Shahmatt

I'm considering upgrading to a 56T chain ring on my bike, and going with the Doval (elliptical) chainring. I'm not sure how effective these are but I need the large size anyway and am willing to give it a try. Link below:

https://list.qoo10.sg/item/DOVAL-ROAD...-56T/407636230

The Doval seller does not sell bash guards to go with it.

After hunting around I've come across a 60T circular bashguard. I'm guessing the 56T may not cover all of the chain ring due to the elliptical shape. Link below:

https://www.ebay.com/itm/Driveline-Ba...item3ccf3b7487

As long as the BCDs match, should there be anything else I need to worry about?

fietsbob

IDK you linked to an italian seller .. and they are, in that link not going to ship it ,
being on holiday.. for a while..

& I dont think it will take much of a Bashing ..

Shahmatt

Yes I did notice that the seller was not available.

I am more concerned about the principle of the thing. Could a circular bashguard do the job?

My main purpose is to keep my trousers clean when commuting to the office. Alternative methods are also welcome.

cplager

As long as the bash guard is consistently bigger than the e ring, it should work as expected.

Mauriceloridans

Get some elastic chord or ribbon from a fabric store and cut and sew it so it fits on your ankle over your sock without stretching. When you get ready to mount your bike just fold your pant leg and pull the elastic over the pants cuff. Just consider it something to wear every day over the sock to be deployed as needed.

Shahmatt

Thanks Charles. That was the idea. I'll have to make sure of that before buying.

Shahmatt

Something like a trouser clip then?

fietsbob

I have a circular guard on my Bike friday , [its 'just' a 53t chainring] ..

I agree .. direct solution, trouser band (make it reflective) at the cuff, to keep it out of the chain..

(and I wear Black Pants , to make any contact with the chain shmuzz invisible)

Tucking my trouser cuff into My sox is a free solution ..


BTW, since its not round no clue as to the Major radius .. ask Seller ..

e0richt

actually, I wear 2, one for each leg... I don't like the feel of my trouser getting pushed into the crank as I ride...

Mauriceloridans

Better, you don't have to keep up with and fuss with another piece of gear. If have on long pants, it's there on my ankle waiting. And I don't need bash guards on all my bikes.

treadtread

56T chainring?! The mind boggles

blakcloud

Small wheel bikes like the one the OP has can certainly use a large chainring. (Oyama folder) Not the same as putting it on a 700 series wheeled bike.

treadtread

Ah, that makes sense. I didn't see the type of bike in the thread, didn't realize it was a folder with small wheels.

fietsbob

Quote:

actually, I wear 2, one for each leg... I don't like the feel of my trouser getting pushed into the crank as I ride...

oh well.. Singapore is pretty tropical wear shorts.

Shahmatt

This is correct. The intention was to use it on a small wheel (16") bike. Not the Oyama but another project I'm working on. The increase in chain wheel size should improve my gear inch range from 30.5 to 74.5 to 35.5 to 87.0. About 16%.

The city I live in has only a smattering of hills, and I'm used to dealing with them on a low end of around 40 gear inches.

Thanks. I shall consider this idea. I may go with the chain guard and trouser clips together.

fietsbob

a 38t chainring on a 1.6x 2 speed crank =60.8't' so you can have a big gear and a small one in one.

Patterson Metro might accept a bigger chainring ..Read them as a 28t[44.8] stock

Sclumpf speed drive certainly will ..

of course the planetary overdrive requires a round chainring
.. as it turns at a different rate than the crank-arm.

Shahmatt

I didn't know that the chain ring was changeable on the Metro actually. Must investigate.

The Shlumpf drive is interesting but it's outside of my budget.

Also I am a little concerned about the weight of the overall drive train and hence the steering mechanism. My project is a FWD recumbent so the drive train is moved when turning. The Shlumpf will weigh at least 800g or thereabouts extra, and this weight would be at the extreme end where the moment arm is longest.

Since the bike is expected to be a city commuter some nimbleness is good. So a simple single chainring for now may be the way to go.

cplager

Hey! I thought that username sounded familiar!

I believe that Christian Blessing has a Shlumpf on his Cruzbike conversion and he's very happy with it. The weight up front will be very noticeable when you are pushing the bike, but not so much when riding it since your legs will deal with the weight.


That being said, I personally wouldn't do it because (1) the cost and (2 - if your so inclined) you can't use an elliptical rings with them.

Here's Christian's bike: