120mm reba's would be up to it, very sturdy fork, basically a shorter travel revleation, the revelations are llike lighter pikes, i wouldnt bother with u-turn and wouldnt go for 20mm axle if your budget is limited , some 140mm revelations would be perfect i reckon, reliability is good and they are very easy/quick for serviceing. The revelation can be adjusted internally to 120 and reba race upwards can be put to 120mm, very little weight difference between reba and revelation unless theyre u-turn, but will be probably 1 pound+ lighter than your z1 (3.8lb reba/rev)

OK, thanks for that - currently studying Reba's on RS site.

£150 was off top of my head, if £200 is gonna get me something a fair bit better, then no problem.

just make sure you dont buy a reba sl,they are capped at 100mm

OK, so the fact that the Reba's are 120mm max is pushing me towards the Rev's. I'm used to the 130mm Z1's I have, although I suppose checking axle - crown length wouldn't be a bad thing.

I'm assuming the non U-Turn models have the usual internal spacers to adjust travel?

Post mount suits me also.

Comparable forks from other camps? Fox Talas (more £££'s)? Marz 55 or the newer 44 (probably too rich for me)?

Yes all non u-turn models can have travel adjusted internally, easy job.

If you're bothered about weight, the only RS forks (that you mentioned) to really stick out as suprisingly heavy are 2009 20mm thru-axle Revelations. They use Pike 20mm lowers and push the fork over 2kg (the dual-air U-turn being around 100g+ more than the dual-air 'fixed'* travel model). They appear to be very similar to '08 and earlier Dual-air and Dual-air U-turn Pikes and appear to have replaced them in the UK at least

Coil U-turn Pikes are heavier again at around 2.3kg for the 454 aluminium steerer model and 2.45kg for 426 and 409 steel steerer tubed models

*'fixed' as in internally adjustable only

Probably all newer forks will be less flexy than the Z1 Wedge (I had the same one ;-)). First it had 130mm travel and only 30mm uppers. Than the M-brace was bolted to the lowers with brake bosses.

I would say a Revelation would be similar to the older Z1 for riding type, but not as flexy. Also if You go for 20mm axle and don't have convertible hubs, a new hub/front wheel will have to be bought.

If Your budget is around £200 You can either look for used Revs OR brand new 2010 Bombers, 44 RLO will be under £200, 120 convertible to 140 travel, open bath damping, 32mm uppers, and 3 year warranty. If the weight is not an issue they are worth considering. My mate has a 2010 44's and after the initial break in period they work beautifully.

[edit]
[url= http://www.cyclesportsuk.co.uk/product_info.php?products_id=6223 ]£172 on Cycle Sports UK [/url]

and You will still get easily £50+ for the Z1 on eBay (sorry Hairychested ;-)) [edit]

And you can send your old Bombers to me as a gift 😉
Lucky you, new forks coming...

Well, when I sort some new wheels out, it's in my mind to go with hubs that are 20mm/QR to suit whichever forks I have at the time.

Those Marz 44's are pretty cheap, are they any good though? Think I need to do a little reading.

Another fork in back of my mind is the Vanilla 32, as I'm used to coil forks already. As air forks are variable spring rate (so to speak) I feel they may be similar to what I already have, in terms of blowing through the first part of travel too easilly. I've never ridden air forks so can't really comment!!

Hairychested - if I do sort some new forks, it's a possibility that the Z1's will be heading for my gf's new bike - if she takes to it that is!!!

Well with the 44's You have a simple solo air spring and probably a coil spring as well (that was the case with my older XC500's) so You run them at lower pressure than normal air spring only forks. The fork will require couple of rides to bed in but after that it's the usual open bath goodness from back in the days when Marzocchi made quality stuff. New redesigned internals, no play in the bushings, 3 year warranty without service requirements. They are heavy, even with alu steerer they are over 2kg, but very solid feel and good small bump sensitivity. Wide adjustment on the rebound adjuster, lockout works fine, but as it's a cheaper fork they put some plastic caps and lockout lever instead of aluminium. But fork itself is very good. My mate isn't known to look after stuff and the fork still works perfectly, didn't loose any pressure, no oil leaks. Big improvement over the earlier models. 2010 is probably the safe year to try out Marzocchi again. Plus the fork doesn't use those fancy systems that used to break like ATA, shiny uppers coating etc. For the money, considering You get 3 year warranty it is a very good option. £170 wouldn't probably get You a newer model Vanilla.

Is it fair to say that the 44's are the same as the xc-500 then?

Such a shame that Marz sold out a few years back, their rep really suffered, although I hear they are not too bad again for 09/10?

Well I would say the 44's would be more like xc600, as the xc500 had only 100mm travel. Like I wrote before, my mate is very happy with his fork and we went cycling not so long ago, fork works buttery smooth and there is absolutely no issues, perfectly holds air, as he didn't have to pump it up.

My XC500 was from 2007, and it was still made in Italy, was good, but not as good as my old MXC from 2003. Also worth mentioning the black uppers coating holds very well and doesn't wear out as in older Manitou forks. Shame about those 2 years with big issues in the top of the range models but moving the production to Taiwan was probably rushed too much. So now after 2 years it is probably safe to buy Marzocchi again. But the prices are pretty high for the higher end models.

If you're bothered about weight, the only RS forks (that you mentioned) to really stick out as suprisingly heavy are 2009 20mm thru-axle Revelations. They use Pike 20mm lowers and push the fork over 2kg (the dual-air U-turn being around 100g+ more than the dual-air 'fixed'* travel model). They appear to be very similar to '08 and earlier Dual-air and Dual-air U-turn Pikes and appear to have replaced them in the UK at least

You sure about that? The weighty bit of Pikes is the crown, not the lowers (solid on the Pike, hollow on the Rev). The lowers weigh hardly anything at all. Plus the axle you get with Revs is around half the weight.