Abu Mahendra

Dabbling in sub-406 for the first time so I am polling for thoughts on the desireabilty of 305 vs. 349 wheels.

A quick back-of-the-envelope calculation shows that a 349 rim with a 32mm tire is only about 8mm taller than a 50mm tire on a 305 rim. Four mm of rubber will be on top and four mm of rubber on the tarmac. The angle of attack is essentially equal. Yet the 50-305 wheel will have more 'cush' because it has a fatter profile, wider carcass, and will be pumped to a lower inflation pressure. The 305 wheel will be marginally more durable because the rim is smaller and it is cusshioned from impact by a cushier tire. The 305 wheel will accelerate just a fast as the 349 wheel because, although it is carrying a heavier tire, it is marginally lighter due to the smaller size, and its radius is smaller.

So, having said all that, leaving gearing aside, wishing to maximize comfort and durability, why would one opt for the 349 wheels over 305? Am i missing something?

downtube

Larger diameter wheels will flex more....maybe a comfort argument in a different context??? I'd go with 305.

Thanks
Yan

Abu Mahendra

Perhaps, but if we assume that Total Flex is the sum of Rim Flex plus Tire Flex, and that Tire Flex dwarfs Rim Flex, can we not say that Total Flex is essentially equal to Tire Flex, thereby giving advantage once again to 305?

downtube

You asked for an argument, so I gave one. As I mentioned I prefer 305's.

Thanks
Yan

Abu Mahendra

Ok, got it. Thanks.

jur

How about tyre choice as a motivator.

jur

Wheel flex is hooey! - Sheldon Brown

Abu Mahendra

Tire choice seems to be about the same, with a bias toward wider tires for 305. It's not like 406/451 where 406 is the definite winner in this regard.

leoho5

Would also go for 305 for more flexibility in the case of the need for mudguards or wider tires. What are you planning to do about the low gear inches with the smaller wheels? DualDrive? Capreo? or just a leisurely city bike?

Abu Mahendra

I'd hear it like this, with a 56T ring, 11-36T sprocket and Zee RD.

Schwinnsta

To me, if I could get supple tires in 305, I would roll that way, with low pressure. As it is, the only 16" wheels I have are 349, and I could not fit 305's.

downtube

36T in the rear of a 305mm wheel???

Thanks,
Yan

ThorUSA

I just finished a project bike ... its 14 inches and singlespeed. I wanted it nicely adjustable AND COMFY
hence I went with 50' Big Apples ...

fietsbob

Lower PSI ; fatter tire, Higher Pressure; thinner tire. works the same regardless of diameter..

The 406 vs 451 .. argument.

Performance or comfort? , Rough road cushioning, bigger contact patch ?

Probably missing the Brompton rear suspension cushion, making the performance tire - wheel more comfortable

people stiffen that block, with various things, to put down more power, at the expense of that cushioning.

edelay

I've gone through this 305 vs 349 size issue recently with our snow in Vancouver. Some things I've realized in the last few months. Not directly relevant to your question, but may be a factor in your decision.

- it appears to be harder to source 305 wheels and rims than 349. Maybe this is just a local phenomenon....none of the folding bike shops in Vancouver having 305 wheels or rims in stock. I have to order them online. One store said that the last time they ordered one from Dahon, it took 2 months to get in.
- there aren't Kojak's in 305 size but there are in 349
- no studded tires in 305 size but there are in 349. Okay, not relevant for you over in paradise
- Big Apples come in 305, but not 349

P.S. Nothing to do with your question, but have to say, I was pleasantly surprised to see in Thor's post that Big Apples are available for 14" tires. Sweet.

edelay

That is a sweet bike. I had no idea there were 14" big apples. Great work with these single speeds and the black 5 speeds.

Abu Mahendra

Aye, 11-36T, with a stubby, short-cage Downhill Shimano Zee RD.

downtube

Thanks for sharing!!!

Yan

Abu Mahendra

Shimano Zee RD with an 11-36T cogset is, imo, the gold standard for 1x derailleur drivetrains on small (406 and below) wheel bikes. Light, taut, smooth shifting, stubby and sturdy, providing a range of up to 327%, greater than Alfine 8. RD plus CS-M771 11-36T cogset weigh 600 grams, and cost under $100 together. Add an XT shifter, and you've got yourself a very slick transmission.

Here' an excerpt from a review:
》It is immediately noticeable how good the Zee mech feels with the XT shifter. Gone is the ambiguous lightness of Shimano from years gone by, replaced by an incredibly solid, positive feeling. Having ridden a few different options on different bikes since setting this up on our long-term test, we find ourselves coming back to this setup and appreciating how good this combination is. In a blind test you'd be hard pushed to pick this out as a cheaper option. Here at Pinkbike we are big fans of clutch mechs and this Zee is no different - it isn't when you use a clutch derailleur that is the big deal, it's if you go back and try to ride a bike without one that you realize just how good they are and the Zee is everything we hoped it would be in that regard - quiet running and precise shifting.

Where the Zee mech really stands out is in terms of survivability. It was with the 2012 XT derailleur that we first noticed that the current Shimano mechs keep working well past the point when you'd expect them to fail. That XT mech was scored, grated and slightly twisted, but it kept going. This Zee mech goes another step beyond that. Just after fitting it, we were riding with it at Lenzerheide, in Switzerland. Coming through the boulder fields, there were dozens of rocks protruding at about derailleur height. Eventually, a few of them hit home and a couple of them were big hits. We were sure we would look back to see a small pile of twisted metal hanging from the dropout, yet it kept working. Looking at the mech at the end of the week there were a number of big gouges on the body and it wasn't what you'd call straight, but it still changed gear every time you pressed the lever. OK, the indexing wasn't perfect and if you are the kind of person who likes your bike to be just so it would probably have upset you greatly. For us, it's reassuring that you can be more confident of making it home, no matter what happens. If payday is still a few weeks away when you hit your derailleur, you can keep riding, even if it isn't perfect (or if you're lazy like me you can just keep using it as it is for months). And that is impressive.《

BikeRadar verdict
"Tough, no nonsense and great value single-ring gearset"

REVIEW: SHIMANO ZEE REAR MECH
》So there you go, this mech has certainly got a place on any DH bike, but I’d also say, don’t over look this mech if you need one for a trail bike as I think it is a little gem with in the Shimano line up.《

SHIMANO ZEE DERAILLEUR AND SHIFTER REVIEW
》If you want a tough reasonably price drivetrain Shimano Zee is worth a look. It’s hard to beat the functionality, ruggedness vs. cost here.《

fietsbob

so tire topic is done, resolved? guess this topic has drifted off.

Yea no chainring difference , short cage RD work, most any . I used a <c> Chorus in 90.

Abu Mahendra

Since I started this thread, i've gotten a 305-wheel FSIR. Issue resolved? Well, not quite yet. I still haven't resolved whether to build the FnHon Gust with 305 or 349...

cplager

You can get Winter studded 349 tires but not 305 tires.

Abu Mahendra

Winter? What's that? We have sunny weather 350 days out of the year here, sunlight 12 hours a day and the temps never dip below 15 degrees here. Studded tires?

cplager

Then it isn't like a concern for you.

Of course, over here, 15 (F) is quite cold...

fietsbob

want more volume, softer, cushion, vs higher PSI easier rolling, harder?

knee jerk disdain for Bromptons?, they're running 349 -32 ~ 37..

so only one is acceptable.. apparently..





..