650B Homegrown?

[bad mechanic]

Has anyone here done a '99 or older Homegrown as a 650B? How did it work out? What were the caveats?

[DEADBEEF]

yup:







I'll swap these for some better quality pics soon.

My impressions: quite good. Before building this up, I had never ridden anything other than 26" wheels. I immediately began to notice all the things people say about 29ers.. easier to roll over roots, rocks, etc. the biggest thing for me is cornering. that larger contact patch just feels right when carving through turns. traction while climbing is also improved.

cons: initially, the steering felt a little twitchy, but i quickly adjusted and it was not an issue... that's about it.

I built up these wheels using Alex XD-lite rims and IRD FireXC 2.1 tires. i just used 26" tubes with no issues. clearance on the frame is no problem, the fork just fits. if i let all the air out of it and push it to the end of its travel, I get a faint buzz from the tire on the crown.

I plan to gradually convert all my bikes to this wheel size.

[CTB]

that larger contact patch

Ooooo...I have to stop you there. I've seen this 10000x times in Mountain Bike Action, and it makes me cringe every time I read it. The contact patch is no larger on 29ers or 650B than a 26er for a given rider, pressure, and tire construction. Pressure is defined as force per unit area (pounds per square inch, etc.): P = F/A. So to define the terms:

P = tire pressure you're running
F = the weight on that particular tire
A = you guessed it, the contact patch internal area

Same rider means Force stays equal. Same air pressure means Pressure stays equal. Therefore, the area, aka contact patch, MUST be the same.

What IS different is the shape of that contact patch. For a given tire/rider/pressure, the 29er patch will be the longest and narrowest due to the "flatter" circumference of the bigger wheel; the 26er will be short and wide. This is what gives the bigger wheels the additional cornering stability.

Again, the only way to get a bigger contact patch is to eat a pizza and run the same pressure, or lower the tire pressure you're running (hence why running tubeless helps out a lot for grip - less pressure needed, bigger contact patch).*

* Yes, different tires have different sidewall characteristics, but that holds true for all the sizes, not just comparing between two sizes.

Sorry, didn't mean to hijack. Deadbeef, I love your green bike, and I hope you give continued impressions as you ride this size. My next new bike build will hopefully be a 650B. The one I rode (Jamis) on a demo was much to my liking; 29ers have not been to my liking, as I am small and not powerful and can't accelerate the generally heavier 29er wheels, nor throw around the usually longer bike. I'd try to build up the 4-Banger, but I'd have to raise the BB/steepen the head angle too much for the tire to not smash into the upper carbon arm in the back.

[DEADBEEF]

ok then. the longer, narrower contact patch feels better in the corners... and while climbing. I have two homegrown hardtails that I ride regularly. my singlespeed is still 26". after riding the 650b exclusively everyday for a week while camping at tsali this year, I then rode the 26" bike on my next ride. the differences were pretty clear. the 650b just sits down in corners better and makes technical climbs a bit easier. for me anyway.

[scottiedubbs]

DEADBEEF,

What frame size do you have? I have a 2000 HG Pro, and I'm thinking of making the same conversion.

Thanks!

[DEADBEEF]

mine is a 1999 17"

[chevcp]

Thanks for the pics and details. Sounds like a good compromise to me and love that you are still riding two Homegrowns. Been riding mine for the last 12 yrs and still going strong.

[bad mechanic]

Been riding mine for the last 12 yrs and still going strong.

PICTURES!!!!!

There are quite a few of us here still riding Homegrowns.

[chevcp]

I'll take some pics and post them. Its an early 2000's in anodized black, been a great bike for me. I'm interested is some 650b's but may have to wait until I wear out my current wheels. Using a wheelset from Stan's Notubes right now.......so nice being able to run with less pressure!