Any good 650Bx35mm tires?

[Mike Klaas]

I'm thinking of doing a 650b conversion but a test fit indicates that 650Bx38mm would be questionable in the rear (testing using pari-motos that measure ~38.5mm).  Looking online, the pickings seem slim for good 650b tires less than 38mm.  There's grand bois cyprès 650Bx32, but I can't find any 35mm tires of note.  Am I missing anything?

Also, if I choose to go with 32mm in the rear, would it look absurd to put a 38mm in the front or would you all match the tire size even with room for a larger front?

Thanks,

-Mike

location: SF

[franklyn]

Hi, Mike,

There are several 650b tires in the 33mm-37mm range.

1. Schwalbe Kojak. In 650b/27.5 size, it comes in 1.35" width. And these tires measure ~ 34mm on Synergy rims. 

2. Panaracer Col de la Vie. Wire bead tires that measure ~ 35mm on velocity synergy rims

3. Soma Xpress 650b. These measure ~ 35mm 

4. Soma B-line. I have never seen these measure more than 37mm, even on the wide-ish Pacenti SL23 rims.

best,

Franklyn

[Mike Klaas]

Thanks Franklyn.  It's good to know those options exist, but none of those tires seem of the same tier as the Compass/Grand Bois offerings.  Perhaps it's not worth converting the rear, which is currently 700x28 (Conti 4000S), but adding a front 650x38. 

[Bruce Herbitter]

I've had great success with grand Bois Oursons which are actually about 35mm. You may still find some of these around, but they were replaced by the Lierre, which is also a great tire, and while listed as a 36, I think it too is really a 35. I use the GB on a Rivendell Road conversion where Pari Motos are just a bit too tight.

https://janheine.wordpress.com/2010/10/29/grand-bois-650b-x-36-mm-tires/

Rivendell Maxy Fasty tires are around 34 mm. Not quite as supple as G.B., but they ride decently and are tough against punctures. I have these on a TREK 660 conversion.

Taiwlinds

[Mark Bulgier]

One theoretical advantage of same size F&R is if you slice the rear too badly to boot, and all the tires you can find on short notice (like at the LBS) are wider, you could buy the wider tire and put it on the front and move the erstwhile front tire to the rear.

The 32mm Cyprès is a nice road tire. Not as capable for gravel or dirt as a Hetre of course but not totally out of place there either. A 35 is not going to be hugely better, maybe not even as good if it's less supple and with thicker tread rubber.

Another option is see if there's someone local who can indent the chainstays for more clearance. That's usually a framebuilder, but some good mechanics can handle it. I know a couple of amateur "enthusiasts" who have done it, here in Seattle, so maybe you have someone like that near you.

Mark Bulgier
Seattle

[Justin Hughes]

Are your Pari Motos marked 1.5" or 1.75"?

[Mike Klaas]

Good point, Mark.  I don't think indenting the chainstays is an option since the frame is aluminum and tubing is already relatively ovalized (there is plenty of room on the BB for them to have simply spec'd the stays a few mm outward, though).

I realize that this frame isn't the perfect candidate for 650b conversion, but finding stock frames that fit my wife (4'11") is almost impossible.  I'd like to go custom eventually, but I'd like her to have a wider-tire machine in the meantime.

-Mike

[Mike Klaas]

1.5".  Definitely not the 650bx42's.

[franklyn]

Mike,

The Soma tires, though are not in the same class as Compass/Grand Bois, are pretty good. I put a pair of the Kojaks on my wife's bike for a while, and they work well--supple enough, and have good slick treads. They are also very inexpensive. 

Best,

Franklyn

[Skylar Nagao]

What frame is your wife riding? I'm sort of in the same spot (my partner is 5'). She's setup on a 42cm Surly Long Haul Trucker with an impressively short stand over around 705mm with 26x1.5" (actual 38mm) tires.

After taking measurements, the Disc Trucker is totally capable of running Compass's Rat Trap Pass or Switchback Hills. If you're looking for a lower cost stock frame to run wider tires, that may be an ok starting place.

[Mike Klaas]

It's a XXS Giant Avail.  Pretty generic aluminum road bike but it fits her better than any bike she's owned.  I think custom is the future but this is a starting point at least.

I built up the wheels this weekend—it went pretty well considering it was my first build.  I just have to decide whether to run 32/32 tires or 38(front)/32(rear) before ordering them.

thanks,

-Mike

[Mike Klaas]

In case anyone was curious how it ended up, here is the finished product.  I ended up using GB Cyprès 650bx32 on both wheels.  I was hoping to get a little more rubber in there, but this'll do.

Fatter tires and ~1 lb lighter = win.

[Scott Stulken]

Looks great, Mike!  I, too, wish for a good option closer to 35mm as my Pari-Motos have very little clearance to the chainstays.

Mebbe you could fill up that empty space with some lightweight fenders?  ;^)

- Scott

[Mike Klaas]

Fenders just might be a go as there are a few attachment points on the bike.  (There is a 5mm braze-on 1/3 the way up the back side of the seat post that could be used for a fender.  It's really unclear what the intended purpose of that was.)

My only worry is that the Cyprès 650x32 might be discontinued one day.  Not a lot of options in small 650b tires, sadly.

[William Lindsay]

Mike wondered:  "(There is a 5mm braze-on 1/3 the way up the back side of the seat post that could be used for a fender.  It's really unclear what the intended purpose of that was.)"

I saw a braze on like that on the back side of the seat tube of the demo bikes made by Scottish semi-custom builder Shand Cycles.  I emailed them to ask what it was for, and indeed it's their idea for a fender attachment point.  Their designs have no chainstay bridge, and up at that height, they say the seat tube is tangent to the arc of the fender, and as such they assert that is an ideal place to attach the "mudguard".  That leaves about 6" or so unsupported dropping down between the chainstays, but they say that works well with a decent fender (they recommend PDW fenders).  

Bill Lindsay

El Cerrito, CA

[Scott Stulken]

Yeah, once I really find a product I like, I start to worry what I'll do if it's discontinued.  But the smaller 650B tire size seems like a healthy niche for now.  The Confrerie des 650B is specifically devoted to making sure ~32mm tires are available (even if their namesake Hutchinson is now harder to get in the US.)

- Scott