolls straight and true in the truing stand. That might be one issue. Seems like 36 should be enough for a 26" wheel.

Any advice would be appreciated, because it doesn't make sense to rebuild their back wheel until I know what I'm doing wrong.

Thanks,
Rich

Richbiker

I should add that the rear hub spacing on my bike is 135mm, but the rear spacing on my friends' 26" wheel is 145, so mine has a "dish" to it, whereas theirs does not.

TandemGeek

1. You need to build tandem wheels with higher spoke tension than you use on single bikes wheels. Of course, you'd need to really know what proper tension feels like for a given wheel build as you can go over-board and use too much spoke tension which can ruin a rim.
2. You must stress-relieve the spokes on a tandem wheel; this can't be over-emphasised. It's a key step in all wheel building, but tandem wheels will prove the point in short order.
3. Unless you have a good ear and know what the proper tension feels like based on cross-checking other tandem wheels build up using similar materials and specs, e.g., another 36h 700c wheel that has been built properly, a tensionometer is highly recommended given the aforementioned use of higher-than-average spoke tension for tandem wheels.
4. Despite Jobst's writings that suggest proper spoke tension will usually keep the nipples fixed in place, I use DT Spoke Freeze when I build wheels.

WheresWaldo

Let me add the in order to accomplish #3 above you really need some sort of tensionometer. You don't need to go out and spend $300 for the DT or FSA you can get by with the Park. It is far better than feel when you are trying to get tension from spoke to spoke as even as possible. Feel and sound is just too subjective. Also the biggest key is even tension, even more so that high tension. Now I am not saying high tension is not important but it must be high even tension. But if the tension is a little low your wheels will still hold up as long as the tension is even.

Make sure you follow TG's advise #2 completely.

I don't use Spoke Freeze, never have, and I've had no issues with spokes loosening, but I do use either spoke prep or an antiseize on the spoke threads, either will perform the same function, although not holding as strongly as Spoke Freeze and it will allow building with higher tensions without as much spoke windup.

jgg3

I second most of what TG says. When I read your story, it sounds like chronic low tension to me. Get a tensiometer if you are going to continue to build wheels.

I do not use spoke freeze and don't really believe it is necessary (I am old-school). It is important to lubricate the threads, so that torque is proportional to tension.

Tandem wheels aren't magically different, they are just normal wheels taking about twice the load of a single bike wheel, and thus problems appear sooner. You don't really need higher tension; you need proper tension, which is pretty damn high.

zzzwillzzz

+1
i learned to build wheels using linseed oil as a spoke prep, it workes a lubricant as you assemble the wheel then dries out act as a type of loctite to hold the nipples in place.

i have a number of prebuilt wheels (not for tandems) that many go out of true due to no type of spoke prep at the nipples and seem to unwind a little and throw the wheel out of true

Richbiker

Thanks everyone. In the initial post I mistaknely said I used Mavic rims; the rims are Sun CR18's.

-So yes, I'll get a Park spoke tension meter. Question: what tension do I need to get it to? Is there a site which lists proper tension for different wheel applications.

-In terms of lubricating spoke threads, is there anything you *wouldn't* use to do that? Does a little grease on each thread contribute to gradual loosening?

-I also did some research, and found that my choice of DT Swiss spokes may not have been the best. This guy who builds a lot of tandem wheels has written an article on his website explaining what DT Swiss changed about their spokes, and why he switched to Wheelsmith: https://www.peterwhitecycles.com/DTspokes.htm

WheresWaldo

The Park tool comes with a chart, which you can also download as a pdf from their site. It is based on spoke thickness, but to be safe you should question Sun about the maximum allowable spoke tension when building on their rims.

Simply don't use "nothing." nearly any kind of lube will work when building a wheel, some better than others. Some make it easier to rebuild or adjust many miles down the road. I now use anti-seize since I need it for other parts and it is cheap and available at every auto parts store.

Peter White has his own agenda, Most of the other notable wheelbuilders do not have an issue with DT spokes. I didn't reread Peter's article but I recall that it had something to do with the J-Bend being too large. If you are really concerned DT sells tiny brass head washers that you place on the spoke before lacing them into the hub. Since they are soft they will conform to the head/spoke hole interface and also fill in some of the gap between head and hole. There really was nothing wrong with the spokes you chose. They were Alpine III's weren't they 14G/15G/13G triple butted? DT Competitions are one of the stronger spokes available, built up to the correct tension they should last a lifetime.

As far as I know, Wheelsmith can't decide if they want to be in the retail spoke market since Hayes bought them. They are really trying to become an OEM supplier of spokes, as such availability has been spotty at best. This might be dated information and the situation for Wheelsmith might be differnet now.

TandemGeek

Information of interest can be found here: https://www.parktool.com/repair/readhowto.asp?id=128

And more info about the Park TM-1 as well as downloadble conversion tables can be found here: https://www.parktool.com/products/det...t=16&item=TM-1

TandemGeek

Alpine III's don't play well with Phil Wood hubs... which is what intuitively most of us used back in the day when building wheels that would be used for 10's of thousands of miles.

The Alpine III's seemed like they'd be the perfect spoke to match up with Phil Wood hubs; however, the combination of the spoke's J-bend girth, depth, and Phil Wood's very hard, punched spoke holes proved to be problematic for a lot of folks -- like myself -- who used them when the Apline III's first arrived on the scene.

Peter definitely marches to the beat of a different drummer; however, isn't completely enigmatic. I belive Peter's frustration with DT had more to do with being surprised by their unannounced design changes and other issues that resulted in difficult build-up and come-backs. Given that Peter's clients have always tended to be folks who look to buy wheels that will last tens of thousands of miles and decades, unknowns and changes aren't what you want in your supplier's products.

For folks who change wheels, bikes, etc... every few years or less and never put long-term demands on their equipment, long-term durability / fatigue resistance isn't really as big of a concern so some of the things that Peter (and, to a certain extent me) take into consideration when talking about wheels are of no real concern.

WheresWaldo

I did not know that Phil Wood punches the spoke holes in his hubs. Is that documented somewhere? Could it be that the process of punching the hole leaves burrs or a rough transition from one plane to another that essentially cuts through a spoke? I am curious about the spoke failures you have mentioned.

Personally other than very loaded wheels I would never see a need to use spokes with a 13G J Bend.

TandemGeek

FWIW: Phil Wood sold the business bearing his name to Peter Enright back in 1991... so "his hubs" are really Peter's hubs these days.

Anyway, I'd actually learned about the manufacturing processes through my early discussions with Brent C. back in '98; coining is the proper technical term... However, on a hunch, I checked and the Phil Wood website contains an outstanding Web page that describes all of their various products and manufacturing processes.

Tech Notes – Hub Manufacturing

Hub shells are blanked out on one of our CNC (Computer Numerical Control) lathes. To produce a hub shell, each is handled 9 separate times. 4 CNC and 5 manual machining operations are performed to produce a hub shell. Each step has its analytical and esthetic quality standards that must be maintained. The hub flanges are canted toward the rim by 5 to 7 degrees, depending on the hub. Spoke holes are placed perpendicular to the surface of the canted flange then coined. Coining compresses the material around the spoke hole; cold forging a cradle for the spoke head. After coining, hubs have a mild heat treatment to stress relieve the work hardening from the coining. The precision boring of the bearing pockets and any other internal machining is then completed. The signature Phil is then cold forged into the hub shell then the final hand polishing is performed.

As for my spoke breakage experience, I had occasion to rebuild our rear wheel in late '99 using the Alpine III's and after only about 1,500 miles of use we had three spokes fail within about a month. Having spoke breakage for no apparent reason with Phil Wood hubs was, at least to me, an unusual occurence. It was about this time that a few other folks as well as Peter White voiced similar concerns about the Alpine III"s being too much of a good thing... at least for something other than hubs with softer material around the spoke holes. Of course, back in the day those other hubs were problematic which is why a lot of us were using nothing but Phil Wood, as Chris King tandem hubs were still about impossible to get your hands on and Hope's Big-uns and BULBs were not a sure thing either. Up and until that point, and since then, I've had just about zero failures on the wheels I've built for our own tandems various other teams, excluding one very big team who were committed to sticking with their OEM Shimano 36F/40H rear wheelset... which I finally replaced with a 48h 5x wheelset.

WheresWaldo

Thanks for the summary, I would guess the coining was the real cuprit. Any cold working of spoke hole would essentially harden the material and, this is just a guess, not allow the spoke to seat properly. Or maybe its just like you said, too much of a good thing.

I am also thinking that it's been a long time since '99 and new alloys, better forgings, machining, CNC can lead to much stronger wheel components. It is amazing that what was once thought of as necessary 40H, 48H wheels today are considered overkill in light of tandem wheels with 16, 24 spokes or even non-metal spokes.

Although I know a bunch of stuff about components from the last twenty years, I was never interested in tandems and did not want to clutter my brain with knowledge I felt I would never use. So all this information concerning tandem use or tandem specific components never crossed my path or I purposely sidestepped it.

I am continually amazed by the wealth of knowledge that all the long time tandemers have here and are willing to share.

TandemGeek

Not much has changed since '99, with few exceptions, e.g., Topolino is new but paired spoke technology isn't. 40h and 48h wheels are only overkill for folks who don't want or need the more robust wheelsets.

Even at our modest team weight of 285 lbs, I can tell you without hesitation that the 16, 24, and non-metal spoked wheelsets do not come without their trade-offs when compared to conventional wheels. What make them "better" is lower expectations and/or a willingness to accept certain trade-offs for marginal reductions in weight, drag, service life, and value by average cyclists who have deep pockets.

Again, I refer readers to the wheel summary for our Calfee: https://www.thetandemlink.com/calfee_tandem_build.html

Of the five different sets of wheels we've used on this tandem since last January (noting only one of the Rolf wheelsets is shown), the "best" overall wheels were the 36h conventional White Ind / Velocity Fusion wheels in terms of overall performance and value @ ~$550.00: rock solid handling and if they had been built with the Daisy hub instead of the MI6 disc hub they would have been only 50 grams heavier than the $959 Rolfs. But, aren't the Rolf's "faster"? Yes, so long as you're tooling along at 30 mph in an aero tuck and even then it's just a tick faster; however, beyond that the majority of the performance is perhaps a placebo effect that comes from less wind noise and a more harsh / lively ride.

The second best overall are the 36h conventional White Ind / Velocity Deep-V. Also about $550.00 and 100 grams heavier than the Fusion wheelset, these wheels track and corner better than any of the others even with the low-flange MI5 front hub. The taller flange Daisy front hub would most likely have a positive impact on cornering, albeit with a minor weight penalty.

The Topolino wheels are truly amazing; nearly a full pound (25%) lighter than the White Ind / Deep-V wheelset and very stiff but very comfortable. However, that comes at a price... $1,350.00. Moreover, like all integrated wheelsets you become beholden to the manufacturer for future support since the wheels are a 'system' where only the bearings can be second-sourced and field repair is not possible. Definitely the hot ticket for comfort, bling, and lightweight without sacrificing too much in the way of handling. Don't get me wrong; I really like these wheels. However, I don't think I spent this much on any of my first three cars.

The superlow spoke count / paired spoke wheels are also quite interesting; light and aero (noting aero is relative to the entire tandem bike / team coefficient of drag) but also a bit pricey @ $959. Being integrated wheelsets you're also looking at big bucks for repairs (about $270.00 for a rim + spokes & rebuild) that must be performed by the manufacturer and a definite hit on handling... if that's your bag. If you don't dive into corners on your tandem with reckless abandon and, instead, tend to cruise along relatively straight roads no worries and, yes, they do 'feel' faster than other wheels in the same weight class or even the uberlight Topolinos.

Of course, most folks in the market for wheels like these have also moved over to carbon forks which, even in the case of the very stiff Wound-Up and Reynolds Ouzo Pro tandem forks, means that most teams have already sacrificed some handling for lighter weight vs. how a lightweight steel performance fork would 'feel'.

Again, it's all about making trade offs.... and always has been, subject to each team's needs and expectations. In fact, if you look in the archives at Hobbes you'll find a posting where I contrast the different impressions of two tandem teams that each fitted a set of Ksyrium wheels to their tandems back around 1999. The team on the West Coast in hill country near Sacramento found the wheels to be problematic and unnerving to ride in their demanding terrain whereas the folks on the East Coast in flat as can be low-lands indicated no issues with the same brand and model of wheels. Now, to be fair, we've had confidential sources tell us the very narrow spaced Ksyriums were replaced under warranty at least once, if not twice and without full disclosure regarding their use on a tandem. Similarly, we've seen other tandems running Spox wheels on a Cannondale RT3000, DuraAce paired spoke single bike wheels on a Burley, and a variety of other non-tandem-rated exotic single-bike racing or time trial wheels on other tandems over the years... In most cases, the owners were very happy with their wheels, even when it was clear from riding with them that some of those wheels didn't inspire confidence with their less than rock solid handling and tracking and noting that several had been replaced under warranty after fatigue issues appeared.

Back to our current tandem and its three current wheelsets, it will take us nearly 7 years to rack up 10k miles on each of those wheelsets... assuming they all get equal time. It's my belief that 10K is a good benchmark for establishing wheel reliability as 10K = one year of riding for the most elite and dedicated tandem teams, or two-years of riding for avid tandem riders, and about 3 years of saddle time for enthusiasts. Of course, therein lies a bit of a problem as most of these wheels have time constraints on their warranties. Fingers crossed, all of the little nits have been addressed and things will go well with these boutique wheelsets over the next decade.

jnbrown

I have a built a number of wheels for both my single and tandem bikes.
My tandem wheels are 36 hole 3x Hadley hubs, DT DB spokes and Velocity fusion rims.
They are trouble free and have never broken a spoke. It helps that the back wheel is 160mm and has zero dish. I probably could go as low as 28 on the front but I am overly conservative on tandem stuff. I go by feel on the tension. I think there is probably a pretty broad range of tension that would not create a problem. I do plan to buy a tensiometer in the near future though. Like others have said possible problems are under tension, lack of stress releiving, incompatible spokes / hubs. I had one wheel I built with shimano ultegra hubs 28H 2X and it broke spokes right off, I decided the problem had to do with the lacing pattern and the where the spoke crossover occurs releative to where the spoke necks down.