pbr2424

I have a Burley Rumba with a triple crank and I believe the gear are 52 / 42/ 30 with an eight speed cassette 11 -30. The gear have worked for us so far but we would like to do some trips with some panniers and rack we have just bought. We are trying to get back in shape and have done some 80 mile rides in the White Mountains in New Hanpshire and have circled around Mount Washington and so forth. We also ride in Quebec between Sherbrook and Vermont with is open farm land with some really large rolling hills. We have gotten the seats and positions of the handlebars figured out so long rides are possibly but 6 -8 hours riding is an adventure. So I had thought some lower gears for backup and to keep the peace would be a good idea. I know they make an 11- 32 cassette eight speed and a 11-36 that has a big jump to the 36. So i was thinking an 11-32 and perhaps changing the chainrings from 52/42/30 to 52/38/ 24 or something like that with an 11-32 cassette. Money is kind of a concerned so going to a nine speed if that is possible and having to change the shifters might be too much at the moment but certainly not out of the question. I am going to try to find a bike shop that would be good for the work. Any ideas or things I should know before changing the gearing would be much appreciated. I would like to just do this once and have it work for us. I would like to get the low gear down to something like a 24 chainring and 32 tooth cassette. I am not a bike mechanic so any ideas are much appreciated.

Thank you

Retro Grouch 

Shouldn't be too hard.

What are you using for shifters? Friction shifters, at least for the front are a big help. If you have a friction shifter on the front, the bolt circle diameter of your existing crank will determine how small of a granny gear will fit.

An older Shimano mountain bike rear derailleur will handle up to a 34 tooth rear cog. It'll also index fine with your existing shifters. You'll probably need to install a new, longer chain to safely cover the 52/34 gear combination. You'll want to do that to prevent major damage if you ever accidentally shift there. I stopped worrying about having enough slack take up to handle the little/little because I never use the granny gear except with the biggest 2 or 3 rear cogs.

pbr2424

The shifters are Shimano Sora STI 3x8. It can get a little complicated but it will good to lower the gearing.

Thank you

LastKraftWagen

The cassette swap is probably the quickest and cheapest first try,it may be enugh.8-spd cassettes are pretty cheap, and as ong as you on't cross chain largest chairing/largest cog wyou shouldn't need t eess with the chain yet. Derailleur may be an issue, but lower level swaps ca also be foud on the cheap.

SJX426 

Before spending the money, check this site out. Set up per what you have now and double check what you like and don't like in terms of gear selection. The play with the options. My Burley came with 52/48/30. I replaced the 48 with a 46 and liked the difference but found that I sacrificed options that I could have used. In fact, I will likely go back to the half step configuration because I can get to the same gear inch with a different combination of gear selection.

https://www.gear-calculator.com/#

hortan

24 granny seems the best solution to me. change from 42 to 38 also makes sense. however maybe you can consider to switch to 48 in stead of the current 52. I know this makes it more expensive but i don't know (for sure) your front derailleur can handle the 52-24=26 teeth gap. Furthermore the 38 to 52 gear change would become inconvenient large, and last but not least: how often will it occur (which time percentage of bicycling time) that the 48/11 gear combination is not enough. The 48 allows you to simply move your front derailleur about 8 mm downwards, and you'll even find the 24 immediately correctly adjusted. Hopefully your current FD inner cable length has some spare length.

pbr2424

I have ordered a 11-32 cassette and some tools to change the cassette myself. I figured better to learn how to do it yourself. I can then change my other bikes cassettes. I also order a new chain and chain tool to do that myself and I am thinking of changing the front ring from a stock 28 to a 26 tooth. But I am still trying to figure out how to change that and if it worth doing myself.

Thank you

nfmisso

First shift the bike the small ring in front, then lift the chain off to the inside.

The small ring is generally, but not always 5 bolts on a 74mm bolt circle (74 BCD). You need a wrench to remove the bolt holding the cranks to the BB, this usually either a 14mm hex socket or an 8mm hex key. Next you need a crank puller; make sure you thread the first piece in all the way before running the second piece in, which push the crank off the BB. If the first piece is not all the way seated, you will damage your crank.

The 74 BCD granny ring is held on by 5 bolts (usually); which accept a 5mm hex key. Note the depression around the thru holes on the old ring (if there are any) and match the orientation with the new one. Tighten in the 5 bolts in sequence: finger tight every other one until you get all, then a bit tighter on every other one, etc.

Place the crank back on the BB axle, making sure that it is 180° from the crank on the other side, re install the nut or bolt, and torque to push the crank to the correct location.

On our T50, when the rear rim failed, I took advantage of the situation to go from 7 speed 12-30 cassette to a 9 speed 11-34, and I was able to source a 26t granny ring for very little changing from a 28t. At the same time, I built new wheels with Dyad rims, Wheelsmith spokes, Wheelmaster hubs. We also went with a SRAM X.9 RD - it is a flat bar bike. Major improvements in every regard.

pbr2424

I saw a video on "you tube" that show how to remove the crank as you mentioned. I appreciate your reply. After I install the cassette the chain ring will be next with a 26 Tooth ring. I have found the ring and tools and also some spacer if needed. Tandems can be more expensive to have someone work on them so I will continue on and learn as I go. I does pay to end up with a bike that is more comfortable to use. Thanks for your reply.