chainwheel

[aseb]

The single chainwheel on the 6 Speed X-Byke is 46T, are bigger chainwheels out there- I'm struggling a bit to find bigger single ones that will fit the square shaft. I've seen a few that use cotter pins (almost forgot about those things!)

edit- crankset brings up more results but the biggest I've seen is 50T, a little under 9% higher gearing- possibly not worth the bother for that?

 

[shemozzle999]

I don't know if this will fit but it does have a square crank hole.
Maybe worth a telephone call to ask for dimensions and check chain compatability.

http://www.sjscycles.co.uk/brompton-chainwheel-54t-3-32-qcw54-prod13740/

 

[neptune]

A very similar topic to this has been covered before. The Powabyke Euro has a five speed freewheel at the back and a 36 tooth chainwheel. Flecc showed us a link to another site where someone decided to increase the overall gearing. It seems that the Powabyke uses a non standard size of square on the bottom bracket axle. The answer is to bolt a larger chainwheel to the existing one. In the case of the Euro, a 48 tooth chainwheel was added. The standard chainwheel on the Euro has 5 spokes, with holes already drilled for a chainguard. I am still looking for a suitable 48 tooth 5 spoke chainwheel.

 

[flecc]

Here's the photo:

 

[neptune]

I have had a bid on a 48 tooth chainwheel on Ebay. I won the auction at 99 pence! It arrived this morning , and I have spent all afternoon fitting it. It took 2 hours with a round file to make the bolt holes line up , but we got there . I have added 6 links to the chain. I only had time for a quick road test, but it looks promising. I now have to use gear 1 or 2 to peddle from a standing start, but gear 5 is now like 6 or six and a half if you see what I mean. I can now pedal at 15 MPH without excessive cadence. I need a while to asses it, but if it does not work out I can easily restore it to standard gearing. Incidentally , the bottom bracket axle on the Euro is not square , but splined.

 

[JuicyBike]

We offer a 52 tooth chainwheel option for the Juicy Sport which suits some riders.
Email me for further details.

 

[flecc]

Incidentally , the bottom bracket axle on the Euro is not square , but splined.

Glad you finally found the chainring you wanted Neptune. That unusual splined shaft was the reason for A to B coming up with the bolt-on solution.

 

[neptune]

Attached is a picture of my modified Chainwheel. Not the best of photos, but you can see what I did. I slightly enlarged the holes in the original chainwheel, to take slightly larger bolts. The spokes of the add-on chainwheel have been shortened slightly at their inner ends, to remove unused metal. The chain has been lengthened by six links. The 2 chainwheels were aligned by eyeball engineering, and whilst not perfect, they are within a couple of millimetres. Any slight eccentricity is accommodated by the derailleur chain tensioner.
I am well happy with the results, and it encourages me to pedal more. I went to see my brother, who lives 6 miles away, and I noticed that the battery recharged noticeably quicker than usual, as a result of my pedal assistance. Total cost, including postage and bolts, under a fiver.

 

[fishingpaul]

I find the exact opposite but not sure why you are finding it easier to pedal,i find the smaller the chainwheel the easier it is to ride without assistance,since swapping the components from a 48t chanwheel torq onto a bike with a triple chainwheel,i am finding it much easier to pedal without assistance i think the large chainwheel is 46t but i can still pedal downhill at 25+mph with ease,and the smaller chainwheels make it much more easy going along flat to small inclines,i can now ride to work without power easilly,48t chainwheel was only good with power assistance,useless without.

 

[flecc]

Cadence varies with individual physiology. Some find it very easy to spin fast while others find it very difficult to do that and apply any power at the same time. It's possible to train many people to high cadences but most merely prefer to use what they find natural and not attempt to change it.

 

[neptune]

I have always been comfortable with a cadence of around 70RPM . I can pedal faster, but not for long . I am a bit old now to change at 66 years old . With my heavy old lead acid Powerbyke, I don`t do a lot of riding without assistance. If I want to ride unassisted, as I often do, I ride my ordinary push bike. So my aim was comfortable pedaling at about 15 MPH. I have now achieved that, and I still have a gear low enough to ride unassisted if required.