Maguras on a 4000...rear swingarm question

[DugB]

Hello all,

So I guess I was bored a few days ago...I splurged on a set of Magura HS33 rim brakes for my K2 4000. They're all installed and I'm somewhat amazed at the braking power. One question, though...when I pull the lever for the rear brakes I can actually see the carbon rear swingarom flex out a little near the brake bosses. Granted, the force I applied on the lever is well beyond what would be needed to stop the bike (but still way less than I could have applied). The flex isn't extreme by any means...maybe 1mm on each side. I checked our V brake-equipped 856's and it's similar...just wanted to make sure a little flex isn't bad for the carbon fiber.

The Magura install was pretty straightforward...but the really simple instructions oversimplified some steps I'd consider a little more involved than represented. It too me about an hour to install them...but the end result is super smooth lever travel and firm braking. The units come with longer than needed main lines, though it's very easy to shorten them. Not mentioned in any product details page I found is the fact that the set (which I ordered from Cambria Bike) also includes 2 Problem Solvers hydraulic line clips and 2 "olives" (needed for shortening the hoses).

Just a word to the wise if you're thinking about taking the plunge...right now Cambria has the set on a "Price Smash"...which means they'll beat a competitor's proce. Chain Reaction Cycles in the UK has the set for GBP 99, which equates to USD 174. So if you have the will power to contact Camabria first before splurging at 2am when customer service folks aren't available ;-) you might save some cash on a great system. I'll post pics if people are interested.

- Doug :-)

[Old Proflexer]

did you install a brake booster?  they virtually eliminate any flex at the boss area.

several mfgs sell them - this one is from the cambria site for maggies - I have a set when I'm running my 33's

[rapiddescent]

OP beat me to it, I would strongly recommend a brake booster.  I used to have Magura Racelines on a Proflex 856 and a proflex 97 beast 'back in the day' both with brake boosters.  Excellent, although the clay soil where I lived at the time (nr london, uk) wore the rims out very fast.

callum

[DugB]

OP beat me to it, I would strongly recommend a brake booster.  I used to have Magura Racelines on a Proflex 856 and a proflex 97 beast 'back in the day' both with brake boosters.  Excellent, although the clay soil where I lived at the time (nr london, uk) wore the rims out very fast.

callum

Hello all,

Yes, I'm using both Magura brake boosters per wheel. The Magura kit includes a lower brace, as well as the top brace pictures below. The way you're supposed to set these up the top brace merely fits overt he Alen head bolt on one side, so you can QR the whole unit to remove the wheel. On the back I opted for fimness over convenience and put the bolt's washer over top of the brace hole, not under, on both sides. That helped, so I'm no longer worried. Just eager to ride now...I was racked up all weekend with the flu or a nasty cold.

Thanks!
- doug

[whisperdancer]

You can also use these original Magura brake boosters in carbon fiber: