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Post by william39 on Aug 21, 2015 20:22:01 GMT
Could try to use calipers on the rim and check thickness that way (find local garage / engineering shop - take tyre off, pop in, ask nicely, they'll do it in seconds); I rebuilt my rear Aksium when it went quite bowed, pads can also rub a groove in. I didn't measure thickness on mine through, they just looked odd and felt dodgy to the touch, a mate's old Dura-Ace wheels (that I've got here for repair) have worn much more than mine though, they've worn so much they started to collapse slightly in one spot near the outer edge but haven't actually failed, you should be able to tell by eye and touch if you give them a close inspection. You're a prime candidate for rim wear failure though with all those hairpin turns to brake for on long fast descents, best not take too many risks stretching them out, if in doubt then replace. What I find curious, is everyone always says you brake harder on the front (true when digging the front in with a car or motorbike) but both mine and my mate's rims wore most on the rear (believe this is normal for most)- either there's more force going through the rear (when people stretch arms and hang out back when braking hard) than people give credit for, or perhaps they just get more gunked up? Interesting. The thing I don't know is maybe my mate's bike with Ultegra had better braking as he hasn't ridden it much so the rims were newer, not because it had Ultegra brakes. Cheapest solution is probably just to order a set of 501s and see if there is a difference, they will serve as useful spares in any case. Otherwise the Campy Khamsin G3 look quite tempting for the price but I wouldn't really want to abuse them through the winter. Big advantage here is that there is virtually nobody about between September and the start of the skiing season so what litle riding I will able to get done will be on the relative flat with little traffic. With regards front and rear brakes, I generally apply both at the same time so the right/left front/back conundrum is a bit of a mystery to me; maybe I am doing it worng but it seems to work!
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Post by Radchenister on Aug 21, 2015 20:59:42 GMT
Ultegra brakes are good, my mate's bike felt good when I last rode his set up but then clean crisp rims, good pads and fresh cables are also a big factor - very difficult to compare like for like. Re braking bias, it's not just about applying the brakes in any order, it's more complex, first it's about trajectory, then it's about position / body weight, that's what's loading front and back axle one way and then it's about relative braking loads applied through rims that are considered in relation to this, your brain knows what balance angles and skidding feels like, it'll have been learning that since you were a nipper and now applying it to your bike riding, your subconscious won't want to induce a fall for self preservation reasons, so it's likely you'll be doing those things without even thinking about it. Rocket will likely confirm that when you ride big road bikes your tolerance for lean angles gradually increases, it's unbelievable to pillion passengers how far they'll lean over and how much grip is available from a decent set up, i.e. good rubber, warm tyres and decent suspension settings - you have to learn new parameters when riding those things and then need to unlearn those sort of lean angles to ride a person powered road bike (or MTBs, I have a story where I slid out across a roundabout a couple of decades back, no big drama, just a good long slide on my @rse on the way into work, my MTB simply wouldn't handle the lean angles my motorbike could). Don't start thinking about it too much though, just keep it smooth and natural - the golden rule is aim not to brake in anything other than a straight line (well kinda, you can get away with a few curves but don't push it until you can work it like Rossi)!
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duplo
Peloton Rider
Posts: 206
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Post by duplo on Aug 22, 2015 6:02:02 GMT
I've used disc brakes for years on my mountain bikes, frankly tiny rubber blocks trying to slow me from 65kph on a downhill is slightly terrifying so I try not to think about it.
My cx bike has discs, and I use it a lot for commuting and winter training.
Discs brakes are easy to maintain, require little servicing, and have a very long lifespan, you can upgrade elements individually. E.G. Get updated disc rotors but keep your original calipers, or get bigger or smaller rotors etc etc.
The development has been done so adopting for road bikes should be easy and relatively cheap. Plus you have hydraulic and cable options. Take a look at the TRP spyre as an excellent example of a cable disc brake.
The only thing I can think of that will be very important on road bikes with discs is effective modulation, especially if you ride in a group. Some disc brakes can be grabby
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Post by jondxxx on Aug 22, 2015 8:41:56 GMT
Most likely. Rear tyres always wear more, reckon that's down to load when seated going mainly through the rear as don't think it's torque and cornering like on a big bike (?). As for braking, I'm uncertain what's happening, although I reckon hanging off the back (like most of us do when braking hard), probably adjusts the relative weighting more than on some vehicles - reckon it's probably more evenly spread than for cars / motorbikes, what proportion front to back is something I'd be interested to know more about, I'm assuming it's likely a pretty dynamic thing. I was going offer my own explanation but decided this link put it more succinctly. As for disk brakes I expect the pro riders will do what their sponsors tell them and he marketing men will then try to convince the masses that they need new bikes. Personally I am quite happy with the Tiagra kit which is well capable of putting me over the bars in panic mode. PS The rest of the article is also worth reading although it's depressing to realise how much maths I've forgotten.
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Post by Radchenister on Aug 22, 2015 9:06:22 GMT
All that blurb is pretty good but I'm still not getting much in the way of how rider position actually effects bias, some actual axle load monitoring would shed light, reckon manufacturers would have some data.
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jksj
Peloton Rider
Posts: 33
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Post by jksj on Aug 26, 2015 11:14:20 GMT
Used the rim ware argument and mudguard clearance as justification for a new Winter bike with discs. In support, did ware one out a rear wheel in the 2013-14 Winter during which road salt was particularly prevalent. Built a Planetx London Road using Avid BB7 callipers. Turned out very well with a softer more comfortable ride than my t3 but that may be just down to bigger tyres. I can confirm that the disc brakes are no better than callipers in normal use but are re-assuring on a steep descent. Basically feels like the braking you get in a car. Noisier than callipers though, best avoided if you expect a silent ride. Recommended only for riding in the hills.
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Deleted
Deleted Member
Posts: 0
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Post by Deleted on Aug 26, 2015 13:31:42 GMT
Eurobike is on. Disc equipped Cervelo and Canyon race bikes revealed.
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