Do you have a "dumb" question related to MTB?

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    • #214627

      Just to be clear, there are no dumb questions around here. However, I know there are probably folks who read Singletracks who have what they think might be a really basic they’re afraid to ask. The good news is, the Singletracks community and staff are here to help!

    • #214680

      I’ll start this off!!

      I have a Cannondale F29er with a lefty fork and I want to put some wider tires on. What is the easiest way to calculate a maximum tire width and how does my rim width affect things?

       

      • #214701

        @aes5455 the short answer is no.

        The long answer is:

        Tire brands can measure substantially differently for what is labeled the same size. For instance, one brand’s 2.3 might be another brand’s 2.5. Apart from the diameter, there’s not much standardization in tires. The best way to find out what fits is through trial and error. Which can get spendy.

        Rim width can have a huge impact on tires. A wider rim places the tire beads farther apart which can make the tire measure wider than it would on a narrower rim. It can also allow you to run lower tire pressures, while still having good sidewall support. However, you need to pair the right tire with the rim. For instance, if you tried to put a narrow 2″ tire on a 30mm wide rim, the tire’s profile would get squared off. In that case, the tire would corner like shit. Why? Because the side knobs are no longer on the side of the tire, they’re on the top. When you lean the bike over, there’s nothing to bite into the dirt and you fall on your head.

        Generally speaking a rim around 25mm wide internally is going to work great for a majority of trail tires in the 2.2-2.5″ range. If you want to go with a substantially wider tire, you’ll probably want a wider rim as well. Most plus bikes (2.8″ tires) run rims closer to 35-40mm wide internally.

        However, if you’re not running really wide tires (2.6+”), don’t get too sucked into thinking you need a wide rim. You’ll be pushing around extra weight without a benefit. The more weight you can cut from the outside of your wheel (i.e. the rim and tire) the faster your bike will be.

        Holla!

    • #214723

      What is the purpose of the stem and headset other than the obvious of holding the handlebar on? lol. I suppose my question is how do these affect a rider’s overall ride for the better or worse? Other than seeing so many riders choosing these components to add some “pop” to their bike how could changing these be even more advantageous?

      You asked if we had any “dumb” questions so I’m sure this one rates right up at the very top! But hopefully I’ll learn some really good information!

      • #214762

        I have used 35mm, 40mm, 50mm, & 90mm stems on a whole assortment of bikes. In my opinion, 50mm is perfect for a mountain bike. The 35mm and 40mm made my bikes’ steering feel twitchy. 90mm was just too long for mountain biking and the agility required for it.

        I find that for most of my bikes, I usually end up swapping to a shorter stem to be able to handle the descents better and not feel like I am falling over the handlebar. My sweet spot has always gotten me to around 50mm long stem, raising up the stem with a couple of spacers, and pushing the seat back on the rails around 1/2 inch. On my 26er, I even had to swap over to a riser bar to get my cockpit to where I wanted with my posture a bit more upright and my weight a bit further back.

        That works for me very well and lets me loft the front wheel as needed. The fine tuning is done on the climbs, if I find the front end lifting too much. I then either slide the saddle forward 1/2 inch, or I can scoot forward a bit on the saddle to keep the front down, or in some cases extend the travel of the front fork a bit (by removing spacers internally).

        I have shorter legs, shorter arms and longer torso than average so these adjustments work very well for me. Your mileage may vary.

    • #214782

      What, exactly, is a roller???

      • #215180

        “What, exactly, is a roller???”

        Pump tracks started out from the BMX days. Berms, jumps, flat tops, and rollers are terms used to describe features on a pump track. Rollers is a series of humps that you “roll” (not jump) your bike through at speed, where you pump your bike repeatedly to maintain speed without losing momentum.

         

         

    • #214789

      Blundar, thank you for taking the time to share your experiences of what works for you on these components. I am assuming it has to do with the “comfort” of ride. However, I was wanting to know how these 2 things add to or subtract from a ride overall for riders. Could adding to one or both of these enhance my bike and ride, and if so, what would be some of the key factors to look for, etc. Again, I do appreciate you sharing what you’ve experienced and did learn a little from that!

      • #214812

        Hey kenwrightjr, my understand is that a shorter stem makes steering more sensitive or twitchy, while a longer stem slows it down. So increasing the physical distance between the bars and the fork also “moves them further apart” in feel as well.

        But, this has to be taken into context with the angle of the fork. A steeper angle (like a road bike’s) also makes steering more sensitive and twitchy, while a slacker or flatter angle (more like a motorbike’s) slows it down. Older bikes have steeper more vertical forks and long stems, while newer bikes have flatter more raked out forks and shorter stems, so in a way the “sensitivity” of the steering is the same. But the newer geometry almost universally improves the feel, traction, and quality of the overall handling.

        The offset of the axle, called the fork rake, is really important too, but that generally can’t be changed, so people don’t talk about it. Interestingly, the Santa Cruz DH team reckons that the perfect stem length for handling is about 50mm too, and is a consequence of the rake and head angle of their downhill bikes. Generally, the 30-60mm range would be normal.

      • #215146

        The length of the stem does a couple of things:

        1. Adjusts the quickness of your steering (long stem is slow, short stem is fast steering)
        2. Positions how far forward your upper body is over the handlebars

        For the first one:

        Slow steering is more stable (great for long distance XC cruising). Fast steering is great for tight and technical singletrack and downhills.

         

        For the second thing:

        If the stem is very long and most of your upper body weight is far forward over the handlebar, then down hills are going to be really sketchy. Hitting the brakes hard will make you feel like you are going to go flying over your handlebars. Another thing is that it will be more difficult to lift the front tire over an obstacle. If the stem is very short and your weight is too far back, then every time you start climbing up a steep hill the front end will feel like it lifts, loses control, and wanders too much.

         

    • #214830

      Thanks for that info jagungal. That helps. I guess if I am reading the specs on my Santa Cruz it says I have the Cane Creek 40, Integrated for a headset. And I really can’t tell if it’s too sensitive or not. So I guess if it’s not broken then there’s no need to fix it! lol

    • #214856

      @kenwrightjr in regards to the headset itself, the biggest benefit between a low and high priced headset is going to be the quality of the bearings. After all, they’re quite simple. In most cases, aluminum cups are pressed into the frame’s head tube, although there are some frames (carbon in particular) that have the cups molded directly into the head tube. As you can imagine, there’s not a ton of difference or weight to be saved between one aluminum cup and another.

      The real difference will be in the bearings. More expensive headsets will use nicer bearings that should last longer because the machining is more precise and the seals are better. Personally, I go with something like Cane Creek’s 40 series headset. They are readily available and fairly inexpensive. Once the included 40 series bearings wear out, I’ll upgrade to a nicer bearing, like their 110 series. That way I can get the best of both worlds – inexpensive cups with nice bearings.

    • #214934

      My Santa Cruz has those Cane Creek 40 series Aaron so that’s good to know those are a fairly popular and trusted headset. On average for someone who rides approx. 25-35 miles per week in northern Georgia how long could one expect these Cane Creek 40’s to last? Is that a legitimate question or is the unknown too large here to answer that? Just curious as to what I could expect.

    • #214984

      It’s hard to say how long a headset will last. It totally depends on the conditions you’re riding in. Obviously, the more you ride in the wet and slop, the faster the bearings will wear out. Check your headset at least once a year and keep it greased. If you do that – and also make sure it’s properly adjusted – it should last years.

    • #215262

      Alright, here’s one.

       

      When should you replace your helmet? Obviously after any kind of impact, that’s a given, but I am on season 3 with my Smith Forefront helmet, and I am wondering when I should replace it. No impacts, just wearing it or storing it in my closet. Manufacturers say 3 years, what do you guys do?

      • #215285

        Hey Christopher94,

        I don’t know if this will be helpful or not but here is what I do, I race MTB so I replace my helmet when I have a bad crash, but given that you haven’t crashed yet (if you haven’t) I would replace the helmet after the manufacture date if the helmet was less than $200, if it is over $200 I would keep it for 1 more year.

    • #215380

      @christopher94

      When should you replace your helmet?

      This is my personal opinion – no need to replace it if it’s in like new condition. Better use that money for something else.

    • #215381

      What do you guys think on cornering technique differences when riding MTB and motorcycle? On MTB I try to stay on top of bottom bracket while motorcyclists shifting their body in opposite direction, closer to the ground. Is it just because of heavier bike and greater g-force? Or there’s something else?

      • #215410

        @stumpyfsr – that’s a good question.

        I *think* it’s partly due to the weight of the bike, but also because of the tire’s contact patch – if we’re talking about a street motorcycle. You want as much rubber on the ground as possible, and that rubber is found in the middle of the tire. To make best use of that contact patch, you want to lean your body and not the bike. Which is the opposite of mountain biking. On a mountain bike you want to lean the bike more than your body so you are pressing the side knobs into the dirt.

        Or something like that.

    • #215411
    • #215451

      Thank You, @Aaron. That was a good article. Cornering indeed is one of the hardest skills to master. Especially in mountain biking, where conditions change so often.

    • #215617

      “When should you replace your helmet?”

      Give the helmet a very thorough inspection. Always repair or replace if you find anything questionable.

      • Look at the straps and clips. Is there is anything worn or damaged that could compromise a perfect fit?
      • Inspect the inside of the helmet. Are the felt pads worn out, misplaced, or missing? Is any of the foam cracked, brittle, loose, or just does not look right?
      • How does the outer shell look? Scuffed? Edge tape coming off? Sun backed color fading? Getting crunchy, stiff, chiping off?
      • Always replace after any kind of head impact. Helmets are only made to handle single hits. Don’t drop or throw your helmet into the back of your SUV when you are done using it (no bueno)!
    • #215954

      I sort of get headsets.  I know there is standard, internal, integrated.  But what is the purpose of “zero stack” headsets?  Also a 44mm headset means it takes 1.5 steerer fork, right?  Why can’t they just call 44mm a 1.5 inch headset?  Speaking of headsets, should the race crown match the headset.  Someone told me you shouldn’t mix and match the race crown and headset.

      • #215984

        I sort of get headsets.  I know there is standard, internal, integrated.  But what is the purpose of “zero stack” headsets?  Also a 44mm headset means it takes 1.5 steerer fork, right?  Why can’t they just call 44mm a 1.5 inch headset?  Speaking of headsets, should the race crown match the headset.  Someone told me you shouldn’t mix and match the race crown and headset.

        @Dan_Thach oh boy. Headset sizing can get super confusing. I just installed a zero stack headset on my new Kona Honzo frame. The bottom of the head tube is 56mm with a crown race seat diameter of 40mm. The top of the head tube is 44mm with a stem clamp diameter of 28.6mm. This is for a tapered 1 1/2 – to 1 1/8 fork.

        Basically a zero stack headset keeps your stack height at a minimum. Say for example I tried to put an external cup headset on the same bike. The bottom cup would stick out of the frame, effectively raising the bottom bracket height and slackening out the head tube angle. That change to the geometry of the bike could be a good thing in some cases, or not so good in other. An external cup on the top would give you a higher handlebar height. Again, this might not be ideal in all situations.

        With the Honzo in particular, I bet they use a zero stack headset to give average/shorter height riders the ability to get their bars to a reasonably low height, without having to run a negative rise stem. For taller riders, they’ll just need to run more spacers underneath the stem, or run higher rise bars to compensate.

        A 44mm head tube generally refers to a head tube that is straight, with top and bottom diameters of 44mm. You see this kind of head tube a lot on steel and titanium bikes. A 44mm head tube is good because it allows you to run a variety of forks. You can run a tapered steerer, a 1 1/2″ straight steerer (if they even make those anymore), or a straight 1 1/8″ steerer. This, of course, assumes that you purchase the correct headset for your needs. So, unfortunately, it’s not just as simple as calling it a “44mm headset/1.5 inch.”

        And finally, you DO need the crown race that matches your lower headset. Since the crown race is designed to mate with the bearing in the lower cup, you really can’t just wing it. You can mix the top and bottom halves of a headset if you want, say a Chris King bottom and Cane Creek top, but I would advise trying to mix bottoms unless you know for sure that the cups, bearings, and races all share the same exact dimensions.

    • #215975

      Hi, I hope to pick up my first mountain bike next week (Lapierre EDGE+ 327) and I’m looking for advice. I’ve only ridden trails once before and that was earlier in the month when I rented a HT.

      I am fairly active, as I road cycle 20KM and walk at least 5KM a day, I play squash twice a week and also do some weight training about twice a week – other than that I am lazy 🙂 However, I am just 50 (sigh) and to start with I shall be doing local trails of about 2 hours/15KM (forest\open ground).

      So I have a few questions:

      (1) I will obviously have a helmet (and gloves) and I presume protective glasses are also wise. Should I start with knee and elbow pads? I was also considering protective shorts (to keep the old hips in one piece)?
      (2) For 2 hour trails, should I use electrolyte tablets and energy gel packs\energy powder. Do I need both or is that overkill? Is a backpack with a hydration pack wise?
      (3) As I live in Ireland, I presume mudguards are also essential?
      (4) If my budget can someday afford it, I’d like to buy an action camera so my wife can see my last moments alive 🙂 I was thinking of buying a cheap one (AKASO EK7000 4K for £60) and if that’s not adequate maybe a GoPro Hero 4 or 5 session camera in the distant future.

      Any other advice for a newbie???

      Cheers

      Damian

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