BTLOS 30mm wheels for pure climbing?

[mcteague]

Originally Posted by fogrider

I stand by my comments based on my own results, your results. Your results may vary! I'm sure some of it is because of 'new wheel' affect but a PR is a PR. to be honest, I doubted too, this was with tubulars when I first got sucked into lightweight wheels...

But are you consistently 2-3 mph faster on the new wheels? I'm not questioning your experience but it does conflict with years of data on weight vs speed.

Tim

[thwart]

Originally Posted by mcteague

But are you consistently 2-3 mph faster on the new wheels? I'm not questioning your experience but it does conflict with years of data on weight vs speed.

Tim

Yep, that’s the key word.

A PR is certainly nice but day in, day out performance over time tells the tale… factors out the psychological aspect.

[Mark McM]

Originally Posted by fogrider

Tex, I've been to Texas...it's mostly flat, you certainly don't need climbing wheels! But lightweight wheels do make a bike feel quick! A 1250 gram wheel compared to aluminum wheels might be like 2mph on a climb. So, if on Alum wheels, you might be climbing at 10 mph, but on carbon, with the same power, you might be doing 12 or 13 mph.

So, if 1250 gram wheels makes you 2 mph faster on a climb, will 950 gram wheels make you 4 mph faster? I've used 950 gram wheels (FSE 20mm deep carbon tubulars) at the Mt. Washington Hill climb race, and if I'd gone 4 mph faster, I would have broken the all time time record for that climb. Yet I only averaged less than 0.1 mph faster. Should I go back to wheel maker and ask for my money back?

[bigbill]

Unrelated to average speed or weight, but if I got another set of wheels from BTLOS, I won't go with glossy again. My bikes are rarely clean other than the drivetrain. The glossy finish shows everything. I'll do matte next time. Otherwise, the Bitex hubs spin smooth and allow for direct pull spokes. I'm not sure if I'm faster but once we relocate to central Wyoming in the spring, I can do comparisons between the two wheel sets I have for my Open Min.d., OG Boyd Altamont or the BTLOS. The bike has a powermeter crankset so I can ride the same loop and compare power versus speed.

[fogrider]

Originally Posted by Mark McM

So, if 1250 gram wheels makes you 2 mph faster on a climb, will 950 gram wheels make you 4 mph faster? I've used 950 gram wheels (FSE 20mm deep carbon tubulars) at the Mt. Washington Hill climb race, and if I'd gone 4 mph faster, I would have broken the all time time record for that climb. Yet I only averaged less than 0.1 mph faster. Should I go back to wheel maker and ask for my money back?

With power to weight to speed, like many things in life, its diminishing returns. Back in the day, it was pretty tough to get wheelset under 1500 grams. And its really not the total weight of a wheelset that improves performance. Its rim and tire weight (and tube) or rotating mass that is furthest from the hub that really affects performance. Look at a modern wheel and how it's built to get to the final weight. With a 1250 gram wheel, the key is the lightweight rim and aluminum nipples. Lets say you're able to get to 950 grams. To get there, spec a carbon hub and spokes, then I would think the performance would be minimal. But if you can get to 950 with a lighter rim, you might be able to get more speed but there are other factors that will start to become a factor. But this is also why so many people like the TPU tubes, there's 60-80 grams savings for 30 bucks.

I'm not going say I know the physics behind it, but I'm speaking from experience. I've recently set PRs on a 35 second uphill segment and a 8.5 mile segment and a 0.2 mile segment. In general, I know I climb faster with lightweight wheels and the bike just feels more responsive and fun to ride.

[fogrider]

Originally Posted by mcteague

But are you consistently 2-3 mph faster on the new wheels? I'm not questioning your experience but it does conflict with years of data on weight vs speed.

Tim

what data are you referring to? to specific, are we talking about weight or rotating weight?

[deluz]

Lighter weight wheels can feel faster but I think it is partly an illusion.
In my case rider plus bike weight is 160 lbs.
If I save 300g in wheelset weight that is 0.4% lighter.
At some point you are spending a lot more money and sacrificing robustness to lose a few hundred grams. Aluminum nipples on carbon rims are a recipe for corrosion.

[nmrt]

Lighter wheels are faster. For some riders, these savings mean a lot. But for many of us mere mortals, how much faster they are does not really matter in our hobby riding.

Even if I many not be significantly faster on my light 1100 g wheels, they sure do FEEL faster to me. And I would definitely pay for the FEELING of a faster speed.

I have only had carbon wheels built with aluminum wheels. My oldest set is about 6 years old. There has not been corrosion yet. Also, among my bikes, I have 8 carbon wheelset with aluminum nips. No corrosion yet.

I understand the science of why the corrosion can happen. But it has not happened yet.

Originally Posted by deluz

Lighter weight wheels can feel faster but I think it is partly an illusion.
In my case rider plus bike weight is 160 lbs.
If I save 300g in wheelset weight that is 0.4% lighter.
At some point you are spending a lot more money and sacrificing robustness to lose a few hundred grams. Aluminum nipples on carbon rims are a recipe for corrosion.