Changing my hybrid into a commuter bike

[defy-one]

I'm hoping you can give me some advice on gearing and making my bike faster for road use.

I have a Giant Rock hybrid and find my gearing is too low, I'm searching for another gear if that makes sense.

A couple of questions I have are ...

A) is it cheaper to change the rear cassette, and is this possible on a basic Giant?
B) road hum is a big problem with the knobbly tyres currently fitted, the bike wheels are Etrto 559x20 and the tyres fitted are 26 x 1.95.

Can I get road tyres that are not as fat which with the gearing can turn this bike into a commuter/urban rider.
Lastly any idea of cost as I'm thinking about buying a fast bike like the sirrus sports or Elite in a month or two , so this one doesn't need the best components.

Thanks in advance :-)

 

[mickle]

Show us a pic of the drivetrain..... we'll prob be able to suggest a fix informed by what chainset you've got.

Be prepared for the (seemingly facetious but not) advice to simply pedal faster.


You can fit tyres down to 26" x 1.0" on those rims, though most people seem to prefer a cross section between 26" x 1.25 and 1.5

(Ertro) 559 is a metric description what is essentially an American Imperial standard. Most folk - including bike shops - find it simpler to talk about these tyres in inches.

 

[tyred]

Schwalbe City Jets are an excellent tyre for very little money. I wouldn't go any thinner than 26 x 1.5" If you fancy splashing out, I recently put a set of Panaracer Peasla Tourguards on my MTB and the improvement is surprising. I got them cheap but unused from Ebay which was lucky but these really are an excellent if somewhat pricey tyre.

Unless your bike is unusually low geared or regularly ride well in excess of 20mph, I would suggest pedal faster

 

[HLaB]

Changing the tyres will make a big difference, I believe Schwalbe City Jets are good 26inch tyres. If possible also lock out your suspension forks on road, it saves it absorbing your forward momentum. I'm not sure what size of cassette you have, if it has a small cog larger than 11t you can make a change there. Larger Chainrings will do a similar job (although not as significant, tooth for tooth), costs a bit more and IMO is more complicated and it'd lose you, your lower gears (perhaps needed for hills). Price it up on line but I think new tyres would be around £25 or less, Locking out would cost you nothing and if viable a new cassette £20 + new chain £10.
Edit: I thinking about fit your self prices and if you have the tools, if you need a shop I dare say you can nearly double prices.

 

[mcshroom]

If it's the one I've just googled then the Giant Rock looks like a hardtail mountain bike, but does seem to be fitted with a 48-38-28 chainset and a 14-28 freewheel (7sp).

Put some slicks on it (Schwalbe City Jets seem to get good reviews, and I like Continental Sport Contacts) and it should be reasonably quick, but you should be aiming to be spinning your legs at somewhere around 80 revolutions per minute (which is a lot faster than you would think - I always find it quick).

If it is a screw on freewheel then going below 14t at the back will be difficult. You would need to get a new wheel with a freehub and then you could get a 7sp cassette down to 11t at the front, but I think you'd be better sticking with what you have.

For reference I ride a bike with the same gearing as yours (although 700c wheels) and it doesn't feel particularly undergeared unless I'm trying to bomb it down a hill

 

[Rickshaw Phil]

With the gearing listed on that bike there isn't a huge amount you can do without it getting expensive. As well as the tyres already suggested, I'd suggest fitting a Sunrace (Sturmey Archer) freewheel with a 13 tooth top gear: here

This will add approx 6 gear inches to your highest gear with that set up. I have them on my bikes and there is a noticable difference.

 

[tyred]

48/18 on a 26" wheel is something like an 86" gear.

That should allow a cruising speed in the low 20s mph. I don't think anything higher is required for this type of bike. If the OP wants to go faster, he would be better to buy something lighter, without suspension and with 700c wheels.

 

[defy-one]

That stuff in the background is sunshine (this morning) ..... I googled it! ROFL

 

[defy-one]

Thanks for the tyre recommendations - I will look into those and go slighter narrower as you have suggested. I should explain that as a teenager I went everywhere by bike and even when I started work locally. My thigh and calf muscled still remain well developed so I find powering along pretty easy on this bike. Not boasting or anything silly like that, just trying to highlight why I feel I need a higher hearing. It's interesting what some of you say about my cadence. I will have to do a rough measure once my knee has healed.

 

[Peteaud]

Same (almost) as my old Giant.

Leave the gears alone, they will be fine imho.

Change the tyres to 26 x 1.5 city or similar, you will not believe the difference.

 

[defy-one]

So this morning I reserved a pair of Schwalbe city jets from Halfords for £25. Picked them up at lunchtime and put them on this afternoon. Gotta say they feel so much better than the nobbly Kendas..
Next I fitted a cheap speed/distance trip computer and lastly some led front/rear lights.

She's all ready for a try out tomorrow - the nurses say I can do some light cycling to strengthen my knee muscles. (hope it don't rain)

 

[cyberknight]

Glad you got it sorted
I have an old giant rigid MTB that i fitted slicks on with a max gearing of 42x14 i can still manage a reasonable turn of speed, within 5 minutes of my road bike over the same 10 mile commute although i have to spin the legs a lot faster .
Seriously considering using the MTB full time as the "roads" and cycle path i use are getting worse and worse, i had to bin a road tyre last week as it got shredded by a metal grate some repair guys had laid across the cycle path.

 

[defy-one]

Now the bike is ready to go , it rains and rains and rains :-(

 

[cyberknight]

Now the bike is ready to go , it rains and rains and rains :-(

Its a commute , your going to get wet at some point ...get out there !