Road race disc brakes?

[King Boonen]

They don't stop faster in the dry. Stopping is limited by the friction of the tire on the road surface. If you can lock up your tires, you've got more braking power than you need. And I can lock my tires just fine with my ultegra rim brakes.

If you're locking up your wheels you need to learn how to break. Besides that, you could lock up your front wheel using half potatoes as break pads with enough force, that doesn't mean they'll stop you as well as your Ultegra brakes when used properly.

If you're not locking up your wheels it is the friction between the brake pad and the braking surface that determines the stopping power. Disc brakes will stop you faster in the dry because of the compounds used in both pad and disc construction.

 

[winkybiker]

Rims wear out from getting wacked, not side walls that wear out. I owned a bike shop for 13 years and I saw maybe 6 rims with the side wall worn thru..I built maybe 350 wheels per year..NO factory wheel has a decent lifespan because of above..wacking the rim..

Calipers on aluminum rims work fine..is the expense, complication, weight of wet discs 'worth' it to you? Maybe but they are a solution' seeking a problem for a dry day enthusiast's bike.

And amateurs with way powerful discs..first panic stop and over they go..great...

Agree with much of what you say, but.....

All my replacement wheels over the years have been due to sidewall wear. This is sometime precipitated by a broken spoke - where I looked at the badly warped wheel, the rim life left and though, "nah, not worth the effort". Whilst you can, in theory, replace a spoke on modern, factory built, low spoke count wheels such as Ksyriums, Rolfs, and Shamals, in my experience, by the time the first spoke breaks a few years in, the rim is pretty much cactus from brake-track wear anyway.

I've never replaced a wheel due to the rim getting damaged by a bump or "whacked".

 

[ustabe]

I'm certain there will be a market for sportive style bikes with discs. Those guys love kit!

It's all about the kit, ain't it?

The best riding of my life was on a 22-lb Gios with a 7-speed SunTour freewheel and wheels I laced from Record hubs and 400g tubular rims. It wasn't super light or super tech, but it took me wherever I wanted to go. In that period the objective of pro bikes was versatile, reliable, and reasonably lightweight.

These days my main ride is a Madone that has gearing to climb trees but likes to skitter sideways on dirt roads and can't take tires wider than 25mm.

We all live with the equipment of our times, but we have to remind ourselves that the goal is to simply have fun riding.

 

[Bustedknuckle]

Sure, but bike shop customers aren't a representative sample of cyclists. High-mileage ethusiasts do their own mechanics, including wheelbuilding so you wouldn't get them coming to your shop. I don't think any of the guys I ride with ever use a bike shop other than maybe a once-in-a-lifetime job like bb shell facing, where the economics of tooling up for it aren't worth it.

I've yet to destroy a rim from a bump, but I'm a careful rider. Have to change a front wheel rim about every two years through brake wear. I'm not alone in this. On the events I ride, rims splitting through sidewall wear is not uncommon. Most of us get the calipers out when changing tyres.



Agree with the last point, but I do have a use for them and I don't mind dry-day guys with fat wallets making this technology economically viable

Balderdash...My customers were almost all 'high milage cyclists', and most don't know a cone wrench from a spoke wrench.

I also did quite well, $ wise, fixing the stuff these DIY wrenches did on their own...I laughed or shook my head after they left with their bike, fixed correctly.

 

[stutue]

Balderdash...My customers were almost all 'high milage cyclists', and most don't know a cone wrench from a spoke wrench.

Exactly.

But you can't talk about the people who weren't your customers, because they were not your customers.

Also, what you call 'high mileage' and what I call high mileage probably isn't the same thing.

I also did quite well, $ wise, fixing the stuff these DIY wrenches did on their own...I laughed or shook my head after they left with their bike, fixed correctly.

Of course you did. That is why they came to you...because they didn't know what to do.

Ironically, one of the reasons I learnt to do all bike mechanic tasks myself was because I got fed up with checking my bike over for badly down work by shop mechanics...and also because my standard of work is higher.

 

[purcell]

Exactly.

But you can't talk about the people who weren't your customers, because they were not your customers.

Also, what you call 'high mileage' and what I call high mileage probably isn't the same thing.



Of course you did. That is why they came to you...because they didn't know what to do.

Ironically, one of the reasons I learnt to do all bike mechanic tasks myself was because I got fed up with checking my bike over for badly down work by shop mechanics...and also because my standard of work is higher.

The LBS that Busted Knuckle ran was not what you or I would think of as "the bike shop", nor was it located "just anywhere".

I am pretty confident, knowing where the shop was, what it carried (and having been in it) that when he talks "high mileage" riders, he is talking about mileage that would MOST definitely qualify by your definition.

 

[stutue]

You don't know what my definition is, but hey ho.

No point turning this into a squabble. I'm sure he knows who his customers were(and I know he knows his stuff)...but equally, I know who I'm talking about too.

 

[richwagmn]

If you're locking up your wheels you need to learn how to break. Besides that, you could lock up your front wheel using half potatoes as break pads with enough force, that doesn't mean they'll stop you as well as your Ultegra brakes when used properly.

If you're not locking up your wheels it is the friction between the brake pad and the braking surface that determines the stopping power. Disc brakes will stop you faster in the dry because of the compounds used in both pad and disc construction.

Ummm, no. The ultimate factor affecting your ability to brake is the traction coefficient between your tires and the road. Don't believe me? How do your disk brakes work on an icy surface?

Any braking force beyond the ability to use the maximum traction of your tires is useless in determining stopping distance. Once your tires start skidding, you have more braking force than you can use.

"One of them is traction coefficient. The higher the traction coefficient is, the shorter the braking distance will be [source: Jones & Childers]. Thus, the braking distance can change greatly based on the type and condition of the vehicle's tires. Tires with little or no tread will be more susceptible to skidding during heavy braking. When the tires skid (a decrease of the traction coefficient), they lose traction and increase the braking distance."

http://auto.howstuffworks.com/auto-...ts/how-to-test-vehicle-stopping-distance1.htm

 

[winkybiker]

Ummm, no. The ultimate factor affecting your ability to brake is the traction coefficient between your tires and the road. Don't believe me? How do your disk brakes work on an icy surface?

Any braking force beyond the ability to use the maximum traction of your tires is useless in determining stopping distance. Once your tires start skidding, you have more braking force than you can use.

"One of them is traction coefficient. The higher the traction coefficient is, the shorter the braking distance will be [source: Jones & Childers]. Thus, the braking distance can change greatly based on the type and condition of the vehicle's tires. Tires with little or no tread will be more susceptible to skidding during heavy braking. When the tires skid (a decrease of the traction coefficient), they lose traction and increase the braking distance."

http://auto.howstuffworks.com/auto-...ts/how-to-test-vehicle-stopping-distance1.htm

Whilst the ultimate brake force is indeed determined by the traction of the tyre on the road, in practice, the quality of the brakes also comes into play. With "poor" brakes, they may well be powerful enough, but somewhat unpredictable meaning that a rider needs to leave some traction unused, lest they inadvertently overdo it and lock the front wheel. With "good" brakes the modulation, control and feedback is much finer. A rider can confidently go closer to the limit of adhesion without undue risk.

 

[elapid]

Ummm, no. The ultimate factor affecting your ability to brake is the traction coefficient between your tires and the road. Don't believe me? How do your disk brakes work on an icy surface?

Any braking force beyond the ability to use the maximum traction of your tires is useless in determining stopping distance. Once your tires start skidding, you have more braking force than you can use.

"One of them is traction coefficient. The higher the traction coefficient is, the shorter the braking distance will be [source: Jones & Childers]. Thus, the braking distance can change greatly based on the type and condition of the vehicle's tires. Tires with little or no tread will be more susceptible to skidding during heavy braking. When the tires skid (a decrease of the traction coefficient), they lose traction and increase the braking distance."

http://auto.howstuffworks.com/auto-...ts/how-to-test-vehicle-stopping-distance1.htm

That's not quite true either. Yes, traction is important to effect braking, but no brake is going to be effective on an icy surface. That's why ABS was invented for cars. Braking modulation is also important for ABS and modulation is supposedly better with disc brakes compared to calliper brakes. Braking modulation allows better tractive control with the road and minimizes locking the wheels up and skidding (like on an icy surface).

 

[ustabe]

Balderdash...My customers were almost all 'high milage cyclists', and most don't know a cone wrench from a spoke wrench.

Same here. The high-mileage guys I know don't have time to learn how to fix their stuff. They work and they ride.

 

[Moose McKnuckles]

I don't know any "high-mileage cyclists" who can do much beyond replace pedals or clean the chain. The reason why they're high mileage is because they spend their time riding, not fixing their bikes. They have the shop fix it while they're at work.

 

[stutue]

Oh ok. And I suppose these are the same 'high mileage' cyclists who neither build their own wheels, nor turn up to bike shops needing a brake-worn rim replaced (because BN says it almost never happens)

They must just be buying entire new wheelsets every time. Either than or they live in a flat country where it never rains.

 

[LugHugger]

Oh ok. And I suppose these are the same 'high mileage' cyclists who neither build their own wheels, nor turn up to bike shops needing a brake-worn rim replaced (because BN says it almost never happens)

They must just be buying entire new wheelsets every time. Either than or they live in a flat country where it never rains.

I can only speak from personal experience. Our group of 15+ riders, which clocks up 300+ kms per week, has no wheel builder. When wheels go pear shaped, we take them to the shop. Everybody can fix a flat, swap a tyre, index their gears and change their brake pads. That's about the extent of our technical knowledge.

And nobody in the group rides, or wants to ride, discs on the road.

 

[King Boonen]

I'm a mountain biker and I think everyone I ride with can build a bike from scratch, a couple could build a decent set of wheels and most of us can true them if we need to.

Must be a different ethos to road biking. Oh, as we have very busy jobs too!

 

[stutue]

I'd say the same about most of the guys I ride with. Most ride bikes built up by themselves. I have 8 bikes, all built by me.

 

[Bustedknuckle]

I'd say the same about most of the guys I ride with. Most ride bikes built up by themselves. I have 8 bikes, all built by me.

Not saying it doesn't happen but most 'high milage cyclists' around here are not mechanics or wheelbuilders...they can't do really much except change a tube, clean a chain, maybe..most high milage bikes are really a mess.

 

[stutue]

Sure, not disputing what you have turn up at your shop

A riding pal of mine, ex pro team mechanic, tells me amongst various other things, that he used to have to service riders bikes in the off-season. Some riders could barely do up a qr in which case he'd have hours of work, whereas some (ok a few) would be pristine and everything tuned to perfection.

 

[King Boonen]

Not saying it doesn't happen but most 'high milage cyclists' around here are not mechanics or wheelbuilders...they can't do really much except change a tube, clean a chain, maybe..most high milage bikes are really a mess.

Is that just road bikes or does it include mountain bikes in your experience?

It seems to be a culture thing with the people I know. Everyone I ride mountain bikes with could build a bike up from a frame and only really need help with the more intricate things like wheel-building (most can true them), hydraulic brake re-builds (all can bleed them) and fork servicing (again, most can do lower services, it's the uppers that get left to the professionals with the right tools).

A lot of the road-bikers I know can't even change a gear cable.

 

[Moose McKnuckles]

Oh ok. And I suppose these are the same 'high mileage' cyclists who neither build their own wheels, nor turn up to bike shops needing a brake-worn rim replaced (because BN says it almost never happens)

They must just be buying entire new wheelsets every time. Either than or they live in a flat country where it never rains.

Honestly, I don't know a single person who has replaced a "brake-worn rim", other than those who have melted or damaged their carbon rim, which I have done on two occasions (Enve and Reynolds melted).

And count me among the ones who cannot change a gear cable.

 

[stutue]

You probably don't know anybody who has built a wheel either then....but many of the people I ride with build their own (including me)

 

[King Boonen]

And count me among the ones who cannot change a gear cable.

10 minute job, if that. Worthwhile learning, unless you have a very good relationship with your LBS.

 

[stutue]

10 minute job, if that. Worthwhile learning, unless you have a very good relationship with your LBS.

You see, to me, taking a bike to a shop for a cable change is unthinkable

The guys I ride with have to know how to do this stuff because if you are on a 1200k ride you don't want it to be over for something stupid.

Beyond basic mechanics, most of us are pretty adept at emergency mechanics. Last weekend, somebody's freewheel stopped working so we zip-tied his cassette to his spokes and he finished the ride on a 20 speed fixed gear

Two years ago, a rider on a local 600k had his chainstay snap on a steel frame. He walked down the hill into a village and welded it back in the local garage by shoving a couple of metal spoons in

I know this might be at the extreme end of things but to be honest round here its only the newby posers with fat wallets that cant do basic jobs on their bikes

(Not in any way suggesting you are a newb poser! )

 

[King Boonen]

I agree.

The only things that go into the shop on my bike are wheels and the forks for a full service (suspension, I only ride mountain bikes).

I'm willing to pay for someone to do a good job of truing/replacing spokes and replacing bearings (cartridge only that need a press) because I don't have the kit to do it properly (and Big Al is cheap!) and there are certain things in the fork that again I can't service properly.

Everything else I do myself. After-all I built the bike, I should know what I'm doing


I do think it's a mountain bike culture thing though. We give our bikes a much harder time than road bikers do, so being able to fix things and replace bits is really part and parcel of owning the bike (for the more experienced riders at least). It's also something most mountain bikers learn early on from my experience.

 

[DirtyWorks]

10 minute job, if that. Worthwhile learning, unless you have a very good relationship with your LBS.

I've replaced lots of cable as a former shop monkey and best case scenario is a 10 minute job. If you don't have years of regular practice, it is time consuming.

Maybe it's the common case that many aren't aware of the time it takes to do the job? For many, it is probably a preferable task too.

I get that fixing it yourself is a part of the cycling culture and mountain biking requires some trail-side skills, but sometimes the best allocation of time is dropping it off at the shop. Especially if you've got the money and kids, and a wife, and.....,