UKH

I want to revive my old commencal hardtail for my son. Its been abandoned for nearly 8yrs but is all OK/fixable apart from the forks which were in bad shape beforehand. They definitely need replacing, but what with..? They're only 100mm travel but that suits the XC frame, maybe 120 would be better, but not important really. I probably want to avoid the jeopardy of 2nd hand because servicing isn't cheap but I want something semi decent. Thoughts?

Cheers

Mike

I've upgraded old bike forks before with purchases from Merlin. The biggest issue is likely to be that an old MTB may be based on 26" wheel and 26" forks are like hen's teeth these days. You may get away with a 27.5" fork (100mm) or 26" (120mm) but not 27.5 (120mm) if you can find something like that, particularly if it is air-sprung (as opposed to coil-sprung). Straight steerer or tapered? Check!

Thanks, good tips. Yeah it's a 26 as you'd expect!

These should fit the bill if straight steerer, disc brakes and front wheel is non-boost quick release.

https://www.tredz.co.uk/.RockShox-Recon-Silver-TK-Solo-Air-26-Disc_106804.h...

You can still get 26inch forks but they are pretty limited in selection these days. These probably resonable bet if steerer is right size?

https://www.tredz.co.uk/.RockShox-Recon-Silver-TK-Solo-Air-26-Disc_106804.h...

Also is suspension a must have, you could replace with solid forks if its just for a run around bike?

Decent 26inch tires also increasingly rare, and choice is rather limited.  

Edit - I see these have already been recommended above

Depending on how bad the 'bad shape' they're in is, another option is to send off the existing forks for servicing (e.g. TFTuned), or service them yourself (good tutorials on YouTube).

Otherwise pick up some 26" forks online (e.g. RockShox 30, 100mm travel, £144 from Chain Reaction Cycles) and fit them yourself, or buy them through your local bike shop who can fit them for you.

Any thoughts on these?

https://airbike.uk/products/air-bike-fork-xc32a-hlo-26-inch-rebound-black-g...

Seem v good value but I've never heard of them..

What forks does it have? 

You say they are in bad shape, what is wrong with them?

MTB forks are not difficult to service yourself unlike rear shocks.

An 8yr old hardtail will have radically different geometry compared to a modern bike, if you son is actually going to be riding technical trails it will be a massive handicap.

If he's racing, then yes. If he's just looking to have fun, then less so.

Full disclosure: I still ride an 8 year old FS bike for (technical) fun. Just don't race on it.

People have been riding technical trails for decades. Their bikes didn't seem to hold them back that much.

I'm pretty sure a lot of bike design is, essentially, fashion.

I bought a set of Z4 Bombers to upgrade an old Lava Dome:

https://www.chainreactioncycles.com/marzocchi-bomber-z4-fork/rp-prod207947?...

I idiotically "donated" the bike to a friend of a friend before I got chance to fit them, so they're yours for the £100 I paid for them if you're interested. I think they're 100mm and not suitable for disk brakes. In York, so local enough.

The steep technical trails I’m talking about aren’t raced on,  If you haven’t tried riding them on a modern bike with long low slack geometry you won’t know how much easier they are than on my 22yr old FS.

Modern bikes are massive talent compensators for technical skill.

Yeah sadly I need disc compat.. my old.commie was decent for its day! I might give servicing a go, but I've never tried. Is it hard? He's not racing anyone, just having fun. If he enjoys it I'll thibk about buying him something modern. It's XC he's into not DH. So light and fast, which it is/was!

Yep, modern geo makes it easier and faster, but that just means that the fun doesn't last as long and crashing hurts more. That's my excuse, anyway.

Unless the original forks we're > £500 new (ish), at 8 years old they are almost certainly not worth servicing.  

There is a quite a lot to think about and get right when replacing front forks:

1. Travel - rule of thumb is that you can go +/- 20mm from factory spec without noticeably affecting bike geometry.  If you go beyond that you risk making the bike behave in some unintended ways.
2. Steerer tube size.  Almost universally.. tapered now but some older bikes are still straight.  If it's tapered it'll be 1.5" bottom and 1. 1/8" top.  You need to buy one that matches.
3. Wheel size - sounds obvious.  You need to buy one that matches (or is larger technically)  Standard wheel sizes on MTB these days are 27.52 and 29" ... some 26" still out there.
4. Offset - this is important.  The front fork is offset on a MTB forward of the steerer tube by X mm.  It would make sense to buy a replacement fork that matches you're existing one or is very close.  A large difference will affect how the bike behaves/steers.  Find out the offset on the current forks and buy one that matches,
5. Thru axel.  If you have QR (which you might at that age) you need to get a fork that will take a QR.  Alternatively .. if you have a thru axel then you need to get a fork that will take that thru axel.  Thru axel's usually come in 2x sizes - 15x100 or 15x110 boost.  Buy one that matches.
6. Break mount.  The disc breaks attach onto the fork post mount.  In theory there is no maximum rotor size that will not fit because you can always add spacers to increase what it will take (in theory), however because the post mounts are fixed it does mean there is a minimum that it will take that you physically cannot go smaller with.  Assuming you don't want to replace the rotors then make sure they'll fit the new bike.  

You get what you pay for with forks - buy quality.  You can probably get a decent 2nd hand set off pinkbike.  Make sure you know how it's been used/abused (I am aware that it difficult).

One gotcha if you buy 2nd hand - you MUST make sure there is sufficient steerer tube left to fit your bike.  Measure the fork you're taking off and ask seller to check the fork he's selling and send you a pic.

If you opt for a lovely Fox fork .. they have a 4 digit code on the back of the fork that you can lookup on the fox website to confirm exact spec & age of the fork.  Ask for the code.

Offset Explained:  https://www.worldwidecyclery.com/blogs/worldwide-cyclery-blog/video-fork-of...

Agreed.

Probably don't agree.

Certainly don't agree with this. I got my new bike earlier this week. My old one is 6 years old and moderately slack, the new one is yet more slack. My local loop that includes some of the great descents of the eastern slope of the Peak District - there's a rocky step down into a rock strewn ford at the end of one. On my old bike I only cleared it when I had a dropper fitted, or if I stopped and dropped the saddle after I broke my dropper! The other night on my new bike (which does have a dropper) I cleared it on the first attempt. The added slackness of the fork means you can just go straight down steps that would push you over the bars on older bikes. My first bike with suspension was a mid-2000s Kona Blast when I lived in Finland. I loved it, but it was the classic XC geometry of that time and meant doing lots of the rock steps and steep rollable slabs that the Helsinki woods are full of, really rather exciting feeling! In retrospect it's amazing it took as long as it did for the idea of droppers to take off.

I did what the op has done a couple of years ago, with a 90s 26" hard tail saracen frame, i thought the geometry of the bike suited me perfectlyand i didn’t mind waiting at the bottom of glentress for friends with full sus to catch up.

Stripped everything off, checked frame for cracks, respray and new modern parts(discs etc). Got some remote lock forks from Germany in the end, seems there are quite a few about in the uk just now. Sadly I've lost the bike to the teen daughter who loves it. 

Trails, it's never going to roll over stuff like a bike with 29s and full sus, but for kids 29" wheels are pretty big, they start to impact frame size, the height off the ground and their ability to put feet down if required. It's about just getting out and having fun. Plus, it's the distance from seat to bars, pedals etc... I think 26" work fine for many kids. 

Op,

Rebuilding isn't cheap, a labour of love, as you'll spend more on parts than if you went out and bought off the shelf, but you will get the bike you want. 

Have you tried posting on singletrack world they’re a pretty helpful bunch over there.