Thank you very much, really appreciate the tips. Like I said, I'm new to slalom sailing, even if I sailed a lot, has a lot of experience, is fairely a good level, slalom and cambered sails are totallly new to me!!

I have a 7.8 Severne Overdrive R6, its not a Mach 1 but an it does need a lot of downhaul too. I'm a similar size to you and I can just get to 1cm past the recommended downhaul setting with my harness hook and using the Severne extension with its extra pulley. I was in a hurry rigging one time and I missed the last pulley, I could only get to -4cm to the recommended setting....I freaked out as I thought mast was not joined properly etc.
So a tip from me is to get a Severne extension (with the extra pulley) if you haven't already, it makes a big difference to getting that downhaul on.

Do your back a favour and buy a downhaul winch. chinook make a good one. wind it on to spec makes it easy. Follow the rigging guide sequence or its easy to snap a batten rigging up. lots of downhaul and not much outhaul (ie set boom to spec and leave clew loose 2cm or so) equals happy days. Add cam spacers until luff pocket is not loose. If you are new to slalom sails dont be scared to rig big. More sail is better than not enough.

I bought a chinook winch after i torned a muscle in my calf by rigging my 7.8 evo8. Whar a wimp!! Lol ?? now I don't take chance!!!

Absolutely buy a rig winch, best money you will ever spend. Why risk your back. I even downhaul my wave sails with one....yes a wimp !

North Power XT 2.0 extension best piece of windsurfing gear I have ever purchased in 30+ years of sailing, trim your downhaul with ease and you don't need to come in to do it.

Yes i also have a 2016 OD,couldn't work it out why I always had a sore back ,after sailing ,I wasn't sure what was causing my sore lower back I was thinking it was my bed my car seat until one day the coin dropped and I worked out it was me pulling down on the sail I brought myself a winch and my back has been 100% since then??

Colin let me try his new 7m Mach 1 the other day in 15-22 knots.

So much lighter than any other 7m race sail I've tried before short of the Simmer race sail.

Compared to the earlier Reflex sails they feel like half the weight.

Not sure if performance is much better though.

You can really feel the difference in weight straight away and during gybes.

Windsurfing is so much more enjoyable not lugging around a heavy sail.

Are Mach 1 the same as R8 without Reflex system, especially in big sizes? I ask because I have rigged both on the same apex pro mast and M1 seems to have less deep profile in the 9.4 size

I have a Mach 1 rigging question: I just got a 5.5 and a matching Severne Apex Pro 400 SDM mast. The sail shipped with the RDM cams in place and the SDM cams in the parts bag. Since I have the SDM, I swapped the cams and rigged. The luff sleeve was very loose and floppy so I started adding cam shims. Long story short, after a whole lot of rigging/derigging and adding more and more shims, the sleeve is a bit tighter, but the cams still feel loose inside the luff (not tight against the mast) and I can move them with my hand. I even ran out of shims in the parts bag and had to pilfer shims from my other severne sails...

Does anyone have this size Mach 1 and can offer any tips for how many shims (they come in 2 sizes...) they added to each cam and whether it's possible to tighten up the sleeve? I don't want to add too many as the instructions say you can damage the sail this way.

Thanks!
S.

I Have that 5.5 size on a SDM mast, it was suggested when I got it to try changing just the bottom two cams to SDM and leave the top two cans rdm, rigs fine like that I haven't added any spacers yet although only used it a few times so far

BTW, do you know if came with tension on battens or you had to put some?

Thanks Dezza. I'll give that a try!

@NordRoi: I had to put some tension on the lower battens to get the panels to clean up...

Spent 2 hours this morning working my way upwind along the shore on my ultrasonic with the 8.6 Overdrive in 25kph winds, awesome. Was really looking forward to blasting back but the wind picked up to 30 gusting 45kph shortly after I turned back. I have to say the sail behaved itself perfectly but the ultrasonic with the 58cm fin was trying its best to kill me.

Select to expand quote

ptlonsdale said..
Thanks Dezza. I'll give that a try!

@NordRoi: I had to put some tension on the lower battens to get the panels to clean up...

This weekend seems to be a 7.0 day so I unwrap the sail and tune it. The batten 7(the one below the boom), i did maybe 200 turns with the allen key and never had any tension. Batten 8 after 3 turns, wrinkles were out and i was feeling the tension. Other batten as well. It seems to not working, any idea!?

That seems odd, there's not enough thread to turn it that many times. My guess is batten much to short or some how not seated in the end of the adjuster. Guessing you have wound the end in to far now, can you back it off all the way so you can see the piece with the hex head sticking out?
You can remove the adjuster easily, might be worth doing to see where the nod of the batten is

Select to expand quote

Ben1973 said..
That seems odd, there's not enough thread to turn it that many times. My guess is batten much to short or some how not seated in the end of the adjuster. Guessing you have wound the end in to far now, can you back it off all the way so you can see the piece with the hex head sticking out?
You can remove the adjuster easily, might be worth doing to see where the nod of the batten is

I found this out a few years back when I was on the Severne Sails Overdrives and NCX. I machined up stainless steel spacers 8mm diameter and 10mm long. Took the end of and put the spacer inside the actual batten. Worked perfect no issues at all. The bottom 2 battens were the only ones I ever had an issue with. Also a little Teflon grease on the thread helped as well..Hope this helps.

I removed the tensioner and it's the tensioner who is the problem. The plastic piece and his thread are not holding and I can push the or remove by hand, without screwing or unscrewing, I'm screwed!! ;-)

Select to expand quote

NordRoi said..
I removed the tensioner and it's the tensioner who is the problem. The plastic piece and his thread are not holding and I can push the or remove by hand, without screwing or unscrewing, I'm screwed!! ;-)

Severenly screwed (-;

Select to expand quote

NordRoi said..
I removed the tensioner and it's the tensioner who is the problem. The plastic piece and his thread are not holding and I can push the or remove by hand, without screwing or unscrewing, I'm screwed!! ;-)

I think I had that problem. I bought a new tensioner and it fixed it..? A while ago now..

Well after spending a few months now on the overdrive m1 I've come to the conclusion that it only really works at recommended downhaul + to -1cm and always at the recommend outhaul. Letting a bit down off may give you a bit more power but strong gust are hell, better to work a bit to get going and once your there it just keeps going. To much down haul and it just get twitchy.
I found the scary answer for high wind is just to go faster, if you just hold on the sail seems to deal with everything, if you try to back of its not happy.

I use my R8 7m with my 135 litre in winds around 12-16 knots. I rig it twisted off to the second or third panel down with max negative outhaul. Guessing around one cm less downhaul than spec.

Were I to rig it with the recommended downhaul,I'd lose performance,especially upwind but also through the lulls and for early planing. The sail actually feels better too in this moderate wind as I can get more powered up.

Were the wind to pick up to15-20 knots or more,I'd give it more downhaul and outhaul and likely swap over to my 100 litre.