How About 29-Inch Tires?

[5-7HEAVEN]

My local bike shop is selling bikes with 29" MB tires. The bike frame sits slightly lower to accomodate the taller tires. Has anyone seen such bikes and what would be the advantage to taller tires?

[ocscully]

The major advantage to the 29" wheel/tire set up is they roll over obstacales better. The major down side to them from the motored bike standpoint is 1) currently there aren't any fat 2.0 or larger street tires available, 2) the frame geometry adjustments that need to be made for the larger dia. wheel/tire makes the front triangle smaller less room for a motor if you are going frrame mount. Not a problem for a rack mount. Also the farme adjustments nesessary to make bikes to fit smaller people are pretty extreme as well.

ocscully

[5-7HEAVEN]

Those 29" mountain bike tires are monstrous and way larger than 2" tires, but more than likely the street tire selection might be non-existent for now. High speed is greater than 26-inch tires, so the engine doesn't need to wind out. At 35 mph with 18.75:1 gearing, there's a 900 rpm drop using 29" tires, which is significant. Gear chain drive might be the simplest engine conversion.

[Easy Rider]

I was thinking of making my next build a 29er but after reading a post from LennyHarp. He made some good points. He said the 29er's were good for onroad biking but would be a little more difficult to manuver in the dirt because of its size. I figured I would be either racing or doing alot of off roading on my next bike. I want it to be agile and easy to manuver on the trials.
BTW I found out they do make 29x2.2 tires for the 29ers but they only have knobbies. Some of the local guys run 24x3 street tires on their bikes and they look awesome!.

[Hitekrdnk]

I have been riding 29"ers since 1999. I have had motors on 29" wheeled bikes as far back as 2001 both electric (hub and Currie) and friction gas. I also used them for my 4 cycle pusher bikes. While they have some advantages off road (so I would have to disagree with LH here) and I still ride them to this day and probably always will as my MTB, I don't think that for motor assist they are any advantage except when using a friction driver or for riders that are over say 6'2 or so that look like they are riding a childs bike with 26" wheels in comparison. That is not going to stop me from motorizing one in the near future mind you but that is more to do with what I have in the garage than anything else.

As far as there not being enough room in the triangle that is not true. The frame per given size, and there is a range of sizes available from 16" on up to 24", has plenty of room in there as evidenced by the attached pix. The black bike is about a 19" frame that I ride @ 5'11" and the silver one is about a 17" frame that is my wife's bike and she is 5'6"es. Plenty of room in there for a motor. There however is not enough room on the wifes say for a sickshaft but I could get one on the black bike because it has horizontal drop outs and I can slide the rear wheel back enough to get the clearance necessary. The red/black bike illustrates the double top tube dilemma that is faced even on 26" wheeled bike in some designs because the drive tube makes the triangle smaller and I don't think I could get a frame mounted motor on that bike, but an electric system would work no problem.







And for those that don't know, a 29" wheel is the result of a 700c rim which has been an industry standard for over a century and most commonly associated with road bikes, with a tire mounted on it that is at least a 2.1 (52/47). This size tire is the same cross section as a 2.1 26" tire, the only difference is in the overall diameter. Because the 29" tire has more overall volume it can be run at lower pressures without pinchflatting and still maintains decent rolling resistance. I have not run over 30 lbs of pressure in my tires for close to 10 years now and have had only a handful of flats.

While there are few fat road specific tires for 700c rims there are certainly enough to make it worthwhile. The original 29" tire is the WTB Nanoraptor and it is a great street tread and to this day my favorite all around tire. Visible on the front of the red/black bike. A company named Schwalbe makes a 2.35 slick that is HUGE and has for years, it is named the "Big Apple". But if you want huge huge then go with the 26" 4" tires as seen on the purple bike, they measure a little over 28"es. Can you say dunebikey? Bikes like this compete on the Iditarod trail also. I hope to motorize one here soon also.



And easy rider you are probably better off with a 26" rear wheel but don't discount using a 29" in the front? That way you are getting a nice strong drive wheel and the larger wheels benefits of angle of attack in the front and your bike will look moto as heck! Slap a set of the 24 3's on there for the super motard look and a lower center of gravity when you hit the track. I have an old pic of a DH bike that I put together that illustrates this and will have to search for it.

All for now.

[Easy Rider]

The first two bike are sweet Hitekrdnk! What kind of forks are they?

I was thinking or its crossed my mind to try a 24 on the rear just to give it more low end punch and a 26 on the front for the handling.

[Hitekrdnk]

Years ago when we were looking for sus forks that would work with 29" wheels, as the cast lowers on all the available forks would not clear them and new castings were expensive, we searched the aisles of Interbike in Vegas for anything that might cross over. In 2000 we found this fork which was marketed by LOOK, a french company and perhaps most famous here for their sponsorship of Greg LeMond in his heyday. But the fork was manufactured by Fournales another french company that makes dampeners primarily for the aftermarket, kind of like the Curnutt of France.

Because all they had to do was stick a longer tube on there we thought Voila! But alas it never came about until they no stopped making the forks about 4 years ago and they sold off their remaining stock cheap to a guy in the Netherlands that sold them off on eBay and I got a few and had a buddy with a CNC mill make up some new dropouts that were 35mm longer and pull out the old ones and glue in the new. They work really well but are only 80mm which is fine for XC use for our purposes. I really like the action on these forks though, it is too bad that they never caught on. At some point I am sure I will be posting a pic here of a MAB with one on it though as once again it is all about what is in the garage eh?

I have been following your progress and it looks like you guys are having some real fun there, keep up the good work!

[blockhead]

it is not a 29er but this is my first engine kit on a 700c cross bike, 700c and 29er's use the same size wheel with a different tire

the rear is 700x44 (about a 1.75)
works great

chris

ps 2 photos still have the road tire on the rear and I plan to change the front
also you can get a 700x38 road tire no problem ( about 1.55)

[Egor]

Wow what a good looking wheel size that is going to make a good looking Happy bike. Keep us posted I need to see this. Our moto X bikes used a large 21" front wheel for all the rolling reasons. The rear would have been that large but for the giant knobby. Have fun, Dave

[UncleKudzu]

wow, cool bikes, Hitekrdnk! that Pugsley is heavy-duty!