As title…

Looking for recommendations for a 650b+ rim which has offset spoke holes.

I’m converting my custom frame to a 650b+ rear whilst using a rohloff. The back end is offset by 15mm as I’m using a standard 135 rohloff but the frame is full fat…hence the offset.

If I like the whole 650b+ thing I’ll get a custom carbon rim made from the likes of Lightbicycle who do offset drilling but want to do some miles on a cheaper rim before committing.

Rabbit holes have 2 sets of spoke holes but I don’t think they do them in 650b size.

Any other suggestions?

It’s only a little offset but WTB Asym? Only a 35mm rim so not as big as you’d probably choose for 3.0 if width was the only thing.

What’s the biggest tyre a 35mm rim can take ‘safely’? I’m ideally hoping to squeeze a 3.8 on for sloppier months and then revert to 3.0 for the dryer times (ahem)

Depends what pressures you’ll be running.
15psi on a 23mm rim was comfy in a straight line but squirm central turning sharply.
25psi on a 23mm rim was bit sharper turning, bit grippier in the dry but that was about it.
12-15psi in a 45mm rim is perfect.

A half way house at 35mm should be ok for a 3″ but a 3.8 would be a bit rounded, & tall…!!!

rosscopeco – Member

What’s the biggest tyre a 35mm rim can take ‘safely’? I’m ideally hoping to squeeze a 3.8 on for sloppier months and then revert to 3.0 for the dryer times (ahem)

I had 3.0s on mine, they were a wee bit lightbulby. 3.8? you want a 65mm rim or thereabouts. I don’t think you can really cross the streams

I had 3.0s on mine, they were a wee bit lightbulby. 3.8? you want a 65mm rim or thereabouts. I don’t think you can really cross the streams
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A 50-55mm rim might just handle both 3″ and 3.8″ OK. I don’t know what’s available in that range though – and isn’t there only one 650×3.8″ tyre currently available?

Hodag?

Yup, the 3.8 Hodag is what I was thinking about.

Surly replied to a query I sent saying they have no plans for a 650b rabbit hole. 🙁

As I say Lightbicycle make a 50mm one with offset holes…guess that’s my only option…was hoping there was something less spendy out there before jumping at the carbon loops. It’ll be light build I suppose.

One other question…has anyone tried a 650b x 3 on a 65mm rim? Nextie make a 65mm although I’ve yet to establish if they do offset drilling.

I should just buy a ‘normal bike’!

IMHO you are trying to make one wheelset do too much because of your Rohloff. B+ on a 27.5 x 40-45mm rim and full fat on a 26 x 65-80mm rim will have almost the same diameter and could be swapped into your frame. Just decide which wheelset should have the IGH

Curious as to why an offset frame needs an offset drilled rim. Is it to do with drive side dishing? Would you mind educating me so i can get my head round it please?

Curious as to why an offset frame needs an offset drilled rim. Is it to do with drive side dishing?

yeah, you need to offset the rim by the same amount as the dropouts so that it sits central to the frame/rider.

Yep, but you don’t need an offset rim to do that, you can offset it with spokes.

Spokes won’t offset it by 15mm though!

What about taking a single wall rim like the Sun ringle Mulefat 50 and drill additional holes every other spoke hole?

Or reversing the rim so the offsets are reversed (sounds bonkers that one but might work!).

reversing the rim

Andy…now that’s a thought I hadn’t considered…cheers!

Just did a little fettling on freespoke with a basic 650B rim with 5mm offset spoke holes.

Turns out a offset rim can be used with both a 15mm offset and 0mm offset with (I think) an acceptable tolerance in spoke tension and angle.