Thursday, October 18, 2007

Derailleurs and Such



You can throw on the brake calipers now if you want. This should be intuitive and require little fiddling with the exception of choosing the correct barrel nut. the SRAM kit came with three or so extras for various depths. The front caliper will have a longer mounting bolt but the greatest burden of reaching through these bladed carbon forks is handled by the extra long barrel nut. This can be an issue when retrofitting parts onto an older bike or trying to reuse older calipers on a new bike with a huge front fork. It's my habit to squeeze the caliper (with shoes installed) shut onto the rim while tightening the bolt. This sort of self-centers it. Torque to spec and you're good to move on.
Derailleurs (DR) are simple devices and have changed little over the years. Function has always remained the same - they rub the chain in the direction of a desired gear. Period. Index shifting is nice in that you can adjust your derailleur(DR - that's the last reminder you get!) to move an adequate amount with the single sweep/detent/click of the shifter. This prevents under/overshooting a gear or constantly adjusting your shifter to prevent DR (see!) rubbing while in the desired gear. That's about as complex as the whole concept gets. Hopefully, you have selected the correct front DR band for your seat tube. There are two basic sizes but just measure it to be sure. I had to turn a spacer for my older MASI to use my newer Veloce front DR. Works fine but I'd rather have the right size.
Mount the rear derailleur to the hanger with the single bolt. Manually press the rear DR in towards the largest gear. It will stop when it hits the low adjustment screw. The uppermost DR pulley should be in line with the largest gear - looking from above or rear. If it is off (and it will be) adjust the low limit screw ("L") until it moves into alignment. When the DR is released, it will spring back out to the smallest gear. Look to see if that upper DR pulley is in line with the smallest gear - again looking from the top/rear. Adjust the high limit ("H")screw to bring it into alignment.
The front DR is mounted either by a band or onto a brazed mount on the seat tube. My SRAM DR came with a separate S*****o band and a front DR that could mount to either. Line the DR rails parallel with the large chain wheel as best you can. Also, from the side, ensure the outside rail is just above the large chain ring teeth.
Mount the chain by wrapping it around the largest front and rear gears, bypassing the rear derailleur. Find where the links meet and add one or two. Cut there using a cutoff wheel for by pressing out the pin. There are tools for this but I used a punch and hammer. SRAM uses a proprietary connector called a PowerLink. It's great! No more pushing pins in and out. Not only is it reusable, you can carry extras to repair a broken chain in the field. You would need the pin press though to remove the broken link. The PowerLink can be seen in the opening pic of this entry.
Wrap the chain through the derailleurs and close the PowerLink. This will have pulled the rear derailleur down and away from the rear cassette.
Per SRAM instructions, place the chain into the lowest rear gear (largest gear) and the front into the lowest gear (smallest chain ring). This moves the chain into the inner most combination it will ever see. Adjust the in/out travel of the front DR by turning the "low" or "inner" limit screw so that the DR inner cage rail is about 0.5mm inside the smallest chain ring - in other words, as close as possible but not touching anywhere through crank revolution. Now is when you attach the cable from your shifter. Run it under the bottom bracket and up to the DR. Turn your barrel adjuster on the frame out 1 turn. Route the wire and pinch it under the washer/bolt on the DR. Don't overdo it, it will crush and deform the cable. You can shift it around now if you want. Now, put the chain into the highest rear gear (smallest gear)and the largest front chain ring. Adjust the "high" or "outer" limit screw so that the DR outer cage rail is just outside the chain without rubbing (again, about 0.5mm). Adjust the height of the derailleur by putting the chain into the largest ring and from the side, ensuring the outer cage rail is above the chain (in the largest chain ring) by 1 - 3mm. You will fine tune it later but the convention is to use a penny between the two. If it is too close or too far, loosen the seat tube band and slide the whole front DR up or down as needed. When you re tighten it, don't forget to look down from the top and align the rails with the chain rings. This is not a step to forgo! In the past I have had my chain "jam" while jumping into the next gear. Since you have a freewheel, this won't do much to the attitude of the bike but when cresting a hill and sprinting down the other side at 30mph+ your chain ring and thus your cranks will lock momentarily but very suddenly! If you are hammering at the time, it will nearly throw you off and at a minimum is very hard on the gears and your knees. Adjust those derailleurs! It isn't difficult but it does require attention.

Wednesday, October 10, 2007

Handlebar setup ..... IMO

Now that you have a roller, mount the handlebars. I ordered some 7075 44cm bars from Nashbar (www.nashbar.com) that are modern looking, black, and lighter than most at 246g. I know 'cause I weighed them. The one who was not obsessed with weight reduction now weighs every single thing. I went with a stem and bars that were the old uncool standard size. The over sized bars, this and that, are just overkill IMO. When these handlebars break on me throwing me over them, I will recant. Speaking of Nashbar, I ordered a lot from them. I was a little embarrassed like it was the WalMart of cycling but they have name brands, great prices, quick delivery, and they have been around forever. I found an article from the early 80s with a Nashbar bike compared to some other racers. It fared very well. Overall, not a bad place to look. When you order, check the "yes" box for e-mails but enter your backup e-mail so you won't fear being stalked by retailers and spam. I seldom, wait..... never, do this but I have received several one day sale notices that are really good. That's how I got the Force/Attack tire set for $63.

Okay, mount the bars and center them. Many of today's bikes have this mountain goat look to them with the bars turned up and the levers looking like horn extensions. Add those highly modified angled top tubes and they look cheap to me. I like them where the flat of the top of the bar is in line with the stem angle shown here. You do what's comfortable but if it looks goofy, this may be why.

Monday, October 8, 2007

What's Next?


It's really up to you. If you are using a traditional bike stand, you can mount the bars, add the derailleurs (but you can't adjust them yet), the brakes (can't adjust those either), or get your wheels built. I'm sure mechanics have reasons for a certain order of progress but I chose to replace the "mock-up" wheels with the final ones. I found some Neuvation M28SLs on our local Craigslist for $150. This is half price and I was considering them anyway so I went to take a look. This guy must've really taken care of his stuff! They looked new to me, were straight, and spun forever. He claimed to have only a few group rides on them and maybe a race or two. I had $160 and since he didn't have $10 change, I said just keep it. I took the wheels, extra spokes, and skewers and left happy that I had scored such a nice pair. I weighed them both and, without skewers, they weighed 1565g. Light for clinchers with semi-aero rims. I weigh about 165 so I hope they aren't too weak at that weight.
Since I was running a Campagnolo 8 speed before, the extra gear on top and bottom should be noticeable, especially on the hills. The SRAM cassettes are Shimano compatible so the tool for that is the same (seen in the pic at the top of this post). There were rumors (from online forums) that the free hub is different for Shimano 8/9 speed cassettes and 10-speed cassettes. John at Neuvation said he had heard nothing of the sort and I had no issue either. Perhaps they are speaking of derailleurs and gear spacers in the cassettes? The SRAM gears come new with a quick loader so you just align the loader on the free hub and slide them on. Even without it, each gear slides onto the hub only when the cogs align. You will also need a chain whip - something to hold the hub/cassette from spinning as you tighten the lock nut using the above tool. It would seam that the hub could hold itself since it's opposite of the freewheel direction but this just isn't so. You can use an old chain and vise grips or a bench vise but you would have to be very careful. Do yourself a favor and drop the $20 on a chain whip or make one. Whatever you do, don't try to wedge the cassette or clamp onto the gears with anything. Though I've improvised several times, it's best to keep such barbaric tools as vise grips and channel locks away from your bike. Remember, top end cassettes from any major mfg. are lightweight and are often made of unique materials (titanium) and are about $150. Take it to the LBS if you are willing to scrimp here.
Mount your tires. The tires were the only thing I reused at the time. By this posting I have received my Continental Attack/Force GP tires and have them mounted. These come only as a matched pair and are considered "racing tires" by some. They are lighter than the Michelin Megamiums by about a full tire and are supposed to be pretty durable. 199g for the front and 211g for the rear. That's pretty light for a clincher set. "Hand-made in Germany" might translate to "Hand-changed (on the roadside) in Kansas City". I have yet to flat on our regular routes this year so I'm hoping these will prove durable enough. Tip: When searching for bike components go to:

There are also other similar review sites for cycling gear but by searching and cross-referencing data you'll get a good idea if a part is appropriate for your purposes. I'm convinced that many of the bad reviews, with tires for example, are from those who did not do research and now are angry that a "race tire" they just had to have developed a flat after only 500 miles. Really? Maybe you shoulda looked that one up! I'll likely eat my words but I'm going into this knowing the risks. I'm remembering the whole "strong, light, cheap" thing.
Once the tires are mounted, (you don't need to know how to do that do you?) slap them on, mount the wheels, and stand the bike up. Step back and take a look. It's starting to look like something.

Thursday, October 4, 2007

Crankset


Not cranks, it's crankset. You must pose and follow the industry standards and say all sorts of pretentious things like this if you want to continue.
There are several types of bottom brackets depending on your frame. Mine took a 68mm (width) American thread. The older Masi I'm building takes Italian thread. The width, 102mm, 110mm, etc. is determined by the crank manufacturer and not necessarily by the frame you have. There are times when a recommended BB is so narrow that the crank arms will hit your chainstays or will give your heels so little room you'll need a wider one. Since the right side (drive side) of the BB cartridge has a fixed flange, it can be shimmed a bit for small adjustments. Go with what the crank guys say at first. Mine wasn't a problem and I suspect it isn't that common to have issues on production frames. I left the included spacers in place, one on each side, which began to groove the inner spider from the BB cups rubbing. This isn't visible and didn't compromise the carbon fiber weave but I wasn't very happy with myself. One shim would have been okay but don't space these types of BBs without careful fitting.
I used a Park tool for my BB. There are several types of BB tools. Get the one for your BB. This is for the Truvativ/SRAM GSX BB shell. The Shimano BB typically has 20 inner splines. Campagnolo has its own inner spline deal that will also fit the cassette on the rear wheel. Kudos to them for making a multi use tool. Then again, they should 'cause they are also the most expensive out there.
There are better BB tools than the one I chose. Pedros has them in a socket.

http://www.pedros.com/index

These can be used with your torque wrench unlike the Park model. Park tools are cheap and easy to find but not the best and not the most robust IMO. They even say things like, "60ft/lb is like 10lbs of force 12" from the BB." Hardly precise and equally unmeasurable. Use a torque wrench so you don't come apart on the street!
Shown here are the basics. On top is the larger ft/lb torque wrench and below, the in/lb. The hex sockets are a necessity. If you have only a bigger ft/lb torque wrench, no sweat. The common specs found in in/lbs can be easily converted to ft/lbs by dividing by 12. Sounds too simple to be true doesn't it? There are cool digital torque wrenches now that you can enter any spec into. Clicking these things up and down gets old fast but not fast enough to go buy new ones now. Cool story: I foolishly trashed my older Craftsman wrench, likely from using it as a breaker bar but I don't publicly remember. I was going to do a brake job on the girlfriend's car saving her/ her dad a few hundred bucks. I whined that I needed a new torque wrench first and what do you suppose I got in the mail? A brand new one! I wonder if Craftsman will replace the old one? Doubt it. Now it really is a breaker bar - an $80 breaker bar!

Staying off the subject I'll make a point on weight, the BB on top weighs 262g while the Campagnolo Record BB weighs 195g. One costs $17, the other, about $130.
You guess which is more. There is a .15 lb difference! You have to decide where to cut your losses or you will soon be bike poor.
Unlike the older style BB shown above, the GSX BB is basically a tube that holds the bearings in place.
Like Shimano's Octalink (for all the Ultegra/DuraAce fans), the SRAM crankset uses a fixed spindle on the drive side. Grease the bearing surfaces lightly and push it through from the drive side. BBs do have a right and left and the drive side has a larger bearing and seal. The drive side takes more direct force at this larger bearing so.......

Anyway, once through, slide the left crank arm on and install the bolt. Torque it to spec - in this case 425 - 478 in/lb (35 - 39 ft/lb). SRAM has a neat feature here. The crank bolt is inside an extractor cap so when you loosen the bolt it automatically pulls the crank arm from the spline. No need for a crank puller! Nice job!
This is also a good time to check the torque on the chainring bolts. SRAM uses a different sized hex on each side, I guess in case you have only one set of wrenches. I have so many accumulated that I have some in a box in a bag under the workbench and I still trip over whats left in the toolbox! You will be using a torque wrench and hex socket on one side anyway. 80-90 in/lb and these were all dead on.

So let's start Assembly

Since I'm not using a production stand, I put some old wheels on and mounted it all on my girlfriend's trainer. I suppose you could build a bike by leaning it against stuff but that's really a pain and kinda "hack-like". I tried to touch the paintwork as little as possible during assembly. At least build a PVC tire rack.The fork has to be on so I started with that. My frame came with an FSA headset installed. Here are the parts:

Once you are relatively sure you have the races, bearings, and shims in the correct order, grease and install them. Mine had some light grease already but I added some lithium. I think clean axle grease is fine too. The old German belief that good bearings should be run in oil may be true but not practical. On the road, grease will stay put and help repel debris. BTW, whose guns jammed in WWII due to ultra-precise tolerances? Not a dig - just rambling. As an aside, most of the vertical bearing load comes from the bottom set of bearings while lateral load is carried more by the upper set.
I just found a great tutorial on the Park Tool website that covers this all better than me. I'll keep typing just to entertain myself.

http://www.parktool.com/repair/readhowto.asp?id=65

The inner races were a slight friction fit in the neck. On a motorcycle and many bikes you must press them in. On older non-integrated headsets where the races are the chromed, visible type, I have used a block of wood and tapped them in. Too hard and you will deform the cup - not good. When in doubt use your LBS and ask if you can watch them do it. They do make presses for drawing the inner races into the stem squarely. They are expensive but cool looking. You could make one from "all-thread", nuts, and appropriately sized washers (fit the washers to inside of where the bearings ride not over the entire cup). But I digress......
Next, install the fork and top races, bearings, and spacers and put a wheel on the fork so you can stand up. Now the dog will be more likely to leave you alone and you will notice an immediate reduction in the dog hair to grease ratio. Add the spacer you bought or made and slide the stem on last. Don't tighten the stem pinch bolts yet just leave it loose.
You don't adjust these like the old 1" type but the concept is the same. Speaking of stems, why do we need 1 1/8" fork tubes and threadless headsets? Who was breaking those 1" alloy stems? I know the French ones had a rep but now I hear advice to occasionally replace even these new stems once every year or two as they develop stress fractures and can fail catastrophically. The best quote on that is, "The threadless headset was an answer to a question that was never asked." I would agree but I will pose with the rest of the lemmings this build.

Looking down the top of the fork tube you'll see the star nut. They must be installed on aftermarket stems. These are different for full carbon forks but this is what an alloy fork tube nut looks like. It is conical so it is pulled tighter by adjusting the stem cap. Install the stem cap. If the cap hits the fork tube before resting on top of the actual stem, your spacer is too short or you need to cut the tube. I don't know what manufacturers recommend but I would say you want the stem to overlap the fork tube by about 1/8" (visible in the star nut pic above). This gives you enough to preload the bearings. BTW, many aftermarket forks must be cut down. Determine where to cut after you have mocked the whole bike up. I've even seen people riding them with extended tubes - it won't hurt anything but your face or, in a head-on, your groin. This way you can play with adding/removing spacers before you determine where to cut it. You can cut alloy tubes with a hack saw. Take your time, cut it squarely, and debur the edges. Full carbon tubes require more care. Tape them first, then ............ just take them to the LBS once you've measured them.

Once you install the stem cap and bolt, you can tighten it to the point where the fork turns at it's easiest but where there is absolutely no play in the stem. This is where I have always cheated on a bike or motorcycle. While it isn't good to overtighten bearings in their races, I do tighten to the point of slight binding then give the fork a couple of turns to help kinda seat the bearings. I then release the bolt and do it the right way. Technically, this cheat should be unnecessary if we installed the races correctly but I still do it.
On threadless stems, the actual stem binding bolts secure the stem. Repeat: The cap nut is only to set the adjustment and the stem pinch bolts secure it. In other words, once adjusted, you could theoretically remove the cap and ride the bike. I wouldn't, as it sure is a nice backup, but if you get to that point, you are a hack anyway and should not be riding anything you assembled. Remember that when you are laying in the ditch and then promise to never again curse your LBS for trying to "rip you off." JMO

Wednesday, October 3, 2007

Weighing Parts


I am not obsessed with weight but if you are buying parts from a catalog, online, etc., you can't help but notice the weights listed - usually in grams. I bought the least expensive parts I could while coming in low on weight. Remember the earlier quote? "Strong, cheap, light - pick two." These three just don't coexist on a non-formula one budget. Even at that level getting light and strong regardless of cost is walking a tightrope. In our world with all the name brand hype and marketing, very often a lighter item is less expensive than the heavier one. Things like "carbon wrapped" are usually a waste. They might as well say, "Carbon weight added for nothing other than aesthetics." On the other hand, if you can afford solid carbon, it will usually be the lightest option. Just remember the above quote.
Buy a food-type scale (with grams) for about $25 and weigh everything - just to make yourself crazy. Actually I was really surprised at how much less today's components weigh compared to those 10 years ago. I weighed 5 seat posts I had and an old aluminum one was the lightest. A "carbon wrapped" post I had was the heaviest. All that glitters isn't gold. Manufacturers often underestimate their items weight as well. A good site for real world measurements is:

http://weightweenies.starbike.com/

The listings section has many common components and their weights as submitted by actual purchasers.

A note on weighing. Prop the scale up on a jar to get the room to weigh your drop bars. Be careful, too high and it will topple over, too low and the bars will hit the counter. I found a peanut butter jar to be perfect.
Test it first to be safe. If your dog's tongue can't reach the bottom of the jar, then the jar is too tall and will likely topple over. This jar proved to be perfect and took only about two minutes to clean. Remember, this test can be dangerous in and of itself. It's difficult to "double tap" the SRAM shifter without fingers!

The few parts I made



A project like this doesn't really have any parts that require fabrication. I did turn the stem cap from 6061 aluminum. I also turned a stainless hex bolt down to fit flush with the cap.


The stem spacer is PVC. I could paint them black but then they'd look like any other store bought piece. I did polish the spacer but that was about it. This is the only chance to be creative on this thing so I'm leaving them raw....... for now. I chose this spacer height because anything shorter would have meant cutting the fork tube. I'm fine with that but I wanted to ride it first to see if I liked the bars up a bit higher. You can cut later - you can't add it back later. According to my measurements from the previous bike, this puts the bars about 3/4" higher than on my previous bike - the only variance allowed.

Start getting your stuff together


Once you have an idea of where you are going with all this, make a mess in an inconvenient place - I chose the living room!

Try to go in and out of the garage as much as possible, leaving a dirt and grease trail behind. It's what we do. I didn't use a bike stand for this build. I did put it on a trainer. Before I bought the new wheels, component group, etc., I mocked it up using other extra parts. I was just impatient.