cyber.snow

I already have too many bikes taking up space in the garage. I went to the "LBS" and asked about a bike that could be great for sand and road conditions and they recommended a 27.5+ bike. So what is the real truth? Can I ride on 2.75 or 3" tires on one day and swap wheels to 1.5" for a ride on the road?

NormanF

You could also get a 29.5+ bike that allows you to do the same thing.

If you want a 27.5 or a 29er and you also want to have a fat bike, now you can buy one bike and change tires with the seasons.

prj71

Almost all 27.5+ bikes will accept a 29er/700c wheelset so yes you could do that. You would have to have a seperate wheelset, not just tires as the 27.5+ bike will have 40-50mm wide rims.

prj71

There is no such thing.

cyber.snow

I looked at the Salsa Fargo 27.5+ and the LBS said I could get 29" wheel set from Salsa. I called Salsa and the said I would need to have a bike shop make me a set and that I shouldn't go any skinnier than 2.25 on the new wheel set. That only gives me a range of 3"-2.25". I want to stay hardtail and have a back rack.

Still looking for the truth behind the rumor that the 27.5+ is a one bike for everything solution.

Cyclist0108

Why would this be? This totally crushes the dream.

I was hoping I could swap the 27.5+ wheels for my 700c road bike (disc) wheels. The frame should allow it, according to their own description of the dropouts.

prj71

Not sure why they told you that. No reason you couldn't put 1" wide tires on that bike.

Darth Lefty 

It's really more like a 31er

FrozenK

Skinnier tires will drop the bottom bracket. My guess is that Salsa -or at least the person the OP spoke to- feels that lowering the BB that much will be detrimental to the bike's handling.

I'd get a set of 700c (aka 29r) wheels with the tires you want to run and put them next to the 27.5+ wheels with 3" tires. That will show you how big a difference there is -or isn't.

Leebo

I think the term you are looking for is 29er +. Wide rims 35-50 mm, and tires in the 2.8 to 3.25 width.

Leebo

The overall diameter should be similar. The issue is hub width. And diameter. 27.5 plus will be 110 x15 mm front and 12x148 rear for hubs. Most likely. Your new disk road? Not quite sure. 100 or 110 width x 12 mm for the front. Rear 135 or 142 x12?

Cyclist0108

Mine is 135 QR, White Industries (which is convertable to thru-axle I am told).

My HED+ Belgium rims with 40mm Nanos are about 710mm (28 inch) in diameter.

Looks like all that is needed are "alternator reduction plates".

The Salsa Fargo 27.5+ website says:

tyrion

650b + 3" tire is roughly the same diameter as 700c + 2.25" tire, about 736mm.

BikeCalc.com - How to calculate Bicycle Wheel Size

You can decide how much you dare lower the bike. A 1" tire on 700c wheels would lower the BB by 1.25", quite a lot. You could get a light, supple, but relatively fat 44mm road tire like https://www.compasscycle.com/shop/co...oqualmie-pass/, which would have a diameter around 710mm, lowering the bike (from designed 27.5+ height) by 13mm or 1/2".

These differences in diameter are probably less than computed because the fatter tires would be used with less pressure.

NormanF

I was thinking of a 29er that could fit 4" tires.

Doug5150

It's probably not, unless you own a bike shop and want to sell somebody another bike instead of just another set of tires.

From my own reading, I suspect that bicycle tire companies decided to maximize their use of the most common sizes of tire-manufacturing equipment.
For the 406mm and 559mm sizes, you could already get on-road and off-road tires.
For 650b and 700c there was only on-road tires, but now they make off--road tires in those diameters as well.
The tire companies probably realized that they could utilize a production line more easily if they had the choice to produce either on-road or off-road tires on it, so they decided to produce off-road tires in the two larger/more-common diameters they had left that were only for "road" tires.

The rest is just marketing, most likely. Is there anything you could do with 27.5 or 29 that you could not have done in 26? Probably not.
Tire size is not considered to be a compelling argument among modern car or motorcycle designs.
It's just a chance for bike companies and bike shops to maybe sell a few more bikes that they might not have otherwise, as people decide they need to try the new thing.

,,,,,

On the other hand, 650c is almost abandoned entirely among triathlon (road) bikes.
For about 15 years if you were "serious" about riding triathlons, you bought a bike that had 650c wheels. But now, even Quintana Roo--probably the most-famous of triathlon bike brands, and the one who played a BIG part in starting the 650c triathlon bike fad--only offers their smallest size frame with 650c wheels. Everything else they sell has changed back to 700c now, and there's not a lot of tire choices left in 650c as tire companies have dropped most of their models in that size.
Quintana Roo used to have a list of reasons 650c was "better", way back then.
But that was then, this is now. And so this is why you need to buy a new bike.

ahanulec

I test rode a 27.5+ bike last summer and I liked it better than the 29ers I've ridden. The tires have that fat bike growl rolling down the trail and the sidewalls soak up the terrain. Good stuff.

I didn't want to like it over the 29er but it really won me over.

prj71

That's fat bike territory.

Canker

That guy has been doing a back to back comparison with a 27.5 compared to his 29er. I ride for fun so I don't care if one is 6 seconds faster or slower than another but it is fun to watch. Think that was his first video on them but if you go to his channel you can look around and find the rest.

prj71

I have a 29er with 29 x 2.25 tires and a 27.5+ bike with 27.5 x 3.0 tires (almost equal diameter to 29er).

My 29er I have to pick my lines riding single track. If I don't then the tires, more often than not, slide off the trail features which may or may not result in a dismount/crash. With my 27.5+ I just roll over obstacles and don't think about picking a line.

27.5+ is about better traction and roll over.

TomFR

+1 for preferring a 27.5 over a 29er, but that was just from a couple rides.

JonathanGennick 

Wouldn't doing that throw off the geometry of the bike? Going from 3" to 1.5" is a pretty drastic change in tire diameter.

prj71

All it would do is lower the bottom bracket height. Rest of the geometry would remain unchanged.

JonathanGennick 

Pretty sure it would affect the trail slightly.

FrozenK

Only that if you knew anything, you'd know that lack of tire availability was the biggest block on the road for 29rs and fat bikes. And that 650b (what is now called 27.5) came about when Pacenti had their own rims rolled and tires made by Panaracer (if I recall correctly) and that, again, it took a while for tire makers to jump in.

But if you want to keep believing is all a marketing ploy, have at it.

Doug5150

Nope.

27.5 MTB tires have been around for about ten years, but the 650b tire size has existed way way longer than that.
This page shows a 1952 bike that has them, and it wasn't the first. That means at least 65 years.
https://janheine.wordpress.com/2014/...se-randonneur/
There are sparse accounts of this size being in use around the beginning of the 19th century in Euro-land.

And likewise, 700c road bicycle tires have been around way way longer than MTB 29" as well.
It's difficult to pin down exact years (and it depends on what country you're talking of also) but they've been around for at least ~75 years.

Europe had clincher tires way before the US did, as in Europe they weren't forced into using tubular tires like people in the USA were:
AMERICAN SINGLE-TUBE TYRES | The Online Bicycle Museum

As for today--
the steps in bicycle tire manufacturing that are diameter-specific are based on the bead size, and modern tire companies already had the equipment on hand to produce 584mm and 622mm tires.
It's just that previously, they were only making narrow road tires in those bead sizes.