XC race mtb ...upgrade options to cut weight

Peetz

Hi there
I have been using a xs Sunn prim s2 2011 for a few years and love the bike, very fast and light but have been considering going for a new sub £1000 hardtail through my works cycle to work scheme thingy in the hope I could get an even lighter xc bike ......(I do the odd bit of trail riding on it as well and it holds up fine)
However no matter where I look it is hard for me to beat the spec/weight on my Sunn prim. What I was thinking is that I may be better just getting new wheels and maybe fork for my Sunn and I am sure I could end up with a perfect fitting hardtail which would probably end up alot lighter and higher specced than anything I could find out there for £1000 on the cyclescheme thing.

Here is the spec for my current Sunn prim s2:
• Fork: Rockshox Recon Gold TK SA 100mm
• Brakes: Formula RX 160mm
• Shifters: Sram X7 9 speed
• Cassette: Sram PG 950 11/34
• Front derailleur: Sram X5
• Rear derailleur: Sram X9
• Chinaset: Truvativ Firex 3.2 22/32/44
• Tires: Hutchinson Python AL NG 2.00
• Wheels: Alexrims TD24
• Handlebar: UN Origine 660-20 SL
• Stem: UN Origine SL
• Saddle: SDG I Fly RL CrMo
• Seatpost: UN Origine 350
• Weight: 11 kg
• Geometry given with a travel of: 100
• Seat tube diameter: 27,2
• Seat clamp diameter: 31,8

Aye so......any ideas on how best to trim some weight .....wheels or forks??
If anyone has a sub 11 kg hardtail suggestion (cyclescheme and in 14 in frame) then I am all ears

RockmonkeySC

Why not upgrade this bike? I would guess there's well over a kilo you could loose off this one depending on your budget.

The Rookie

With that spec I very much doubt your at 11kg I'm afraid, I've seen that before with Sunn bikes, I think they have a whacky standard for weighing them (like no tyres!).

Practically everything there is heavier than can be achieved on a reasonable budget, forks and wheels give the biggest impact, but you can also get some useful savings with some intelligent tweaking and low cost mods.

You may find some ideas in my lightweight build thread, link in sig.

If you can cope with the gearing, going to 1x is an easy save of circa 250g, also anytime a part needs replacing you need to look at going lighter.

Peetz

It is an incredibly light bike considering all I paid for it...was around £600 quid at the time....you might be right but it has always seemed lighter than any of my friends hardtails.....frame weighs 1.7 kg according to chain reaction who are currently selling it in the UK. The xs thing is important too as I am such a short censored and I am so used to the Sunn
So do you guys reckon a wheel upgrade isnt really worth the hassle??.....its either £1000 quid on a new hardtail or spend something upwards of £500 on upgrades??.......I like the idea of a new hardtail but just cant find anything that would warrant me going to all the expense of getting rid of the Sunn.....dilemna

Peetz

The Rookie wrote:

With that spec I very much doubt your at 11kg I'm afraid, I've seen that before with Sunn bikes, I think they have a whacky standard for weighing them (like no tyres!).

Practically everything there is heavier than can be achieved on a reasonable budget, forks and wheels give the biggest impact, but you can also get some useful savings with some intelligent tweaking and low cost mods.

You may find some ideas in my lightweight build thread, link in sig.

If you can cope with the gearing, going to 1x is an easy save of circa 250g, also anytime a part needs replacing you need to look at going lighter.

Just seen the 9.6kg kraken...damn...ill check it out ......my first bike was a carrera fury..was an awesome bike too

RockmonkeySC

It's probably light because of the tiny frame.

Ferrals

For 500 quid I'd have thought you could shave a lot of weight. Especially if you look at online deals etc. for example I got a gobi saddle for 25quid in a sale which saved over 100g on my old one. You need to check the weights of your existing stuff.

supersonic

First thing I thought - that is not 11kg. Sunn (and CRC) have a habit of underestimating weights by miles. Don't get me wrong, a nice bike, but 11kg is narnia.

It's a very even spec. This makes weight upgrades hard.

RockmonkeySC

I think I would go for new wheels and tyres. A set of Stans Crests on Hope hubs and Racing Ralph tyres will loose a bit of weight from where you're going to notice it most.

Peetz

I will check that out Rockmonkey...thats exactly the kinda ideas I am looking for ......I was hoping just with a few changes, wheels etc .....for some renowned xc lightweight items I would be able to take a fair bit of weight off........I agree with yas that it would be good to be able to clarify the exact weight though...might be that buying an off the shelf xc bike or whatever may be viable if the bike is infact radically over 11 kg. Any ideas on what is the lightest £1000 hardtail out there...(has to come in xs frame though ) .....really appreciate everyones input!

RockmonkeySC

I had a set of those Alex TD24 wheels. They are fairly heavy and weak. It would be a good upgrade.

Peetz

So for wheels... Hope Hoops Pro2 Evo MTB Wheelset with arch ex rims (arch ex over the crests as I still wanna have the option to thrash it bout a bit on the trails) , tubeless with racing ralph tyres.......if my research is right...that should knock almost a kilo off my total weight.....thats more than I expected!!
...any other obviously heavy parts on my spec list that can be easily upgraded?

The Rookie

I agree with the crest/hope combo as a good strong and cost effective option, Ralph or Ron tyres, folding in Evo compound and tubeless and you'll be saving pushing a kilo.

Foam grips are always a cost effective way to shed a surprising amount of weight, also the Superstar stems are pretty light for the money and it's easy to weigh what you have, likewise with seatpost and saddle.

A good way to look out how to save weight and where is to make a spreadsheet with every component on it and the weight, then look at what is available at a sensible price and look at the saving per £.

The frame is about the same weight as mine, so not heavy, but not fantastically light.

njee20

Peetz wrote:

So for wheels... Hope Hoops Pro2 Evo MTB Wheelset with arch ex rims (arch ex over the crests as I still wanna have the option to thrash it bout a bit on the trails) , tubeless with racing ralph tyres.......if my research is right...that should knock almost a kilo off my total weight.....thats more than I expected!!
...any other obviously heavy parts on my spec list that can be easily upgraded?

Just get the Crests, they'll be plenty tough enough and a chunk lighter. I used to use Podium MMX rims, which are a lot lighter than Crests, and never had any problems.

RockmonkeySC

Strength is more about the build of the wheels than the components. Well built Crests can be surprisingly strong.

njee20

Aye, that was my point really, and I'm guessing that someone riding a 14" frame probably doesn't weigh 18 stone either!

Ferrals

I've been looking at wheels around about your budget and for rims have been suggested Ryde trace xc, 320g in 650b and assymetric so apparently can be built very strong. I havent got a price for them yet but with American classic hubs, brass nipples and d-light spokes wheelset according to my guestimate could be sub 1380g or 1520g on hope hubs

mudsucker

Just one thing. If you get a hope pro 2 rear hub you will need to get an XT cassette as it has an aluminium spider. Your 950 cassette will dig into the the Hope alu freehuba nd damage it.

This will of course save you a bit weight too!

njee20

Not essential, but good practise. Same with any alu freehub.

The Rookie

Won't be quite that light, around 1420g (Crests, AC hubs, DB spokes and brass nipples) would be my estimate, so not exactly heavy.

I went for the latest Novatec rear hub with one steel spline to protect it from digging in (although I have an XT cassette anyway!).

RockmonkeySC

My experience with Novatec hubs was not good. Four freehub bodies cracked in a year. Maybe they have improved.

WindyG

For info Crest's on Hopes would come in around the 1600g most likely under that on 26" rims, I have just got some 650b's and they weigh 1660g

ravenvrider

Having been sucked into the upgrading path on both my road and mtb I can honestly say I think your best bet is to sell your bike and get a secondhand one for £1000. A friend just bought a mint 2012 Cannondale flash carbon 2 for £900...It weighs less than 8 kg and has a top end spec to match...bargain.

Upgrading kn my experience always seems to cost more than you expect...

njee20

I'd agree with that. D-Lights aren't that light and brass nips add weight.

Ferrals

On the net I read D-light spokes are 307g for 64 in 26in so 27.5/26 x 307 =325g
Ryde trace xc are 320g each so 640g
Alu nips 20g for 64
Am classic hubs are 130 fr and 225 rear so 355g
So potentially a wheelset at 1340g

Obviously you'd probably want brass nipples so it goes up to 1390 ish but still pretty light. I'm going to save a bit of money and get dt350 hubs and brass nipples so my build will be about 1520g I think but still good for less than £500.

The Rookie

27.5 wheels are 27" not 27.5"....... Spoke weight depends on length which depends on hub Falange diameter and spacing as well as the rim ERD.

If you use the DTSwiss spoke calculator and input rim and hub weights it gives you a pretty accurate total weight based in spoke and nipple selected.

andy37

So i recently changed the wheels on my 2nd hand Orange 5 because i fancied going tubeless and wanted to put on the lightweight crest rims. However when i looked closely at the wheels the rear was buckled and the chain had gashed the spokes and the front needed new bearings and a true up so i decided to buy complete wheels and went for Hope sc6 lightweight hubs with crest rims. These have a recommended max weight so you are fine to fit these on your stead, anyway i weighed the old and new wheels and here are the figures less tyres, tubes and cassette. Front hope pro 2 hubs (forget which rim) 906g, new Hope sc6 and crest rim 658g. Hope rear pro 2 (forgot rim) 1025, new sc6 with crest rim 788g which equates to roughly half a Kg in weight saving.

kajjal

ravenvrider wrote:

Having been sucked into the upgrading path on both my road and mtb I can honestly say I think your best bet is to sell your bike and get a secondhand one for £1000. A friend just bought a mint 2012 Cannondale flash carbon 2 for £900...It weighs less than 8 kg and has a top end spec to match...bargain.

Upgrading kn my experience always seems to cost more than you expect...

This is the route I would take if you are serious.

njee20

ravenvrider wrote:

Having been sucked into the upgrading path on both my road and mtb I can honestly say I think your best bet is to sell your bike and get a secondhand one for £1000. A friend just bought a mint 2012 Cannondale flash carbon 2 for £900...It weighs less than 8 kg and has a top end spec to match...bargain.

Upgrading kn my experience always seems to cost more than you expect...

No way is a Flash 2 sub 8kg. The top Hi-Mod barely squeaks that. 10kg perhaps.

Ferrals - no way will your wheels just weigh the sum total of manufacturers claimed weights, unless you get ridiculously lucky!

WindyG

9.4kgs is the best I've seen a top spec'd Flash at, can't see anyone getting under 8 kgs no matter what money they chuck at it.

Ferrals

njee20 wrote:

Ferrals - no way will your wheels just weigh the sum total of manufacturers claimed weights, unless you get ridiculously lucky!

No I kind of figured not but I guess that's the same as advertised whole wheelset weights, so it's more a check on the relative weight compared to other builds.
The main thing really I guess is light rims in terms of angular momentum etc.
This thread has made me want to try and weigh my whole bike [heads off to the garage...]