Triple conversion.

[Cubist]

I have a Boardman Hybrid Pro. To cut a long story short, it's got a compact double chainset, 50/36 and a 9speed 11-32 cassette.

I live in a hilly part of the world, and being a bit of a bloater run out of gears on the steepest hills. Plus, I'd like to do a bit of touring, so would like a fully-laden twiddling gear.

The current chainset is a Truvativ Elita which has a GXP BB, and I have managed to find a Triple Elita on Fleabay for 80 quid. Add into that the cost of a front mech and I reckon I get it home for about a hundred quid.

However, there are some other bargains out there, such as discounted Tiagras, 105, Campag, all of which will of course require a change of BB. (I found a Veloce BB for 18 quid which should fit a Record?)

What do I do, go for the all in for a ton Elita, or start along the Campag/Shimano route. Oh, and what are the pitfalls?

 

[Rob3rt]

I really dont know the answer to your question.

But what I do know is the tiagra front shifter is triple compatible (its not a different shifter) so i dont know if you need a different deralier in the conversion (if you only pop it one click it will make some not nice noise and not shift because this the the middle ring possition on the triple), or just front cranks(or whatever the collective name is for the front gears etc).

 

[GrasB]

I'd stick to SRAM/Shimano, besides SRAM 1:1 rear mech/shifter compatibility the spacing etc are all the same. At the front if the shifters are triple compatible go with what ever is cheapest over all.

 

[TheDoctor]

My gut reaction would be to get a 34T inner ring, and a 11/34 cassette. Less hassle than getting a triple together...

 

[Cubist]

My gut reaction would be to get a 34T inner ring, and a 11/34 cassette. Less hassle than getting a triple together...

But would that not leave huge lumps in the gearing? I suppose I could do one or the other to see if things improve.

Which is the biggest gear advantage, two more at the back, or two less at the front?

 

[adscrim]

Which is the biggest gear advantage, two more at the back, or two less at the front?

I don't think there's much in it at the extremities. The difference for me would be that on the flat, the 34 front would be pretty much useless where as I'm nice and happy spinning along at 17mph-ish on 36:13/14

 

[Cubist]

I don't think there's much in it at the extremities. The difference for me would be that on the flat, the 34 front would be pretty much useless where as I'm nice and happy spinning along at 17mph-ish on 36:13/14

Yes, but the difference here is that the flat doesn't exist as much! All my routes are either uphill or downhill. For example my ride to work is 6 miles descending 900 feet. I can spin the 50 ring on the smallest sprockets if I want to! On the way home however, spinning goes out of the window as I mash my way back home (well, sort of, the last hill sees me walking if I'm not in the right mood!)

I therefore want to be able to spin rather than wear my knees out getting fit enough to ride it, hence the idea of some spinney gears.

 

[Cubist]

Spooky
If I change the front chainring to 34 and keep the 11-32 I get a lowest gear of 1.06:1
If I change the cassette to an 11- 34 and keep the 36 chainring I get a lowest gear of 1.06:1

Obviously changing both gives the lowest gear at 1:1 , but the first step of a 34 T chainring is the cheapest option until something wears out.

 

[GrasB]

A second thought Cubist, how much do you use the top-end of your current setup? maybe look into a 29/44 crankset this gives you a 0.9:1 bottom end & you're only losing the top 2 gears.

 

[Cubist]

A second thought Cubist, how much do you use the top-end of your current setup? maybe look into a 29/44 crankset this gives you a 0.9:1 bottom end & you're only losing the top 2 gears.

On my ride to work there's a couple of places where you can go all out in top, and run out of touch with the pedals. Places like that aren't all that rare round here, and with the constant changing gradient I like to bomb the descents to make up for mile after mile of 6, 7, 8 mph climbs.

 

[GrasB]

Assuming 700x28c tyres here 44:11 = 38mph @ 120ppm. So you either can't really spin or you're seriously going for it.

 

[Cubist]

Assuming 700x28c tyres here 44:11 = 38mph @ 120ppm. So you either can't really spin or you're seriously going for it.

Err, I lose touch with the pedals just over 40mph on the first hill. Tucked I've topped 47 mph

 

[GrasB]

So you're not a spinner, nought wrong with that, just I was driving the pedals at >45mph in the same gear on 700x23c tyres (both gears were 4:1). My advice would be tuck in & enjoy the ride

 

[GrahamG]

If you seriously want to load the bike up a bit for touring I'd just change the crankset for a MTB triple (26/36/48 or something similar is probably a sensible compromise rather than the more common 22/32/44) - your rear mech is likely to be compatible to accommodate that 11-32 cassette so it's just front mtb mech.

Don't worry about sticking with truvativ or keeping current bottom bracket, you can flog those together on ebay for decent money to avoid spending extra on sticking to the one brand.

I'm thinking these two things plus some basic (borrowed?) tools, or cash to LBS will sort you out:

Crankset (includes BB):
http://www.parker-international.co....ogle&utm_medium=froogle&utm_campaign=pid13893

Mech:
http://www.parker-international.co.uk/13902/Shimano-Deore-M590-Top-Swing-Dual-Pull-Front-Mech.html

Just to check - is your front gear shifter compatible with a triple?

 

[jay clock]

Buy another bike. Seriously. A Carerra Subway would probably work quite nicely and it now has 21 speed MTB gears - not sure what but probably 24 on the front small chainring