Ask the experts

[toast2266]

I want to know what the hell their test methodology was, because a lot of those results make very little sense based on my experiences with those brakes.

There's also a lot of nonsense in their writeups, including citing the Hope E4 as having 4 16mm pistons in one place (correct) and then saying that the E4 has 2 16s and 2 14s (wrong), with the V4 having 4 16s (also wrong) elsewhere.

Yeah, no idea. I feel like brake testing is really hard to do consistently, because any dyno test I see is all over the board.

Mostly I think it's hard to quantify modulation. Sram's power comes on gradually and builds with more lever pressure. Shimanos power comes on quickly but then doesn't really build that much. Both are good, but in different situations. Not sure how to quantify that effectively with a dyno test.

[HAB]

Yeah, no idea. I feel like brake testing is really hard to do consistently, because any dyno test I see is all over the board.

Mostly I think it's hard to quantify modulation. Sram's power comes on gradually and builds with more lever pressure. Shimanos power comes on quickly but then doesn't really build that much. Both are good, but in different situations. Not sure how to quantify that effectively with a dyno test.

Totally, it's a hard thing to do well. I'm just very suspect of that test, based on having tried a whole lot of those brakes, and how little their results line up with my experience.

[summit]

New wheelset, DT240 MS 148x12, put my XT 10-51 on it, and shifting is all off vs the DT350 MS on the other wheelset, almost like the the cassette isn't all the way flush to the hub, except it appears to be so.

Mech required moving both high and low limit, barrel adjust out all tension, still feels like there is too much tension, and if I tighten the rear axle all the way there is cassette drag on the stay that can be felt when pedaling (but wheel spins with no friction).

What is wrong?

[NuMexJoe]

If I had a spare pair of SPDs lying around I would just use them and not bother looking to buy pedals, lol.

You want a pair? I've got a drawer with several 20-year old SPD pairs (Wellgo & Ritchey, mostly) that have collected dust since I made the switch to Time ATACs long ago. Yours for the cost of shipping.

[toast2266]

Totally, it's a hard thing to do well. I'm just very suspect of that test, based on having tried a whole lot of those brakes, and how little their results line up with my experience.

I also just think lab conditions are different than real world conditions. One of their tests that they put some emphasis on is a steady deceleration from 45kph to 0 with constant pressure at the lever. While that's a decent test and fairly repeatable in a lab setting, it's realistically not something that probably happens in the real world all that often. They seemed to indicate that heat build up had a pretty significant impact on brake performance, and I would imagine quantifying the impact of heat on the system in a real world setting is tough.

I don't really doubt their results. I just doubt how applicable those are to all the nuances of how real world use actually happens.

[El Chupacabra]

How's Specialized with tire warranty?

Mounted a new Purgatory 2.6 yesterday on a new wheel (1 ride), it seated properly all around the bead. On Mrs C's new Ripley, on an Ibis Blackbird rim. Left it sitting on the bike in the workstand, occasionally spin the tire when I walk by. Zero rides on this tire. Sitting at maybe 30psi.

Today while wrenching on the truck, tire blew off the rim and sprayed sealant all over. Remounted and tried airing up, it blew off immediately. It remounted way too easily so I expect the bead is damaged.

Bought it from Performance Bike online, and have a message in to them. Wondering how, warranty works on tires. I've never warrantied a tire - and never had a new one blow off before.

[Whiteroom_Guardian]

What kind of fuckery is this? I pulled the crankset like 30ish miles ago. 8 miles into my ride today and I look down and see a big gap on the spindle non-drive side...did I break and lose a spacer? The arm is torqued on there to spec and not loose or backed out. There is no spacer on the drive side.

[EWG]

You want a pair? I've got a drawer with several 20-year old SPD pairs (Wellgo & Ritchey, mostly) that have collected dust since I made the switch to Time ATACs long ago. Yours for the cost of shipping.
[ATTACH=CONFIG]423323[/ATTACH]

You should definitely take the Ritcheys and then report back about how many times you crater onto your side from a complete stop when the things hold on like a pipe clamp.

Video would be nice for us. Entertainment value and all.

[nickwm21]

Converting an old mountain bike into a bike path/gravel/townie/backup mt bike. Because of the multiple uses, looking for SPD/flat pedals. The more inexpensive the better, so long as it works well. I can accept a little weight penalty given the expected uses.

This from Venzo (never heard of them but decent reviews): https://www.amazon.com/dp/B01M5J9VGY/
This from Shimano (more $ than I want to spend if possible): https://www.amazon.com/SHIMANO-clipl...dp/B000NORMU4/

Are there other better options? Should I just stick with a name brand like Shimano? Anything (products or thoughts) I'm not considering?

More money than you want to spend but I have Shimano T8000s on my townie. Real XT spd on one side, real aluminum flat pedal with replaceable pins on the other. Neutral weighted (some of the other combo pedals are weighted to spin to the clip side or flat side)

https://bike.shimano.com/en-EU/produ.../PD-T8000.html


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[HAB]

I also just think lab conditions are different than real world conditions. One of their tests that they put some emphasis on is a steady deceleration from 45kph to 0 with constant pressure at the lever. While that's a decent test and fairly repeatable in a lab setting, it's realistically not something that probably happens in the real world all that often. They seemed to indicate that heat build up had a pretty significant impact on brake performance, and I would imagine quantifying the impact of heat on the system in a real world setting is tough.

I don't really doubt their results. I just doubt how applicable those are to all the nuances of how real world use actually happens.

That's kind of what I mean though. Like, I don't doubt that they collected data that says what they reported. I just don't think what they're tested is relevant to the real world. A well designed lab test absolutely can be representative, but achieving "well designed" is hard.

[Eluder]

What kind of fuckery is this? I pulled the crankset like 30ish miles ago. 8 miles into my ride today and I look down and see a big gap on the spindle non-drive side...did I break and lose a spacer? The arm is torqued on there to spec and not loose or backed out. There is no spacer on the drive side.

need more info, they look like 8120s?

[Whiteroom_Guardian]

need more info, they look like 8120s?

Shimano XT 12-speed on GG Gnarvana. Assuming I somehow lost a spacer by either it breaking or somehow losing one when I pulled the cranks which side do I put the spacers on? I feel like when I pulled the cranks there were two on the non-drive side and now only one?!

Edit to add: So I think I need one on each side of the BB and I think maybe the one on the drive side cracked and fell off somehow.

[Eluder]

Look at the back of the drive side crank arm by the pedal hole and it will tell you the exact model, this will tell us how many spacers you are suppose to have.

https://dassets.shimano.com/content/dam/global/cg1SHICCycling/final/ev/ev/EV-FC-M8120-4558B.pdf

it is more likely it fell off during installation than broke so look around where did the deed.

the "rings" in this diagram are just orings that are part of the spacer.

[grskier]

New wheelset, DT240 MS 148x12, put my XT 10-51 on it, and shifting is all off vs the DT350 MS on the other wheelset, almost like the the cassette isn't all the way flush to the hub, except it appears to be so.

Mech required moving both high and low limit, barrel adjust out all tension, still feels like there is too much tension, and if I tighten the rear axle all the way there is cassette drag on the stay that can be felt when pedaling (but wheel spins with no friction).

What is wrong?

Do they have the same offset?

[grskier]

I also just think lab conditions are different than real world conditions. One of their tests that they put some emphasis on is a steady deceleration from 45kph to 0 with constant pressure at the lever. While that's a decent test and fairly repeatable in a lab setting, it's realistically not something that probably happens in the real world all that often. They seemed to indicate that heat build up had a pretty significant impact on brake performance, and I would imagine quantifying the impact of heat on the system in a real world setting is tough.

I don't really doubt their results. I just doubt how applicable those are to all the nuances of how real world use actually happens.

Only thing I'll say about a test like that, while it doesn't simulate riding your brakes on a steep decent constantly, or long stops coming up to a trail crossing or whatever, what it may do is answer some variable in the equation that you all think about. More of an empirical test than anything. How long to stop from X speed with 4N of force applied to the brake lever... I don't know if they did a series or whatever to develop any equations, but I could see that being part of a process.