Cycling UK Forum

As per the subject, has anyone bought or riden the Merlin Axe7 Tiagra? It's pretty tempting at £593.73 including delivery (at time of posting).

https://www.merlincycles.com/merlin-axe7-tiagra-gravel-bike-2017-104289.html

I'm currently running an old and shoddy Carrera TDF which just doesn't have the gears I need for hilly hilly Plymouth.

Is it worth a try? I can't see myself travelling all the way to the shop just to try it unless it's recommended, considering the distance!

TIA

As you seem to struggling to get up the hills, the first question that I would ask is "Is the lowest gear on this bike low enough for me?" If it isn't then how much is it going to cost to fettle or would it be a better idea to buy something else or build what I really want.

The lowest gear 34 x32 is around 29". This may be considered very low by some and too high by others.
I would like a much lower gear but you may be happy with it. If you are in an area with steep hills it may be too high.
You need to compare it with the gears you are already using.
Beware of those who tell you you'll be fine with a 39 x 25.
The bike I use in winter has a low gear of 27 (34 x 34) - I don't use it if I'm doing a seriously hilly ride.

My current bike is 34-28 at its lowest. Do you think that the leap to 34-32 is a big enough one? The bigger hills I face are mostly doable, with a few that cause me to grind to a halt.

Although the parts for a like for like swap would be relatively low, due to the low end spec of the bike, I am looking to go down the CX/Gravel route so I can fit chunkier tyres. Also the frame is a bit too small for me. I've only just shoehorned 28c tyres in at a push. After coming off my bike in a country road last week I really do feel a new setup is required.

The long cage Tiagra rear mech will take a 34 tooth cassette, which is what I use on my Tiagra Cannondale CAADX. Some reports say you can use a 36 tooth cassette with it, which is what this video review says https://www.youtube.com/watch?v=m3y-ehRkhr4

If you are grinding to a halt with a 28 tooth I'd fork out the extra £25 or so for the 11-34 cassette.

The best way to judge how low a bottom gear you need is to climb the steepest hills on a MTB (borrow or hire one if you don't have one) because these usually have very low gears, down to say 17". Make a note of the highest gear that you can comfortably conqueur the steepest hill with, then see if you can replicate that on your new bike.

I guess that you know how to calculate gear inches but, if not, it is simply (no. of chainring teeth/no. of sprocket teeth) x diameter of rear wheel in inches. Assuming both bikes have 27" dia wheels then your Carrera has a (34/28) x 27 = 33" bottom gear whereas the Axe comes with (34/32) x 27 = 29" bottom gear. Or you could say that the Axe's bottom gear is 12.5% easier than the Carrera.

rotavator wrote:I guess that you know how to calculate gear inches but, if not, it is simply (no. of chainring teeth/no. of sprocket teeth) x diameter of rear wheel in inches. Assuming both bikes have 27" dia wheels then your Carrera has a (34/28) x 27 = 33" bottom gear whereas the Axe comes with (34/32) x 27 = 29" bottom gear. Or you could say that the Axe's bottom gear is 12.5% easier than the Carrera.

Or you could put the numbers in this.

http://www.bikecalc.com/gear_inches