Friday, September 18, 2009

Q&A: Chain stretch, wheel centering, transporting a trike

Q: Hey Jim,
I'm sure that you've answered this over the years, but I couldn't find the issue addressed. I came to riding a bit late in life (about 35) and fell in love with the sport. Recently, I was told that I needed to replace the chain on my Viner because I had stretched it over time (4,000+/- miles this past year). I ride Dura Ace and am fine with the $50ish expense, but I just can't imagine that I produce enough torque to 'stretch' metal. I ride in Georgia and so there is quite a bit of climbing, but still... So my question is - "Is this for real, or are the wrenche's at my local shop snickering as I walk out the door?" And as a follow up 'If I can stretch metal, can I also leap tall buildings in a single bound?"

Ross

A: Good question, Ross. It’s a matter of slang. The mechanic said you “stretched” your chain. But, this is slang for wearing it out. What happens is the parts (the rollers and pins) that make up the chain get smaller and when this happens play develops between the parts of the chain – creating more clearance. Then, when you measure the chain to tell if it’s worn out, it has actually gotten longer due to all the parts wearing. So, the word we often us to explain that the chain is worn out is “stretched.” But, your massive legs didn’t really stretch the chain, they just wore it out from all those miles ;-)

If you get a tool like the Wipperman Chain Wear Indicator shown, it's easy to check your chain and tell when it's worn out.

Jim

Q: Hi there,
I wonder if you could advise me on why my bike pulls to one side so I constantly have to straighten up while riding, please? I bought it only recently, so I could take it back to the shop for fixing, but the shop is over the other side of town, so if it is something easy to fix I would rather do it myself. The brakes are the normal block ones not disc.

Thanks in anticipation,
Irene

A: By any chance did you remove the front wheel and then reinstall it crooked, Irene - like after putting it in your car? The front wheel must be exactly centered in the fork. If it is off to one side or the other, it can cause the bicycle to pull. So, I would loosen the front wheel, make sure it's centered in the fork and then tighten it. You can usually see if a front wheel is centered just by looking from the front for even clearance between the wheel and the fork on each side. A better way to tell is to use your fingers as feeler gauges. Just use the same finger on each hand and slide them in from behind and next to the rim or tire to feel the space between the wheel and fork. This should feel exactly the same on both sides.

If this isn’t the problem, you should check with your bike shop because it might be an issue they need to address,

Cheers,
Jim

Q: Hello! I need to transport an adult tricycle and I have no trailer hitch, trailer, or truck. The only thing I can come up with is to disassemble the trike and cram it into my Chevy Cobalt without trying to tear up the interior of the car. Do you have any suggestions? Mechanical things stupify me. Any reasonable suggestion is appreciated! Thank you!

Debbie

A: Here’s what I’d try, Debbie. It should work fine and shouldn’t hurt the car or trike. No disassembly is required. Simply pick up the trike and place it on the trunk of your car. The tires are rubber and they shouldn’t hurt the paint and the bike doesn’t weigh a lot so it shouldn’t be able to dent the trunk. If the trunk lid is super soft and might dent, first put a towel down and then put a piece of wood like a piece of plywood on the trunk (not a whole sheet - just enough to fit beneath the trike's rear wheels). Then put the trike’s rear wheels on that piece of wood (the front wheel is facing forward, probably resting on the glass, or even roof). Now the wood will spread the weight and there’s no way the tires will be able to dent the trunk lid. So, you now have a towel down on the trunk lid, next the piece of wood. It just needs to be wide enough to go under both trike rear wheels. And then the trike is on top of the wood.

To hold the trike on, use stretch cords. Wrap them around the rear wheels (you want to wrap the wheels well to lock them as that will prevent the trike from moving), and then pull the cords to the edge of the trunk lid or under the wheel wells and attach the hooks there. If it's easier you can just tie or tape the wheels so they won't turn and then just attach the stretch cords from the trike to the car. You may have to get long stretch cords - and get good quality ones. The stretch cords will hold the rear of the trike on the trunk and keep it from moving left or right, while the tied/locked wheels will keep it from rolling front to back.

Now, to hold the front wheel of the trike that will be resting somewhere near the roof, you just run a rope or a long stretch cord across. Pass it beneath one window and then roll up the window to hold it in place. Or tie it to something in the car. Then where the rope or bungi meets the trike's front wheel, wrap it around the tire a few times. Then take the other end and pass it through the other window and tie it inside the car somewhere. (You can also tie or tape the front wheel to the trike's frame to lock it and keep it from turning like you did with the rears.)

Your trike will now be held securely on the back of your car. The only thing you need to be careful about is not driving under anything too low because you now have something tall on your car. Other than that this should work fine.

I hope this makes sense. Let me know if you have questions,

Have a nice trip,
Jim

Q: Jim - I have an older Norco & recently I changed the rear tire - since then, I've had issues with the rear wheel nut. I get the wheel in the right position but then when I tighten the nut to secure the wheel, it gets pushed out of line & then the wheel rubs. Any suggestions?

Deborah

A: Yes, Deborah,
You need to outsmart that wheel :-) To do it, only snug one nut on one side. Then check to make sure the wheel is centered. When it is, snug the other nut. At that point the wheel will stay in place and you can fully tighten both nuts. But do it gradually, adding a little to one nut, checking that the wheel is still centered, then adding a little tightness to the other nut, checking, and so on, until both nuts are fully tight and the wheel is centered. What's causing your problem is trying to fully tighten one nut first. This can cause the axle to turn with the nut and the axle can move out of position changing the wheel position as you tighten the nut. Tightening the nuts as I explained will prevent this happening.

Give it a try,
Jim

7 comments:

Simon said...

Interesting advice about chain stretch Jim. Would the chain appear to slip under load if the chain was stretched? I've just purchased a vintage men's commuting bike which needs a bit of love and care. I've noticed the chain slips every once in a while, especially when going up hills. Despite the fact that it needs a good clean and a lube, I'm thinking chain stretch might be the problem. Your thoughts? Thanks, Simon.

Jim Langley said...

Hi Simon,
Slipping could be a few things but usually it's not caused by a worn out chain. You might have a stiff link in the chain. You can pedal backwards and watch for it to pass through the derailleur pulleys. A stiff link will cause slipping/skipping when pedaling and it will usually "trip" when going through the pulleys making it easy to see. You would then try to loosen it pushing gently sideways with your hands or using a chain tool to move the pin back and forth to free the link. A stiff link will cause the bike to skip in all gears. If it skips in only one gear, it usually means that gear is worn out and you'll need to replace the gears on the rear wheel to fix it since it's almost impossible to get individual cogs any more.

There are other possibilities, but that's a couple of likely problems to check out. Hope it helps.

Jim

jeep-suv-and-parts said...
This comment has been removed by a blog administrator.
Susan said...

When tying a trike to the top of a car as you describe, use webbing tie-downs, NOT anything that stretches! It sounded to me like you meant bungie cords, which I'm sure is not what you meant.

Anything that stretches will let your trike bounce on the trunk, at best creating scratches and dents (no matter how hard you try to cushion them), and at worst allowing your trike to fly off into traffic creating a huge safety hazard.

Also, the lightweight hooks that bungie cords have bend very easily - another way that your trike could wind up in someone else's windshield or on top of a pedestrian or cyclist.

It's not necessary to get the highest quality tie-downs as you would for a motorcycle, since they don't need to support a lot of weight, but do use ratcheting webbing tie-downs.

Jim Langley said...

Actually, stretch cords are fine, you just need to use good ones ;-) Those are good tips to avoid el-cheapo bungi cords. And, yes, anything you strap to a car should be fixed on there nice and tight so it can't move or bounce. Of course, you need to drive cautiously too. And, no matter how well you tie things down, all bets are off if you are unlucky enough to get into an accident.

Thanks,
Jim

Anonymous said...

Jim, have you ever owned or worked in a bike shop? In some of your replies you are pretty quick to suggest that a local shop should be willing to work for free or cheap.

Jim Langley said...

Yes. Six shops, actually - in NH, VT and CA. And for over 17 years full time. I still work for bike shops but on the website/content side of things now. So I fully support and believe in bike shops. I know they're not all perfect, but most love and care about cycling and are happy to help with advice, suggestions and information. Typically shops will be happy to help you with a problem and only charge you if they fix the problem for you. In this way, you will buy parts needed from them if you fix it yourself. Most shops realize that a little free info and assistance goes a long way towards selling bikes, accessories and service when the time comes. And, I think most cyclists realize that their LBS has to make a living and has to charge for things. Hope that helps explain and answers your question. Thanks for the comment and enjoy your rides! If you work in a shop, here's to a great 2010.
Jim