Please educate me...what the eck is this

[BlackCat]

Burro

The ski "will fit any bicycle". $149

Hmmn... wonder how that works.... do you keep your front brake locked? Don't much fancy one of those things spinning round and thumping my downtube..

 

[one-eyed_jim]

Like a low budget Hanebrink:

http://www.hanebrink.net/

http://cgi.cafr.ebay.ca/ws/eBayISAPI.dl ... 0277516682

 

[one-eyed_jim]

Like a low budget Hanebrink:

Interesting - I didn't know there was a connection, but both companies seem to be based in Big Bear, California. Anybody know the story there?

 

[barry2017]

Rear mech is awfully close to the ground, though. Use a breakaway bolt!

 

[one-eyed_jim]

Rear mech is awfully close to the ground, though. Use a breakaway bolt!

Too bad they don't get the mech up out of harm's way like this clever Whyte.

The Burro's a bike where a Rohloff would make a lot of sense.

 

[orange71]

Too bad they don't get the mech up out of harm's way like this clever Whyte

much better - but I'd just worry about the seatpost snapping instead :shock:

 

[Xesh]

WHY? :?

Although the smaller wheels are very strong the are very inefficient. A smaller wheel is harder to get over a bump than a larger wheel is. Also the gearing must be stupidly low.

Yes, it looks different but I bet that it's a nightmare to ride.

 

[one-eyed_jim]

WHY?

One advantage of a small wheel is that the weight of a fat tyre and rim drops in proportion to the smaller diameter. You get the float and cushion of a fat tyre without the weight and clearance problems of a big diameter wheel.

Also the gearing must be stupidly low.

Lower than with a bigger wheel, obviously, but a 20" nominal (406mm) rim with a 3" tyre gets you a 22" diameter wheel, which makes an 88" top gear with 44:11. That's not a sprinting gear, but these aren't sprinting bikes.

I'd like to try one. Looks like fun.

 

[Harryburgundy]

Also the gearing must be stupidly low.

Lower than with a bigger wheel, obviously, but a 20" nominal (406mm) rim with a 3" tyre gets you a 22" diameter wheel, which makes an 88" top gear with 44:11. That's not a sprinting gear, but these aren't sprinting bikes.

I'd like to try one. Looks like fun.

Same here...can see me plodding through the local woods on that....mmm...now what ratio for a singlespeed?

 

[GrahamJohnWallace]

Big wheel v Little wheel

These two bikes, both from 1988, show that the big wheel / small wheel ATB debate is nothing new.

The Moulton ATB is strong, accelerates quickly, and is multi-purpose.

The Highpath made Cleland, is designed for riding over soft rough ground with the minimum rolling resistance. It's large 650B x 2 inch tyres run at very low presure, are its secret.

On soft ground the Cleland is fast and efficient and the Moulton slow, as it digs a small trench as it moves. This feels like you're towing a plough behind the bike.

On smooth, hard ground, the Moulton is faster. It's perfect for road use with the occaisional off-road section. You do need to look out for wheel sized holes though.

In theory small wheels should not be as good for hill climbing as large ones. This is because there is a force vector from the rear axle (fixed point from the ground) that pushes against the centre of mass of the machine and rider. The steeper this vector the smaller the proportion of the total pedalling energy is actualy pushing the bike & rider up the hill. The remaining vertical component of the vector will then cause the front wheel to lift more easilly than with a large wheeled bike in the same gear.

Small wheels are of course inherently stronger and so can be made lighter.