John N

OK, in some areas size does matter, i.e. frame size, handlebar width, etc. But what about wheel size, i.e. 650 vs 700?
I am looking to replace my stolen Co-Motion Americano but there is currently a 4-8 month build time depending on the builder. Arrgh.

I have an option for a bike with a 650 wheel size but I would prefer the larger wheel diameter of a 700c to help smooth out the bumps. Plus, I am old school enough so I am somewhat reluctant about that size due to whether it will go away some time in the next 10-15 years. Who knows.

I ride a mix of both paved & off-pavement routes, maybe a 70/30 ratio, but nothing technical as this is strictly for touring. I tour in the USA, Mexico, and Europe.

Has anyone here ridden both a 700 and a 650? If so, what are the differences.

Any thoughts and comments, i.e, limitations with the 650?

Thanks, John

ClydeClydeson

The rim size is not as important as the diameter of the rim+wheel, and 650B wheels are often run with wider tires that approximate the diameter of a 700c wheel/tire, but with more air acting as a cushion.

Even with the same width tire, though - say, 600Bx40 compared to 700Cx40, the difference is miniscule. If you are using 650B and your buddy has 700C and he is faster than you, it's not the tire's fault.

I would stick to 700 because there are more tire options, but on the road it makes virtually no difference.

robow

If possible, I would definitely continue with 700c as there are so many more options sold and availability will be much greater if you need to secure a tire in the middle of nowhere. 650's are just not that common.

bobh123

I have a Co-Motion Speedster tandem that came with 700c wheels. I recently changed over to 650b. With a slightly smaller wheel diameter, I was able to use wider tires so the pressure is lower. The ride is more comfortable, even on asphalt. Lower pressure will more than compensate for the slightly smaller wheel diameter. The difference in radius is something like 1/2"-3/4", so hardly enough to affect ease of rolling over bumps. Fenders fit with more clearance. The feel of steering is a little different with the 60b - sort of like having power steering on a car. I expect this effect depends on the bike's specific bike geometry, weight distribution, etc. It's not bad, just different. The selection of 650b tires is more limited than 700c, but it is adequate. Same thing with wheels, both new and used. Interest in 650b seems to be growing, so I expect tire selection will improve. 650b has been around for a long time, so I don't expect it to go away in the near future. I expect 650b tires will be generally available in the US and Europe, but don't know about Mexico.

Tourist in MSN

Your bio says you have a Nomad Mk II. I think you should ride that while you wait for the perfect bike to be built instead of buying a compromise. Yes, I know that a Nomad Mk II is a heavy bike, I have one.

A year from now you will have waited for a while for the perfect bike to be built. And then you would already have had several months of riding on that perfect new bike. And you will be happy you waited for it.

I have not ridden a comparable 650b bike, my 650b bike was built in the 1960s and has a three speed hub, so not worth commenting on. I ride it to the grocery store and that is it.

But I can't see much difference in touring on my 700c bike with 37mm tires and my 26 inch Thorn Sherpa with 40mm tires. A 650b bike would be in between those wheel sizes. Both of my 26 inch and 700c bikes are derailleur, both drive trains are identical for gearing. The 26 inch bike has slightly lower gearing being a smaller wheel, my 700c bike is titanium so the frame material has a different feel. But otherwise both bikes feel the same once I have a set of panniers on them.

I think you should be patient and not accept compromises.

Photo is of my Nomad Mk II, just to get you in the mood for touring on one.

GamblerGORD53

Whatever frame you get, make it a size BIGGER. It looks like you are not too tall for a 650B. Mid 40s tires would be good, IMO.
I think 650B is taking over in Asia. The overall length will be maybe 2" shorter, helps with alternate transportation.
My CCM 3 speed is 650B x38. Definitly feels nicer than the 700x36 I've had on most all the bikes I've ever had. I do centuries on it, easy as pie.
I still got by with 36 mm tires on wet clay in China. My Dyad rims are only good up to 38.

ClydeClydeson

GamblerGORD53 Did your CCM come with 650B wheels or was that a mod? I have only seen old 3 speeds with 650A (26x1-3/8).

GamblerGORD53

Yah it came with 650A/ 590, it's a 1973. I wanted a SA RD3 drum brake and did that soon after I bought it in 2017.
I used the front wheel 1930 miles with the old tire, till it finally died. LOL. It was at the co-op when I was looking for a nice swept handlebar. The new smaller rims made room for bigger SMP tires.
This bike was in real nice condition.

timdow

In a great number of situations, the choice between 700c and 650b depends upon the desired tire width.

Example: I am currently working with a Trek 7500 that I recently acquired that has disc brakes. I can go 700c X 40 (1.6"): fine for on-road w/some off-road. With the smaller wheels, I can go much wider... at least 27.5" X 2".

The bike is currently 700c X 32. Since I already have a road touring bike, I bought the bike with the intention of bike-packing with significant amount of it off-road. I am currently balancing the expense of purchasing a 650b wheelset vs need for wider rubber.

djb

first of all, crappy about the theft.
So from what you describe the 70/30 pavement gravel riding, and from my experience using 700 and 26 over the years, it seems to me that 650 would be my preference partly because its in the middle of the two, and my preference for wider tires would mean that 650 probably has more options for wider (fitting in frame etc)
I do like the quicker steering aspect of 26, although I'm aware frame geometry is a part of this aspect, so 650 gets my nod over that.
I know a lot of excellent tire options are there for 650, and yes this has reduced what is available for 26 now, but I would expect 650 to be very popular for ages to come.

I haven't ridden on larger 700 or 29 wheels on rougher surfaces with tires any larger than 32, so I don't really have that experience, but given that your riding seems close to my riding experience (70/30 and not specifically off road stuff) and the fact that I'm ok on my smaller 26 wheels, one would think that 650 woiuld be great--with the option of using bigger tires for certain situations if the frame can handle them width wise.

I personally like how on my 26 bike that I can slap on tires with chunkier tread over 2 inches easily , for different trip ideas, so while we get back to the specific frame limitations of a new bike for you, being able to put wider is a lot of fun. Don't know how wide you've ever ridden, but 2.2 to 2.5 tires can really open up where you can ride---if thats something that appeals, and makes all the difference of being able to ride more competently on various looser surfaces.

thats my take anyway

John N

Thanks DJB for the detailed post.

djb

you're welcome. It seems that there are lots of neat bikes out there that can take a wide range of tire sizes, so I suspect there are some good 700 options also. I guess it depends on how wide you think you'd ever go to, and then think about the gearing range that you know works for you and your riding.
have fun researching

Polaris OBark

I have two wheel sets on my main (non-touring) ride, one 700c and one is 650b. The primary advantage of the smaller wheels is that I can fit a larger tire. Ideally, the outside diameter of the 650b wheel with a fat tire should be approximately the same as your 700c with a road tire, which would allow it to handle and fit similarly. (Mine doesn't quite do that, due to frame limitations.)

I just put on some 55mm 700c tires on my touring bike, and the handling is rather awkward, and toe overlap is now an issue. In retrospect, I should have had 650b for that width.

The only significant disadvantage I can think of is that 650b road tires might be harder to find in some regions. On my bike that has a set of 650b tires, the frame isn't able to accommodate as wide a tire as I like. (On my touring frame, this is not an issue). Because the tires aren't as fat as I would like, their outside diameter is a bit smaller, and I have some issues with pedal strikes off road.

sloppy12

For what you are riding I would go 650b around 48mm to 2.1" range. Assuming disk brake you could also swap on a 700cx38-42... there are plenty of good 650B tire options its gonna be a smoother ride offroad and it will open up more offroad areas.. I have both wheel sets and never put the 700c wheels on for what its worth.

fourfa

Same here, on my current main ride I have both 700C (with 28mm road race rubber) and 650B (have tried a few 47-50mm options from mild tread to full knobby) in the same rolling diameter. 650 (aka 27.5") will remain an extremely common wheel size in MTBs for decades, it's not going anywhere as MTB geometry gets lousy with 29" (aka 700C) on XS and S size suspension bikes. And there will always be commute tire options available for the common sizes. Right now there's a wealth of options in gravel tires that would suit your needs, and it's growing.

I use the road wheels on pure road days and the 650s on any mixed conditions ride, both have roughly the lowest rolling resistance tires you can find. The 700s are unquestionably faster but the 650s (currently Pirelli Gravel H 650x50) are quite fast enough to be hella fun, tough enough for serious MTB trails, long lasting, better touring tires than the 700x35 Marathon Supremes I rode on my last tour IMHO. FWIW I am running them tubeless and frequently deflate/inflate mid-ride to suit conditions. Modern tubeless tires at mid pressures on choppy fire road is really quite pleasant!

John N

Thanks for the info. I am leaning toward a bike that has capability for both 650 & 700 with the 700s being for all paved tours and the 650s for mix surface tours.

John N

Thanks. I am sort of surprised you don't use the 700 wheels much. Is it because you no longer do all paved tours or what?

John N

Thanks for the useful input. I am surprised that gravel tires are better than Supremes on paved tour or did I misunderstand you?

fourfa

No tube = less friction, new supple tire carcass materials, newer lower rolling resistance compounds, wider/lower pressure setups... lot has changed since Marathons came out. I find a wide supple tire at 40psi to be far more comfortable and less tiring than a stiff tubed Marathon at 75psi, and the same or better rolling resistance. I'm a big guy, I rolled at ~270lbs on the tires on my last heavy tour, and less than 75psi was a risk of pinch flats on unexpected edges on the Marathons. No such thing as pinch flat anymore on tubeless (to a close approximation), barely any flats at all for that matter

Do be aware that modern 650B rims may have a max pressure lower than you're accustomed to (and much less than the max pressure of the tire). Many are MTB-derived rim profiles where 30psi is considered high. No problem if matching a modern, wider tubeless tire. Could be a problem running traditional narrower tubed tires as you might not be able to reach high enough. My Salsa Vaya shipped with a MTB rim, 60psi max, and the shipped tires (Clement 40mms, tubed only, max 90psi) routinely blew off at 61psi, which was not a good fit for me. But there's wiggle room, some tires have a tighter bead and can hold more pressure. Same goes for tubeless, some tires are absolute monsters to mount, probably not going blow off a hooked bead, but I don't plan to mess with it after the Clement experience

But for sure TL is more hassle in setup, a bit more maintenance keeping sealant topped up. USA and Europe not an issue (all MTBs in every small town are now tubeless or close to it), Mexico I would carry spares, a bit more gear to handle sidewall cuts, and a tube or two for insurance.

sloppy12

Its because they are a better ride. and I like to explore which leads to not paved pretty often.

djb

I ride 26 bikes and 700 bikes. Still haven't really figured out if there's a speed difference, certainly not with a bunch of crap on the bike, and I'm just as slow as always it seems.

KC8QVO

Lots of technical replies already so this is probably of little significance in the grand scheme of things:

I have been riding 700c since 2014 and wish I could get wider tires on my bike than I can. The widest I've run is 42-43mm. I believe the tires I have now are 40's and in between I ran 38's (the OEM tires - but I replaced them with the 42-43's after the first several months).

A lot of people tend to recommend 30's to mid-40's for general touring - even non-paved trails. With the riding I've done and places I've rode - I don't think this to be 100% accurate.

If you only consider fair weather with dry trails and paved trails/roads - then yes. You can tour in these conditions just fine down in to the 20's and on smooth surfaces as narrow as you want to go.

However, that does not help you when non-paved surfaces get wet - especially if you are around the in-between seasons. When some types of crushed gravel used on a lot of rail-trails and canal towpath trails gets wet it gets soft. More over, in the in-between seasons (spring and fall, early/late winter) in the colder climates when it is below freezing at night then above freezing during the day the freeze/thaw of the trail surface causes it to be a lot more "mushy". When the trail surface is frozen it is hard and the rolling resistance is low. When it thaws and turns to mush you can loose over half your speed for the same effort you would have exerted on hard surfaces. This seriously impacts your mileage and time.

Yes, you can argue that wider/larger tires have more rolling resistance on hard surfaces. However, please consider the other end of the spectrum - soft surfaces.

In some areas that I have rode where this has been an issue I have been able to get off the trails and on to roads to adequately navigate my routes. I don't like doing that because I don't like riding on certain roads due to traffic and the obvious safety problems. However, when push comes to shove and I am really bogged down on mushy trails - jumping off on to the roads keeps me moving and I can make much better miles.

With all that having been said, I know the perspective here does not speak directly to the question of 650b vs 700c - however, my point is that it doesn't matter. There are much more important things to consider in how/where you ride and equipment for it than the simple slight variance in rim diameter between 650b and 700c. To that point - I would question the tire width clearance of the frame. If you wish to run fenders (I highly recommend them, but that is just me) - then you need to consider that in to the tire question as well.

If you are OK with "smaller" width tires and have proven them in all your riding then that is fine - in that case I agree with most others here that you won't notice much difference. I think frame geometry and your fit to the bike will be bigger scenarios to dial in. Spend some quality time adjusting things - getting the right saddle for you, proper pitch, proper fore/aft, proper bar height, etc, etc.

Good luck with your new bike quest!

John N

Thanks for the info. I will consider them.

John N

Thanks. At this point I am leaning toward bikes that can handle both 700c and 650b. That way I can have narrow "paved" tires and wider "unpaved" tires depending on the tour. While I would guess most frames could theoretically handle both wheel sets sizes, it is the 650 width that seems to be the limiting factor. The total outside wheel diameter going from a 700x35 to a 650x55 should be about the same so the bike's handling should not change all that much.

Tailwinds, John

Germany_chris

I’d think on a tandem you’d want the toughest wheel possible while still being able to get quality tires, to me that means 650b.