Tyre vs Rim size question…..

hey all,
currently looking at a 650b+ bike build and weighing up all the options/costs involved

one thing I cant seem to find a definitive answer to…

Currently happily running Stans Arch MK3 rims on my bike with 2.35 Schwalbe MM & HD combo. Stans website blurb says (I haven’t physically measured yet) they have a 26mm internal width on the rim, for my plus sized bike I’m looking to go no more than 2.6 tyres (probably a MM & HD again)

some places say that putting 2.6 tyres on my current rims would be fine, some places would passionately disagree so I turn to you, singletrackworld hive mind(s)

what say you?
good to go or new rims would be a must?

I know it’s WTB but it gives a guide

https://www.wtb.com/pages/tire-rim-fit-chart

I’ve got a 2.6 butcher tubeless on a stans arch mk3 no bother. Probably comes up a bit narrow, which makes me wonder if it’s worth it over a 2.3 but its not caused me any issues at all.

You’ll get both answers. I think it’ll probably work fine tbh. Schwalbes do tend to be a bit “round” so they often work better on wider rims than most tyres do.

One thing is, you meantioned b+… 2.6 isn’t plus really, it’s just a big tyre. That’s good because it’s less fuss, you don’t absolutely need a wide rim and you don’t get as many of the disadvantages of a bigger tyre. But it’s bad, if you want it to feel “plussy” and big, because it’s not really, it’s just a normal tyre but a little bit more and it rides way, way more like a 2.4 than it does a 2.8 on a big rim

So it’s maybe not so much a question of “do you need this for it to work well” and slightly more a question of “will this really do what you want”

You can do it, but performance will be sub-optimal… The 2.6″ will be a little pinched on a 26mm internal causing a rounder profile with less edge bite.

FWIW I find the 26mm internal Arch Mk3’s ideal for the 2.35’s (60mm) but a 27-30mm internal is better for the 2.4’s (62mm) and a 30-32mm internal ideal for 2.6’s (65mm) to preserve the best tyre shape.

Thanks for all the replies so far

@Northwind what you say makes a lot of sense and I only ask as the frame I’m looking at is a 650b+ frame, after enquiring how well my regular 2.35 tyres would work on it, I was told that it wouldn’t be a good idea due to throwing all the geo off of its intended stance.

Maybe I’ve got this wrong but I then figured go with the smallest + tyre which landed at me looking into 2.6’s which keeps me relatively close to the tyre size I’m used to

Does that make sense or have I got it all wrong and am now talking gibberish?!

Nah, sounds sensible to me. You’ll end up with a slightly lower than usual, pretty much normal bike rather than a “plus bike” but as long as that’s what you want then why not?

I run a 2.6 on a 29mm rim. Wouldn’t want to run it on a narrower rim. It’ll probably be fine at higher pressures but then that defeats the purpose of a bigger tire.

frame I’m looking at is a 650b+…..2.35 tyres…..wouldn’t be a good idea due to throwing all the geo off of its intended stance……landed at me looking into 2.6’s which keeps me relatively close to the tyre size I’m used to

Why are you looking at a 650b+ frame, doesn’t sound like it’s what you want?

@Rubber_Buccaneer I can see what your saying, the frame I like ( This One )is a 650b+ specific frame, the website for said frame suggests that it is…

“suited to a low profile 2.8” tyre or aggressive 2.6” tyres”

Which has led me to looking at the 2.6’s due to my fondness of Schwalbe Magic Mary & Hans Dampf combo

From what I gather from the advice given so far, 2.6 tyres on my current rims is a no no and I should be looking at closer to 30mm ID

For the most part, I guess I’m just trying feeler out what I can and what I can’t transfer from my current bike hence the “can I use my old wheels” question

Ah, Sonder Transmitter.  I see the appeal.  I wouldn’t really call that a proper plus bike especially since they state it won’t take some 2.8 tyres let alone 3.  With a 51mm bb drop I think you’d be fine with your current wheels and tyres

Stans have an infograpihic for this.

I wouldn’t run an arch mk3 on anything but a 24″ kids bike..because its the best (lightest) reasonable width 24″ rim available

@Rubber_Buccaneer

With a 51mm bb drop I think you’d be fine with your current wheels and tyres

That’s what I thought initially but the. The response from alpkit threw me off somewhat…

“ I wouldn’t recommend 27.5s over 27.5+ as it changes the bike somewhat and makes the bottom bracket rather low.

The adapters shouldn’t be an issue, they’re pretty good at the job they do, but I think the prevailing issue is the tyres and how much dropping to 2.35s would throw the geometry off. “

You can hopefully see my dilemma…

I’m sure you’ll be fine running bigger tyres on your rims. Chris Porter had something to say about narrow vs wide rims on the latest NSMB Podcast. You could always build it up using your current wheels and tyres and then if you don’t like it buy wider ones.

Personally I’m not a big fan of wide tyres for most UK riding, maybe in the Alps, Canada or big chunky DH runs, maybe. I’v3 had 2.7 Minion and High Rollers on Mavic 521 rims and they were problem free (personally I’m a 2.35 – 2.5 man myself), cornered well, didn’t fall off the rims, etc.

The only geometry it will effect would be the BB height and I can5 imaging that it would actually change so much that it would be a problem unless you’re running really long cranks.

They appear to be caught somewhere in the middle because the blurb on their site says

The Transmitter frame is suited to a low profile 2.8” tyre or aggressive 2.6” tyres, some larger 2.8”s may rub the chainstays in use

which isn’t really 27.5+ is it, I’d think 27.5+ to be 2.8” to 3.0” wide.

Yes the bb will be low but not ridiculously so.  If money or availability is tight I’d give it a go but ultimately the choice is yours.

Do you like really low BB heights?

@chiefgrooveguru to be honest, I’ve no idea, I’ve always been a have bike will ride, kind of guy and have only recently started getting more interested in what numbers do what etc

I think people exaggerate the rim size limitation. It might not be the optimal width for the tyre, but you aren’t going to explode in flames from running a 2.6 tyre on a 26 mm rim.