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Tech letters for February 11, 2003
Edited by John Stevenson
Confounded by carbon fiber? Need to sound off about superlight stuff? Tech letters is the forum for your gear-related questions and opinions.
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650C vs 700C wheels
Buying race wheels
Speedplay Zero's V's SPD SL's?
Crank length
Pedal/shoe position
Carbon rear stays
Deda Synapsi handlebars
Fork/headset compatibility
Pedal Axle Length
Pedal platforms
Rolf wheel noise
Time Impact pedals
Tire wear
Titanium frame
Wheels
XTR concerns
650C vs 700C wheels
I have a question on the merits of 650C wheels vs 700C. What are the pros and cons of using the smaller sized wheels?
The smaller wheels would be lighter (all other things being equal) and would accelerate faster. However for one revolution of the pedals you would not travel as far. I have had a search through your web site but was not able to find any points of reference.
Robin Donohue
Buying race wheels
I am in the market for some race wheels for the road bike. I found some wheels made for Bianchi, using carbon hubs and Ambrosio rims. These are known as the 'Levitation' wheelset. Does anyone know anything about these wheels, as the seller is interstate and I would like more info on them before buying. Any help would be appreciated.
Tim Lee
Australia
Speedplay Zero's V's SPD SL's?
I'm trying to decide between the above two pedal systems and was after a bit of advice.
Speedplays seem to have the float, (I'm always conscious of knee issues), and the weight advantage however the new Lance Dura-ace pedals seem to be very highly rated. Detractors from the Speedplay seem to focus on potential loss of power due to the lollypop design.
Any thoughts??
Christopher Flanagan
Crank length
What length crank arms do most pro roadies use? I'm six feet, two inches tall and would like to know what similarly built pros use. What considerations should I weigh in choosing between 175mm and 172.5 mm?
Stephen Maluk
Pedal/shoe position
I have a new set of Time Impact Mag pedals and CX Pro shoes. I am trying to dial in the fore-aft cleat position. Do you have a formula I can use besides just eyeballing my ball-over-axle position while seated on the bike? Thanks.
Evan Ruzanski
Santa Barbara, USA
Carbon rear stays #1
The bikes I have tried that use carbon stays tend to have a bit more vibration absorption in the rear end than those without, a similar difference to that felt between a carbon and aluminum fork. The compliance of the rear end stays much the same, if not slightly firmer, perhaps a result of the requisite wishbone formation required by carbon seatstay systems. I find that the benefits of carbon rear stays diminish as the frame moves towards compact geometry and may not be worth the additional weight. While the feel of a carbon stay equipped compact frame differs from that of a standard variety using a carbon seatpost, the difference is hard to call beneficial. If the goal is to build a comfortable bike: why not? But if the weight reduction is the plan I would opt for the traditional configuration.
CJ Eder
Carbon rear stays #2
The simple answer is yes, if you can afford it. The carbon rear end will essentially suck up a lot of road vibration (something that you might well need in a Scandium frame), allowing a smoother ride, which will be a factor in reducing fatigue over a long ride. That being said, if your friend doesn't ride long distances (training or racing) then it really comes down to a question of aesthetics. The carbon rear looks very cool.
For the record, I have a custom steel frame (Denti) with Carve front and rear, and I love it.
Lindsay Norval
European Cycle Imports
Brisbane Australia
Deda Synapsi handlebars
Having ridden on a pair of Synapsi bars for two months I can advise that what you see is mostly what you get. The pair that I use (130mm x 44cm) was the only change on my bike and I was migrating from a Deda Newton OS bar and stem. Weight savings was insignificant while stiffness increased and comfort decreased. The lack of the normal cork wrap on the top of the bar does allow a slight bit more road shock to transmit to you hands which is only noticeable initially and would only be a concern for riders that rest heavily on the bars. The aero grip on the front of the bar is revolutionary. The benefits of narrowing your front profile have been known for years and the grip provides an excellent option for road racing. Your transition from the hoods to grip and back is extremely smooth. The hand position in the grips is very ergonomic and secure allowing you to ride in an aero position for lengthy periods over varied road conditions.
Over the years I have used other road racing options such as Scott Rake Bars and Cinelli Spinacci and could provide detailed comparisons but if you can stomach the cost of Synapsi I can assure you that they do offer a new option that you should consider.
J. Grant Mann
Fork/headset compatibility
Ahhh, this is the problem with ordering parts online or from discount magazines. I wrench at a local shop and recently had a customer bring in the same combination of headset and fork. To make a long story short he had to buy another headset because his "great internet deal" turned out to be not so great. Do not force the fork into the headset as it will then be part of your bike forever. The fork should work with a cane creek or similar headset. Oh, the lessons learned in bike maintenance.
Ryan
Pedal Axle Length #1
Look makes two pedals - the CX6 and CX7 I believe - that are designed to have an adjustable Q factor (this is the distance between the centerline of the bike and the pedals - bigger Q factor = feet further apart). The new Time Impacts also have adjustable Q factor. Surprisingly each of these pedal systems is pretty light given the adjustability. Also I've heard that Campy cranks tend to offer more room between the shoe & the crank arm than Dura Ace so if you are on DA now you could consider switching cranks.
Karl Etzel
Pedal Axle Length #2
John, there are two much simpler solutions I can think of for you. One is to upgrade to the Look CX-7 pedals. They have an adjustable Q factor so you can set one pedal further from the crank arm than the other to accommodate natural variances in your body's ergonomics. The second solution is to go to your local bike shop and swap just the left side crank arm out on your bike to one that has a higher Q factor. The Q factor is the distance between your pedal axles, and different cranks have different measurements. Test out some used crank arms that are the same length as the one on you drive side and see if you can reach a balance of comfort for your particular body.
Russ Williams
Gainesville, FL
Pedal Axle Length #3
Try Time pedals - they allow a much more acute angle between your foot and the pedal, you can also by sensible use of a file allow the shoe to rotate even further round than the original spec, I have seen this done by a friend with complete success!
Also choose shoes which allow you to push the cleats as far inboard on the
shoe - sidi seem to be good for these.
Good luck!
Matthew Rowley
Pedal Axle Length #4
Take a look at the Kneesavers Pedal Adaptors: http://www.bikescor.com/product/knee.htm
"Kneesavers TM allow up to 20 degrees of toe-out by increasing the clearance between the pedal and crankarm. These case-hardened steel extensions are 20mm long and are inserted between the pedal and crankarm thereby increasing the range of both fixed and floating pedal systems from a maximum of 4-5 degrees of toe-out to as much as 20 degrees.
Suggested Retail....$45/pair = $2 shipping and handling"
SCOR Productions
12300 E. Washington Blvd.,
Suite W, Whittier, CA 90606
(800) 548-4447
Fax (760) 728-7737
I am not associated with this company. Just passing on the info.
Jack Elias
Pedal platforms
I don't think it your imagination. You can tell the different in the wider platform. I have Shimano SH-R 212 shoes with the carbon sole using SPD-R pedals. Now I am using the new Time Impact pedals. And there is a difference, I don't feel the hot spot and more contact area at the bottom of my feet.
Rithana R. Chea
Rolf wheel noise #1
Robert needs to make sure that his quick release skewers have serrated edges to give them a better bite when holding the wheel. The same is true of the flat part of the axle end cap that is flush against the fork or dropout tip. If the end caps are smooth, try roughing them up a bit with sandpaper to get a better bite. Additionally, the anodized finish on the end caps (if black, gold or red) makes the problem worse as is the case with aluminium dropouts that often have a clearcoat on them as well.
Phil Pulley
USA
Rolf wheel noise #2
I had a similar creaking problem with my Rolf Vector Pros. This only happened when I was standing to climb a hill or for a sprint. The source of my noise was the tube valve stem rubbing against the rim. I simply took a piece of 3M electrical tape and wrapped the valve stem one time (more than one wrap won't allow the valve stem to go through the hole in the rim). Give it a try, it certainly can't hurt.
Keith Arbuckle
Rolf wheel noise #3
My Rolfs were equally creaky. I was dubious when my shop suggested that it was the skewers, but I'll be darned if they weren't right. I greased them up and made them tight, and to my surprise - no more noise. Even so, because of the sharp edges and poor cam action, I ultimately replaced the Rolf skewers.
Steve Rempel
Mountain View CA USA
Rolf wheel noise #4
If your frame has a replaceable derailleur hanger I would clean and lubricate it with anti-seize compound to eliminate it as an issue.
CJ Eder
Rolf wheel noise #5
My Rolf Vector Pro front wheels used to creak when climbing. The noise stopped after I cleaned the grit from the axle, then re-lubricated the axle with household oil, and finally replaced the wheel tightly into the forks.
John Fry
Macon, Georgia
Time Impact pedals #1
I recently bought (and immediately returned) some new Time pedals. The reviews mention trouble engaging, to which I can attest. However, I didn't see this as a big issue, they are simply harder to get into than other models I've used. (Look & Speedplay) My problem was the Q-Factor. Time boasts they have 5mm of left-right adjustment for Q-Factor, but even at the narrowest setting, it wasn't enough. I could not get my feet close enough to the cranks for comfort. A quick spin on my trainer proved rather uncomfortable. Basically, if your current set-up is to with your foot close (within 2-5mm) to the crank arm, I wouldn't go with the Time pedals. Honestly, I was pretty bummed to send them back, everything else is wonderful. I should note I have Northwave shoes, maybe the hole placement (and thus the cleat placement) is significantly different on other shoes to nullify my issues.
Brent Davis
Anchorage, Alaska
Time Impact pedals #2
Ultra-distance cyclist Perry Stone just completed his 14,000km ride around Australia in 57 days using Impacts and says they are the best pedal he has ever used. Says a lot for the reliability of the product.
Mark Williams
Time Impact pedals #3
I have been using the Time Impacts for about 6 weeks now and they are great. Easy to get in and out, no unwanted pull outs, nice wide stability under the foot (just like the old times), float is great, no additional adapter plates needed for my Sidi shoes, and I especially like the Q factor adjustment. If you were a fan of the old Time pedals, like I was, you will certainly like these better. I have no complaints.
Chris Streight
Portland, OR, USA
Time Impact pedals #4
I have had a pair on my new Principia since September last year and even though I haven't put many miles on them I can assure you they feel every bit as good in operation as the Time Mag's (full size Time pedals!) I have on my other bikes. Plus they are lighter and give a better cornering angle. Durability is still in doubt but knowing Time they should be every bit as good as the pedals I've already had (fingers crossed!)
Matthew Rowley
Time Impact pedals #5
I have a pair on my bike. I have been using for three rides total of 70 miles. To me I can feel the wider platform coming from SPD-R pedals(2 yrs). It is a little harder(longer) to get in them. I like the pedal because of the lower distance between the sole of the shoes and the pedal axle. I change out of my SPD-R and did not have to adjust my seat height. The cleats are a lot thinner (less than half) of look's cleats. I used to have pain in my right knee with the SPD-R pedals and now the pain seem to disappear. More on that after some longer rides. This pedal has a Q-factor and I used the adjustment and that maybe why there is no pain in my knee. There is a lot of float in this pedals. You can move your toes and heels unlike the look pedals where your toes are lock in only your heels can move. I have to admit I was a little worry about all this float at hard effort. But to my surprise it was very stable when I am out of the saddle. Overall I like the pedal can wait to try it out on the Saturday ride!
Rithana R. Chea
Tire wear #1
I have just commuted into my office through the Derbyshire hills in horrendous weather conditions (snow/slush) on a pair of Schwalbe Blizzard Sports without even a single backwheel spin. These are easily the best winter training tyres I have ever used. They are unfazed by mud, leaf mould, oil, slush and even thin snow - any weather conditions except ice. My nerve usually gives out before they do. They are also very cheap (£10 each). The only downside to the "incredible traction" is that they do wear a bit fast (I have to change the rear 2-3 times over the winter) but this is a small price to pay for performance and safety.
Ian Campbell
UK
Tire wear #2
Replace 'em, and rejoice that you got 3,500-4,000 miles out of them. I'd think the Axial Pros would fit the ticket you describe for an all round tire that could be used for racing. You may also want to try the Continental GP3000.
Brad Brown
Tire wear #3
Eric, usually your rear tire will wear out twice as fast as your front tire.
The first really noticeable signs of wear are that a tire that once had a slightly
rounded profile will look like it is box shaped.
It will wear the curved crown on the tire to a flat profile. Another really
good sign is an increase in flats. That is a sure sign your tires are getting
thin (of course it could also be more glass on the roads than normal too) but
as the rubber wears thin, you will flat more. As for do it all training racing
tires, I am a really big fan of Michelin Axial Carbons. They are moderately
light enough to race, have really nice traction on clear dry roads, and have
pretty good tread life. You should rotate your tires front to rear, if they
are not specific to either end, every 1,000 miles or so, and should get around
5,000 miles out of the Axial Carbons.
That's about what I got on my last 3 sets of them. I have also had good luck with Continental Gran Prixs as well. Rotate them periodically and when you do, check thoroughly for glass or other debris stuck in them, as well as for burrs in your rims, and you should be set for about 5,000 miles or so. Anything beyond that seems to be above average and I would be very happy with that kind of life from a tire.
Russ Williams
FL, USA
Tire wear #4
In response to Eric Gribbell's letter on tyre wear, I have recently replaced my rear tyre for similar reasons. With my old tyre, I lost it on a corner (going up hill!) in the wet and fell badly. I had also noticed that the back end was losing grip from time to time even though the wear was not too bad.
The fall made me decide to to get a good tyre for all conditions and I opted for the Continental GP3000 4 season. I have found it to grip and roll well, it is also pretty light and has good side wall protection. Only down side was the price!
Getting over 3500 Miles on a tyre is pretty good going so I would think of changing soon. If money is tight then you could swap back and front tyres if you have not done so already.
David MacVicar
Perpignan, France
Titanium frame #1
The advice I received when I scratched my Litespeed was to buff the frame with a 50cent (typically) green, soft washing up scourer. My bike was knocked over in a coffee shop accident and scratched on the top tube. The buffing took the scratches right out. I don't know for sure if this would apply to the satin finish frame, but it worked beautifully on my brushed finish frame.
Martin Mullin
Canberra, Australia
Titanium frame #2
If they are just oil marks, some degreaser should bring it up nicely. If you've got more stubborn marks in a brushed Ti frame, the best way to bring it up is (as you thought) with a brill pad/scotchbrite, whatever you want to call it.
Sam Alison
Czech Republic
Titanium frame #3
Mudguards are banned by the UCI, so they must make you faster.
Gilles Berthoud makes some carbon fibre fenders, would look great with a Ti bike. As for the discolor on the frame, wrap the frame with some carbon fibre tape from an auto parts store, very stylish, and stiffer ;-).
Scott Goldsmith
Milford, Ohio, USA
Titanium frame #4
Ti is impervious to cleaning materials. I use acetone for really ornery gunk. I like to polish it up with Pledge, which also forms a thin waxy coat and makes the next layer of dirt fall off very easily, and is way cheaper than specialty bike frame polishes. This trick works nicely on painted frames too, I learned it from a LBS.
Karl Kretzel
Titanium frame #5
Firstly, with regards the Raleigh titanium frame, I would strongly advise against metal polishes or abrasives such as Brillo pads, especially if the frame has been lacquered. If the frame is raw then a quick metal polish may remove the mark. My preference would be to use a de-greaser such as X-lite's Muck off or finish line's citrus de-greaser. Sometimes a reasonable quality car wax e.g. Turtle can remove such stains quite easily.
Secondly.. I am fastidious about the maintenance of all my machines but a few months ago I removed the seat post from my winter/all-rounder and added a touch more Waxoyl down the seat tube and put some ti-prep (copper-slip type) anti seize around the seat post and reassembled (after first cleaning the post). Last week, deciding it was time just to re-grease the post, I found it was very resistant to move ( even though it is a close fit in the frame)and concluded there was a chemical reaction facilitated by the copper. Magazines have been foretelling this for a while but opinion was very mixed. I have now arrived at the conclusion that unless you are mating a carbon fibre post to an aluminium frame, a quality grease should be employed over ant-seize products. I freed the post without too much fuss but shuddered to think had strip downs been less frequent!
Michael Stenning
UK
Wheels #1
Last year I purchased a set of Zipp 303 tubulars with American Classic ultra light hubs. These wheels weighed in at just over a 1000 grams and cost just under a $1000, which was a great buy . As a local cat. 4 racer and obsessive weight weenie I figured these hoops would be a great addition to my current setup. At 174 lbs. I was assured my weight would not be a problem with such light wheels. What I encountered was total lack of control on long fast descents, constant trips to the local shop to get them trued, and absolutely no safe way to stop when they got wet. I have learned that adding carbon components such as a crank and seatpost have done wonders for my ride.
But adding such light wheels as these made riding at times down right dangerous.
Sure they're great when the road bends up, but remember, you normally have to come down and when you do hold your breath. Stiff, stable wheels are invaluable and well worth 300 to 400 grams more.
David Kornblum
Wheels #2
Here is some info on:
testing aerodynamics with SRM:
http://www.srm.de/aero.html
testing some of the best wheels made:
http://www.sheldonbrown.com/rinard/wheel/grignon.htm
The bottom line in all of these tests is that the subject must at least ride between 40 - 50 kph (at least for 1 hour) to see any benefit what so ever.
And I am talking about shaving off seconds here in a 42 Km time trial not minutes.
Sure these expensive wheels are light, strong and have a lower rolling resistance then the less expensive wheels but most of us mortals really do not need to spend $1500 on wheels when in fact we can improve fitness and lose extra weight by merely training and eating right. I can guarantee you will lose your friends on any grade with a pair of Mavic open CD rims and Shimano 105 hubs by eating and training properly.
Ernest Quagliariello
Rochester, New York
Wheels #3
I have read a study about the relative effectiveness of wheels, weight reduction, etc. Sorry, I no longer have a copy. By far the factor you have control over is training. Yes there are advantages to "buying" speed, but over effect is very small compared to increasing you power output. You can do some comparison yourself at http://www.analyticcycling.com/.
Best way to spend your money - hire a coach. Buy bike stuff for fun. Train smarter for improvements.
Sean Bujold
USA Cycling Elite Coach
Menomonie WI USA
Wheels #4
John Stevenson's reply is of course one of the most accurate statements that can be made. Observing somebody spend an extra $500 to save a few grams on wheels can be hard to watch if it's obvious that losing weight will have a far greater impact on their cycling.
Despite someone's physical condition however, it is still human nature to want the best gear affordable, and to seek the advice of experts when confronted by many choices. Many of us look to the cycling press for that expertise, and from a from a consumer's standpoint it would be nice to see more empirical research to assist us with the "comparative" aspect of comparison shopping.
Just as an example; I recently researched the purchase of a new road bike and found no fewer than 5 manufactures that claimed to produce the lightest frame available. Of course, weight is only one of the metrics involved in determining the quality of a frame, but you would think that somebody in the press to play sheriff over these claims right? Instead we get lots of comments in reviews like: "it accelerates well", "it felt nice and stiff", or worse yet; "I shaved a full minute off my time" (well maybe you slept better the night before). Cannondale uses some stress testing machine on their bikes, wind-tunnels are available to test the actual shape of frames and wheels and there must be a dozen cool ways to test clothing.
It would be nice to see some empirical research - just about every other industry (from automobiles to skiing) does it, why not our sport?
Pete Seckinger
New York, NY
Wheels #5
John, Your reply doesn't answer the question. Quite a lot of people (myself included) have made the job/lifestyle choice not to have the odd week to ride in the hills, but do have a few £s to spend on our hobby every so often. I've often though that it would be nice to be able to choose parts based on objective performance rather than cooked-up weights, marketing spend, and whether the frame is painted nice colours. However, you just need to look through the pages of a couple of German cycling magazines to find that following this line of thinking results in measuring the weight and stiffness of everything, which really isn't a pleasure to read and ignores all the small details that experienced cyclists appreciate, as well as more pertinent issues such as whether you can buy replacement spokes for the superwonderwheels and whether the bike will impress your mates.
Therefore I think that seasoned bike riders should keep writing about bikes and how bikes make them feel. I don't think people like Marcel Wust and Robert Millar (writing in Cycle Sport I think) would keep quiet about crummy products. Nowadays bike companies stay in business by £500 bikes that are as good as Big Mig used to win the Tour, and I'm afraid the fact is that 99.9% of pro-level bikes are so good that swapping from one to another will make little difference to anyone's performance on the local chain gang.
If you truly must have the 'best', then you need to do some thinking about what 'best' actually means to you. After a while you'll be scanning pictures of early-season races for the new Dura-Ace 11-speed rear cluster and obsessing about whether U721 tubes are better than Megaoctagons. Next year it'll be worse and you'll end up buying hydraulic brakes with Kevlar cables and helium cartridges for your tyres. It's much easier to buy a C40 because you like the paint job, Campag Record because you like Campag and Mavic Cosmos wheels because they're reliable and you don't like things that disrupt your ride. It made me happy, not to mention making things much easier to explain.
Andrew Salmon
London, UK
Wheels #6
Ahhh, the debate still rages!
I'm often confronted with riders with a reasonably big budget who feel that the answer must lie in the equipment. They're constantly assaulted by a barrage of ads and "reviews" with often dubious claims of "lighter, faster, stiffer, etc. A while back a triathlete new to the sport came in looking for a "triathlon bike". I asked if he had invested in a heart rate monitor, some good coaching and a goal-oriented training program. I also asked if he was regularly placing in the events he entered. A sheepish "no" was the answer to both questions. I said he'd be better off with a nice, reasonably light, "middle of the road" bike and spend some real dough on preparing his motor! Then I suggested that when he was placing regularly, come back and see me and I'd set him up with a great bike, because now, he'd have a much better idea of his real needs. This whole issue can be seen in the wheels people choose.
As a wheelbuilder, I know I can build someone a wheel that will be light, responsive and strong. Not to mention easy to fix if something does go wrong. But new production bikes can't afford to do this, so the trendy, low-spoke-count wheels are sold as lighter, stronger, etc. They often aren't! They're just different. Aero anything pretty much cracks me up. For road racers, who are often in a pack, wheels need to be light and strong-not necessarily aero. For recreational cyclists, strength is number one. Aero is a joke at the speed most non-competitive cyclists ride! For the tri-guys, aero is number one but only if they can stay in an aero position for the race's duration. The bike industry has to reinvent itself constantly. That doesn't mean you, as a rider, need to do the same. I seem to have about the same average speed on my 20 year old, 12 speed Fuji as I do on my 21st Century superlight wonderbike at the end of a ride. Go figure... As Maynard Hershon says about bikes: "Speed: It ain't for sale".
Doug Hamilton
Oxford, OH, USA
Wheels #7
Buy Campagnolo Record 32 or 36 spoke hubs. Let a solid shop with race competition experience make some "old-fashioned" hand made wheels with low profile rims by for example Mavic. Rear wheel spoked cross-two and you can cycle a lifetime. Try not to imitate the pros, they get a new pair every day if something is wrong with the wheel.
Solid and steady the old fashion wheels.
Simon Kooij
Netherlands
Wheels #8
After reading your review on the American Classic 350's which are a conventionally laced 28 spoked set, I purchased a set and was pleased to find that not only were they light (1340g) but comfortable. I'm pleased with the investment but will add finally that the suggestion to ride the hills posted previously is still the best advice.
'AZRoadburn'
Wheels #9
What wheels to get, It's all a trade off depending on what your real needs are.
Aero wheels do make a difference, I did not believe this until I spent a week pedaling on a set of Campy Bora wheels. If you are in competition and going for an edge over your competitors at a race, a good set of deep section carbon tubular wheels with good tires makes a lot of sense. I pedal Zipp 404's on Veloflex tubulars during races, but my daily wheels are 32 spoke semi aero section tubular wheels and Veloflex tubulars. If you're just out to enjoy your ride, $1000.00 aero wheels might not be your best choice or make any real sense. For most cycling, the traditional 36-32 spoke wheel will be just fine. They can be built with very reliable parts and become a very long lived and reliable wheel. The traditional 36-32 spoke wheel might be fashionable, but when you pop a spoke or two you can still ride home and get it fixed at the nearest bike shop.
Bernice
USA
XTR concerns
I have over 200 offroad miles on the new XTR and found that downshifting can be accomplished by tapping the lever with the back of your fingers as well as wrapping fingers around the lever. Also there is a reach adjustment for the lever as well. Hope that helps.
Jim Morg
USA
