Jimmy Legs

Hello. First post. I'm new to the cycling world and overwhelmed...I bought my first 'adult' bike in 2018 - a Salsa Journeyman 650b Claris with 2.1" WTB Nano tires. It's been a good bike for my purposes. I recently took it to our cabin where I now only ride on paved roads. For my regular bike at home, I just recently purchased a new Trek Domane AL 2 which has 28mm tires. It has made me realize how slow my 650b gravel tires are on road. Since I don't have any intentions of using it on gravel anymore, I'd like to have a more road friendly setup without breaking the bank. Obviously going to a more road friendly tire will help. But I'm also considering switching to a 700c wheel so that I can run narrow/low volume tires without dropping my bottom bracket too far (which would happen if I used significantly smaller tires while sticking with 650b wheels). It looks like a 700c with 32 or 35mm tires will closely match my current 650b 2.1" tires outer diameter.

Questions:

I see switching to road oriented tires as following two main parameters: (1) switching from knobby gravel tires, (2) switching from high volume/wide tires to lower volume/skinnier. I’m interested in each parameter’s general contribution since I would not invest in 700c wheels if more of my existing inefficiency is related to the knobby tires. However, if both are big contributors then I would upgrade both.

If there is a big gain in efficiency from going to the lower volume tire, then I would need a 700C wheelset. Considering I have disc brakes, I'm confused as to what wheels to get. The original wheels are:
Front: Formula, 32h, 100mm, WTB STP i23 TCS 650b, 2.0mm spokes, brass nipples
Rear: Formula, 32h, 135mm, WTB STP i23 TCS 650b, 2.0mm spokes, brass nipples

Can you recommend an equivalent 700C wheelset so that I can swap the rotors and have everything fit-up? I'd like to spend no more than $300-$350 for new wheelset and tires if possible.

Thanks!

Iride01 

Continental makes GP 5000's in a 584 BSD or the lower cost Ultra Sport III. Other tire makers have plenty of 650B or 27.5" tires too that are good for the road. If you can find the ETRTO on the rim, then the small number will be your internal rim width and then you'll be able to better figure out how narrow a tire you don't want to buy. But I think your rims are probably good for anything down to 28mm or maybe even 25mm width. Finding that ETRTO will also insure what you have is a 584 BSD wheel. ETRTO should also be on your tires too and that will also confirm your wheel BSD.

Not sure why you want to get 700C wheels and go through all the hassles of trying to figure out what will and won't work along with the inevitable gotcha that will stop you cold for a while when you finally do try to make the swap.

I wouldn't change wheels until you have tried a 650B (584 BSD) road tire on your bike and have determined a better reason to change. Like perhaps you have great power in your legs and find yourself in the big front and tiny gear on the rear and are still spinning out your cadence wanting more speed while on fairly level terrain.. <grin>

Welcome to BF... we don't always give the answer you might be asking for.

HTupolev

Depends on how slow the slow tires are.

My gravel bike which runs 2.1" performance-oriented slicks trends a few percent slower on the road than my skinny-tired road bikes.

How much slowness is caused by knobs depends on the knobs. Some really gnarly MTB tires rumble and rub like crazy on pavement, but some knob patterns - due to shallowness and/or knob layout - aren't that much slower than slicks in paved performance.
Casing construction and protection is often just as significant. Many MTB tires are toughened to have extremely high resilience to cuts, and this generally increases rolling resistance. Some road tires, especially of the "urban" or "touring" variety, are similarly burdened with various forms of puncture protection layers. How much performance is sacrificed depends on how well-designed the tire is and how it's willing to compromise. An ultra-flimsy super-thin "puncture protection" layer that serves as catalog decoration might cost almost no performance, while a bombproof reinforcement that leads to a tire having the word "plus" in its name could cost over a mph.

Jimmy Legs

Thanks for the feedback. I'm going to try slicks on my 650b wheels first.

Iride01 - wouldn't going to a skinny tire from my 2.1" tires significantly drop the bottom bracket enough to cause problems? Wouldn't I need to keep the overall outer diameter of the tire the same?

HTupolev - what 2.1" slicks are you running?

Iride01 

No. Imagine your bike with no tires on the wheels at all. Besides no traction and a bad ride, where do you see any problem for the BB? While in a turn, your pedal might be a tad closer to the ground. I doubt you will be banked over that much. And if you do pedal through turns and have a strike, you'll learn quickly not to be pedaling through those turns at that bank and speed.

If you know the ISO or ETRTO size of your tire and just compare the difference in ISO width of the two, then that will also roughly be the change in height of your bike from the ground. So if you are looking at a 32 mm wide tire then your bike height only changes about 3/4" to maybe not quite an inch.

zandoval 

I would suggest a second wheel set used or new.

HTupolev

Rene Herse slicks with the Extralight casing.

WhyFi

Even with a good gravel tire, I think that there's a very noticeable difference in feel when moving to a lightweight, supple ~28mm tire. Well, let me qualify that: I think that it's very noticeable with the kind of riding that I do, which tends to be on the spirited end of things - lots of accelerations, out of the saddle regularly, sometimes aggressive handling/cornering. Bigger, heavier tires/wheels just feel more sluggish in these kinds of situations. That said, on rides where long, steady stretches are the norm, the bigger, heavier tires are less bothersome to me and, as long as they're good tires, they're not significantly slower.

Oh, and while I understand that you want to keep it on a budget, I'd def invest in rotors for the road wheels, too - eliminating a rotor swap will remove a hurdle when you want to swap wheels... meaning that you'll be more likely to actually swap wheels.

cyclezen

given the bike was designed/spec'd for 650B x2.1 (=53.3mm) or 700c x 37/38 (from website); going to a 650B x 28 would be a very significant drop in bike height.
And maybe not a desirable drop in BB ...
quick calc ... the difference between a 650B x2.1 and a 650B x 28mm wheel/tire combo is 2.75 cm !!! over an inch lower...
quite a long drop... and given the propensity for putting longer cranks on gravel and mtb type bikes... pedal strikes would certainly be more likely with the 650b x 28, would not be my choice.
AND, the bike handling will suffer also... dropping the wheel size significantly affects 'trail', in a negative fashion (assuming the bike geo design for the larger wheels gives a good balance of steering quickness and 'stability' in straight running) - would be quite a bit more handful on speedy downhill descents.
whereas ...
a 650b x 2.1 compared to a 700c x 28 : 700 x 28 is only 7mm lower... and if a 32 mm is used then the difference is only 3 1/2 mm lower...
I would opt for getting a 700c wheelset and use 32mm, to keep the handling as close to 'optimum' as possible. Pedal strikes don;t bug me as much as a spooky descent... Wheel shimmy on short trail geo is very possible as you go further over 30 mph... my experience... (happens also on steep head angle design - 74+ - which don;t compensate with more trail...)
Ride On
Yuri

t2p

with a budget of $300-350 - a top quality 700c wheelset with tires,tubes, and rotors is basically not going to happen

but Continental GP5000 tires on your existing 650b wheelset should wake up that Salsa big time ... maybe 650x30 ... 650x32 ...

GP5000 in those sizes might weigh around half the OEM WTB tires - and the GP5000's roll ... maybe just a handful of tires compare

Sardines

The biggest gain you'll feel going to a bigger wheel and skinnier tires is the aero and rolling resistance drop. Now the gains are probably in the real world gain of less than 1 mph, but you'll see minutes drop from your usual time range over a long ride. Since you want to relegate the old bike as a cabin bike, I would suggest you upgrade your 700c wheels on your main bike and transfer the old wheels to the older bike. This way, you'll enjoy the both bikes more. If you up the budget around $400, you can get a set of Hunt 4 Seasons, which are good AL wheels for all sorts of riding, plus tires. A pair of Schwalbe Pro One TLE 32/34-622 will set you back another $140, Switch your 28mm to the hunts and use the Schwalbe on the old wheels.
There is another issue you haven't touched, the gearing change from the circumference of the smaller tire. He'd be essentially running about 5-8% slower because of the smaller tire for the same effort. Pickup will be faster but once up to speed, the rider has to pedal faster for the same speed, negating the rolling resistance and aero benefits of a smaller tire.

Jimmy Legs

Thank you for this. You described what I was worried about but don't have the experience to articulate. After googling the definition of 'trail' I found what i was looking for. As you better described, I am concerned with the change in overall geometry when making a significant change in the outer diameter of the tire.

Jimmy Legs

Thanks those look like nice tires!

Iride01 

While I do agree with virtually all of what cyclezen said. I've had the feeling that this it just for a bike you aren't going to use often. So still, maybe just try tires and see what you think. For riding at less than a adrenaline crazed level, it might do just fine if you aren't going to be using it very regularly throughout the year.

Polaris OBark

If you get some Rene Herse 650b slick tires, even wide ones, they will be great on the road. Chances are you will find they are also MUCH better off-road than the Nanos, which are terrible tires (in my experience).

https://www.renehersecycles.com/prod...ts/tires/650b/

msu2001la

cyclezen nailed it. 650b x 32mm will be a mess on this bike. BB would be way too low and the handling would likely get weird. I would highly recommend getting a cheap set of 700c wheels, some nice 32mm road tires (GP5000's) and you can swap over your existing rotors and cassette. Shimano's GRX wheelset seems perfect for this application - they're reasonably lightweight, tubeless ready (you can run tubes as well) and can be found online for $375. The 21.6mm internal/26mm external width would work great with 32mm road tires.

Anecdotally, I've been without a true road bike for 18 months or so, and have been running my CX bike with 28mm GP5000 (700c size). I wouldn't do crits or road racing on this setup, but it's been fine for both solo and faster group road rides.

cyclezen

OK, if you decide to get new wheels - 700c - moving the Domane wheelset over is not gonna be easy - Domane road wheels are 130mm rear. Domane Gravel is 142, you need 135, conversion - v-complicated...
Gravel wheelsets are pricey and mostly 142+ rear...
CHinese wheelsets from AliExpress - I guess...
The selection of wheels will be limited...
I would look for 'cyclocross wheels' (usually 135mm) and also anything labeled "29" (making sure the ISO 622 rim size) - 29s might be heavier, since they're rated for mtb use...
moving discs, dependz... 6-bot or cntrlock,,, prolly easier to just get some new rotors - SRAM has some good rotors for $25-30 ish...

I recently bought of FSA Non-Series Convertible Wheelset as upgrade for my gravel bike - Very Nice Wheels!
they will work for 135mm QR and also 142 - 12/15 Thru axle ! I can highly recommend... They normally sell for $450 ish, but can be had - on sale - for higher $300rds when they're on sale -$360 ish ???)
then you need rotors, tires...
Or get 650B slicks - really wide, like 45mm + and deal with small bike handling adjustment...like the Panaracer GravelKing 650B Tire in 48mm
Good luck, let us know what you decide..
Ride On
Yuri
EDIT: 650b x 48 tire is gonna be about 4mm shorter - so much smaller handling changes from the stock 2.1 tire
EDIT 2: thinking while riding this morning... I remembered Tom Anhalt, local and one of the go-to guys for tire crr and other things tire and aero related, had posted a report to his blog Re Gravel tires Rolling Resistence/crr and watts differential...
rather than the GravelKing, on his report/list:

• Panaracer Pari Moto 650Bx48c .0047 crr 33 Watts (just about the best of the few 650b tires he tested...)
  (as compared to a Conti GP 5000 700x23) .0029 crr 20 watts

at double the width of the Conti GP 5000, that result is pretty awesome.

Hackman61

I have the exact same bike. I have been riding on Gravel King Slicks, 650x42mm. Wide enough for comfort but still roll very fast on the pavement. I can just about keep up the same pace as my Cannondale Synapse that are 700x28mm. Tubeless on at the 650's and tubes with the 700c. That Salsa is a good little bike. I've been very happy with it.

Banzai

2nd wheelset.

However, if you want to avoid “gotchas”, match the hubs between the two. That way brake rotors will be identically spaced, as will the cassette.

Nothing like dropping in a spare wheelset and finding out the rotors are about 1-2mm different spacing, and now graze your brake pads.

terrymorse 

If minimal rolling resistance is the goal, there's no need to get a fully slick tire.

Continental makes the Speed King RaceSport, which has an amazingly low rolling resistance that rivals the GP 5000. The appropriate size is 27.5 x 2.20.

bicyclerollingresistance.com found the Speed King RaceSport has the lowest rolling resistance of any MTB tire.

prj71

Can't seem to find these ones for sale online...

terrymorse 

Try this link at Starbike:

Continental SpeedKing 27.5x2.2 (55-584) folding tire RaceSport BlackChilli

RB1-luvr

second wheelset is the way to go. I have a second wheelset for one of my cyclocross bikes with 30c slicks for road riding.

prj71

Sorry...I meant in the 29er size.

jsigone

save your money and just ride the Domane you have when you want to go faster. Keep the gravel bike a gravel bike....

N+1 is life