ChanceCoats123

Well, I am new to this biking forum, but I am not new to forums so I will try and cut to the point as to avoid upsetting anyone.

To start, I recently started riding my bike hard. Before it was simply a get around, but I have been jumping recently on the track we made in the woods by my house. So I have been getting pretty serious about my bike (in sig). I am basically leaning towards a hyraulic disc in the front, and staying with linear pulls in the rear as I use my front more. First, I have riden cable disc and HATED them with a passion. So if I do discs in the front they are going to be hydraulic. Secondly, I haven't decided to go 160mm or 203mm. Obviously 203 would offer better stopping power, but I am not doing down hill riding so I really don't think I need that much rotor. Thirdly, neither my fork (RST 281 R), nor my front hub are disc compatible. So I was wondering if anyone could give me a list of components I would need to get for just fronts? I know I will need a new hub, fork, rotor, caliper, bracket for mounting and a new lever, but I have no idea on anything else. Also, since my current lever and my gear shift are a single part, I would need a new gear shift as well.

Thanks in advance, Chance.

JonathanGennick 

I think you pretty much have the list of parts nailed.

There is a 185mm size brake that you can get, that's in between the two sizes you mention. I find that size a good compromise.

If you go higher than 160mm, do take care to verify that your fork is designed to withstand the larger-diameter rotor. Most forks that I've checked are good for at least 185mm. But not all forks are made to handle the 203mm rotors.

You might want a whole new wheel rather than just the hub. It might not be cost-effective to pay your bike shop to rebuild your existing wheel around a new hub. Then there's the problem of probably having to buy new spokes. Were it me, I'd just replace whole wheel.

Think twice about the cost of all this. I had the same desire several years back to upgrade a Rockhopper to disc brakes. Totaling up the cost made me change my mind. I saved for a new bike instead, and kept the old Rockhopper around as a spare and a loaner.

ChanceCoats123

Thanks for the advice! I wasn't quite positive on this because yes, it is a rather large amount of money for something I don't really need. Also, I was looking at suspension forks last night and with prices of disc brake compatible forks that have a nice amount of travel, I am thinking twice there... Basically all the other parts are decently priced, but the fork is kind of over the top.

Zan

you won't need the 203 rotor up front if you're sticking with rim brakes on the back. the size of the rotor doesn't really improve braking power, just improves heat distribution. When you start going downhill for long stretches the heat build up is huge and you'll start to have your brakes fading if it gets too hot (something i experienced on every lap of my race yesterday on the final, huge descent). If you have a V-brake in the back, odds are you aren't needing the full disc up front.

If I were you, I'd just save my money and get an entirely new bike. V-brakes are not that bad to begin with anyways.

Cyclist30907654

That only true if he can lock up the front tire with both rotor sizes.

Zan

why wouldn't he be able to?

ChanceCoats123

Why is that? I really see no point in buying a whole new bike when I have a hardtail frame in great shape and a set of gears I'm in love with. One of my other hobbies is building computers so I am a big fan of simply replacing parts instead of buying a whole new computer. Say you buy a $1500 Dell pc, for the same price you could get twice the power or for half the price get the same power. In this case for half the price I can get an upgradeable bike in the future as well. I don't really ever see myself going mountain bike crazy so I don't need a disc compatible frame being as front's are plenty and since the only difference between my current bike with a front disc setup and a new bike with a disc setup is that the frame would be disc compatible.

ca7erham

185mm Rotors

Darth_Firebolt

which cable disk brakes did you use?
i have an avid bb7 on the front of my bike (160, though) and have had no problems out of it.

willtsmith_nwi

You can analyze this issue from the standpoint of mechanical leverage or heat energy production. Either way, larger rotors provide you with more braking power.

Reinforcing what another responder said, you do have to check for 203mm rotor compatibility. 180/185 is a nice sweet spot.

BTW, hydros are not necessary for more "power". An Avid BB7 teamed with an SD7 lever will provide lots of power and "tunability" that really isn't available in hydraulics.

I will also advise the OP that a front upgrade only is a good move for your application. The rear brake is really just a "drag brake" and isn't that useful for controlling the bicycle under heavy braking when load is shifted to the front of the bike. Any tuned and clean V-brake with decent levers (I recommend Avid SD7s) should be able to lock up the rear. This is much harder to accomplish on the front.

ChanceCoats123

They were some generic brand, came on a stock bike, don't remember which brand though. I didn't have issues so to speak, but I get more stopping power out of my linears in the front than with those particular cables.

Darth_Firebolt

they were just generic ones, i think that's the problem.
and they probably didn't have time to be broken in properly, either.
if you remember back, your linears took a while to break in, too.
the bb7 with a 160 will endo anytime you want if you just give a good tug on the lever. go with a 185 if you weigh more than you want to or if there is a lot of downhill stuff. the 203's are for the 45 pound dual suspension downhill bombers with super heavy wheels and tires.

ChanceCoats123

I have come to another idea... Since my current shifters/levers are one piece and plastic, I am thinking I should get some new levers, (FR-5's, I don't need any special gadgets) and then go with sram X.4 trigger shifters (also don't need anything special.)

Jameson

You should try to arrange a test ride on a bike equipped with Avid BB7s. I guess you'll just avoid the rear lever when test riding. I currently run hydros but I've never had an issue with these and would not hesitate to purchase them again if needed.

ChanceCoats123

Hmmm... Sounds like a good idea to me, I wonder if I could do that when I go to the local bike shop tomorrow.

9kBud

I have taken a bit of an interest in this thread since I am looking to do the same with my bike. My plan is to go with a Juicy 5 160mm on the front when I upgrade my fork, and a single digit on the back. I'm not jumping the bike other than what I encounter on the trails, but I love the feel and power of the Juicys. The trails around here have a lot of steep technical sections where the V brakes don't quite cut it despite the Kool Stop pads. Sorry, didn't mean to jack your thread, I just thought that you would like to know the opinion of someone else riding stock V's making the switch to a hydro front.

DirtPedalerB

+1 to new bike.

Zan

the cost of the upgrades is going to be what percentage of the original purchase? that's why i think the way i think.

do whatever you wanna do, i don't give a ****.

you can buy the complete avid 3 juicy set for something like 70$ + taxes/shipping. If you want to put it all together yourself you'll need a bleed kit (~30$), or you can get the shop to do it. I don't know what will cost more... but if you choose to do it yourself, it's a piece of cake.

ChanceCoats123

That's the thing, my mom won this bike in a beef jerky bag like five years ago. So any money I put into it is automatically coming back as gains for me. That is why I don't want to buy a new bike...

9kBud

Won the bike in a beef jerky bag? Ultimate win!

ChanceCoats123

Hahaha, very true. At the time this was a $450 bike. It was basically top of the line. I mean seriously, no one even knew 24 gears existed in 2k4! Haha. It is a damn nice bike and has stood up to numerous hard ships from me. So I would actually feel bad leaving it for a new bike...

Cyclist30907654

Because with proper braking technique, meaning with all the weight back, locking the front wheel is relatively difficult, especially with nice tires.

We've covered this already. The argument of greater lever arm = greater torque only matters if the tires don't lock up, which is what I was saying a couple posts up.

mtnbiker66

Wow, that must have been one big ass bag of jerky.

ChanceCoats123

Haha, yupp.

That is why am I getting new levers instead. I currently have plastics so I will probably see a big difference riding with metals.

BearSquirrel

Very true.


And when you put this together with your previous statement, this means that a larger rotor up front is very advantageous. And it also explains why you can only by 140mm rotors for the rear.