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Letter of the Month
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Dear MBT:
I’m currently running Shimano xt br-m775 hydraulic disc brakes on my bike. The brakes are literally two weeks old yet emit a loud squealing noise, which actually vibrates at the saddle whenever I pull the brake levers. There’s no leak at the calipers and the disc and pads all appear aligned. The spaces between the pads and rotor are also equal on both sides. What can I do to stop the loud squealing at the rear calipers?
Gilbert Calderon
Gilbert:
We are assuming that you properly burned your brake pads in during your initial ride? With new brakes some degree of squeal (especially during break-in) is normal albeit annoying. Sometimes the culprit is simply a slight glazing of the pad material. Here's what we propose, head over to an automotive parts store (Autozone, Car Quest, Advanced Auto Parts, Napa, Pep Boys, etc.) and pick up a spray bottle of brake squeal silencer (for automotive disc brakes).
Apply a few light bursts of the cleaner both on the rotor and into the pads. You'll notice that the cleaner comes out in powerful blasts so use it with caution. However, it also evaporates nearly instantly and leaves no greasy residue. Once you've blasted out your pads and thoroughly cleaned the disc, treat the brakes like new and perform the burn-in procedure again.
Now let’s get into the science behind the cure. Brake squeal is actually caused by rapid vibration of the pads themselves (the same principle that makes the top of a shot glass hum when you rub a wet finger around the rim). Spraying brake anti-squeal material (often sold as brake cleaner in the automotive stores) creates a layer of vibration absorbing lubricant between the pad and the disc hence the squealing usually stops instantly.
However, if this does not alleviate the annoying squeal when you grab a handful of stoppers, the next area to address is the very source of the noise: the contact between the rotor and the pad. There are complex interactions taking place between materials the moment your pads make contact with the rotating disc. This is why sometimes the only sure-fire way to end strange sounds is to replace the pads with a different set. Before taking those measures however, there is a very simple way to alter the properties of the pad material and rotor surface on your brakes and that is to use them hard. Find a steep hill, pop your bike into the big ring and get up to as high a speed as you can handle then jam on the brakes hard until you come to a stop. Push the bike back up the hill (which will allow the brakes adequate time to cool down). Repeat this process five to seven times in succession and you should have re-bedded the brake compound, which almost always cancels out even the most stubborn of squeaks and squeals.
For your question, we’ll be awarding you $20 good toward Evomo’s online store.
For making us think, we’re going to send you a $20 gift certificate to spend at Evomo. Go get yourself a kick ass shirt, and send us a snapshot of you rocking it out: www.evomo.com/
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Dear MBT:
I was digging up research on the Foes FXR 2:1 as a potential purchase for my next “all in one” bike. The problem is that I like everything about the design except I’m not completely sold on the 2:1 thing. Am I worrying needlessly? Is my paranoia keeping me from owning a great bike?
Andrew Beckwith
Andrew,
At the risk of pointing out the obvious, perhaps you could save yourself a lot of stress by considering a model in which you aren’t skeptical of its primary design feature. In other words, it is the low leverage shock design that makes the Foes FXR special, if that’s the technology you are fearful of, you are kind of missing the point of the bike’s appeal. That said, we recently spent a little frigid time in the saddle of the FXR and came away with mixed results. The chassis is quite nimble (especially for a 6.5 inch travel bike) but the 69-degree head angle made the steering a bit vague and sluggish in the really technical stuff. The fork, in this case a Fox 36 Float, was very impressive in this application. The Curnutt air shock (XTD) was fair, but did wallow under hard acceleration and standing efforts. The bottom line is that the FXR 2:1 is a solid ride for a majority of riders out there but your doubts of the very principle on which the bike is founded force us to recommend demo’ing one before laying out the cash.
Dear MBT:
I noticed from your bike tests that you often run platform pedals even on XC models. Why no love for the clipless?
Craig Keyes
Craig,
Excellent observation, but unfortunately the pedals you see in our bike tests have less to do with our preference for platforms and more to do with the logistics of setting up a test. Since it isn’t uncommon for three or four riders to spend a day swapping a bike around miles from civilization, the idea of lugging around half a dozen different pedals suddenly becomes less appealing. Especially considering that different shoes work with various pedals exclusively. Since any pedal (clipless in particular) is a personal choice, our testers are encouraged to carry along their own personal favorites if they feel that riding without them will affect their opinion of the bike in question. However, most often the bikes wind up getting photographed with the simplest most universal configuration; in this case a platform that anyone can step on and hammer regardless of the shoes they have on.
Dear MBT:
I know you guys must get a hundred “which bike should I buy?” questions every month so I won’t add to the problem. However, I’ve been giving a lot of thought to upgrading to the Ibis Mojo SL (from an Ellsworth Truth). I ride just about everything and wonder if I’m just bored and looking for a new toy with which to plop down that Economic Stimulus tax rebate. I figure this would be a good way to inject a little money back into the failing American economy.
Mike Strigler
Mike,
Well, questions like yours are always difficult if for nothing else, because they are very personal decisions that nobody else in the world is qualified to make on your behalf. That said we hold the Mojo SL in very high regard and quite frankly, would love to get a hold of one for testing purposes ourselves. If you feel there is a lot of life left in your Truth and that it handles the type of riding you enjoy, why send a loyal friend packing? Buying a new bike is the right idea for a whole plethora of reasons but typically boredom isn’t one of them. If it were our money (and just to be clear, our tax rebate checks were spent long before they were even issued) we would probably hold onto the Truth and purchase a Mojo frame with our tax return. This way we would still be out romping as usual, while slowly enjoying the carefully selected component build-up project of a great second bike.
Dear MBT:
I have searched high and low for a test of the Sette 7 frames that Price Point has up for sale. For some reason nobody and I mean nobody tests these bikes! Why is that? Do you think the Ace is a good deal?
Bill L Mosher
Bill,
For starters we must confess that while we queried Sette (www.setteusa.com) a while ago to request a frame to test, they never returned our call. As such we have very little (meaning no) saddle time logged on the Ace or any of their frames for that matter. Even still, their affordable prices do make the products quite appealing. At the time of this article’s writing, Price Point is advertising the Ace 4 inch travel frame (5.5 lbs) with a complete with Manitou SRL S-Type air shock for $499. Suffice to say, that’s quite a good deal. Since it doesn’t appear that we’ll be riding one first hand anytime soon, do check back with us if you decide to pull the trigger to share your thoughts on the bike. That goes for anyone out there with a Sette for that matter. We’ll publish the results in a future issue.
Earn Money by Making Us Work
Attention ASK MBT fans: You’ve always got questions and we like to think that we have the answers but now you could earn some swag just for putting our collective melons to the test. In each issue we will choose a winning question or comment to become Letter of the Month and send its author $20 toward the Evomo online store. What are you waiting for? Get hammering on those keyboards.
Got a question? Fire it away to us and we'll do the best we can to answer it. Send your inquiries to Ask Mountain Bike Tales.
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