Tiagra triple chainset (50/39/30). Advice needed!

[andy753]

I am recovering from a major knee rebuild (ski crash) and have decided to ride the Bike 4 Cancer London to Brighton bike ride on 6 September 2015 in memory of my dad but also as a rehab ride after my op. If anyone else fancies it, more info at: http://www.bike4cancer.org/london-to-brighton-bike-ride

I am very worried about Ditchling Beacon though. Having ridden the route several times before, I know that my knee will be very sore if I don't have some gentle gears up my sleeve.

I am currently running a Tiagra triple up front (50/39/30) with a 9 speed cassette (12 to 27) via a Tiagra RD-4500 long cage rear mech. This is going to sound really pathetic but this is not enough at the moment while my knee recovers! Does anyone know if I can run a bigger sprocket at the back? Aleternatively I could run a smaller chainring up front but I can't find any info on the Shimano website of the crank FC4503 can take smaller than 30T!

Many thanks in advance for your help!

[tatanab]

Shimano say that the FC4503 inner PCD is 74mm so you can use chainrings down to 24 teeth.  http://bike.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FC/EV-FC-4503-2594D_v1_m56577569830707832.pdf  That would certainly be cheaper than changing the cassette and chain, especially if it is only for temporary use.  Depending on your present cahin length you might find the chain runs slack in the little/little combinations but you should not be using them anyway.

[ACyclingRooster]

I am recovering from a major knee rebuild (ski crash) and have decided to ride the Bike 4 Cancer London to Brighton bike ride on 6 September 2015 in memory of my dad but also as a rehab ride after my op. If anyone else fancies it, more info at: http://www.bike4cancer.org/london-to-brighton-bike-ride

I am very worried about Ditchling Beacon though. Having ridden the route several times before, I know that my knee will be very sore if I don't have some gentle gears up my sleeve.

I am currently running a Tiagra triple up front (50/39/30) with a 9 speed cassette (12 to 27) via a Tiagra RD-4500 long cage rear mech. This is going to sound really pathetic but this is not enough at the moment while my knee recovers! Does anyone know if I can run a bigger sprocket at the back? Aleternatively I could run a smaller chainring up front but I can't find any info on the Shimano website of the crank FC4503 can take smaller than 30T!

Many thanks in advance for your help!

Hi Andy. Have you tried riding the bike with the current cranks ?

The reason that I ask is because if you have not yet attempted to ride your existing cranks (presumably 170mm) you might not get the full circulatory action of the crank without pain or not at-all.

In November of 2007, I had a total left knee replacement and being rather short in stature I could no longer get a complete bend of the knee that would allow me to continue riding 170mm cranks. The best that I can achieve is 92* but having re-jigged the bikes I can ride in perfect comfort and with no issues.
I set about a geometrical puzzle on my drawing board and concluded that the way forward was 140mm cranks,these I purchased from SJS Cycles,Bridgewater and I also ride triples but they are Stronglight rings and currently ride 30:40:50 on a 13-26 9spd with Campagnolo Mirage on my Bianchi Via Nirone 7 Alu Carbon and 30:40:50 on a 12-23 8spd on my Benotto Modelo 850.
The reduction of 30mm is roughly the equivalent to a 2 Tooth larger ring in all three cases.

[Mr Larrington]

I've had no issues bunging a 24T inner on assorted chainsets with a 74mm BCD wossname save that the chain occasionally wanted to overshoot when dropping onto the inner ring.  Gadgets are available which clamp round the bottom of the seat tube to prevent such embarrassment.

[Dtcman]

I run that Tiagra chainset with an 11-32 on the back using an XT rear mech. Never had any problems with that.   

[sojournermike]

I've currently got a 11-30 cassette working nicely with a 52/39/30 chainset all ultegra sl (6603 and gs mech). I think that would be fine. Fit a 24 or 26 tooth inner ring and stayvaway from small small and all will, as has been said, be good.

[Ningishzidda]

Don't worry.
Chances are you and hundreds of others will be walking up.

Only the leading groups 'ride' up it. 

[TimC]

Wot Ning said. But you can certainly get a 30 working underneath a 4500 long-cage dérailleur. You can also go smaller than 30 on the granny ring - but it's worth using a chaincatcher to stop it dropping off the inside on an uphill shift. 26-30 should be small enough to make it a better option than walking.

[Ningishzidda]

If the BB is a squaredrive and the front mech is a clamp, nip into Decathlon and buy a Shimano MTB 44/32/22 chainset and move the 44 ring into the middle. Put washers where the big ring should be.
Move the front mech and re-adjust.

Go to Halfords and buy a rear LED lamp spare seat pin clamp. Only use the clamp half. Put it on the seat tube between front mech and BB so the knuckle is in a position to guide the chain onto the  small ring.

Hey presto, you have a 22 x 30 bottom end. 20 inches.
You have a 44 x 12 ( 99 inches ) top which is high enough for any charity bike ride.

[contango]

I am recovering from a major knee rebuild (ski crash) and have decided to ride the Bike 4 Cancer London to Brighton bike ride on 6 September 2015 in memory of my dad but also as a rehab ride after my op. If anyone else fancies it, more info at: http://www.bike4cancer.org/london-to-brighton-bike-ride

I am very worried about Ditchling Beacon though. Having ridden the route several times before, I know that my knee will be very sore if I don't have some gentle gears up my sleeve.

I am currently running a Tiagra triple up front (50/39/30) with a 9 speed cassette (12 to 27) via a Tiagra RD-4500 long cage rear mech. This is going to sound really pathetic but this is not enough at the moment while my knee recovers! Does anyone know if I can run a bigger sprocket at the back? Aleternatively I could run a smaller chainring up front but I can't find any info on the Shimano website of the crank FC4503 can take smaller than 30T!

Many thanks in advance for your help!

On my (now deceased) Tricross I ran a 50-39-30 triple at the front with 9-speed 11-32 at the back. 30-32 was enough for me to get up most things, but a few hills still defeated me.

According to the BMI charts I'm not tall enough.

[Biggsy]

I've found 50/39/24 tricky to setup and not entirely pleasant.  50/39/26 with a slightly larger cassette is what I recommend, if keeping the same crankset.

[perpetual dan]

I run a Tiagra as 50-39-28 and something-I-rarely-use to 25 at the back, without too much trouble. I forget what mechs, but IIRC they are 8 speed Sora. Worked alright with Sora levers before I went to bar ends too.

Good luck with the recovery and the ride.

[Ningishzidda]

At the end of a charity ride to Paris, we arrived at the Jaguar Land Rover dealer. The way UP to the car park on the roof was a spiral driveway which rose 4 meters in every 20 metre circle. There was a 3 to 4 metre stretch of level with near 25% slopes between.
The others who had 30 tooth rings and 27 or 28 sprockets, got off and pushed after the first circle.
I had a 22 ring and 27 sprocket, so merrily wound the bike all the way UP seven flights.

BTW. I learned about putting MTB chainsets on road bikes in San Francisco.

[P Walsh]

With Shimano 9 speed road systems it is easy to get lower gears by changing the rear mech to a 9 speed Simano MTB mech (Deore will do) and choosing a Shimano 9 speed cassette with a largest sprocket of 32 or 34 teeth. You will also need a new chain if your current one is too short. With 9 speed systems this works perfectly.

[Hedgebanger]

With Shimano 9 speed road systems it is easy to get lower gears by changing the rear mech to a 9 speed Simano MTB mech (Deore will do) and choosing a Shimano 9 speed cassette with a largest sprocket of 32 or 34 teeth. You will also need a new chain if your current one is too short. With 9 speed systems this works perfectly.

This was the system my LBS fitted to my compact equipped Giant roadbike new out of the shop . 50/34 chainset with 11/32 cassette, Tiagra front deraillier, Deore long cage mtb rear deraillier. 9 speed chain. It all worked fine
At a later date I fitted a 12/36 cassette and new chain. By accident I found the rear mech could even handle a 50/36 combination!

[Hedgebanger]

With Shimano 9 speed road systems it is easy to get lower gears by changing the rear mech to a 9 speed Simano MTB mech (Deore will do) and choosing a Shimano 9 speed cassette with a largest sprocket of 32 or 34 teeth. You will also need a new chain if your current one is too short. With 9 speed systems this works perfectly.

[Ningishzidda]

With Shimano 9 speed road systems it is easy to get lower gears by changing the rear mech to a 9 speed Simano MTB mech (Deore will do) and choosing a Shimano 9 speed cassette with a largest sprocket of 32 or 34 teeth. You will also need a new chain if your current one is too short. With 9 speed systems this works perfectly.

This was the system my LBS fitted to my compact equipped Giant roadbike new out of the shop . 50/34 chainset with 11/32 cassette, Tiagra front deraillier, Deore long cage mtb rear deraillier. 9 speed chain. It all worked fine
At a later date I fitted a 12/36 cassette and new chain. By accident I found the rear mech could even handle a 50/36 combination!

Go on,,, go the whole hog and fit a 22/44 alpine chainset. 

[mrcharly-YHT]

I think the perfect triple (for non-racers) is 26/36/46. Used to be something of a standard on touring bikes and MTBs.

My own 'best' bike has a compact double 50/34 on the front. I've replaced the big (50) ring with a 46 - much, much better. Far more useable gears when on the big cog.

Ningis alpine setup is just an easier version and very similar to the old touring double (before triples existed).

I'd try to avoid walking up hill pushing a bike if I were you. That will put twisting torque through your knee joint, which you really, really don't want.

[Biggsy]

26/36/46 makes sense, but 26/39/50 can be close enough to perfection, too, depending on taste.  The 39T (or 38T) minimum limit for the middle ring can be worth accepting when you like a "road" triple crankset for a small Q factor (which applies to my Campag ones anyway).  It can help with these to use cassettes that start with 13 or 14T.

[P Walsh]

Spa's XD2 triple chainset has a smaller Q Factor than you find on MTB chainsets, and you can choose the rings you want. But you have to bear in mind that the front mech will probably not like it if the difference in teeth number between the two larger rings is much different to the chainset it was designed for.

[Mr Larrington]

They tend not to like it if the gap is a lot smaller than standard either.  Not that anyone is using half-step these days.

Or are they?

[Ningishzidda]

This will make some folks drool.

http://dawescycles.com/product/ultra-galaxy-2/

But please note the gearing fitted.

[mattc]

They tend not to like it if the gap is a lot smaller than standard either.  Not that anyone is using half-step these days.

Or are they?

I've got a 7T gap. (not quite "half-step") Due to the limits that Campy BCD gives.
Currently 26-39-46. This works well,  with both an old-ish Campag Veloce der'r, and a Shimano 105 taken from a bike with a double. So I havent tried it with the more "modern" style that tend to have a large back-plate, and I think are intended for gaps that are the other way round.

The one drawback is indeed a tendency to overthrown on down-shifts. A zip-tie fixes this (much lighter than commercial metal alternatives )

[mrcharly-YHT]

This will make some folks drool.

http://dawescycles.com/product/ultra-galaxy-2/

But please note the gearing fitted.

Rear is a MTB Shimano RD-M771 Deore XT
I thought they weren't supposed to work with the latest STI?

[zigzag]

This will make some folks drool.

http://dawescycles.com/product/ultra-galaxy-2/

But please note the gearing fitted.

Rear is a MTB Shimano RD-M771 Deore XT
I thought they weren't supposed to work with the latest STI?

it's a 9sp mech so perfectly compatible (10sp mtb ones are not)