Ask the Bicycle Mechanic

With spring almost here, I wish to offer the SDMB the chance to ask questions about bicycles to a former bicycle mechanic. I worked in a bike shop for 2 years building up bikes and fixing some customer ones. My knowledge specialization is in road bicycles but I can answer pretty much any question you have about bicycle racing, technique, buying, fit, marketing, etc. If I can’t answer it off the top of my head, I can point you in the right direction. I remember how it was like to be a newbie in the great world of cycling so don’t be afraid to ask simple questions.

I will start this thread off by answering a question that is on many minds here:

No! Do not buy your bicycle from Wal-Mart, K-Mart, Target, Costco, or any other place where you can buy dinner at the same time you are buying your bike.

Is your real name H. G. Superman?

Nope. I’m Chinese. My real name is more like “Bruce Lee”! :smiley:

We live in Chicago, and my son’s been riding his bike to school even in the slush, snow and road salt. (It’s a Giant, but I don’t know what model - it’s mountainish, but may be a hybrid of some sort. My brother in law bought it for him, so it’s undoubtedly expensive. He’s that kind of uncle.) It’s stored indoors here at home, but sits out chained to a bike rack during the day at school, where it gets rained and snowed on.

I’m guessing he’s going to need to take it in this spring for a going-over, cleaning, oiling, whatnot, right?. The last time they did it was in August, just before he started riding it to school. Would you recommend I did anything with it before then? Spring here comes about May 1, so we’re about halfway through - should it be in more than twice a year if there’s nothing obviously wrong with it?

Yes, if your son has been riding his bike consistently in the snow and slush, then you should definitely bring it in for an overhaul once all the snow is gone. The overhaul should at least consist of pulling out the seatpost and bottom bracket to clean and grease these areas because they are prone to corrosion and water.

Your bike shop may also tell you that it is a good time to get a new set of brake and shifter cables installed because your current ones are gritty. This is a subjective call and you could opt out if you don’t feel too much friction in your cables.

I’ll bet the chain on your son’s bike has seen a lot of corrosion from all the water and salt. This is one item I would definitely recommend replacing.

Typical overhauls don’t include the cost of rebuilding the suspension on a mountain bike. Depending on what bike model your son has, it may or may not be worth it to pay the bike shop to rebuild the suspension.

From now until spring, I recommend that you hose down the bike when it gets dirty and it is warm outside so that you can minimize the corrosion on the bike. Just don’t use a pressure washer or aim directly at any bearings.

If your son is knowledgeable about bicycles, he should have a chain cleaner and bicycle lubricant. He should use the chain cleaner every couple of wheels with some degreaser to keep the bike in top shape. He should also remember to lubricant the chain at least every week and more often if it sees lots of water.

It is also very important that you keep the tire pressure between 35-65 psi to avoid getting a flat.

How frequently you take your bicycle into the bike shop for maintenance depends on your skill level at maintaining bicycles and what you use the bicycle for. In general, 2 times a year would be fine if nothing is wrong with the bike and you just use it for short commutes. Your son could learn to fix the bike himself and then you wouldn’t need to bring it in at all except for major repairs.

Is it possible to fit a 1-1/8" steer tube fork into a Gary Fisher that has that Gawd-awful 1-1/4" head tube? Is it just fitted with shims that I can transfer over to the new fork? WTF was Fisher thinking? Didn’t he learn his lesson after trying to use sealed bearings bottom brackets held in with snap rings?

Anyway, I’m too lazy to take the fork off to see for myself right now, so I thought I’d ask.
Oh, and how former are you? Know anything about the new SRAM 10 speed road grouppo?

My (awesome) Burley Solo trailer has a “speed limit” of 15 mph according to the manual. What harm am I risking when taking my 3-year-old out at higher speeds? It seems pretty dang stable to me.

Yes, you can fit your 1-1/8" fork into a 1-1/4" if you buy a special conversion headset like this one: http://www.chrisking.com/headsets/hds_devo.html . I assume you have a traditional external headset. There are no shims in headsets, they are press fits.

I think Fisher was just trying to innovative. There is a small trend even in road bicycles to use oversized headtubes, eg: Cannondale SystemSix and Canyons. 1-1/4" steerer tubes can handle higher stresses and suspension travel without going to bulky downhill forks.

I left my place of wrenching 3 years ago. During my time as a bike wrench, I helped usher in the era of carbon fibre bikes. I can still remember when all the high-end bikes were aluminum. I haven’t had a chance to work with 10 speed groups. However, I have been very diligent in my bicycle mechanic studies and know that there is nothing mind boggling different about 10 speed groups vs. 9 speed groups.

As for the SRAM 10 speed, there are two groups: Force and Rival. There is too much about them to talk in depth here, but head over to http://www.cyclingnews.com/tech.php?id=tech/2006/reviews/sram_force for an indepth look at them. The major thing that sets SRAM 10 speed apart is that the shifting is done all by one lever on each of your brifters. This simplification saves you about 130 grams over Shimano brifters if you compare Force with Dura Ace. I tried the SRAM brifters out once and I can say that I do not like them compared to my Shimano brifters because it is not as intuitive in my mind.

I better stop here with this response. I think I just made 95% of the SDMB go “Whoosh!” :stuck_out_tongue:

Thanks so much for a thorough and great answer! He’s 14, and very handy with mechanical things. Can you recommend a book or website where he can learn at least simple bicycle maintenance?

When you build a wheel, do you build with the pulling spokes head in or head out?
If you’re building on a rebuilt hub, do you use the same lacing pattern as the original build?
Does the bike stand on its spokes, or hang from them?
What’s sexier, a seat-tube reamer, a nipple wrench, or a chain whip?

I googled your trailer up to see what type it is. I have helped set up quite a few of these kid type carriers. In general, these things use low quality bearings, tires, and wheels because they are not meant for lots of abuse. However, this won’t inherently stop you from going over 15 mph because even Wal-Mart bikes can do that and they don’t blow up. Bicycle tourists regularly take their trailers down a side of a mountain and live to tell about it.

The problem is that a trailer with your kid in it changes the handling of your bicycle. If you are traveling fast and have to take a sharp corner, your trailer won’t take exactly the same line as the rest of you and will more than likely overshoot the corner. This will send your trailer with your kid flying in one direction while you are trying to head in another. The trailer can also cause stability issues if you are going fast downhill because it tends to create oscillations due to the nature of trailer itself and how it is attached to the bicycle. For personal accounts on trailer stability, see http://www.crazyguyonabike.com/forum/board/message/?o=lt&thread_id=41006&v=z&page=1&nested=0 .

The Burley guys probably placed a speed limit on their trailers just so that they don’t get sued when some parent decides to ride like Lance Armstrong down a mountain with a kid hitched in the back. The speed at which you can comfortably go will depend on your bike handling skills.

Hmm, your questions indicate an above level of bicycle knowledge and you may be trying to yank my chain, but ok.

All spokes “pull” but I think you are getting at whether you should build a rear wheel with the drive side spokes on the outside of the hub flange or on the inside. It doesn’t really matter. There are lots of wheels with both orientations and there is nothing discernibly different about either type. Do what you feel like and what clearance you have between the hub flange and your cassette.

If you are rebuilding a wheel with the same hub, wheel, and same length spokes, they you should typically use the same pattern you had originally because it will be very difficult to make any other pattern work properly. If you have different length spokes, go crazy.

A bicycle stands on the spokes. I can remember the website that shows the physics and computer modeling but I will find it later.

And lastly, I think women are sexier. Tools are manly. :smiley:

I recommend you show your son http://www.parktool.com/repair/. It’s a very good and detailed website. If you want to buy a book, I would recommend the Zinn & Art of Mountain Bike Maintenance .

Do you have any advice before I attempt to true a wheel for the first time? I found the how-to article on the Park Tool website but I’m a bit apprehensive, having never tried before. It’s a 32 spoke 700c road wheel FWIW.

I have no illusions that I’m going to be the next Lance Armstrong. Performance is not my concern. I want a good, sturdy bicycle for hauling groceries. I don’t want to have to rely on a backpack. I want the bicycle itself to have room for cargo. I plan on being able to haul two full grocery bags. What would you recommend?

In late 2001, I bought myself a new Trek 4500. I’ve done some off-road riding, but I primarily ride on roads and paved trails (wonderful thing about Minneapolis, there’s a lot of off-street paved bike trails). I’d normally ride 3-5 times/week, and do anywhere from 15-40 miles/day depending on the conditions.

Because I do such long rides, I’ve been considering buying a bicycle that would be more suited to paved trails. I already ditched the knobby tires off the Trek and replaced them with smoother road tires, but most of what I’ve read says that I should invest in a road bike.

Do you have any recommendations or suggestions? I don’t want to spend an outlandish amount. (The Trek was about $350 when I bought it, IIRC, and I could see myself spending $700-800 on a better bike, possibly more if the fit was right). Perhaps the most important factor is that I’m a pretty big guy… 6’4", about 265 lbs, so I’d have to find a bike that would be sized appropriately for me.

When I trued my first wheel, I ended up making a taco! :stuck_out_tongue: If you have never trued a wheel before, I would recommend you do it with someone who has the experience. It will make it much easier and you’ll pull less hair out of your head. If you do decide to do it alone, just remember that if you screw up, you can just head over to the local bike shop and get them to fix it for you.

I assume that you have the correct size spoke wrench for your nipples. If you don’t, just head over to your bike shop and pick up one of those 3 in 1 spoke wrenches that will fit virtually every conventional wheel you encounter.

To do a proper job, you should use a truing stand that holds your wheel at eye level. I’m not sure if you have this but I would recommend getting one if you plan to do a lot of wheel truing or wheel building in the future.

You can also try to true your wheel by leaving it on the bike and flipping the bike upside down. You would then use your brake pads as the reference to see if your wheel is true. This is the crude way of doing it, and it won’t get you the same trueness as a truing stand.

Before you start, I would recommend putting a drop of lube on the threads of each nipple and let it sit for a few minutes. This will make turning the nipples easier.

Remember to use nothing larger than a 1/4 turn at a time. After you turn the nipple, turn the nipple back in the other direction slightly to help relieve spoke twist.

It is very important to know whether you are tightening up a spoke or loosening it up. When you turn a nipple with a spoke wrench, a lefty tightens it and a righty will loosen it. This is probably the most difficulty part for a beginner.

For your first time truing, just focus on trying to get the lateral dimension true and don’t worry about vertical hops.

Good Luck!

For the bicycle itself, a recreational mountain bike, such as the Trek 4300 or the Giant Boulder SE would be ideal because they are relatively inexpensive, sturdy enough to carry large loads, and you can always take it to the mountains.

You have two main options to carry two full grocery bags if you don’t want a backpack. The first option is to put a bike rack on the rear of your bicycle. You can then put panniers on the bike rack and carry your groceries in there. There are many different types and sizes of panniers on the market and your best bet would be to check out your local bike shop and see what can work for you. The main thing to watch out for is to make sure your combination of bicycle + rack + panniers will give you enough heal clearance when you are pedaling.

The other alternative is to get a trailer for your bike. This will allow you to carry a refrigerator size grocery load.

Of these two options, I recommend you go with the bike rack and the panniers. The bike rack is quite cheap and if you shop around, you’ll likely find suitable panniers for around $50 CDN.

It seems like you are pretty serious about bike riding and do a pretty decent amount of miles. If you do lots of on-road riding, a road specific bicycle is definitely the way to go because you will be faster, be placed in the proper position for sustained power output, and have more hand positions on your handlebars.

The first thing you will have to decide is exactly what type of road riding you want to do. Are you primarily riding for pure enjoyment and to enjoy the scenery or are you riding because you want to race? Do you still want to maintain some off-road ability?

For the more tourist oriented riding, you should consider a touring bike like the Cannondale T800 . If you are race oriented, then you’ll definitely want a race oriented bike like a Trek 1200 . If you ride primarily on the road but also want to occasionally go off road, then you should consider a cyclocross bike like Specialized Tricross .

Decide on which type of riding you see yourself doing then I can give you more advise. Keep in mind that quality road type bicycles will typically cost over $1000 CDN. I would say the low range is $1000 CDN+, the middle range is around $3000 CDN, and the high range is $5000 CDN+. If you do not want to spend $1000 CDN+, then you should consider getting a used road bicycle off ebay or craiglist.

If you buy your bike from a bike shop, your height won’t be a problem because virtually all the manufacturers make their models in your size. It would be best to go to your bike shop and ask them to size you up. Your weight is more of a concern because it could cause durability issues.

Okay. I wanna buy a bike.

I’m a big guy. About 125kg, whatever that is in cubits or fathoms or whatever you guys use. :cool:

I want a bike to commute to work (about 6km). I want comfort, load-carrying capability, and some nice low gears (I’m out of shape and will need 'em). I don’t care if it’s slow and the lycra crowd laughs at me as they overtake. I don’t want to spend any more than about US$400, but I’m happy with a secondhand machine.

Any ideas?