Need large chainwheel

[Old timer]

I`ve just upped my chainwheel size to 52 tooth from 48 and it`s fine. I`m looking for a slightly larger chainwheel or crank set( square tapered drive) the exisitng spider is 5 fixing) 170mm crank arm. Any ideas?

Thanks

 

[MajorMantra]

A 53t should be easy enough to get but the difference from a 52t would be tiny. Bigger rings might mean looking at stuff sold for TTs and the like.

Why do you need a bigger ring? Is changing the cassette/freewheel not a possibility?

Matthew

 

[Old timer]

A 53t should be easy enough to get but the difference from a 52t would be tiny. Bigger rings might mean looking at stuff sold for TTs and the like.

Why do you need a bigger ring? Is changing the cassette/freewheel not a possibility?

Matthew

Mathew

The rear cog is one of those fixed wheel types( a freewheel I think it`s called) with a 14 top gear. It`s on an e bike so don`t really want to work on the rear wheel where the hub is and I`m not sure you can get much smaller on a freewheel type. It`s all to do with balancing the pedal assist with a comfortable cruising speed. The jump up to 52 gave an improvement over the 48 and I just want to see if there is anything left in the assist with a slightly higher gear. To be honest, if something like a 57 is a bit too high then it would be a good flat or downhill gear and I could maybe use the 5th gear as my normal assist gear.
Does that make sense?

Thanks for replying

Dave

 

[ufkacbln]

I have a 63 from Middleburn on the Hurricane.

I found that even with a 53 or similar I was still spinning out.

I now have 42 gears ,although with a fair overlap in the middle. WHich is fine as the changer is my hand!

Simply use the 53 for mixed days and the 63 for fats flat days.

 

[MajorMantra]

I don't understand this bit. Are you just talking about a cassette? They are available in many ratios with top gears down to 11t to don't discount the possibility of changing it:

The rear cog is one of those fixed wheel types( a freewheel I think it`s called) with a 14 top gear.

Is it a single, double or triple chainset up front? If it's not a single, you run the risk of creating too large a jump between rings. Also, a chainring larger than 53t is going to be expensive as they're a specialist item.

Without wishing to be undiplomatic, have you considered pedalling faster?

Matthew

 

[marinyork]

I don't understand this bit. Are you just talking about a cassette? They are available in many ratios with top gears down to 11t to don't discount the possibility of changing it:

Whilst no expert, I believe what old timer has said is correct, that there is less choice on a freewheel. Cassettes no problem but freewheel's are different. I think you can get below a 14 though.

 

[TheDoctor]

I believe the OP has a freewheel block, not a cassette, and a block with lower than 14T is hard to find these days. Spa Cycles do chainrings up to 56T, for shimano or campag road cranks - 130 or 135 mm BCD.

 

[MajorMantra]

Whilst no expert, I believe what old timer has said is correct, that there is less choice on a freewheel. Cassettes no problem but freewheel's are different. I think you can get below a 14 though.

Ah, I sort of assumed that an e-bike (being fairly new no?) would have a cassette. How many speeds? 13-28s or 13-32s are easy enough to come by and that would make a noticeable difference.

Matthew

 

[Old timer]

Ah, I sort of assumed that an e-bike (being fairly new no?) would have a cassette. How many speeds? 13-28s or 13-32s are easy enough to come by and that would make a noticeable difference.

Matthew

Sorry, my days of knowing all the techie terms are long gone. It`s a 6 speed block of cogs and I am told it`s a solid mass rather than seperate cogs.

Now BCD It had a single chain wheel(all cast in one 48 T) I managed to pick up a double chainwheel set and arms large wheel 52T(I wont use the small ring) they are fitted to a spider(ali) and the rings are steel. Fitted it and it works fine, all gears work freely and no jumping. The pedal assist still works while turning the crank at a nice leisurely pace (if I turn them much faster the pedal assist magnetic disk that is fitted to the BB shaft) will turn off the assist.
So! what I need is a chain ring that has 56T and I think that will be as far as the system will let me go.

The double that I have fitted has 5 fixing ring bolts, the distance from the centre of a fixing bolt to the centre of the BB spindle is approx 65mm. the distance between each fixing bolt is approx 75 mm. From looking on the net it would appear that Spa cycles mentioned does have a 55 or 56T ring BCD 130 that might do me? for £32

What do you think?

Dave

 

[TheDoctor]

Ought to go on, and without taking the crank off, which saves some arseing about.
You'll probably need a longer chain, but I expect you knew that.
A quick Google has turned up a few blocks with 13T, but the difference between that and 14T is so small it's barely worth the bother. The Shimano 11-34 7 speed block is really what you need, but they're like rocking-horse poo.

 

[ASC1951]

A quick Google has turned up a few blocks with 13T, but the difference between that and 14T is so small it's barely worth the bother.

I dunno - it's the same as Old Timer upping his chainwheel from 52T to 55T and probably much cheaper.

 

[MajorMantra]

A quick Google has turned up a few blocks with 13T, but the difference between that and 14T is so small it's barely worth the bother.

It's not totally negligible. Dropping a tooth makes a lot more difference at the back than at the front.

Matthew

 

[TheDoctor]

Could always do both, I suppose!!!

52/14 x 27 = 100"
56/14 x 27 = 108"
52/13 x 27 = 108"
56/13 x 27 = 116"