Help please.

phlodge

Suffering from bad knees is preventing me climbing up fairly steep hills, hills I used to climb a few years ago. I make it so far but often end up walking the last section. Save having a knee operation which will happen at some point, would changing either the front (single) chainring or rear cassette ratios make a difference.

The front is currently 30t, would say 28T (or lower) make much of a difference or is changing the rear cassette the better option.
I am aware that changing the front to say 28T (or lower) would result in "pedalling out" going downhill, but thats a price worth paying for the uphill benefit.

Never been one for understanding gear ratios’s, should of listened more in physics class, hence the question.

My current setup is as follows ..

Specialized Stumpjumer 27.5,

Front chainring.. RaceFace Aeffect 6000 series alloy. 24mm spindle, 52mm chainline. 30T

Cassette .. SRAM XG-1150, 11 Speed. 10-42T

Any help would be appreciated.

Thanks

nickbotfield

I know this is a bit sacreligious, but would you consider putting a double chainset and front derailleur and shifter on your bike? The link below shows you how your gear shifting would change - namely 3 easier gears as well as 1 harder one.

http://ritzelrechner.de/?GR=DERS&KB=30& ... 2&UF2=2215

BikerGroveish

Think of it in terms of gear inches. How many inches a bike with a given wheel circumference will move forward per revolution of the crank. It will make the choices less baffling. It were my bike and I was in your position I’d go for a 50-34 compact chainset up front and an 11-32 cassette. Change the RD cage or add an extender as required.

http://www.cyclesdeoro.com/Shop/gear_chart.htm

Here’s a table to help.

Uber_Pod

Your legs spin faster with less teeth on the front ring and more teeth at the back.
30t front and 42t back already seems quite low gearing.
It sounds obvious, but are you really shifting down to the biggest ring at the back?

When you have to stop, is it because your legs are going too slow and have to push too hard?

(the post about gear inches makes it sound even more confusing to me. Plus the chart seems to be based on road bikes, which isn't relevant here. And the suggested ratio's are all wrong)

steve_sordy

BikerGroveish wrote:

...........It were my bike and I was in your position I’d go for a 50-34 compact chainset up front and an 11-32 cassette. Change the RD cage or add an extender as required.

http://www.cyclesdeoro.com/Shop/gear_chart.htm

Here’s a table to help.

That advice will make it harder for the OP to get up a hill. His easiest gear is a 30 driving a 42 = 0.714
Your easiest gear is a 34 driving a 32, 34/32 = 1.0625, which is almost 50% harder! Not what he wants at all.

A 24/34 2x is available in 11-speed. Keeping his cassette would give the OP a 20% easier climbing gear, and still provide a 13% faster gear for the downs.

If the OP is reluctant to go 2x, then he only has two options. Either put a smaller gear on the front, he may have to buy a different crank to go below 28T. (7% easier). OR go for the Sram Eagle 12-speed. They have become cheaper now that Sram have launched some budget options. The Eagle cassette is 10-50. So if the OP stays with a 30t front ring, he will have a 30 driving a 50 = 0.6, which will be 16% easier to climb with. There will be no loss of top speed.

I too have dodgy knees and the effect is difficult to comprehend for those that have healthy knees. I have a 30T ring driving a 10-50 Eagle 12-speed cassette, and sometimes even that is not enough! I have good days and bad days.

JBA

BikerGroveish wrote:

I’d go for a 50-34 compact chainset up front and an 11-32 cassette. Change the RD cage or add an extender as required.

That set up will be fine for a road bike but the OP has a mountain bike.

phlodge

Hi and thanks everyone for the help and your time.

Quite a bit to consider here, not sure I want to go back to 2x unless I really have to, dont think I am quite there yet. I do like the sound of the Eagle cassette tho.

Its the difficulty pushing down on the pedal that restricts my momentum and thus going slow results in a stall and therefore a bollox to it. Recently went back to clipless and have been out twice, it has made a slight difference in that I have the pull on the pedals as well as the push.

My mate has a smaller chainring on his bike so may give that a go and see if that makes a difference and then decide from there.

Maybe I am asking to much for a pair of 62 year old knees with osteoarthritis, but damed if I am giving into to them without a fight.

Many thanks.

02gf74

Changing to less teeth on the chainring is the first thing to try, to 28 or even 26.

There is 11 speed xd cassette 9-46, don't recall the make that you can try instead but that is much more expensive.

Ultimately ad we get older, the hills we breezed up when we were 30, we will even tally have to walk up, throw in a pair of bad knees and it happens sooner than later.
.

There is the option of an e-bike that can assist uphills as having really low gearing it becomes a circus balancing act rather than cycling.

phlodge

Had it not been for buying this bike late last year then an ebike would be on the list.
Defo my next bike purchase, probably in 12/18 months if my knees last that long

Cheers

BikerGroveish

JBA wrote:

BikerGroveish wrote:

I’d go for a 50-34 compact chainset up front and an 11-32 cassette. Change the RD cage or add an extender as required.

That set up will be fine for a road bike but the OP has a mountain bike.

Ah yes good point well made.

The Rookie

The obvious answer to me is a wider range 11 seed cassette, an 11-46 (such as the Sunrace MX8) will give you effectively one more gear lower than you currently have and no loss of top end, if you then go to a 28T it will give you even more.

steve_sordy

phlodge wrote:

.................

Maybe I am asking to much for a pair of 62 year old knees with osteoarthritis, but damed if I am giving into to them without a fight.

..........

Don't give up!

I'm 67 with osteoarthritis afflicted knees, ie wear and tear. My knee problems stated about three years ago, right after I bought a YT Capra! I kept it because I was convinced that I would solve the problem and be able to ride it as it should be ridden. With a combination of physio, pain-killing gels, drugs and KT tape, I have gone a long way to help the problem. But no more long climbs for me! While the almost un-ridden Capra languishes in the shed, I ride my Whyte T130 and have loads of fun. But there is no doubt that my next bike will be an e-Bike.

phlodge

Again thanks for the replies.

Just popped into my local bike shop and told them what I wanted, i.e. a bigger range cassette on the back and apparently it cant be done without expense.

To go 12 speed such as the Eagle would require an upgrade of shifter, derailleur etc and thats £320.
Going for a SunRace MX80 11 Speed Cassette isn't possible without changing the SRAM XD Freehub as its only compatible with Shimano.

Unless someone at my LBS is talking bollox, which I doubt, I have limited options as I dont want to spend a few hundred pounds it looks like changing the front chainring to a 28T or below is my only real choice.

02gf74

A quick look on ebay shows 11 speed 46-11 cassettes are available for not huge money, starting around. £50 but are for shimano freehub.

. Depending on your hub, these should be available and can be replaced simply by pulling off the xd freehub. Again I would expect price to be in 50 £ range.

Only question is if the cog spacious is the same, see as I have xd cassette with shimano 11 speed I reckon the answer is yes.

. You have option of e thirteen 9-46 cassette but look at paying £200-300.

steve_sordy

It depends upon what one means by "expense"

Here is an 11-speed 11-46 Shimano SLX cassette for £45. That should swap directly for your 11-42.

https://www.evanscycles.com/shimano-slx ... gJ0WPD_BwE

That should give you another 9% easier gear, with no loss of top speed.

You will need a new chain (£10-15), or a few extra links if your existing chain is already newish. Best to go with a new one though.

If you do that and find it is not enough, then also fit a 28t on the front. That will give you another 6%. Together you will have a 15% easier climbing gear but with a 6% loss of top speed. (£10-£40 depending upon how it needs to fit to your crank).

So for £65-£100, and some effort, you could be riding again with less pain. Where is the loss? That is an "expense" I'd be prepared to pay for.

phlodge

steve_sordy wrote:

It depends upon what one means by "expense"

Here is an 11-speed 11-46 Shimano SLX cassette for £45. That should swap directly for your 11-42.

https://www.evanscycles.com/shimano-slx ... gJ0WPD_BwE

That should give you another 9% easier gear, with no loss of top speed.

You will need a new chain (£10-15), or a few extra links if your existing chain is already newish. Best to go with a new one though.

If you do that and find it is not enough, then also fit a 28t on the front. That will give you another 6%. Together you will have a 15% easier climbing gear but with a 6% loss of top speed. (£10-£40 depending upon how it needs to fit to your crank).

So for £65-£100, and some effort, you could be riding again with less pain. Where is the loss? That is an "expense" I'd be prepared to pay for.

My understanding was that as my rear hub is SRAM its therefore not compatible with Shimano .. apologies if its me being thick. Price is fine, if it did fit, but the LBS seemed to suggest that the hub would only take a SRAM fit.

steve_sordy

You are correct, I searched for an 11-speed 10-46, but it came up 11-46 and I didn't notice. The rest of my post was bulit on that. oops! :oops:

There is this however, if you don't mind a bigger jump than usual to your last gear. You could call it your bail out gear.

http://dirtragmag.com/wolf-tooth-introd ... -and-more/

phlodge

steve_sordy wrote:

BikerGroveish wrote:

...........It were my bike and I was in your position I’d go for a 50-34 compact chainset up front and an 11-32 cassette. Change the RD cage or add an extender as required.

http://www.cyclesdeoro.com/Shop/gear_chart.htm

Here’s a table to help.

That advice will make it harder for the OP to get up a hill. His easiest gear is a 30 driving a 42 = 0.714
Your easiest gear is a 34 driving a 32, 34/32 = 1.0625, which is almost 50% harder! Not what he wants at all.

A 24/34 2x is available in 11-speed. Keeping his cassette would give the OP a 20% easier climbing gear, and still provide a 13% faster gear for the downs.

If the OP is reluctant to go 2x, then he only has two options. Either put a smaller gear on the front, he may have to buy a different crank to go below 28T. (7% easier). OR go for the Sram Eagle 12-speed. They have become cheaper now that Sram have launched some budget options. The Eagle cassette is 10-50. So if the OP stays with a 30t front ring, he will have a 30 driving a 50 = 0.6, which will be 16% easier to climb with. There will be no loss of top speed.

I too have dodgy knees and the effect is difficult to comprehend for those that have healthy knees. I have a 30T ring driving a 10-50 Eagle 12-speed cassette, and sometimes even that is not enough! I have good days and bad days.

Steve_sordy. Thanks for your response.
I have been told I can’t fit a 12 speed rear cassette without changing the derailleur as it’s not long enough and I also need to change the selector as it needs 12 clicks. Think they also said chain needs changing
Is this your understanding or am I being misled.

Thanks

steve_sordy

phlodge wrote:

[....................

Steve_sordy. Thanks for your response.
I have been told I can’t fit a 12 speed rear cassette without changing the derailleur as it’s not long enough and I also need to change the selector as it needs 12 clicks. Think they also said chain needs changing
Is this your understanding or am I being misled.

Thanks

My apologies for not making myself clearer. :oops:

When I wrote "OR go for the Sram Eagle 12-speed. They have become cheaper now that Sram have launched some budget options." I was referring to the whole system. The GX will cost about £400, less if you don't have to change the hub.

The 12-speed chain is not just a narrower version of an 11-speed chain, it is different in many ways. I have done over 1100 miles on my 12-speed chain and I measure the length extension (ie wear) with a vernier caliper gauge. I am predicting chain life of at least six times more than I have ever had before. I am not riding anywhere different to normal and I'm not doing any different maintenance practices.

JBA

Unless you can change the free hub and then fit an 11-speed Shimano 11-46 cassette your only option is to fit a smaller chain ring and see how you get on.

It might be simpler, and maybe cheaper to buy a second-hand rear wheel that is already fitted with a Shimano free hub to see if it makes riding easier for you.

JGTR

Sunrace 11- 50 wide range cassettes fit both SRAM & Shimano.

phlodge

JGTR wrote:

Sunrace 11- 50 wide range cassettes fit both SRAM & Shimano.

Think I still need the new derailleur and selector etc.
Might just go for the 28T chainring for now and see how I cope

Thanks

JGTR

phlodge wrote:

JGTR wrote:

Sunrace 11- 50 wide range cassettes fit both SRAM & Shimano.

Think I still need the new derailleur and selector etc.
Might just go for the 28T chainring for now and see how I cope

Thanks

Should be a straight swap for your current casette as both 11 speed.

phlodge

JGTR wrote:

phlodge wrote:

JGTR wrote:

Sunrace 11- 50 wide range cassettes fit both SRAM & Shimano.

Think I still need the new derailleur and selector etc.
Might just go for the 28T chainring for now and see how I cope

Thanks

Should be a straight swap for your current casette as both 11 speed.

Great, I will take a look at that today

Cheers

phlodge

phlodge wrote:

JGTR wrote:

phlodge wrote:

JGTR wrote:

Sunrace 11- 50 wide range cassettes fit both SRAM & Shimano.

Think I still need the new derailleur and selector etc.
Might just go for the 28T chainring for now and see how I cope

Thanks

Should be a straight swap for your current casette as both 11 speed.

Great, I will take a look at that today

Cheers

Bummer, doesn't fit.
My rear hub is a SRAM XD body which limits the options. Gone with a 28T front ring for now and see how that works.

Cheers, all help was really appreciated.