Wednesday, July 27, 2005

We Put the Hell in Helicomatic

I got Henry a bike from The Spoken Wheel in Iowa Falls last April, a circa-1984 Trek 620 touring bike (you can read the sales brochure here). It's generally very nice and I'm hoping that the long wheelbase, lovely double-butted and lugged Reynolds 531 touring frame will prove as comfortable and satisfying to Henry as my Atlantis is to me. However, the bike comes with a Maillard Helicomatic rear hub which has the reputation of being troublesome. It's living up to its reputation.

Henry rode up to the Library yesterday. When it came time to ride home, the freewheel on the Helicomatic, an early form of cassette hub, stopped working. Or maybe it worked too well; it freewheeled in both directions! Kind of the opposite of a fixie! Poor Henry couldn't apply any power and, as I had ridden to work on my bike and Karla was off at a music seminar, he had to walk the bike home, coasting down any hills or slopes. He'd get on to ride and it would catch for a half-turn, then disengage and he would spin the crank and the freewheel would just go around. He found this annoying.

I think this may have happened a couple of times on the way to Baker Park earlier in the month, he'd complain about his gearing acting funny then of course it wouldn't happen again while I watched. What he had then described as the pedals skipping I had assumed was the rear derailleur shifting so I tightened the tension on the bar-end shifter, thinking maybe it was too loose and allowing the spring tension on the derailleur to move and shift down a cog. I think my interpretation of his complaint was incorrect and the tension on that shifter hadn't felt particularly loose.

I got home and hung the bike up in the garage from the ceiling ropes I use for working on bikes, and of course, under no load, the hub/cluster worked perfectly. We took it down and Henry rode it around the driveway and there it goes, the cogs spinning uselessly around when he pedalled, not engaging or applying any power, then catching for a second, then spinning uselessly again.

He's getting a wheel upgrade in August as it is, all-new 700Cs on an eight-speed Shimano Deore LX cassette hub, left over from my Marin's orignal back wheel and its corroded nipples, all I need is for this to work for about three weeks. I looked at the Helicomatic but it needs a special tool to disassemble. How much effort do I want to put into this wheel when even Francophile Sheldon Brown doesn't like them? But wait! I have that Schwinn World Sport in the 68cm size I bought for $125 last month and it has 27" wheels, like this Trek. I pulled the back wheel off the Schwinn and slapped it on the Trek and it worked perfectly! It even has a six-speed freewheel.

The tube valve stem on this wheel was at a severe angle so I thought I'd move the tube around and straighten it out. The last thing Henry needs to endure is a stupid flat on the way home, he'll think this bike is cursed. I got the tire off the rim and saw that the tube around the stem was layered in like a set of intestines around the valve. It was too big. Sheesh. We rode over to The Bicycle Chain to get a new tube of the correct size, a $4 item that cost me about $95 when I also bought a book and a new Bell Metro helmet for Henry, then came back, installed the tube, inflated the tire and reinstalled the wheel. A couple of minor adjustments to the derailleur stops and he was all set. That ought to hold him until mid-August.

Meanwhile, I have a Helicomatic wheel sitting around. The guy over at The Bicycle Chain said he had a tool to get it apart, maybe I'll go over and pop the cluster off just to see what this thing looks like inside.

3 comments:

sui generis said...

Let me know if you solve that problem! I'm experiencing a similar issue with my "new" '66 British 3-speed, and I'm stumped.

Anonymous said...

I actually fixed that problem with that Helicomatic hub just by putting alot of pentrating oil inside the freewheel assembly. I think there was to much dirt inside so the clutch wouldn't engage. It seems to have fixed it for now :)

indiaxman1 said...

Have an 80's Peugeot...helio still works well...smoked some vintage bikes on long hill...flat flies on all grades