Tuesday, April 22, 2008
A: Thanks for the question. It's important to get cleats right to prevent knee injuries and also to ensure you can get in and out of your clipless pedals easily. The diagram on the right shows the correct placement for cleats. It's from a page I have on my website where I explain how to find the right cleat position and give easy instructions that help you align and position your cleats in the right position. Click to learn more about cleat placement.
Hope this helps,
Q: Hi Jim,
I recently purchased a set of Dura Ace 7850-SL wheels to use with tubeless tires in part because of your positive reviews. I've noticed that the only criticisms are from those folks who haven't ridden them - you, Zinn and others who know their stuff seem to like them a lot. So far, I've been very pleased, but I have a couple of questions that I'd greatly appreciate your advice on. I weigh 165lbs and the Hutchinson website indicates the following: 65 - 75 kg / 140 - 165 lb = 6 - 7 bars / 87 - 101 psi. That strikes me as higher pressure than I would have thought. What do you recommend (especially for someone who places a high emphasis on cornering grip)? Also, my rear tire seems to have a very slow leak. It always seems to lose 10 - 20lbs of pressure overnight. Should I use the Hutchinson Protect'Air? If so, how much (ml) should I use for a 700x23 tire?
Thanks in advance!
A: Thanks for the email, Mark. I'm about the same weight as you and I run 90psi in the front tire and 95 in the rear. I have run them lower on really bad roads, approx 87 in the rear, 85 in the front. Note that gauges are usually inaccurate so it's hard to know the exact pressures, but according to my gauges, that's a ballpark setting you could try that should work nicely. And, you can certainly experiment with lower pressure to see what's right for you and your roads. I would think you wouldn't want to run too much below what the company recommends, though. Usually if a tire is run too soft it tends to crack sooner but you could try it and see if you have any problems, too.
To figure out the slow leak, I would put water around the valve and see if that's what's leaking. I had trouble with one of mine. The little O-ring wasn't sealing well. I finally replaced the valve, which wasn't easy because I had to special order it from a bike shop and it took a long time. They don't seem to be available yet so the shop could only order them from Shimano direct instead of from their usual distributors.
You could also dip the wheel in a sink to try to spot a slow leak, but the only problem with this is that there are holes in the rim and the rim will take in some water and it's a pain to get it out. So, you should seal the holes first with little pieces of tape.
I'm assuming that you haven't run over a tiny piece of glass or wire that's causing the slow leak, too.
Some feedback I've gotten from others riding these tires is that theirs lose air overnight, too. I have only had this with the tire with the bad valve. The other tires hold air overnight but need a little air every few days like regular clincher tires with tubes.
I believe if you use Hutchinson's aerosol inflator you're supposed to use one per tire. That's based on them sending me 2 with 2 tires. They told me that there's a light sealant in there that will help seal the tire. I used it on one tire and didn't notice any difference, but some people swear that sealants fix flats and are worth using. I can't tell if it made a difference or not in sealing the tire or preventing flats. I have checked that tire and rim and haven't noticed any issues with sealant eating the rim (as I mentioned in my RBR article can be caused by Stan's sealants - or so Shimano says).
I hope this answers your questions and you enjoy riding tubeless as much as I do. Last week I flatted my front tire in a race and was able to ride 10 miles on it to the neutral support tent to get a spare wheel while keeping right up with the lead group I was in. I don't think I would have dared try that on my old regular clinchers. There was no damage to the rim.
I am not sure how much of a problem I am having with my bottom bracket. When I stand to climb I hear an awful lot of creaking noise. I have an aluminum frame Cannondale CAAD 4 with a Shimano Dura-Ace crankset. I am by no means a bike mechanic. Just like my car, I know where the gas goes and how to turn it on. So I don't know if this is just stress noise or if something is loose that can be tightened.
Thanks for your time and consideration,
A: Hi Rob,
Your crankset shouldn't make noise when you're riding. You probably have a loose crankarm or a loose bottom bracket, or if you wear cleated cycling shoes, you might have a noise coming from your pedals or cleats.
This article on my website goes into great detail on noises and you'll find a lot of common noises and solutions here including bottom bracket, crank and cleat noises.
Of course, you could also take your bike into any bike shop, describe the noise, ask the mechanic to take a test ride and he should be able to hear it and tell you what's needed right away and maybe fix it right away, too, for not too much money, even.
I hope this helps,
Friday, April 11, 2008
Always good to read your opinion where I can. It sure helps. I'd like a short answer from you. I run Campy Chorus bikes. I'd like to buy the SRAM Force gruppo but would like to be able to ride my Campy wheels without having to change cassettes and hub body. Do you think it will be fine? Where could I find info about SRAM/Campy compatibility?
A: I have not had the opportunity to extensively ride or test the SRAM components so I did a little research and discovered that my friend Lennard Zinn, tech writer at VeloNews magazine has - and has written about compatibility issues. Unfortunately, he says that SRAM works fine shifting Shimano and SRAM cassettes but that Campagnolo cassettes (10-speed) have different spacing and won't shift correctly. You can read his explanation here: http://www.velonews.com/article/73404
Hope this helps,
Q: Next week is my boyfriend's birthday and I wanted to buy him a bicycle. I was hoping to stay in the price range of $250-$300. The bike would be used for pleasure, leisure, and extra activity. We would not be racing or doing any serious competing. We live in Philadelphia so there are some bike trails near us that we could ride on. I talked to some people and they said to look
into last year's models. My boyfriend is also close to 300 pounds - and I was wondering if I should take that into consideration when finding a bike. If you could give me some suggests/model/brands of bikes you think would be good I would greatly appreciate it - thanks!
A: What a nice birthday present, Colleen! I would recommend checking out the Trek 820, which sells for $290 (sug retail) and should be available at just about any bike shop that sells Trek bikes. It will come fully assembled and with a full guarantee and the shop will be happy to adjust the seat and bars to him and answer any questions he has. They'll also give the bike a free tune up after he breaks it in with a month or so of rides.
The 820 is a basic mountain bike. It's good for a big rider because it has a
strong frame and wheels, a nice upright riding position so he'll be comfortable and it has low gears for easier pedaling and for riding up hills. It also has quality brakes and a suspension fork for some more comfort.
He'll need to try the seat to make sure it fits right and is comfortable but that's the case on any new bike. If he doesn't like the way it feels after a few rides he should ask the shop to try another and he should be able to find one he likes after trying a few.
Here's a link to the bike online so you can check it out. It comes in 2 colors and you can click the colors to see the different one: http://www.trekbikes.com/us/en/bikes/2008/mountain_hardtail/820/820/
I hope this helps and that you have a nice birthday party and he loves the bike,
Q: Hi Jim, I don't have a question on repairs, but i do have a question about cone wrenches. I have 3 wrenches made by Park Tool which are in sizes 11/16 ,7/8 ,and 1/2 inches. They are the old style. About 8 inches long with the old Park Tool logo. What I was wondering is how many sizes were there and in what years were they made? I do own 13-20, 22mm in the new and old style. Thank you for your time,
A: Ah, a Park Tool trivia question......
We've made several different versions of cone wrench over the years including a complete set of fractional wrenches. A complete set would have included 1/2, 9/16, 5/8, 11/16, 3/4 and 7/8". The photo shows wrenches from two different times. The circular logo would be from the 70's or early 80's and the sprocket logo could go as far back as '85. We discontinued fractional wrenches in about 1990 as there was no use for them. The first cone wrenches we made were for Schwinn starting in the late 60's early 70's. They had red handles.
I hope this helps,
Park Tool Company
Q: Hi Jim,
I bought a used one-speed freewheel bike a few years ago and it came with quick release axles on both the front and back. I know a little bit about hubs, like how to adjust them. But I have one question. I would like to change from my quick releases to bolt-on wheels. Do I need to buy only a new axle with cones and bolts, or do I have to change my hub completely? I keep hearing about solid hubs vs. quick-release hubs, but I can't find any info.
A: Hi Katie,
It depends on what hubs you have but in most cases you can simply remove your axle set (the quick release axle, cones, spacers, lockrings) and replace it with a bolt-on axle set (you can use your old bearing again unless they're old, in which case you should go ahead and put in new ones). Good shops should carry the bolt-on axle sets and if you're lucky you'll find ones that will work on your front and rear hubs. You may find that the dustcaps, which are original to the hubs may not be completely compatible with the new bolt-on axle set's cones. If that's the case you can usually
easily "shrink" the cones by grinding or filing them or enlarge the holes in the dustcaps with some emery cloth or sandpaper.
What you might do is head down to the bike shop with your wheels, having already removed the QR axles. Then, you can take their bolt-on axle sets and test fit them into your hubs to see if they will work. If you're lucky they'll go right in. Be sure to get chromoly bolt-on axles, not cheap carbon steel, because carbon steel is more likely to bend with a lot of use. Chromoly axles should hold up to almost anything.
Happy hub overhauling!
Saturday, April 5, 2008
Designed and built in Italy by Effetto Mariposa, the Giustaforza torque wrench is only about as long as your hand. To use, simply insert the bit you need (held in place with a magnet inside the head of the tool), set your desired torque with the small knob and gauge on the end, and tighten the bolt. The Giustaforza (translates as correct force) makes, and you feel, a pronounced click when the proper torque is reached preventing you from ever overtightening again! This sweet tool is small so that it's easy to handle, and so it provides just the right leverage for working on even the largest Allens and torx bolts found on bicycles. The 16 included bits (see photo) allow you to use it on almost any bolt or screw on modern bicycles, and a plastic protective case is included, too. If you like to own great bicycles and equally great tools to work on them, you'll want a Giustaforza in your toolbox. I love mine.