Carrera Furnace I - 1x11 conversion

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Zielonyman
Posts: 2
Joined: 19 May 2022, 5:36pm

Carrera Furnace I - 1x11 conversion

Post by Zielonyman »

Hello All,

Last year I've got myself Carrera Furnace I with 2x8 groupset (Shimano CS-Hg200 mounted on 10x135mm qr rear hub).
Seemed like a decent spec for the money.
I really like this bike and would like to covert it to 1x11 but I don't know if its possible with my current wheels/hub.
I'm a complete novice and could do with some advice.
I know I should be able to swap my 8 speed cassette to a 9 speed cassette with ease as it is available on Furnace II which was unavailable at the time when I purchased it, but dont think it is worth the hassle and not sure if 1x9 would be sufficient.
I was wondering if anyone else has this bike and if you would be able to recommend anything.
I know it would probably be cheaper to sell it and get something more expensive, but I would like to learn something new by gradually upgrading this bike.

Here's full specification:

Tyres
DELI SA-281 All terrain tyres
Forks
Suntour XCM, 120mm
Bottom Bracket
Sealed, 68x122.5mm
Cassette/Freewheel
Shimano CS-HG200 8-speed, 12-32T
Chain
KMC 8-speed
Chainset
Prowheel TM-CY10, 36/22T, 170mm
Front Hub
Black, alloy, Quick release 9x100mm
Front Brake
Tektro HD-M275 Hydraulic Disc Brake, 160mm
Front Derailleur
Shimano FD-M315-TS, 31.8mm clamp
Handlebars
Riser bar, 20mm rise, 31.8mm clamp, 740mm
Headset
Semi-integrated, 1 1/8"
Pedals
Mountain bike pedal, 9/16"
Quick Release Front Wheel
Yes
Rear Hub
Black, alloy, Quick release 10x135mm
Rear Derailleur
Shimano RD-M315 Altus 8-speed
Rims
Alloy double wall
Tyre Size
Front Tyre: 27.5 x 2.25" Rear Tyre: 27.5 x 2.1"
Suspension
Front Suspension
Seatpost
Alloy, 27.2x350mm, 31.8mm clamp
Fork travel
120mm
Frame Material
Alloy

Cheers for any suggestions
Jamesh
Posts: 2963
Joined: 2 Jan 2017, 5:56pm

Re: Carrera Furnace I - 1x11 conversion

Post by Jamesh »

Picking up a groupset like this is probably your best bet either new or s/h

https://www.ebay.co.uk/itm/275306931654 ... media=COPY

New

https://www.ebay.co.uk/itm/175274436844 ... media=COPY

You'll need a x1 chainset to suit your BB which will be another £70....+ Bb if the alignment is out...!

Which for me would mean I wouldn't bother .!
mattsccm
Posts: 5095
Joined: 28 Nov 2009, 9:44pm

Re: Carrera Furnace I - 1x11 conversion

Post by mattsccm »

Anything up to 10 speed will go on the hub. To fit 11 you either, change the free hub which may be tricky to identify, machine 1.8mm off the back of the 11 speed cassette or take the same off the back of the free hub. I do the latter but it won't work on all free hubs. Stick to 10 speed. You'll need a gear shifter and possibly a rear mech (can't remember if 10 speed Shimano has the same cable pull as 8) . It may not be long enough anyway say say a new one. Fancy narrow/wide front chain rings do keep the chain on and may be fitted to the middle place in a triple chainset but who knows with yours.
You do get big gaps with 1x anything if yyou want a good gear range. I would go 2x 10 myself if you really want to get a few more gears and buy some flasher kit.
User avatar
Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: Carrera Furnace I - 1x11 conversion

Post by Tigerbiten »

Not worth it.
If you plug your numbers into a gear calculator you will see that a 2x8 setup can be rewritten as an 8 normal +3 granny gears setup.
That gives you 11 unique gears, the same as a 1x11 setup.
The 8 speed 12-32 cassette is a very evenly spaced wide cassette, matched up with the sub-compact double gives you a nice range of gears.
You'll only get a wider range running an 1x11 setup if you use a 11-50 cassette.
So IMHO you'll spend a lot of money for very little gain.

What don't you like about your current setup ??
If we know that then we can probably give you better ideas on what you could do.

Luck ............ :D
Bonzo Banana
Posts: 413
Joined: 5 Feb 2017, 11:58am

Re: Carrera Furnace I - 1x11 conversion

Post by Bonzo Banana »

I think you need to work out what you don't like about the bike and think about how you use it.

The bike seems quite low geared to me but then I don't do any serious off-road riding so I'd probably be looking at replacing the cassette with a 11-32T or 11-34T to get a small improvement in high gearing but to be honest I would wait until I'd worn out the original cassette in a few years. The Suntour front suspension is decent entry level suspension but again if you are going seriously off-road a better fork would be be a big upgrade. I don't go seriously off-road so I'd be looking at fitting rigid forks to make the bike lighter, faster and more responsive. For proper off-roading the current setup is not great for chain retention. I guess a 1x setup with narrow wide teeth and a clutch derailleur would be a great upgrade but its a lot of money for everything. I guess its all about being over-biked and under-biked you sound happy with the current bike which often means a bike well suited to your riding.

The Carrera spec seems very well chosen for an entry level real mountain bike but its not easy to make huge upgrades without spending a lot of money and that money would probably be better off spent on a new bike and selling the old one. The next level of mountain bike drivetrains really starts with 10 speed and clutch derailleurs and you need a better fork. It would be easy to spend £400 plus on that but a bike equipped with such components might be possible for £600-700 new or less s/hand and you could get a chunk of money for your old bike. All this is pointless though if you don't do serious off-road riding on technical trails.
Zielonyman
Posts: 2
Joined: 19 May 2022, 5:36pm

Re: Carrera Furnace I - 1x11 conversion

Post by Zielonyman »

Cheers for your replys.
You gave me a lot to think about.
I may actually go for a 10 speed casette as I feel like I can't get enough speed with my current 2x8.
I'm still a novice and I don't do jumps yet, but really want to learn it.
I'm 37 year old father of 2 and I need to take baby steps as I can't afford time off work if I injure myself.
I probably will get another bike, once I progress enough and will leave this bike to my son.
Thanks again
Bonzo Banana
Posts: 413
Joined: 5 Feb 2017, 11:58am

Re: Carrera Furnace I - 1x11 conversion

Post by Bonzo Banana »

Just saw this deal and this would be a next level up mountain bike from the Furnace. Offering a better fork and drivetrain combination but not at huge expense.

https://www.hotukdeals.com/deals/vitus- ... 27-3938810
User avatar
Tigerbiten
Posts: 2503
Joined: 29 Jun 2009, 6:49am

Re: Carrera Furnace I - 1x11 conversion

Post by Tigerbiten »

What are you aiming/trying to do ??
The trouble is once you start to alter the speed of the cassette then you also need to alter the speed of the shifter as well.
This can get expensive as it soon starts to add up, simple change = new cassette + chain + shifter.
If you just want to go faster it may be easier to just change the chainrings and move the front shifter up a little.
You will loose your first gear but something like 26/42 will shift all your gears up one slot.

Luck .......... :D
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