HPV derailleur adjustments - Nightmare!

[Falco Frank]

I though this was bad on some DF bikes I worked on in the past - how wrong was I!

Should of guessed, Changing my front crankset to smaller rings was just too easy, shifting to the smallest ring on the front needed a nudge on the chain tube, which obviously isnt ideal. Read up & watched adjustment video's for a refresher and upon looking at the bike realised it had been setup for the mammoth 60T big ring that was present before

I need to read up on chain tension too as I now know the source of the odd vibration at anything faster than 4th gear on the back, using the smallest front chain ring - the jockeys wheels (chain) of the rear mech are actually TOUCHING.

This setup is going to be a real compromise as the front mech 'end arm' (opposite the cage) is striking the frame mount on the small ring and is very tight shifting onto the big ring - so my other half is going to be a garage widow, once again

 

[FrankCrank]

...my 2 MTB's are both single speed, folding bike the same, trike has 3-speed Sturmey Archer, and LWB is one speed - soon to be 3-speed Nexus.

Yes, I'm not a fan of derailleurs!

Sorry, this doesn't help you in any way, just to let you know there are alternatives

PS - I live in a flat area, which makes things easy I guess.......

 

[classic33]

Long or short cage derailleur fitted?

 

[BlackPanther]

If you've changed the size of the front rings, the whole mech may need moving down the post a few cm. I needed to move mine up when I fitted a bigger ring to the Strada. You may not be able to make it work if you have too big a size difference of chain rings though, like if you have a small 26t, there's no way you'd be able change up to a 70t ring.

If you mean the chain is touching the cassette there should be an adjuster to bring the jockey wheel towards/away from the cassette.

 

[raleighnut]

If you've changed the size of the front rings, the whole mech may need moving down the post a few cm. I needed to move mine up when I fitted a bigger ring to the Strada. You may not be able to make it work if you have too big a size difference of chain rings though, like if you have a small 26t, there's no way you'd be able change up to a 70t ring.

If you mean the chain is touching the cassette there should be an adjuster to bring the jockey wheel towards/away from the cassette.

B screw.
Although you may need to shorten the chain as well if you have fitted smaller front rings.

 

[byegad]

B screw and chain length. My most extreme trike an ICE QNT runs 24-40-55 to 11-34. It can and often does run all 27 combinations without any issues, at least none so far with 9000+ miles on it. Get the two items correct by measuring chain length big ring to big ring, the mech should be pulled nearly, but not quite straight forward, unless you have rear suspension it need only have a little movement/slack left. If like the the QNT it has suspension check chain tension does not change as the suspension moves. Then run small-small and use the B screw to avoid the mech rubbing as it tucks fully up. This exceeds the 'recommended capacity by a hige factor' but don't let that bother you.

My set up has an odd cable replaced, new chains at 0.75% worn, worn cassettes replaced twice IIRC, 2 worn chainrings replaced and a new Right hand Shimano bar end changer due to loss of indexing at 8000 miles. The mech is a Deore long cage and is original as is the Campag Veloce front mech. The changes are crisp and on a 20" rear wheel gives 14-100" gearing which I find close to perfect for most terrain.

 

[Falco Frank]

Thank you for the replies.

@classic33 on the cage length I'm not too sure if its long or short, really. Seems a longer style to me (Shimano Diore), it seems odd to me, adjustment screws are on a vertical plane, not the horizontal I expected & when lining up the outer cage parallel to the big ring, the cage tapers away and is not the gap away from the teeth all the way back to the closed end.*

*With apologies for feeble explanation.

 

[fixedfixer]

As you have now got smaller rings you may need to shorten the chain. Deore is mtb and likely to be long cage to cope with range of gears on mtb bikes.

 

[fixedfixer]

unless you have reduced the size of the rings by a huge amount the front mech should work as long as, suggested in an earlier post, you lower it to be within 3mm of the large ring. You normally have to adjust limit screws as new cranks may not sit exactly in same place as old ones.

 

[Mr Magoo]

I though this was bad on some DF bikes I worked on in the past - how wrong was I!

Should of guessed, Changing my front crankset to smaller rings was just too easy, shifting to the smallest ring on the front needed a nudge on the chain tube, which obviously isnt ideal. Read up & watched adjustment video's for a refresher and upon looking at the bike realised it had been setup for the mammoth 60T big ring that was present before

I need to read up on chain tension too as I now know the source of the odd vibration at anything faster than 4th gear on the back, using the smallest front chain ring - the jockeys wheels (chain) of the rear mech are actually TOUCHING.

This setup is going to be a real compromise as the front mech 'end arm' (opposite the cage) is striking the frame mount on the small ring and is very tight shifting onto the big ring - so my other half is going to be a garage widow, once again

OK first thing I assume a figure of speech when the headline reads "HPV derailleur adjustments - Nightmare!
All the adjustments and fine tuning are basic bike servicing .
I would suggest you call Kevin at D.TEK HPVS ...have a chat through and gain advice
.......It all sounds easy if you know A screws from your B screws and your stop screws and your long and the short of mechs and shifter range and chain types and gear trigger lever twisty things .................how confusing it all seems !"£$%^
If you feel the need to use a local "upwrong cycle repairer" first ask this test question
DO YOU SUPPLY CHAINS FOR RECUMBENT CYCLES ?
If the response is " Sorry we don't do recumbent chains Sir or Madam "
Just walk out of the shop .
Kevin's heard it all before he has dealt with recumbent bikes "laid out in the wrong order according to some ! " for over 25 years .

 

[Tigerbiten]

You really need to move the derailleur down by 2mm per chainring tooth reduction for it to be correct.
But you do have a bit of a margin for error if you don't move it down enough.

As for chain length, check how much slack you have when it's big-big.
If there is slack, then you can take out a link or two to shorten the chain.

 

[Falco Frank]

Some words from an obviously very wise man...

http://sheldonbrown.com/derailer-adjustment.html

 

[classic33]

Some words from an obviously very wise man...

http://sheldonbrown.com/derailer-adjustment.html

Other wise words given by @byegad, @Mr Magoo & @Tigerbiten above

 

[Falco Frank]

All very useful it must be said.

Chain tension is a little less than optimum but not enough to worry about yet.

Shifting however, is still substandard. From what I can see its an old-style Deore front mech that is actually for a dual ring crank not really a triple and because of the odd angle of my chainstay I need to angle the mech cage away from parallel to even shift to the granny ring. Ho Hum.

Time to renew it I think, so next question dear readers, shifters are actually SRAM, simple gripshift front and 'Attack' for the rear so, do I go with something nice like an XT Shimano or match up with an SRAM, no particular preference, I'm sure they are both good.

 

[classic33]

Deore is currently being cleared at Halfords. Have a look online or at your nearest store. Got two for 50p!