Is there any downside to having both rim and disc brakes on the front wheel?
Assuming I can fit the second brake handle where it doesn't get in the way?
Having a "spare" brake could be critical in some cases, i.e. when going downhill and a cable snaps...

extra weight, and the odd stares from other cyclists?

Aside from these, I don't think so. Pretty odd, pointless, but cool idea that I've never seen done before

Pointless. You have a rear brake. Also if you maintain your bike properly the odds of you breaking a cable (especially on the front) are slim.

Well, a few hundred grams of extra weight is definitely not a big thing for me.

The thing is, I just want to know that if one brake fails during a long descent, or a steep one, or both, that there is a second brake to cover for it.
I'll likely just use the regular rim brake 99% of the time, but when something happens, I believe it would feel pretty good to have...

Are disc brakes difficult to add yourself? I assume I'll need a new front wheel...

Ah, but I've tested the rear brake alone, going down a local hill.
If I'm going above around 20 mph, the rear wheel/brake wont slow me down enough - it skids!

It is not practical or necessary unless you are transporting active nukes down a mountain each day.

It will make you appear foolish to other cyclists.

Well, if it's necessary or not can be argued about forever.
When something happens...

And I REALLY don't care what other cyclists (if I ever see any) think about it.

What I wanted to know was if there's any technical/mechanical downside to it, other than weight.

I've seen drum brake/rim brake combos on tandems (And triples for that matter), so it's certainly possible to have rim & disc brakes (Given you have a frame/fork and hubs that are set up for disc brakes - if not, consider SRAM's drum brake). On drop bars you could add a mountain bike/bmx lever on the flats for the second brake. On a straight or riser bar you'd just mount a second brake lever somewhere on the bar.*

But why stop there. What happens if you have a flat - It might be possible to lace up dual rims so you have back-up tires front & rear. And what about the possibility of your frame coming apart - Could you run double tubes along side each other? And what if...

Just kidding - Good luck!?

*Do you own a car? If so, I can't imagine the type of brake system you must have.

I don't think its neccessary. I think a better idea would be to get a nice beefy rim that can hold alot of heat. Also inspect your cables often. An undamaged cable won't just break for no reason, those things are strong.

Well, ok, since no-one's objected to the technical aspect of it, I'm happy.

The general agreement seems to be that it's unnecessary and silly, but that's not a problem for me...

And yes, my fork has the two thingies that hold the disc brake.

Another vote for unecessary.

[QUOTE=CdCf...I'll likely just use the regular rim brake 99% of the time, but when something happens, I believe it would feel pretty good to have...

Are disc brakes difficult to add yourself? I assume I'll need a new front wheel...[/QUOTE]


I predict once you try disc brakes, they will become your primary brake system and the rim brakes will become your backup.

To add discs, you'll need a disc compatible hub and proper lacing to the rim. If you buy a pre-made wheel, most disc wheel sets don't have the proper rim for rim brakes. Hopefully, your fork can accomodate disc brakes, if not, you'll need a compatible fork. And of course you'll need the brake set.

BTW - I've been riding road and mountain bikes for over 15 years and never snapped a cable. But, I also inspect and change cables every 2 years or so. So with proper maintenance, a snapped cable should be a rare occurence. Plus, you have the rear brakes as a backup.

I predict that once I try disc brakes, they won't become my primary brake system, for the simple reason that I have these over-complicated brake/shifter combos.
Can't very well replace just the brake there, unless, of course, I can swap the brake cables...

The fork, as I said, is compatible.
Too bad about the need for a "combo" wheel.

I understand your brake/shifter combo issue. I guess you could get a separate brake/shifter pod setup, but may defeat your intended purpose.

You can easily build a "combo" wheel (one with disc hubs and rim-brake rims). It really shouldn't cost more than buidling a standard disc compatible wheel, since the labor is the same and cost of either rim should be about the same. It is usually cheaper to find pre-make wheels from online bike stores (they're probably spit out by a machine). You might be able to find some "combo" wheels out there, I never looked. You can imagine that some factory had a bunch of rim-brake rims that they put onto disc hubs because they had a surplus of rim-brake rims.


CdCf = coefficient of drag / coefficient of friction? (just curious)

One more factor to consider - hydraulic or mechanical disc brakes?

Yup!

I'd go for mechanical. Simplicity first, and the slight matter of cost...

And I'll check how much it would cost to have a wheel rebuilt if I can't find one that works both ways.

It's not something I'll do this year, though. Maybe in April/May...

In the unlikely event your front brake fails, use rear brake.

Unless the descent is too steep...
I have one of those just round the corner from where I live.
If the front brake fails, and I'm going fast, I have no way of stopping until a quarter of a mile later...

you could have dual disks and a rim brake on the front ....also you could add a disc and a u brake to the back that way you could have three breaks on each wheel.


Or you could get real.. and just sit on your rear wheel if you get into real trouble on a downhill like every one else.

I don't get this. I simply wanted to know if there's an actual PROBLEM with having both kinds in the front. That question was answered by Mudpie.
Whether you think it's necessary or not doesn't matter to me.
Some ride without helmets as well. Works great, until something goes wrong...

How do you propose I sit on my rear wheel???
Do I unscrew the rack and fender while descending faster and faster?

If you got hydraulic rim brakes like Maguras, you could run discs and rims from the one lever with a bit of ingenious plumbing . PS Don't try this at home...

if you pull the brake and can lock up the front, lift the rear, or both, you have as much braking power as you can get. the only thing to do is increase the friction between the tyre and the road, or change weight distribution.

if your front brake fails, you have a rear. if the rear fails you can always jam your shoe between the rear wheel and the seat-tube.

fsnl
sparky

sorry man I didn’t realize you had fenders

Lol at worldwind - But... fender??? In England we call them mudguards... I thought fenders were what Americans called what we call bumpers on a car - as in a 'fender bender' ie minor bump in a car? Not being pedantic - it's all in the cause of Angle-American relations ...