Evening gents. Firstly apologies if this has been done to death.
I have a set of old downhill wheels on my hardtail that i’m reluctant to change as altough they are heavy, they are as strong as hell.
They are Mavic D521 on a hope big un rear and bulb front. They are not disc specific and are schrader valve type.
My question is, would I be able to convert these to tubeless? I’ve been a bit sceptical up until now but I quite fancy giving it a go to see what all the fuss is about. I’m wondering whether this is possible as all of the kits ive seen have presta valves.
I’m using a specialized butcher control front and purgatory control rear. both are 2bliss folding type.
I look forward to hearing your advice. Cheers. Luke.

Not done a D521 but I usually run a rimstrip on non-tubeless rims. Works well. I run a D321 on the front like this.

Yes

I use the same rims on my full sus bike. Easiest way is to buy 2 BMX inner tubes, and convert via the ghetto method (search “ghetto tubeless” on here or on YouTube). Easily as reliable as buying expensive rimstrips, and a whole lot cheaper.

Word of warning though, tubeless success depends mainly on the tyres you choose to run. Pick tyres that are known to convert well and you’ll be fine, but don’t and you’ll end up swearing lots!

ghetto is definitely cheaper but rimstrips are easier to re-use, and thus better value/less faff over the longer term, especially if you like to swap tyres about. IMO.

reggiegasket – slight hijack (sorry OP), what tyres are you running on your D321? Got D321’s on the tandem and been trying to get a non-UST Advantage and a WTB Motoraptor to seat without success. Loads of leccy tape before the rim strip, but even the magic STW ghetto inflating pop bottle won’t seat it 🙁 How did you manage it? Black magic?
Cheers, Rob

I’ve converted plenty of D521s and the ghetto method is probably your best bet~ you can reuse them if you’re careful~ I have done it with rimstrips, but the advantages don’t justify the cost.

Also, in case you didn’t know, D521s are exactly the same as EX721s, apart from colour and age.

I run a D321 on the front with a std 2.4 HR2

I run a EX721 on the rear with a UST 2.35 Fat Albert.

Both run rimstrips.

Thanks for the replies chaps.
Upon the advice given I’m going to give ‘ghetto tubeless’ a go. I’ve got some schwalbe threaded schrader bmx tubes and some stans sealant on the way.
Stans rim tape aside, what would you guys recommend to tape up the rims? Cheers. Luke.

Use a normal rim tape underneath the BMX tube, nothing special. I prefer Velox cloth tapes, but any old rim tape will suffice. The BMX tube is doing all the sealing so you don’t need any fancy rim tapes.

Ahh ok, I’ve done a bit of research and it says on one website i was looking at about using double sided tape to secure the tube in place. Is that necessary?

Stans rim tape aside, what would you guys recommend to tape up the rims? Cheers. Luke.

Just run standard insulation tape around them a couple of turns (take out the old rim tape first), keep an even stretch then just pop the BMX tube through.

I’ve never used it. Can’t see that it would do anything to benefit you either. It’d just add weight. Once you’ve got the seal, air pressure is holding everything where it needs to be anyway (crucially the beads of the tyres up against the bead hooks on the rim) so I just can’t see a point.

I’ve done many many Ghetto conversions now, and aside from the initial faff, I’ve got to say its probably my prefferred method of running tubeless. It’s one of those “why didn’t I think of that” bodges that actually just works (tyre choice dependent). Just find a cheap supply of inner tubes (or don’t change your tyres til they wear out) and you’re laughing!

I always thought it was to seal the nipple holes in the rim.

But as you say once the strip has created a seal this shouldn’t matter, next wheels I do i’ll skip that step.

Tubes £1.99 at jejames, and £12 for a pint of stans.
🙂

next wheels I do i’ll skip that step.

Still use a normal rimtape though, you don’t want the sharp holes on the inner wall of the rim potentially puncturing your BMX tube.

Afternoon chaps. A quick update on this. My inner tubes turned up today so I thought I’d make a start with the conversion as I’m still waiting for the stans sealant to arrive.
Basically I have followed the instructions i’ve read on various websites and i can’t believe how easy/well it went. Granted, I haven’t finished and actually ridden on them yet but I cut the tubes and fitted them to the wheels. I then fitted the tyres and removed the valve cores to inflate them with a track pump as recommended, and much to my amazement they inflated with minimal fuss and appear to be holding air!
I must admit I was expecting the conversion to be much more of a pita.
I’m lookling forward to getting the sealant in the tyres and testing this out now to see whether i’ve blown my own trumpet too early!

I’ve used these rims for years. Have a pair of grey ones on my primary King-hubbed 26er wheels. Excellent balance of weight, durability and width for general riding IMO. I have a spare pair of the correct Stan’s rim strips if you struggle with ghetto.

I have a pair of D521s for the DH bike – now used as a spare set of wheels.

Bought the rims new around 1998/9? Just after the 121 was discontinued?

Utterly bombproof!

alpitudeluke – Member
Ahh ok, I’ve done a bit of research and it says on one website i was looking at about using double sided tape to secure the tube in place. Is that necessary?

I’ve done that a couple of times – it makes it a bit easier to change tyres and still use the same rim strip.It does work but whether the extra faff is worth it or not is another matter.