Bicycle Tech/Gear Discussion Thread

Sep 11, 2013 at 04:11 PM

Hey Craig. I keep spare tires in the bags my sunglasses come in, along with small pieces of rubber I can use in case I get a blowout. I usually have 3 different sizes, widths, lengths. I've had to use them a couple of times to prevent the new inner tube from bulging out after a blowout.

I just did a Google search. I should have written 'boot'. I'm not sure where I got the term 'bumper'. I tend to make stuff up when I don't know.

I've ridden with someone who uses cut up pieces of a Fedex package, which works well. A dollar bill will work, too, but I usually only carry hundreds and fifties with me, so never have a dollar bill available. . .

Craig Zolan

Sep 11, 2013 at 06:13 PM

ahhh a boot. yes, i like the fedex (tyvex) envelope trick. I once used the end of the box the tube came in for some hapless guy whose sidewall was in tatters. think jeans that are threadbare at the knee, the whole knee.

Jules

Sep 11, 2013 at 06:22 PM

@Brendan that is the best lighting for a tire picture I've seen in ages.

I think of it as an insurance problem; is the price of a new tire worth the peace of mind to you? It is so hard to know if the fraying is significant or not because it depends on some degree to the kind of riding you'll do.

Hopping curbs and screaming downhill a lot? Probably not.

10 mph commuting on country roads, yeah probably.

Alex Vaughan

Sep 11, 2013 at 08:46 PM

Hey all - 4 chain / cassette questions for ya.

1) My bike has been shifting for shit, and cable fiddling isn't fixing it. Using another set of wheels, though, it's much better. Diagnosis: one of the cassette spacers is broken. Is this replacable, or a sign that the cassette has taken enough damage that it should probably be replaced? The closest I can find is: http://www.amazon.com/Origin8-Freehub-Cassette-Spacers-Bag/dp/B00ACTJTYW/ref=sr_1_8?ie=UTF8&qid=1378932023&sr=8-8&keywords=shimano+cassette+spacers

2) Regarding said new chain, I just re-used the pin from my last chain because I couldn't find the pin that came with the new one - and because I wanted to race the next day. Was that dumb / have I fucked the chain? For reference, this is the symmetrical Ultegra chain, (CN-6600 I think).

3) Since I was going to ride cross the next day, I shortened the chain one link to keep things a bit tighter as I don't enjoy losing my chain (and was expecting to inflict some small ring-small ring abuse on the poor thing). Right now it's pretty tight - in the large/large combination, there is still a significant bend in the chain as it goes through the derailleur pulllies, but it's more of a sigmoid than an actual S curve. Anyway, how tight is too tight?

4) Does anyone bother to lube their derailleur pullies themselves? They seem a little bit stiff to me, but I'm reluctant to do the Full Parktool (http://www.parktool.com/blog/repair-help/rear-derailleur-overhaul).

dstokes

Sep 11, 2013 at 09:45 PM

1) You can replace the spacer. Only important measure of wear is the cogs themselves and as long as the chain doesn't skip, you are ok. I would imagine that someone on this forum has spare shimano spacers lying around (10-spd?)

2) don't know about these chains

3) Shorter chains make for crisper shifting. Smaller chain rings for 'cross require shorter chains. In the big chain ring and the largest cassette cog, the rear derailleur pulleys can be pretty stretched out. If you push forward on the pulley hanger, you will see that it can go quite far forward. You shouldn't be using that gear much anyway.

4) If you are worried about derailleur pulley friction, get TACX pulleys which have nice cartridge bearings. Cleaning them and lubricating the chain should be good enough.

Brendan Rigby

Sep 12, 2013 at 01:04 AM

4) If your derailleur pulleys have bushings instead of ball bearings, spray them with degreaser to flush them out, then go at them with a penetrating lubricant. Or just take the pulleys off; it doesn't take as much time as the full overhaul you linked to.

If your derailleur is crusty, rebuild it! I subjectively feel that everything works better after I disassemble, clean, lubricate, and reassemble it.

As for rear derailleur pulley cartridge bearings, I opened mine up once and serviced them as SRAM recommends. Not worth the effort. I may have slightly bent the seal and created more friction by servicing them. Plus, the ceramic balls will supposedly shred anything that does get in (other than diamonds, which I am always running over...first world problems). I was all excited to service the bearings when I got the new derailleur, but now my thinking is that derailleur pulleys are about as important as which direction you wrap your handlebar tape. They effect a shift by moving sideways, not by rolling more smoothly.

Brendan Rigby

Sep 12, 2013 at 01:07 AM

thanks everyone for the tire fraying advice. love being able to solicit the opinions of fellow bike fiddlers. i will make a decision soon but might end up going with the economical choice of buying a purpose-made tire boot: http://www.amazon.com/Park-Tool-TB-2-Emergency-Tire/dp/B000YBGJRS

@jules good point. that lighting is remarkable! and there wasn't even a flash. i'm sure it will never happen again.

mugwump

Sep 12, 2013 at 01:25 PM

re: boots. cut up tires work decently, but thinner solutions like tyvek envelope pieces or energy bar wrappers work better. the reason I believe this is that the tire inside the tire feels much lumpier when riding. Never tried the Park boot. Going to look into it, but I do love the utilitarian goodness of the old wrapper.

Alex's list

2. Ultegra chain. Get yourself a few reinforced connecting pins STAT. Their pins are made to be used once. This, to me, puts you in far greater danger than Brendan's frayed tire.

3. If your derailleur arm is pulled almost parallel to the ground in the big/big, the chain is probably too short. What are your rings and what is the tallest and smallest cog?

4. Derailleur pulleys can add serious friction to pedaling. Clean them out and/or replace them. The Tacx pulleys are pretty cheap and work well.

mugwump

Sep 12, 2013 at 01:27 PM

Peoples,

I'm heading off to the fake Sin City to experience the two-wheeled overdose known as InterBike. Curious to know what others are curious about.

dstokes

Sep 12, 2013 at 01:50 PM

I would like to know where is the real Sin City.

Marc Bertucco

Sep 12, 2013 at 01:50 PM

mugwump said:

Peoples,
I'm heading off to the fake Sin City to experience the two-wheeled overdose known as InterBike. Curious to know what others are curious about.

Well, you know, the usual stuff. Power meters and carbon wheels, the design/quality/price conundrum, head unit tech advancements (maybe you can sample the 510/810?), and cyclocross...disc breaks?

Will you race cross vegas this year?

mugwump

Sep 12, 2013 at 01:51 PM

dstokes said:

I would like to know where is the real Sin City.

you're living in it, baby!

mugwump

Sep 12, 2013 at 01:52 PM

Marc Bertucco said:

mugwump said:

Peoples,
I'm heading off to the fake Sin City to experience the two-wheeled overdose known as InterBike. Curious to know what others are curious about.

Well, you know, the usual stuff. Power meters and carbon wheels, the design/quality/price conundrum, head unit tech advancements (maybe you can sample the 510/810?), and cyclocross...disc breaks?

Will you race cross vegas this year?

All that is assumed. I'm hoping to test ride disc braked road and cx bikes at the Outdoor demo and see if I can detect an improvement in braking. Might set up my own deceleration lane.

No to CrossVegas. I want to do it, but my grand UCI points total of zero makes it impossible.

Marc Bertucco

Sep 12, 2013 at 02:06 PM

And here's another sort of general issue that has confused me of late. Carbon rims and cross? First I thought they were the shizzle because of deep dish profile sheds mud and are light. But then I feel like I was hearing, stuff like, "one muddy race and you'll ruin your braking surface, thereby ruining the wheel!"

Alex Vaughan

Sep 12, 2013 at 02:53 PM

Thanks @mugwump, @stokes and @brendan. I'll fix the chain, and take the aggregate advice on pulleys and just remove them altogether and replace with dishwasher bearings. #obreeforlife

dstokes

Sep 12, 2013 at 04:57 PM

Marc Bertucco said:

"one muddy race and you'll ruin your braking surface, thereby ruining the wheel!"

If this was the case, then I believe they would quickly disappear from the 'cross courses of the world. That doesn't seem to be the case, though I'll have to look more carefully at pictures of muddy courses. I will note all of the top 10 riders in the 35+ field at Nittany on Saturday were riding deep dish carbon wheels. Though it was dry.

Jeff Owens

Sep 12, 2013 at 08:13 PM

mugwump said:

Peoples,
I'm heading off to the fake Sin City to experience the two-wheeled overdose known as InterBike. Curious to know what others are curious about.

Snag me Rapha swag. Thx, duder!

twoyacks

Sep 13, 2013 at 01:32 AM

I don't care if the chain is carbon...I'm getting one ! If Betsy starts building bikes, I'll likely buy one of those too..

http://www.cyclingnews.com/news/lemond-revives-bike-business-with-time

twoyacks

Sep 13, 2013 at 01:55 AM

bid now broheims...

http://www.ebay.com/itm/BIANCHI-EV-TITANIUM-VERY-RARE-59cm-2003-2004-SAME-AS-S9-MATTA-/130985922820?pt=US_Bicycles_Frames&hash=item1e7f5e9104

mattie davitt

Sep 13, 2013 at 02:50 AM

@mugwump, are you racing the industry cup crit? i'm pontificating upon it, pricey though

Jules

Sep 13, 2013 at 02:41 PM

@Wump I'd like to know more about:

The MIPS helmet technology and the various manufacturers approaches (POC, Lazr, etc) and any other improved helmet-safety/quality stuff on the horizon.

More about the wahoo-trainer and related products.

Thanks again for taking our questions to the Oracle; remember to pack a current kit this time!

mugwump said:

Peoples,
I'm heading off to the fake Sin City to experience the two-wheeled overdose known as InterBike. Curious to know what others are curious about.

Alex Vaughan

Sep 13, 2013 at 03:30 PM

So, this is a thing: http://www.ebay.com/itm/Garmin-Edge-500-Handheld-GPS-Receiver-Orange-And-Blue-Team-Special-Edition-Rare-/190899848959?pt=GPS_Devices&hash=item2c728486ff

So matchy matchy!

jim_nelson

Sep 13, 2013 at 05:17 PM

The bit above about carbon hoops for cx got me wondering how they view the question in PDX where they often have muddy races every single week. I emailed my buddy Mark and asked him the scoop. (disclaimer that this is only one opinion from obviously a huge scene out there but I thought it may be worth sharing anyway):

It does ruin the braking surface. If it's a muddy year here in the NW, people have ruined a pair in one season.

But I can't speak from experience because I have discs. Other racers tell me at races while staring at my brakes, "Hey, that's the only way I would run carbon rims in cross."

I would avoid carbon hoops in muddy parts of the country unless you have disc brakes or a metal brake track on the rim. If the rims got a metal brake track, it's almost as heavy as it's metal counterparts and the carbon hoops aero advantages are rarely utilized in CX.

Sometimes I regret having the fancy hoops. With the money I spent, I could have bought 2 less expensive wheelsets and glued up different treads on each pair. The biggest advantage of carbons are looking snazzy. It seems a few years ago, carbon hoops were all the rage but out here they are becoming less common of a sight at races.

If you only race once or twice a year in the mud, I think it is simply an aesthetic issue as to whether you go carbon or alloy as they should last a while. Carbon are slightly lighter, stiffer, and sexier, but are more expensive to replace after a crash and don't give like an alloy rim that may survive a crash that cracks the carbons.

Erika Tarte

Sep 13, 2013 at 07:50 PM

Any recommendations for a cheap but effective repair stand or DIY hack?

Alternatively, would anyone happen to have a repair stand, free standing or bench mount, that I could borrow while I build up my cx bike? I can offer beer and/or homemade ice cream (in any flavor you can dream!) in return.

Jeff Owens

Sep 13, 2013 at 08:39 PM

Homemade ice cream?!? Chocolate peanut butter?!?! You can borrow my low-end park tool stand for that! But it's big an heavy. I'm in, wait for it.... Williamsburg.

mperlberg

Sep 14, 2013 at 12:06 PM

@ Erika - if you want to avoid the trouble of having to get your vaccinations updated before heading to Williamsburg, I have a stand available to loan in Lefferts Gardens.

eragot

Sep 14, 2013 at 12:11 PM

@Erika - You are welcome to use my workstand and tools in my basement to build the bike up. I would also be available for advice if needed. Probably crack a beer or two as well.

Erika Tarte said:

Any recommendations for a cheap but effective repair stand or DIY hack?

Alternatively, would anyone happen to have a repair stand, free standing or bench mount, that I could borrow while I build up my cx bike? I can offer beer and/or homemade ice cream (in any flavor you can dream!) in return.

JoshuaC

Sep 14, 2013 at 09:03 PM

Was inspecting my bike and I noticed sections of rubber missing on my rear tire (there are brown spots, I thought it was dirt, went to clean them off, realized they were indentations, rubber had peeled off). Well, that sucks, new trainer tire I guess.

So off to the bike shop, I purchased a new tire. "23 or 25" LBS dude says ? 25 I think - I am running 23s but winter is coming. Remove the tire and tube, cut the packaging off the new tire, and then I notice on the wheel a really small decal that says min 19mm max 23mm. The wheel is a Mavic Open Pro 32 spoke clincher.

Can I mount the 25mm tire and get away with it or is this asking for trouble ?

Alternatively, anyone want to buy a brand new Conti Ultra Gatorskin 700*25C ?

Brendan Rigby

Sep 14, 2013 at 09:50 PM

someone here will likely know, but they might be referring to something like ERTRO sizing, not the normal sizing? as in, bead width not tire width?

mavic's website says you're fine up to 28mm, assuming that the open pro on their website is the one you have. http://www.mavic.com/rims-roadtriathlon-open-pro#.UjTZl8Z018E

JoshuaC

Sep 14, 2013 at 10:31 PM

Thanks Brendan. Yeah, I think you are right. Re-reviewing said sticker, the min max are for tire pressures. It has min max pressure for a 19mm and a 23mm tire (but 19 and 23 are not min max tire sizes).