A look Back At The Maillard Helicomatic Hub



Looking back at the Maillard, Helico Matic hub it was/is a design that has it all...well as far as engineering goes. Let's just say the engineer was far ahead of the quality.

 

I first came across the Maillard, Helico Matic in the mid 80's when the store I worked at sold Trek bicycles spec'd with these hubs. Most people at that time used thread-on freewheels. Another option was the cassette, but these were the days of 6 speed clusters and Campagnolo, Super Records hubs ruled the road way. The Shimano cassette mechanism was a minority, but would soon grow in popularity as more and more cogs were added to the clusters over time.

 

The problem with the thread on freewheel was once the freewheels started going to 7 and beyond this lead to bent axles because of the demand put on them from having to become longer and longer. As you can see below the axle has to extend past the freewheel threads by a little over 30mm.

Below is a Helicomatic hub, and as you can see only has 8mm of axle extending out, making this axle a lot harder to bend. The cassette design would also have the same amount exposed.

One great thing about the design is the ease of removal. All you need is that thin spline wrench that can fit in your wallet, (pictured on the right). The freewheel requires a special tool,( in the case for a Regina America spline tool (They were made by Phil Wood)), and a wrench or vice to turn it. The cassette design uses the same tools as the freewheel only you need an additional chain whip (Not Pictured).



As you can see it's a 6 speed, and a rock solid design. To bad not rock solid parts.

To remove the freewheel as you need is a thin little spline wrench.
Once you get the ring off, just pull...


....Voilà!  Its off!




And one thing you still can't do today. Remove a freewheel without removing the quick release.


It's even called a "Helico Matic".

Avid, Juicy 7: caliper; piston and seal replacment.

I'm having to replace the seals and pistons in an old set of Avid, Juicy Seven calipers. I've had the opportunity to use a lot of different hydraulic brakes over the years and I really like the modulation and actuation of these brakes.

The slotted mounting holes and concave and convex washers allow for flawless setup...assuming the pistons are actuating, which the performance in these calipers has eroded over the last 8 years (heat, cold, dirt, and road salt), which leads us to today.

 

The first thing you need is an Avid rebuild kit for your calipers (contents pictured in orange square). Not only does it supply you with the pistons, piston seal, and o-ring seals, but also the 4 bolts, bleed port screw (torx 10), and clips.
When you rebuild the caliper it's not a bad idea to flush out the old fluid. I got Avid, dot 5.1 brake fluid. Any 5.1 or 4.0 will work. The higher the number, the higher the boiling point. It's hard to find 5.1, or at least around where I live. Most automotive places carry dot 4.0 and since I don't ride down mountains 4.0 would be fine if I was in a pinch.

Most automobiles take dot 3.0, so it is the most widely available, but it is not recommended. Also you might find dot 5.0 and that is silicone based and not recommended. Also some systems take mineral oil like Shimano Deore XT. Don't use that either if you system calls for dot fluid.

I also got new Kool Stop brake pads. There is usually a choice between Organic and Sintered. Organic is softer, so it bites better, but it wears faster. Sintered brake pads are harder, bit less than organics, but wear longer. It's a personal choice.

Also pictured above are the syringes for the bleed kit. Avid Juicy Sevens suggest bleeding the system with 2 syringes.

Here they are taken apart. Looks they might need a little clean up. Now all I have to do is get the pistons out. Let me make this clear. You just don't pull these out. Before you get to this step, you should pump on the brakes while it's all still together to get the pistons as far out of their bores as possible. I got a good start on one side, but one piston was stuck in it's bore.

The trick now is to use compressed air to pop the pistons out of their bores. Here I rigged a shock pump with a Rock Shox air valve adapter that fits prefect. This might take as much as 250psi. so have your hands and everything clear for them to POP! out.

Ahhhh everything cleaned and replaced. Don't forget to lubricate the seals and pistons with some of that dot fluid for easy action.

Reassembled and in it's place. Now to fill and bleed the brakes. Rather than recreate the wheel Park Tool has a wonderful How-To.
http://www.parktool.com/blog/repair-help/avid-reg-juicy-caliper-brake-bleed-service