waterrockets 

I built up my old first race bike (Bridgestone RB-1) as a single-speed, primarily for hill repeats I've been single-speed MTBing for a couple years, and really enjoy it.

I rebuilt the rear wheel with an ENO hub (same spokes, nips, and rim), threaded on a massive 22t BMX freewheel, and a 39t chainring. The bike ended up weighing maybe a little less than my geared road bike. It has a stainless 150mm stem, steel forks, and a 4.6 lb lugged frame, so it's not going to win any weight weenie awards. It's probably around 18.5 lbs.

For starters, on top of the car, the cranks spun backwards at like 300 rpm until I tied them down. My geared drivetrain has enough resistance to keep the crank from spinning (same with my training partners' bikes on the same rack). If I lift the bike off the ground and spin the rear wheel backwards, it will coast for a minute, dragging the crank along with it.

Anyway, I did hill repeats on it today (six at a 13% avg grade for ~1/2 mile). The 39-22 felt a little tall at first (I'm usually in a 39-23), but I was able to get on top of it and stay there. By the time I had finished my 6 repeats, my average time was down 4.25%. I do repeats on this hill a LOT (Far West, Austin), and I've been really consistent for the last 5 weeks on it. I'll credit a little of that time to the dropped weight, but the drivetrain is the big change.

The bike is a lot flexier than my Ritchey, but it only bothered me on the sweeping descents -- I was wandering a bit.

Now I need to take it to Jester and cash in my 7 second improvement there

You guys who are doing flat TTs on single-speeds know what you're doing

KevinF

So you essentially have one data point (today's hill repeat times) and you're comparing that against the last five weeks worth of data and you're deriving conclusions from that?

waterrockets 

correct

I've been climbing this hill for 2 years, 6x, weekly. I've never gone as fast as today, even when I've had a stiff tailwind. The last 5 weeks have been particularly consistent.

Also, it's 6 data points, because I climbed the same hill 6 times.

superdex

39-22 is how much taller than 39-23? Maybe about the same as your improvement? I'd go back with the other bike and run it at the same gearing...

waterrockets 

Hmmm. I've got a 23 and a 21 on my road bike. I go slower in the 21 (I've tried that trick). This is a steep hill. The bottom nears 20%.

EDIT: I assumed everyone knew that SS was more efficient than geared -- that's a given

dmotoguy

now do it fixed and see what happens.

eippo1

I'm about to do my 7 hills ride on my 42 x 16 fixed gear tonight.

derrumbe

Don't happen to have a google maps or motionbased snapshot of that hill, do you?

After 2.5 yrs of nearly constant international travel, I finally have the time to invest on the bike. Looking for a "proper" location here in town for intervals/hill repeats. The ints I can do anywhere (s. mopac, for example), but since I lack a garmin, it's hard to tell what the actual slope of the roads are around here.

Or, if anyone has some approximations of slope, that would be great - say for scenic, mt. bonnell, ladera (yes, could do a search, but I'm feeling lazy today).

waterrockets 

Here's the course. The elevation profile is messed up (the Google data is bad), as there is no downhill on this climb. It does shallow out for a bit, but it doesn't approach flat.
https://www.mapmyride.com/ride/united...stin/538277462

A great hill to get started with repeats is Mesa (again, ignore the descents -- they don't exist):
https://www.mapmyride.com/ride/united...stin/538304150

I still go back to Mesa every so often because it takes a little longer. It's shallower, so it tends to be more aerobic.

MIN 

waterrockets you are an animal - all your posts are about suffering!

Check out this thread in the SS/Fixed forum. Exploring the idea that fixed is faster up the hills due to (1) mechanical efficiency (2) momentum (3) mental result of "can't stop on a fixie on this hill", etc.

derrumbe

Thanks for the route. Just went out and tried it out - starting from 6th and mopac. Figured that anyday without rain that I'm not riding is a mortal sin.

Flipped the streets, though - thought you had posted that Far West was the good starting point; lesson learned.

Youŕe right, of course. Had to create my own flat, so to speak.

slvoid

It's funny cause I've also noticed that my fixie is faster up the hills compared to my road bike, no matter what gear I grab. But this is only on short hills, on something that's like, a mile, after the first 1/4-1/2 mile, I could really start using some extra gears.

Grasschopper

I am for sure faster on my fixie than I am on my geared bike...I haven't tried any big hills yet as my gearing is 42-16 but on rolling rides I avg as much as 1.7 mph faster than when riding gears...and now I am also getting faster on my geared bike.

I am locvng the fixie.

chipcom 

Little less weight, probably a better chain-line than your geared bike and a taller gear right between what you normally use and what has proven to be a little too tall for your liking. Yeah, I can see why you are faster.

waterrockets 

Yep, it all adds up. I had predicted 3-4%, and there it was, just from equipment

KevinF

This "map-my-ride" site has to have the worst elevation data I've ever seen. I checked three local hills that I know well. Its elevation profiles for all of them are so laughably bad that I question anything I see on there.

eippo1

I tried doing my hill loop on my fixed and ended up doing the hills part at about 2 min faster than usual. Unfortunately, my gearing 42 x 16 made me stand up for most of the hills, but then I trying to learn how to climb while standing anyway. But thanks for the inspiration Waterrockets, I dunno if I would have done this without you being the guinea pig.

Below is my route profile:
https://www.bikely.com/maps/bike-path...gton-arlington

waterrockets 

It's all google. Toporoute displays the same messed-up profiles. Interesting though, I just tried bikely and got a much smoother graph, but it's missing a big steep section at the end of the climb. https://www.bikely.com/maps/bike-path/51035

That's a pretty crazy gear for those hills (looking at the profile). Sounds like you got your payback with efficiency though

operator

+1 billion

close thread

UT_Dude

What're the grades on Mesa and Far West (La Dera Norte?)? I've been trying to figure that out forever and gmap-pedometer just isn't cutting it.

waterrockets 

I keep forgetting about this page:
https://homepage.mac.com/craigrowland/AustinHills.20030902.pdf

I think Mesa is 7%. Ladera Norte is probably the same as FW, just because of that long shallow section. The bottom of LDN is near 20%, and in another thread, a guy with a GPS said the top of LDN is 20%. That jives with the page above, as it lists 19% for Beauford, and I think the steep parts of LDN are steeper than the steep parts of Beauford.

I've done Beauford repeats, but it's just a little too short and kind of out of my way. The descent is a total blast though. Really windy and rough.

Smokey Valley is the steepest I've seen in town, and you can finish it off by continuing up LDN. I don't know what Smokey Valley's grade is, but I've done repeats on it in the rain, and you have to be really smooth to maintain traction (at least I did in my 39-23, out of the saddle). I really think Smokey Valley would be approaching 25% near the top.

UT_Dude

Know of anything else that's longer than any of the above, but not near as steep? I'm thinking 4-5% or so for V02 intervals...

ratebeer

Killer post, Rockets!

(I wish I had a flat TT course.)

And hey, I just thought you were faster due to the Oreo recipe change!
https://www.kraft.com/update/faq.html

truckin

A link to Performance's Aheadset page, waterrockets?

waterrockets 

What duration do you want to ride, and at what output? (%LTHR -- I'm powerdumb here) I can ride conversationally slow up Mesa, and even most of Far West. At an aerobic pace, Mesa would probably take me around 5:15 or so? All-out, I can get up it in 3:10, so there's a lot of range on that hill. It's steep at the top though.

I haven't ridden it yet (I just haven't made time), but Big View may be what you're looking for. It's not shallower, but it's twice as long I really want to go hit it some time though. It should feel a bit tougher than Mesa, but not as bad as Far West. It's nearly a mile long, so it should take 10 minutes or so at an aerobic pace:
https://www.toporoute.com/cgi-bin/get...BPCPOKSLTYICJH

Honestly, as unattractive as it may be, 360 from the Pennybacker bridge going south may be just about right. 1.72 miles at 2.6%. You might have to do a right-turn/u-turn/right-turn at Westlake Dr to keep moving, but that's not the end of the world:
https://www.toporoute.com/cgi-bin/get...IPUIHGBTSJSEYB