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hello, i just started mtbing about in september. before i bought my trek 4900, i bought walmart bikes ( rong idea). so no i am wondering if i should upgrade to disk brakes, is it worth it thanks
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"jwiggs" wrote
hello, i just started mtbing about in september. before i bought my trek 4900, i bought walmart bikes ( rong idea). so no i am wondering if i should upgrade to disk brakes, is it worth it thanks
Welcome to the forum!
In my opinion, and I’m sure other people may have different opinions, assuming your current brakes work okay, I think there are better upgrades to make first.
First, I’d get clipless pedals. They’ll give you more power, and more control.
Next, convert your tires to tubeless. More comfort, grip, less rolling resistance, and less chance of flat tires.Then, maybe get disc brakes.
Disc brakes are great, but I think those other two upgrades will improve your riding experience more. 😃
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"dgaddis" wrote
Next, convert your tires to tubeless. More comfort, grip, less rolling resistance, and less chance of flat tires.
How exactly do tubeless tires have lower rolling resistance than any other tire of comparable tread, size and air pressure?
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I looked up the trek 4900 and it should come with disk brakes, your post said you wanted to upgrade "TO" disk. If you want to upgrade, brakes would be the first thing I would do. I would respectfully disagree with maddslaker. Your brakes are very important and if they are not very good then you wont be able to use them properly and your ride wont be as fun.
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"pinkmtb" wrote
I would respectfully disagree with maddslaker. Your brakes are very important and if they are not very good then you wont be able to use them properly and your ride wont be as fun.
you mean dgaddis…
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The reduction in rolling resistance is the lack of friction between the tube and tire. …
It’s a small difference but a difference never the less…
Cheers
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However, isn’t that negated by the most often stated purpose of switching to tubeless in the first place: the ability to run lower pressure?
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I would have to say yes and no.
Yes if you run lower pressures you have more resistance (but more traction)
No if you run the same pressure.
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The mtn bike community as a whole as come to realize lower pressures actually reduce rolling resistance when riding offroad, over bumps and dips and whatnot. Lower tire pressure off road allows the tire to conform to the terrain and continue moving forward instead of bouncing up and losing momentum. To a point of course, if you run too little pressure you end up with more resistance.
This has been widely debated, and roadies are still arguing about it as tubeless tires are just recently becoming available for them. But you won’t find many mtn bikers who have tried tubeless and then went back. The only realy downside is it can be hard to change tires, especially if you have converted nontubeless wheels – it can be hard to get the tire seated, and may require an air compressor. Good tubeless rims however, do not. I’ve got stans arch rims and tires air up nearly as easily as if there was a tube. My old bike had converted wheel, and while they were a hassle when changing tires, it was well worth the effort. I rarely change tires anyways.
Google "bicycle tire pressure rolling resistance" for more reading on the subject. I think Schwalbe even had a good article on it on their site.
If you haven’t tried it, you really should, that’s the only way to know for yourself. The feel is totally different and has to be felt to understand.
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Back at the OP’s question: disc brakes are nice, but hardly a necessity. I have two bikes, one with disc and one with rim brakes. The discs brakes are definitely better, but I also don’t feel like making the effort to convert the other bike, as the rim brakes work just fine.
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"maddslacker" wrote
[quote="pinkmtb":35amjoso] I would respectfully disagree with maddslaker. Your brakes are very important and if they are not very good then you wont be able to use them properly and your ride wont be as fun.
you mean dgaddis…[/quote:35amjoso]
Ooops, sorry
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thanks all you guys, so can you guys give me the exact products i should get, i already have clip in pedals, with specialized s-works shoes
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"jwiggs" wrote
thanks all you guys, so can you guys give me the exact products i should get, i already have clip in pedals, with specialized s-works shoes
Well, what do you want to do? Tubeless tire conversion, or disc brakes?
What’s your budget? Going tubeless with a Stans kit is about $50 if I remember correctly. Not sure on brakes, depends on what you get.
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so now why is tubless better, and what if you have a flat on the trail
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If you have brakes that already stop you, why spend the money on changing to disc? Unless you’re riding serious downhill or riding through a lot of streams, I don’t see the benefit. I have V brakes, and they stop me every time. They’re low maintenance and they work. How’s your derailuer working? Smooth? It would be a good investment to install Gore Ride On gear cables. They don’t get any smoother! I think that’s a better way to upgrade your bike, and cheaper too. My shifts are perfect every time.
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"jwiggs" wrote
so now why is tubless better, and what if you have a flat on the trail
No pinch flats. With sealant, very little chance for puncture flats as well. Low tire pressures for reasons mentioned above as well as increased traction. Carry a spare tube and pump and it will still work in the rare case you do have a full flat. Most flats with tubeless setups and sealant are a result of "burps" where the tire bead gets pulled out of the rim and air escapes. It’s rare, but it does happen.
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Also, the simple physics of less weight on the outer edge of the cirlce(wheel) means faster acceleration. Gotta love physics! 😎
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In most cases the UST tire it self is heavier than the non-UST tire….Also when using a non UST tire your still using sealant which still takes up weight…2Oz or so of Stan’s still is in the order of about 70 grams or more.
The weights are about the same….Maybe a bit less…
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Forgot about the thicker sidewalls.
http://www.youtube.com/watch?v=FTlZvOVG8zs
Is all I have to say.
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That video is graphic,hahahahaha.I’m kinda 50/50 on tubeless,like element says,the weight diff is minimal and you still gotta carry a spare tube and pump in case of major blow out’s.I havent had a flat on my tubes in I dont know how long,but I do wish I had tubeless when I cut around the rail road crossing right next to my work and picked up about 25 thorns in each tire,hahahahahaha,so I developed a 6th sense and an eagle eye for that kinda stuff and like I said,I havent had a flat in a long time.Not to knock tubeless,I’ll end up with tubeless one day when I can afford it because I like the idea but to reccomend tubeless for a beginner and in need of several upgrades,,I would reccomend upgrading somthing else…..
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one thing i noted with V Brakes and Disc is the weather. The UK air is quite damp and i noticed that when V brakes get wet and the rims they tend to stay wet longer than disc as discs heat up easily.
end result being i dont tend to have breaks that stop working when in the rain or ploughing through muddy puddles giggling (puddles is compulsory, giggling is optional).
Dac
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Second that…disc brakes dry out waaaay faster.
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if you want disc brakes, which I highly recommend, make sure your hubs have the six-bolt mounts for the rotors, or a Shimano Centerlock interface. I have Avid BB7s on my bike. they are easy to set up and work very well. I had the BB5’s before that and they were a pain to maintain and not as snappy as the 7’s.
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Not meaning to hijack the thread, but I have a similar question, for a different reason.
I have a 2010 Trek EX6 that came with the "Shimano Branded" hydraulic brakes.
I’m having continuous problems with the rear brake. It makes a "ringing" noise most of the time, and the lever is very soft. I’ve messed with bleeding it using the Shimano bleeder tool (expensive gadget) but still find that the brake lever gets soft in almost no time. I’m convinced that the stock brakes on this bike were not intended for a serious rider. I’m planning to spend the entire summer in Colorado and don’t want to have to wonder if the brakes are doing something weird. My local Trek guy says "feels normal to him" and he adjusted the lever reach — not at all helpful. The lever will literally come back and touch the grip with little or no effort. The front brake works perfectly.
Has anyone had a similar experience with this brake setup? Is there a way to make it work properly and reliably?
I’ve given up, and on the advice of a fellow rider, I’ve ordered Shimano XT brakes and hope that they will provide a better feel and reliability. But before I open the box and commit to keeping the XTs I thought I’d check to see if there is an answer.
Any thoughts?
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You may want to double check the spacing of the caliper. Sometimes when installed the caliper is a bit to much to one side or the other from the disk this could slightly warp the disk as the brakes are applied and cause the brake to vibrate causing your ringing..It also will make the brakes feel a bit soft…
There are a few ways of fixing this. Using a two business cards install them on each side of the rotor and while lightly applying the brakes (so the cards do not fall out).
Then loosen the caliper bolts holding the caliper onto the adapter.
Apply considerable brake pressure and then re tighten the bolts a bit at a time (making sure that the friction of the bolts do not move the caliper)
Tighten them unit you have the correct amount of torque (5 – 8 Nm) depending on brand
Remove the cards and you should be fine with the caliper centered.
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Thanks so much element22. That procedure is something that one can only learn from people who have been there. I’ve got a couple of bottles of Shimano mineral oil coming on Monday and I’m going to give it another shot — I hate to spend a couple of hundred dollars needlessly (although I’m sure the XT brakes are a major upgrade, it may be one that I really don’t need).
These brakes use a simple cotter pin for a slide. Would it be helpful to polish that pin to smooth the sliding action? I know it can’t be lubricated, but it appears to be soft metal that may lend itself to uneven pad movement.
Once again, thanks — your advice is invaluable, and again, I apologize for the partial hijack of the thread.
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No point on attempting to polish it…You may remove the nickle coating of the cotter pin. Which may cause rust later on.
It’s fine as is.
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If you really wanted try and source out some stainless steel ones and that solves everything…
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I’m going dump the cotter pins entirely and have a couple of solid ss pins with groves for "C" clips machined (I have a machinist friend, etc). If that seems to be an improvment, I’ll share the results. Thanks again for the advice.
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More than likely you can just pick up pins that already have that hole or a groove that you can use if you check out your local fastner store…
Here is a tip that you will like better…
Every few months say 2, remove wheel from your brakes and pump the brakes a few times to bring the pads almost touching themselves then push them back all the way in with the tool provided when you purchased you bike or visit a bike shop and they will give you one ( they have tonnes ususally bikes are shipped with them). Cycle the brakes a few times like that..It will help lubricate the seals and make for a drag free brake.
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Once again, great advice. I sincerely appreciate it.
I’m still on the fence about installing the new brakes. They were expensive, but the look to be much better engineered and the quality of the levers almost justifies the change all by themselves. Have to "meditate and cogitate" as I was always told as a kid. I’ve always hated to skimp on things that increase safety. Might not mean anything here, but part-way down Trail Ridge Road, I may find some confidence knowing that the brakes are first rate pieces.
But they are expensive.
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