I'm brand new to MTB riding and maintenance, but I have over a decade of experience building and maintaining BMX bikes. So the main parts I am unfamiliar with working on are derailleurs, shocks, and hydraulic/disc brakes.
After a lot of research, I bought myself a 2012 Cannondale Trail SL3. I'm pretty happy with it overall but I don't really know much at this point. It has Shimano BR-M446 hydraulic disc brakes. After a couple riding sessions I noticed some rubbing between the front rotor and the brake pad, but this was very easily remedied by loosening the bolts that attach the caliper to the fork and slightly re-positioning it to center the rotor better. Easy peasy, no problem since, even after removing/replacing the front wheel multiple times, the rotor stays centered. Any more complicated adjustments to the hydraulic system are beyond my current skillset.
We just bought my wife the women's version of the same bike. I assumed it would be identical other than the different frame geo, but it appears some components are different too... most notably the brakes. They are also hydraulic disc, but they are Cannondale Helix 6. Immediately after getting her bike home from the store and out of the car, and re-installing the front wheel, the front rotor was rubbing BAD. So I made sure that the axle was evenly seated against the fork before locking the QR lever... still some rubbing. So I adjusted her caliper the same way I did mine, and was able to get the rubbing to go away. Small problem... the rubbing returned 5 minutes later. After tons of tests, the best I can conclude is that (a) her pistons do not consistently return to the same center after every brake application and (b) the gap between her pads is a bit less than on mine, which exacerbates problem a (a similar problem exists on her back brakes, but less bad). I've tried compressing the pistons all the way to get it to reset and center... but it still ends up leaving a relatively small gap for the rotor, which no matter how many times I get it perfectly centered, will somehow be uncentered again in the near future. So I did some research on her brake model and found some unfavorable reviews stating a few different bad things, most notably that there are no known replacement pads for this model, that you have to buy "Hayes Sole" pads and file them down to fit in the receptacle here... which sounds lame. There are a few other negative things about these brakes, in summary of all the points:
1) Pistons can not seem to maintain center between braking applications
2) Apparently no replacement pads exist
3) Brake system uses DOT4 which I understand is much less desirable than the mineral oil used by the Shimano's on my men's model
4) I have already noticed LEAKING brake fluid (just a few drops) from a small hole on the top surface of each of her brake levers, front and back. This seems like a pretty bad thing, right? Admittedly I have turned her bike upside down to work on it, but only briefly and I have never squeezed the lever while upside down, which I understand is the important part. I have done the same thing with mine, with the Shimanos, turned it upside down many times and even squeezed the lever a couple times before I knew that was bad, and those brakes still work perfectly, maintain center, and have not leaked a drop of their fluid.
So either I'm missing something obvious in my inexperience with hydraulics, or her brakes just suck. We're contemplating returning her bike for the men's model, which I guess is technically unisex anyway so should work fine, right? The only concern is she's on a Women's medium frame which there is really no equivalent to... the Men's medium is about 0.5" larger on most of the frame geo dims, but I don't know if that 0.5" will be significant to her... although the geo of this current women's frame was kind of right at the upper limit of what I wanted her on in terms of size.
It seems kind of silly to return a whole bike because of a brake set, but then again at a $900 price point I think this brake set probably accounts for more than 10% of that price. From BMX I'm used to building bikes from parts... but I didn't know enough about parts at this point to do the same thing here... buying a complete bike is frustrating.
Any advice would be appreciated. Thanks!
Results 1 to 7 of 7