Bigger chainwheel

[JonB]

Hi

My bicycle repairman has a had time finding a bigger front chainwheel. Which size and type mounting should i look for?

 

[Gromit]

A bit more info about your bike might be helpful perhaps.
Freerider yes? V1 or V2? Early V2? Hence a single chainwheel right? The latest ones have a double chainwheel.
Is there a maker's name and model on the cranks?
You have fitted a Rohloff, haven't you? So I guess that it is a bigger single chainwheel that you need?
These guys might be able to help you.
http://highpath.net/cycles/notes/02.html
They're in the UK. Wales.

As an alternative, could you fit a smaller cog onto the Rohloff instead?

 

[JonB]

Re: biger chainwheel

Gromit wrote: A bit more info about your bike might be helpful perhaps.
Freerider yes? V1 or V2? Early V2? Hence a single chainwheel right? The latest ones have a double chainwheel.

Then you should call it the v2.1 or some other name to indicate that it has changed.

Quote: Is there a maker's name and model on the cranks?
You have fitted a Rohloff, haven't you? So I guess that it is a bigger single chainwheel that you need?

You tell me. I bought it last spring in April. I dont know what parts is on it, i tried looking it up at the website, but no dice, no information.
And yes, it is a bigger single chainwheel

Quote: As an alternative, could you fit a smaller cog onto the Rohloff instead?

I could, but i heard that if the cog is too small, it is worn down more easily.

 

[Gromit]

Re: biger chainwheel

JonB wrote:

Gromit wrote: A bit more info about your bike might be helpful perhaps.
Freerider yes? V1 or V2? Early V2? Hence a single chainwheel right? The latest ones have a double chainwheel.

Then you should call it the v2.1 or some other name to indicate that it has changed.

Quote: Is there a maker's name and model on the cranks?
You have fitted a Rohloff, haven't you? So I guess that it is a bigger single chainwheel that you need?

You tell me. I bought it last spring in April. I dont know what parts is on it, i tried looking it up at the website, but no dice, no information.
And yes, it is a bigger single chainwheel

Quote: As an alternative, could you fit a smaller cog onto the Rohloff instead?

I could, but i heard that if the cog is too small, it is worn down more easily.

As you know. Small changes at the Rohloff sprocket are equivalent to much larger changes at the chainwheel.
How many teeth has your existing hub gear sprocket? How many teeth would you need to have to achieve your ideal set of gear ratios?
I'm sure that you've already done the calculations. I've always found this gear calculator helpful myself because it has a setting for the Rohloff or other hub gears such as the Shimano Nexus 8.
http://sheldonbrown.com/gears/internal.html

 

[admin]

Hi Jon,
how many teeth do you want on your chainring and how long cranks do you want?

 

[JonB]

Re: biger chainwheel

Gromit wrote:

JonB wrote: I could, but i heard that if the cog is too small, it is worn down more easily.

As you know. Small changes at the Rohloff sprocket are equivalent to much larger changes at the chainwheel.
How many teeth has your existing hub gear sprocket? How many teeth would you need to have to achieve your ideal set of gear ratios?
I'm sure that you've already done the calculations. I've always found this gear calculator helpful myself because it has a setting for the Rohloff or other hub gears such as the Shimano Nexus 8.
http://sheldonbrown.com/gears/internal.html

I have done calculations and i want something like 48, maybe 46 is enough, but for now, 48. And i have the 44? it came with.

I do not plan to change the crank arm length.

 

[JonB]

Re: biger chainwheel

I have now measured using the supplied link and sheldonbrown's.

http://highpath.net/cycles/notes/pcds/05b.html says: Shimano 'road'
http://www.sheldonbrown.com/harris/chainrings.html Standard Road double and Road Triple middle, outer

So i guess this means road gear. The funny thing is that the bike shop i tried in, my usual, is called Sprint, and the owner drives a roadbike. The shop does contain road, MTB and normal leisure upright bikes. But still, i would expect such a shop to be able to find or get shimano road gear, but they cant. Or wont.

 

[Doug Burton]

Re: biger chainwheel

Hi Jon,

If you're using the original V1 crankset, you'll need to get crank arms and a chain ring because the V1 chainring is riveted to the crank spider.

The 48t chainring is very common and I'm surprised it's difficult to find. It is frquently used on "trekking" bikes and is a popular choice for single speed bikes as a single ring.

Here's an example, this site has others and is based in the UK:

http://www.chainreactioncycles.com/Models.aspx?ModelID=35783

Let me know if you continue to have problems sourcing these parts.

Best,

Doug

 

[JonB]

Re: biger chainwheel

Hardtailcruzer wrote: Hi Jon,

If you're using the original V1 crankset, you'll need to get crank arms and a chain ring because the V1 chainring is riveted to the crank spider.

I will take a picture and post it, then you can tell me.

Hardtailcruzer wrote: The 48t chainring is very common and I'm surprised it's difficult to find. It is frquently used on "trekking" bikes and is a popular choice for single speed bikes as a single ring.

I think that maybe the apprentice measured the wrong size? or they forgot to times the measurement with 1.7 (five arms) or maybe they used 1.4, they could just be too busy with other customers that actually buy bikes from them, and not just repair service?

 

[Sylvain]

Gromit wrote: A bit more info about your bike might be helpful perhaps.
Freerider yes? V1 or V2? Early V2? Hence a single chainwheel right? The latest ones have a double chainwheel.

Why does the page Freerider V2 specs still speak about 8 speed bikes?

 

[JonB]

Sylvain wrote:

Gromit wrote: A bit more info about your bike might be helpful perhaps.
Freerider yes? V1 or V2? Early V2? Hence a single chainwheel right? The latest ones have a double chainwheel.

Why does the page Freerider V2 specs still speak about 8 speed bikes?

doesnt it come with 8 speeds?

 

[Sylvain]

JonB wrote: doesnt it come with 8 speeds?

Doesn't double chainwheel mean twice as many speeds?

 

[Doug Burton]

Sylvain wrote:

JonB wrote: doesnt it come with 8 speeds?

Doesn't double chainwheel mean twice as many speeds?

The Freerider is still offered with a single chainring, 8 speeds. It employs the V2 frame and high pressure tires, so we call it Freerider V2.

The Sofrider V1 was 8-speed, single chainring. When we introduced the Sofrider V2, we added a double chainring and front derailleur. For the second Sofrider V2 production run, we shortened the crank length, used smaller chainrings to preserve the gain ratio, and changed the mixed-manufacturer drivetrain to a single manufacturer (MicroShift) to improve drive system compatibility. I've written a technical summary update to address these topics; it may be posted to the website soon.

Best,

Doug

 

[John Zabriskie]

Re: biger chainwheel [simple 16-spd upgrade]

After comparing the V2 Freerider (8-spd) with the V2 Sofrider (16-spd), I noticed the basic crank arms are essentially the same. The chainrings are 5-bolt on a 130 mm pitch circle. The spacing between the double chainrings on the Sofrider is similar to the spacing between the inner single chainring and outer pantleg guard on the Freerider. I won a set of SRAM 53/39 chainrings off e-bay recently & replaced the 44T single ring & guard. I used a set of .035" chainring bolt spacer washers to offset the inner 39T ring inboard to get enough chainline clearance. With a used left side MTB shifter & front derailleur -- a simple 16-spd upgrade. Unfortunately with the snowy weather recently, I haven't been able to check it out. More when the weather clears.