Re: [CR]rebuilding classic MA-40 wheel


Example: Bike Shops:R.E.W. Reynolds

Date: Wed, 12 Dec 2001 21:18:30 -0800
From: Bill Bryant <Bill_Bryant@prodigy.net>
To: garth libre <rabbitman@mindspring.com>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR]rebuilding classic MA-40 wheel
References: <001801c18387$2e4b6080$0ba056d1@Marta>


Hi Garth-- Judging by your note, I think you still need to work on your spoke gauge info. I suspect you mean 15 gauge, not 12. You were correct in your original assumption--the higher the number, the more slender the wire is. For instance, a 15 gauge spoke is lighter than a 14, a 14 is lighter than a 13, etc. Maybe there is indeed some translation problem between English and Spanish as you mention--a 14-12-14 spoke would be fatter in the middle than at the ends.

I don't think you could run a massive 12-gauge spoke in your hubs unless you had drilled the spoke holes over-size. Probably you are on 15 gauge spokes. If they are a snug fit in the hole and don't rattle around during the building process, they should hold up better than what you are reporting here. However, nearly all hubs in use are drilled for 14g (or 2mm) spokes and I suspect your 15 gauge (or 1.8mm) spokes are too loose and unsupported at the elbow, thus all the breakage. Very predictable stuff. Let you mechanic lace up some 14-15-14 spokes cross 3. That should work fine unless the spoke holes are ~really~ big. If so, then try some 13 gauge (2.3mm) spokes. They would be a rather tight fit in a normally drilled hub from Japan, but probably could be squeezed in okay. In any case, translations from your mechanic aside, riding 15 gauge spokes on the rear wheel is indeed for "weight weenies"; you'll find the 14g items more reliable.

One caveat: older high quality European hubs, particularly Campagnolo, say pre-1975-76 or so, were often drilled for 15g spokes. The French Robergel "Trois Etoiles" stainless spokes were frequently imported into this country during the 1960s and '70s. That was the norm to use with 5-speed, 120mm rear axle spacing, so too tieing and soldering to increase wheel strength since the rims were generally a little softer than we're accustomed to nowadays. But with the wide-spread adoption of 126mm 6-speed spacing and the need for more "dish" and spoke tension on the gear side of the wheel, most good wheel-builders switched over to 14g and the hub spoke holes soon reflected that. I don't recall exactly when Campy started doing this at the factory, but it was around 1975-76 or so, if memory serves. I think 1976 was about the year I got my hands on my first DT spokes and never looked back. The poor Robergels, quite a good product otherwise, were just too light to offer the same guarantee for reliability to customers. At any rate, if you run across some older NOS Campy 5-speed hubs they may well have smaller spoke holes. Depending on the restoration project, that might be a consideration for some folks.

And at the risk of incurring the wrath of CR members, countless Robergels went to the scrap yard for a few pennies in the mid-1980s. By that time we couldn't give them away as DT ruled the roost, and rightly so. At Cupertino Bike Shop, an importer of many French and Italian components, we had about three dozen ~crates~ of unsold Robergels, which just collected dust and took up much-needed storage space. Finally, one day we reluctantly decided to pull the plug and toss them. As spoke holes had grown larger, we couldn't use them in good conscience and offer a guaranteed wheel. Each wooden crate weighed about 75-80 lbs, so it was some job! (We did save some for rebuilds of older hubs.) Now, all these years later, seeing all the intense interest in older bikes, it sure would be great to get them back for period correct restorations. Sigh...

Good luck with your wheel rebuild, Bill Bryant Santa Cruz, California

garth libre wrote:
> I keep on breaking spokes on the drive side and the non drive side of my training clinchers. The rims are MA-40 Mavics and the hub is Suntour Superbe Pro. It is 36 spoke, cross 3 and 12 gauge spokes. The spokes snap at the hub bend during a heavy sprint. The wrench here, says that for a strongish (glowing me) rider of around 160 lbs, the rear wheel requires better than 12 gauge, no matter how smooth the roads are. He wants to rebuild using double butted 14-12-14 gauge also cross 3. He also says that straight 12 gauge is for weight weenies, not the real world. I am ashamed to say that I thought all along that the higher number is the lighter wire (not the other way around). This wrench is Spanish only speaking, and my Spanish is only fair. Is his advise on the money? Garth Libre Surfside Fl