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scozim · Last edited by scozim on Mon Jul 20, 2009 6:55 pm; edited 1 time in total

So, do spokes get brittle with age?

I'm having a great ride with intervals today (ok, maybe that's overstating a little bit because of the intervals) and in the middle of them I broke another spoke. Same wheel as before (5 weeks ago), same side - non-drive side. I shifted from the 42-17 to the 52-17 stood up and on the initial pedal stroke heard the pop. The wheel is an original Mavic Module E on the 84 Sprint. I'm not sure how old the spokes are - but wouldn't be surprised if they are original.

I'm also wondering if it's a torque issue combined with weaker/lighter gauge spokes. Last time, I shifted into the 52-17 a little too quick and the chain spun and then suddenly caught the freewheel and the force appears to be what popped the spoke. Today it was the quick acceleration. When I bought the bike last September it had a broken rear spoke (also non-drive side) - so that makes three replaced in a year.

I'm seriously contemplating having them all replaced and hopefully avoid the problem again, especially since I use the bike for time trials.

Wisey

Yep, old spokes can do that. Just re-build the wheel while your rim is still in good condition. Use good spokes. DT are my favourites.

verktyg

Scot,

Many years ago I was slightly involved (as a short term student grunt worker) on a research project to find out why metal gets harder when it bends and eventually becomes brittle and breaks.

With older spokes it could also be a matter of metal fatigue. Mavic Module E rims date from the mid to late 1970s. That's over 30 years old and if the spokes are original then they could be worn out from repeated stress.

Also, are the spokes stainless steel, zinc plated steel or chrome plated? Most stainless spokes have the advantage of higher elongation percentage than plated spokes, that is stainless will stretch a little more before breaking.

I'd recommend having the wheel respoked by a competent wheel builder or you could do it yourself, 1 spoke at at time. Start off by loosening all of the spokes. I prefer 4 cross for 36 hole rims but that's fallen out of favor.

Use stainless spokes. DT has a good reputation but there are some other decent brands. You can probably use 14-15 gage butted spokes.

Here's a link to an online book on wheel building that you can download for $12.50 USD (£9).

http://www.wheelpro.co.uk/wheelbuilding/book.php

Good luck,

Chas.

scozim

Thanks guys. I just dropped off the bike at the shop and they'll rebuild the wheel tomorrow with 14/15 gauge spokes. The originals do not appear to be stainless and are thinner than the few that were replaced in the last year.

The bike shop owner was telling me the Maillard hub that I have creates a lot of extra stress on the spoke and the Module E's flex more. In my ears I was hearing, blah, blah, blah because I know he was trying to sell me a new wheelset. However, that's not in the budget right now so I'm sticking with the Module E's. Besides I have some Mavic GL 330 tubular wheels with Campy Record hubs waiting in the wings to go on this bike.

Wisey

Yeah, bike shops don't like building wheels any more. After you factor in the labour costs, there is not much mark up (profit). Whereas, a factory built set of wheels will bring in a 40 or 50% mark up. And on top of that, the number of competent builders is dwindling....... oh well, the world changes.

scozim

The nice thing is I don't want to change from the freewheel set up or original wheels - trying to keep the bike somewhat period specific - so even if he had sold me new wheels he still would have had to build them up. Very Happy

The shop owner is a really nice guy and tolerates my vintage bike interests by letting me rummage through his boxes of parts once in awhile. I do give him some regular business, even if it's smaller items, because I like going through the boxes.

verktyg

To change the subject a liitle (metal strength issues).... used to hear a lot of talk from the competitve set about frames getting "soft".

With the exception of a poorly built frame about to fail because of badly mitered tubes where only the lugs are holding the frame together, the notion of a steel tubing frame getting soft falls into the catagory of urban myth or old spouse tales.

If anything most metals as they flex become harder and thus stronger until the point of embrittlement which relsults in cracking and eventual failure.
I've seen bikes made of plain carbon steel tubing that were "soft" to begin with. That is the forks and stays were easy to bend making the frame easy to align (the first time). After several bending actions to correct the alignment, the tubes definately became stiffer.

I've worked on bikes with carbon steel forks and stays that were ridden for a long time by strong riders and they were much stiffer than similar model new frames.

Alloy steel tubes like Chrome Moly, 4130, Columbus, Super Vitus, Reynolds 531 and especially Reynolds 753 are very difficult to bend to align a frame or forks. They have much more "spring back".

If anything, the riders have gotten stronger over the course of several years riding the same bike.

Chas.

Gtane

Scott,

Super advice here. Factory wheels are the thing but non standard spokes can be very tricky to obtain nowadays. For the classics over the cobbles, the Pros still prefer handbuilt wheels. Check that you can get spares before you buy factory wheels, and even buy spares when you buy, if you buy.

Wisey's right, DT are superb and I would go further. Try building your own with DT, or similar. From my experience, it's really worth taking the time to build your own wheels to your own spec. Just get a good quality jig. I've built many - never a broken spoke, always have spares and you can always rebuild. No cost other than spokes, your time and patience. I'm speaking from my own personal non professional experience.

Lots of good advice on this site - http://www.wheelpro.co.uk/ (no connection other than I've found it to be a very useful resource). Years ago when I began building for myself, way before the internet, there was precious little available other than the odd basic guide or another wheel to use as a template.

Tim

sandranian · Site Admin

Ugh. Wheel building and truing is the only thing I will not do!

Wisey

verktyg

And just like The Little Red Hen, the pleasure of growing the wheat, making the flour and baking the bread and...

Nay, Nay said the little red hen! Confused

Chas is hitten' the plunk again.

I have a little arthritis in my thumbs so I had the last 3-4 sets of wheels built for me by a local wheel builder. He did a better job than I ever would have/could have. They're dead true within about .2mm.

With the current economy I guess that I'll just have to take some aspirin and get down to work.