Hello all,

I have a set of Mavic D321s on my hardtail and despite my best endeavours, they’ve remained true and free of damage over the years of punishment.

I’m riding Scotland Coast to Coast in a couple of months time and am looking to shed some weight from what is a fairly heavy build and thought that going tubeless would be one of the things that I could do.

The rims are quite old and I’ve done some research on t’internet to see if I can find something to tell me how wide the rims are, so that I can buy the appropriate rim tape. The only thing I’ve found so far says that they’re 32mm – do any of you have information otherwise? Better still, have any of you done the same, and if so which kit / route did you take?

Thanks, Dan.

Not done this rim personally, but Stan’s do a DH rimstrip specifically designed for this rim (it fits others too).

The other (very reliable) option is to go buy yourself a couple of BMX inner tubes, fit them to the rim, slit them open, then use them as the rimstrips.

Thanks. With the BMX tube route, I presume you mean slicing it in half before installing?

ha ha… a D321 is almost 700g and going tubeless won’t save any weight.

I did try a D321 tubeless (about 13 years ago, BMX tube and Michelin comp 16 – “nagasti” pretty much the only tubeless ready tyres available back then) it was useless, burped air at anything under 30psi

Take a fresh BMX tube, put a bit of air in it, stretch it over the rim (with the valve in the valve hole obviously), centre it so its not twisted, then take some scissors and slit it open along its length…

hey presto, you’re ready to go tubeless…

This is a pretty good video…

[video]http://www.youtube.com/watch?v=IQX3CciWsSg[/video]

If you’ve not got a compressor, a good trackpump usually suffices, though you’ll need a LOT of fairy liquid quite often (more than this guy uses). But I’ve not done one yet I couldn’t inflate with a trackpump, even if I did get more than a little sweaty.

burped air at anything under 30psi

Your point being?

I burped my rear tyre on Saturday, had approaching 40psi in it. Me being clumsy over a rocky section on my hardtail and poor preparation (old sealant! Doh!) didn’t help, but that’s the first time in about 8 years I’ve had a burp running tubeless.

The rims are quite old and I’ve done some research on t’internet to see if I can find something to tell me how wide the rims are

you could try a tape measure/ruler?

29mm (internal), it’s ‘practically’ the same rim as the (now renamed) EX729

mboy – point being 30psi was too high for a 12st reletively quick DH rider/racer to run up front (yes, I said front), a DH tyre was absolutely fine at much lower pressures than that with a tube. Bottom line is 30psi was too hard for the majority of DH tracks I rode/raced, I may add the burping was simply from hard cornering without rock (or any other object) deflection.
All current mtb tubeless systems are still a flawed for proper hard use IMO

Got an old skool d321 rim tubelessed with stans strip, been like that for about 5 years no bother now. Maxxis high roller USTs.

Okay, thanks for all the information.

ha ha… a D321 is almost 700g and going tubeless won’t save any weight.

Yep, appreciate that it’s not a light wheelset but given the money I have available to address the weight overall I’m not going to be able to start doing anything more – I thought that at least it would lose a little of the revolving weight. I’ll also be going from thick downhill style inner tubes and 2.5″ Maxxis through to 2.2″ Rubber Kings – I’m hoping the difference will be noticeable.

Running a D521 on the rear with a bmx tube. A couple of runs round with leccy tape and wacked the original strip over the top for good measure. It stayed good till the other day when I went down a really rocky section. Now It wont hold air for any more than a short ride. I’m putting that down to still running the same sealant so my job before mayhem is to redo the fitting.

Edit: If you have an Asda near you, they have bmx tubes for less than £2 with removeable cores. Does the job nicely.

The rubber queens are a good tyre and roll quickly for their size. I just went tubeless and second ride in, they blew off the rim (trashed the tyre too!). Even before the blow off, I was having to run over 35psi to stop them rolling off the rim, and even then I could still feel them squiming uncontrolably. Previously I was running about 28ish.

I won’t be tublessing the RQs again, i’ll stick to tubes for those tyres.

Note: using Stans 355 rims and stans tape etc.

Rubber Queens are great tyres, but get the UST version. The non UST are too thin and porous, and the beads aren’t that tight, you’ll have real troubles running them tubeless on your 321’s.

You say money is tight though, but you want to save weight. Firstly, I’d ditch the rims and build up with something like an EN521, or maybe some Sun Ringle EQ27’s or something cheap from CRC right now. You’ll save almost 1lb in rotating weight without losing too much strength before you even look at the tyres.

druff – Member

Hello all,

I have a set of Mavic D321s on my hardtail and despite my best endeavours, they’ve remained true and free of damage over the years of punishment.

I’m riding Scotland Coast to Coast in a couple of months time and am looking to shed some weight from what is a fairly heavy build and thought that going tubeless would be one of the things that I could do…

…to save about 100grams per wheel.

(i’d spend the time making sure i’d packed ‘light’)