Can't Maintain Pressure with Stan's Kit on Mavic 317: Ideas?

myopic

I tried to convert a set of Mavic 317 Rims to run tubeless using Stan's noTubes Standard Kit. I drilled the inner rim valve hole to 3/8 as recommended and used the in kit rim tape (2 layers). The rim strip seated fine, the tyre seated OK (Kenda Nevegal) and I was able to inflate without sealant. So far so good. Popped in the sealant and after the usual leaks, shaking and leaving on its side to seal, all appeared to be well. The problem is that the tyres are still leaking air 2 days later. If I inflate to 30 psi they are down to less than 20 psi overnight. There are no obvious leaks, but if I lather soapy water round the rim, there are tiny leaks. These seem to be sealing, but others must be opening up. Nothing dramatic but air is constantly leaking out. Both front and rear are doing this.

Would adding more rim tape to push the rim strip up closer to the lip of the rim help? There was a slight gap in places, but the fit of the rim strip was very neat round the valve and I'm not sure I could lift it much there at all and still get the tyre to seat properly.

Anyone got any ideas how to fix this?

davewalsh

I ran a Panaracer Fire last year, it it took a couple of weeks for the sidewalls to seal properly. Just give it more time and it will seal eventually.

myopic

Thanks, Dave. There's plenty sealant in the tyres (btw they are used, not new), and they are slow leaks, so I can ride on them. Just wondering if there are any shortcuts to keeping on pumping and hoping it will eventually stop!

gilesjuk

Proper tubeless tyres are tighter on the rim and as a result hold air really well.

If you're using non-tubeless then the end result can be really variable.

myopic

They are Kenda Nevegals DTC with folding bead - I thought these would be OK as I've heard of other people using them without problems?

myopic

well after shaking as per Stan's recommendations and leaving each wheel on its side afterwards for about a dozen times (and having a couple of rides) both have now held their pressure for 4 days.

bails87

gilesjuk wrote:

Proper tubeless tyres are tighter on the rim and as a result hold air really well.

If you're using non-tubeless then the end result can be really variable.

I used tubeless ready Mud Xs last winter and they wouldn't seal at all :?

myopic

bails87 wrote:

I used tubeless ready Mud Xs last winter and they wouldn't seal at all :?

That's not good news Bails - I have the same tyres and was going to switch to them once we got into winter (which I may be a bit late for since it seems to be well under way). What rims were you using and what tubeless set-up?

Chunkers1980

I've just got a stans rim to replace a 317, had to take the tyre off once I got a new inner tube and the bead was so much better 'in' the stans rim that it was ever in on the mavic.

I would say your problem more relates to the rim and the bead hook than anything else.

myopic

Thanks, Chunkers. I have Stan's rims on an other set of wheels and I know this, but don't want to buy new wheels (or retrofit new rims) and my problem is solved.