Carbon or Aluminium for a fast lightweight XC bike

[Hell27]

Hi all, I've come to the conclusion that I generally dislike road bike riding. I currently have a Scott Speedster 30 2015 with full shimano ultegra wheel and groupset, but the problem I have is that I hate riding on roads due to the quality of ride on the awful potholed highways of the North West. My normal commuting bike is a CX on 35mm rubber, which rides a lot better and does me for the road bike experience. I have therefore decided to sell the Scott and look at lightweight XC hard tails at anywhere between the £1500 - £2000 mark. I have a full Susser too so aren't looking for one of those. I'm after a light fast bike that can handle trails and commutes well.
At this price point there does not seem to be that much difference in weights between the two - I've seen aluxx around the 11-12 kg mark and carbon around the 10-11.5 kg mark. I guess you'll get better components on an aluxx frame in this territory, plus I still have reservations about a carbon framed mtb that will see a lot of rough riding. So I was wondering of the pedal powered community, what are your thoughts on this? Cheers.

[Herman Toothrot]

I had a Carbon Vitus Rapid275 for a year or two when I was wanting to do more XC stuff, £1300 it was new form chain reaction, XT drive train, SLX brakes, Easton XL wheelset, own brand finishing kit. Once setup tubeless it weighted 10.4kg, great value bike and for XC I'd go carbon everytime.

[gazza285]

I'm looking at a Cube Reaction GTC SL and a Trek Superfly 9.8. It's one or the other, carbon all the way...

[Usget]

A mate has just bought the alloy Boardman Pro 29er. 11kgish, great looking spec for the money, and can be had for £810 if you do the BC discount + vouchers trick. Leaves you with some budget for upgrading the wheels, and possibly a dropper post.

http://www.halfords.com/cycling/bikes/mountain-bik...

[poo at Paul's]

My mate bought an ally Cannondale Fsi 29 last week, £1500 and out the box it weighs fack all! 10.4kg in Large, although the lefty front fork accounts for a lot of that. But he reckons the carbon one is only 400g lighter.

It's a misile of the thing, really impressive, so quick. Seems quicker than my road bike!

[BenGismo]

Id easily recommend carbon for a fast & light xc bike. Ive more than one sub 9kg carbon hardtail and love them.

Im a fairly heavy rider too and ive never managed to break a frame.

I wouldnt choose the bike purely on the frame material though. Try a few and see what you like, even the difference in stiffness between two carbon frames can be fairly suprising.

[Hell27]

BenGismo said:

Id easily recommend carbon for a fast & light xc bike. Ive more than one sub 9kg carbon hardtail and love them.

Im a fairly heavy rider too and ive never managed to break a frame.

I wouldnt choose the bike purely on the frame material though. Try a few and see what you like, even the difference in stiffness between two carbon frames can be fairly suprising.

Thanks for the advice - however for a sub 9kg hardtail, what make/ model and price are you looking at?

[BenGismo]

My point regarding the weight was only that the bikes are very robust and ive not broken any of them even though they are lightweight and im a heffer.

You didnt mention if you want brand new (apologies if you did and I missed it) but id guess that you do want a 2017 model. Its difficult to buy a brand new sub 9kg carbon hardtail mtb off the shelf without spending a ton of cash and isnt worth it just to have the latest model as far as im concerned - but each to their own. A light MTB off the shelf is as you have already said....around 10.4kg or so.

Ive a 2013 Scott scale 900 SL which was a 8.2kg bike when new. I only bought the frame second hand and built it up myself with choice of parts and so it ended up at 7.7kg which IMHO is very light for a mtb. I spent less than £1600 on building the scott 900 but was the second owner. Ended up with a bike worth 3x that when new and lighter than even the newest ones too.


Ive had a scott scale 35 since new and that it is also a great bike (currently weights 8.7kg). As you can probably tell I like scott scales (I dont work for them honest) I have no less than 3 Scales myself right now (2 Carbon and 1 alu) and a few others in the past. As such id recommend taking a look at the 2016 scale 710 or 910 as they can be got for between 1.5-2k right now. Ive ridden Cannondale Fsi's and Giant's (XTC) too and liked them ALOT and they should also be around the 2k mark depending on the exact model.

Edited by BenGismo on Tuesday 9th May 13:10

[Hell27]

Thanks for the reply Ben, I'll take a look!