by Jon “Sevo” Severson
My first snow race on a mountain bike would be around ’91 near LaCrosse, WI where each year this little time trial was set up. Back then braking at it’s best was a set of Grafton’s w/Scott-Mattheuser pads. Even then…..
One key innovation since then that really made it easy to create modern day fat bikes was the disc brake, hands down. Oh sure, the Pugs, until recently, had canti mounts. But you couldn’t run v-brakes which really left you with standard canti’s….or Magura’s rim brakes.
Which is why I thought there was really no one better than Jude Monica to look up to talk all things disc brakes on Fat Bikes. Magura has been a leader in hydraulic brakes for years…both their legendary rim crushers to the modern day disc, of which they are the first to offer an all carbon setup. And as I got talking to Jude, I was informed his experience with snow bikes goes back a hair further than the Modern day Pug….
Jude, so you were telling me you were working with Mike Curiak in the Pre-Modern day fat bike era…can you give me some background on what the problem was, the solution you created, and what Mike needed it all for:
Yes, Mike Curiak is a friend and I was fortunately “around the scene” early when he was helping pioneer the oddity of “extreme adventure racing,” namely The Iditasport Extreme Race in Alaska.
He was using a competitor’s brand of brakes but back then (as now) we all helped each other. It was super cool to closely inspect the bike creations he was working with that would endure such attempts at Mother Nature.
Obviously, the main problem in this scenario is extreme cold and the effect on metallurgy expansion/contraction and to the fluids.
Now, Does Magura still make the Canti style brakes and, if so, are they easy to purchase? There are a lot of old Pugsley’s out there with Canti mounts and the Large Marge does have a brake surface on it. You recommend them for this application?
Absolutely! Magura makes more “rim crushers” than any other model brake we manufacture and by a large margin. The rim brake scene in Europe is huge with all of their trekking a pannier bikes running around. http://www.maguradirect-shop.com/magura/brakes/rim-brakes.html
So, the development for these brakes have continued and they have actually become more refined, easier to set up and completely maintenance free, and let’s not forget the legendary rim crushing power! They would work perfectly for “Fat-Bike” applications without disc provisions.
Modern Day fat bikes are pretty much all discs these days. Many are using Mechanicals I think just because of cost. But for the record, can you give us an idea of operating rang temperature wise of Mineral Oil (like in Magura) and Dot 5? And where do you see a mechanical brake has an advantage over a hydraulic in the extreme cold (like 30 below, 40 below):
Well I am uncertain as to why someone would use a mechanical disc brake these days aside from possibly a cost advantage. When you consider simply adding the costs of mechanical calipers to existing mechanical brake levers/cables and housings, OK but aside from that, no reason.
There are several manufacturers with affordable hydro options competitive with the costs of mechanicals like our MT2 at $104.00 per axle retail including everything needed, built, bled, rotor and hardware.
Speaking of fluid, you think either Dot 5 or Mineral Oil has an advantage over the others….or past a certain temp are they all going to be sluggish?
Both fluid types have advantages but the performance differences may be surprising! Extreme temperatures negatively affect both fluids hot and cold. DOT is typically lighter in viscosity, which is better for flow in extreme cold but also is hydroscopic which absorbs moisture. This can occur more so in humid (snow) environments and quickly adversely affect the small flow advantage of the DOT fluid. Moisture in the system in this case equals freezing! Mineral fluid is not hydroscopic!
I have experience first hand and to my surprise there are some problems with mechanical disc brakes in extreme conditions like snow, mud and freezing rain that affected hydros much less.
First, the mechanics of the calipers cantilever arm, cable and housing become encrusted in muck (in this case, freezing muck) which prevents leverages and power to the brake. Also, more of an issue is the fact that the return springs/cable housing for the caliper itself become contaminated (and frozen) to the point that the brake doesn’t release and the pads drag and ,more importantly prematurely wear pad material away extremely fast!
Out of curiosity, do you see the colder climates with high humidity (Northern MN, Wisconsin, Upper Northwest, etc…) where humidity in the winter months is almost double what lower humidity places (Like Colorado, Utah, Wyoming) affecting hyrdaulics one way or another? Or one system (Dot 5 vs Mineral Oil) one way or another or not enough to even matter?
As in the previous answer, you can see where this is a problem and why. Yes humidity is horrible for DOT fluid! Mineral base fluid does not absorb moisture and has a function life of approximately 10 years!
Dot 3 boils around 330-400 degree F and Magura’s mineral base fluid boils at 300 degree F but never deteriorates in performance, ever!
Many use currently 6” rotors on Fat Bikes. Do you think there is situation in which someone should try an 8” rotor? Or maybe a smaller rotor? With some coming in at 30lbs up to 40+lbs loaded with gear…what should someone be asking themselves when it comes to such scenarios?
Today, braking systems have such good power and modulation that a 6-inch rotor should do the job. There are of course scenarios where a larger rotor would apply and a rule of thumb is a 15% increase in power with every step up in rotor size.
As you mentioned, heavy payloads and riders when combined with lengthy descents is the first clue. You are positioned in cold climates so this helps keep things cool enough, possibly Too Cool. If your brake system can’t build proper heat, then it can’t build proper friction and power! Heat is your friend, heat is also your enemy!
There seems to be some confusion when it comes to the Front brake spacing. It can be a bit head spinning. Can you help us understand this a bit? First off, just to clarify, about what year did everyone start making their calipers all the same…ie rear caliper is the same as the front vs the old standard of a special front caliper and a special rear:
From what I can determine and after speaking to Chad Eskins at DT/Swiss, there shouldn’t be an issue any longer for bolt spacing and calipers. First, all calipers are the same now since replacing IS or international standard mounting with Post Mount. All of the brake manufacturers have always made a PM caliper due to Manitou requirements but now un-officially, that has become the standard. With PM, there is only one caliper configuration and only the brackets to mount the caliper to the frame or fork are specific front or rear.
In the past, there was a specific International Standard caliper or “IS” that had axial mounting tabs, each front or rear distinctly different mounts and bolt spacing.
International Standard was established as THE standard in the year 2000 by a group of manufacturers, Magura included and for some reason the industry has moved away from it.
Next, Can you explain the “rear disc spacing vs front disc” spacing thing a bit. One camp (Surly, 9:Zero:7, Salsa) using a “rear disc” spaced front hub. The other camp (Jones, Paul’s Comp, and White Brothers) go for the “Front disc” spaced front hub. For the layman out there who just rides bikes and doesn’t know what size his handlebar clamp is or how much his valve caps weigh…what does all that jargon mean?
From the Surly web site – http://surlybikes.com/info_hole/spew/hub_fork_and_disc_brake_compatibility
Our stock Pugsley fork is spaced 135mm and is offset (one curvy leg). This fork requires the use of a rear hub and rear caliper adapter. Next, we offer a Pug fork in 100mm hub spacing which requires the use of a front caliper adapter and front hub. Easy enough. Not confused yet? One more. Our non-offset (no curvy leg) 135mm fork requires a hub designed with rear hub rotor-offset dimension and a front caliper adapter. Absorb that: the 135mm non-offset Pug fork needs a front caliper adapter but you need to use a rear hub.
And then add in the new Wide 135mm Jones-spec hubs from Paul and Phil Wood and the White Bros. Snowpack and you have a 4th variation. Aren’t fat-bikes fun!
So as stated above, The old IS days required specific calipers, these days only require specific adapter brackets as the PM caliper is exactly the same front or rear so as far any difference between the “old” 135 rear-hub-used-on-the-front spacing and the “new” 135mm wide standard like the Paul hubs will simply require a different bracket.
Last, appreciate you taking the time to chat with us here. Seems only fair to let you plug quick Magura. How many brake options do you have and what’s the low end going to run the consumer to throw on his bike and what does the high end of it all offer/cost?
I really appreciate the opportunity to interact with you guys at Fat-Bike.com, cool shit!
Magura was founded in 1893 and is credited with being the first official hydraulic bicycle brake manufacturer and that was the original HS (hydro-stop) rim brake in 1987, it is still alive and thriving.
Another first for the industry from Magura, we currently offer the first ever carbon fiber hydraulic disc brakes available to the bicycle industry. Complete carbon fiber master cylinders using a new manufacturing control technology called “Carbotecture” and “Carboflow” that offers controllable / repeatable processes (quality control) typically foreign with carbon fiber manufacturing.
The highest end brake of our line is the MT8 – $379.00 per axle for the most bling for the buck but also offer the $104.00 per axle most affordable glass fiber master cylindered MT2. Between those two, we offer the MT6 – $279 and the MT4 $179.
Jude Monica has over 13 years with Magura, which not only is one of the leaders in bicycle hyrdaulic brakes…but motorcycles too (BMW since 1926, KTM, Husqvarna, Triumph, Ducati and Victory). Before that he worked for a Porsche tuner to make an already uber fast car…faster.
Sevo has been around the bike industry since ’90. Working in shops in Winona, MN, Decorah, IA and LaCrosse, WI. After that helped build/sell/design/take out trash at the infamous LEW Composites. Founder of Front Range Cyclist based out of Colorado Springs, as well as Monstercrosser on FB, and founder of Colorado Fat Bike. He also drank his fair share of beer with Sven and Gomez!