Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Folding Bikes (https://www.bikeforums.net/folding-bikes/)
-   -   Downtube full suspension. Can I install an IGH? (https://www.bikeforums.net/folding-bikes/639108-downtube-full-suspension-can-i-install-igh.html)

coolio 04-22-10 04:24 PM

Downtube full suspension. Can I install an IGH?
 
I have a 09 full suspension DT-the orange one. The included rear derailleur is kinda problematic; I'm tired of making adjustments. I'm thinking about swapping the rear wheel and installing an IGH (3 or 7 speeds).

The rear drops looks like this:

http://www.downtube.com/images/Hange...ur_Removed.jpg

I remember reading that this would require a tensioner, which has its own problems.

jur 04-22-10 04:37 PM

Yes you would need a tensioner... but a much cheaper alternative is to simply install a quality rear derailer, likeDeore LX or XT, short cage is sufficient. That would fix the RD adjustment issue. Maybe also a good shifter to match.

snafu21 04-23-10 02:13 AM

I'd echo Jur, the Ju-Ju derailléur on the Downtube IXFS I had was utterly reliable, but very close to the ground, and thus always at risk. A short cage mech and a shifter would be a great upgrade. Once set-up all of mine have been utterly reliable, with only initial cable stretch to adjust out.

There's a more detailed discussion here:

http://www.bikeforums.net/archive/index.php/t-265339

A major requirement is that the shifter indexing ratio matches that of the mech (1:1 or 2:1) and the capacity of the sprockets. See Mikejos post in the thread above. I don't know what the Downtube shifter ratio is. You may in the worst case need a new cable and housing.

(Short cage mechs on rotary twist grip shifters give a surprisingly fast, precise and crisp change. They are a delight to ride with, and twist grips don't hinder the fold of the bike.)

Niked 04-23-10 05:31 AM

I have the same issue with my DT-FS. Right now, it's a two speed. :(

snafu21 04-24-10 02:11 AM

They're east to adjust or replace if bent or mangled:

http://bicycletutor.com/adjust-rear-derailleur/

I must be lucky, I 've not had a problem with a rear mech for years, but I'm no long distance rider. Maintenence involves, wiping off the crud, oiling the chain, dangling the bike from the garage rafters with a piece of rope, putting the chain on the smallest cog and adjusting the barrel thing. I think once pivots and guide roller bearings wear, the thing is better replaced than fiddled with. But the Downtube was always reliable in the cog department.

coolio 04-24-10 08:23 AM

Thanks. I have recently acquired a IGH full size bike and love how I can just shift down at stops. Not gonna do the tensioner.

I hadn't thought about the benefits of the short hanger. Good point. Looks like I'll look into upgrading the derailleur.

coolio 08-31-10 06:57 PM

Ok, I'm getting tired of doing all these adjustments. I want to start out small by just replacing the shifter. What do you all think of this one:

http://www.amazon.com/Sram-007015093.../dp/B001OQR64W

It looks like the compatibility is ok: 1:1 ratio. However, my FS is a 9 speed. Would this be a problem?

JosephLMonti 08-31-10 07:05 PM

@coolio - one other option would be to go with a friction thumb shifter like this one that nashbar is selling for only 99 cents:

http://www.nashbar.com/bikes//Catalo...=thumb+shifter

Obviously, friction shifting isn't as "easy" as indexed shifting, but at least you wouldn't have the problem of needing to dial-in the derailleur all the time.

BruceMetras 08-31-10 07:24 PM


Originally Posted by coolio (Post 11390240)
Ok, I'm getting tired of doing all these adjustments. I want to start out small by just replacing the shifter. What do you all think of this one:

http://www.amazon.com/Sram-007015093.../dp/B001OQR64W

It looks like the compatibility is ok: 1:1 ratio. However, my FS is a 9 speed. Would this be a problem?

Big problem.. you need a 9spd shifter .. 1:1 ratio is generally SRAM X series compatible stuff .. Shimano compatible is usually 2:1

mulleady 08-31-10 09:41 PM


Originally Posted by jur (Post 10709997)
Yes you would need a tensioner... but a much cheaper alternative is to simply install a quality rear derailer, likeDeore LX or XT, short cage is sufficient. That would fix the RD adjustment issue. Maybe also a good shifter to match.

+1 That's what I did with the matching trigger shift and it turned into a different bike:
http://www.bikeforums.net/showthread...wntube+fs+2007

coolio 08-31-10 10:22 PM

Thanks, guys. Joseph is a man after my heart in that he recommends a cheap option. However, I remember hearing that those friction shifters are kinda dangerous in urban traffic.

I'd like to do this upgrade myself and I don't want to sink a lot of $$ into it. The rear derailleur is a "Juju" of some sort. I want to try to swap shifting mechanism first to see how that works then go on to the rear etc. Now to look for a cheap 9sp option...

nigelme 09-01-10 03:25 AM

I looked at the IGH (Alfine and SA) for my Downtube 9FS but decided the expense was unnecessary.

In the end I just changed the shifter to a Shimano LX and it's great. It was only £10 (England). The inner cable it came with is very good quality.

I tried it with a Short-cage 105 dérailleur which just about made the 32 cog. I eventually got a Nexave 600 rear dérailleur - a bit heavy but seamless shifting.

In all, super upgrades for very little cash.

mulleady 09-01-10 01:54 PM


Originally Posted by nigelme (Post 11391949)
I looked at the IGH (Alfine and SA) for my Downtube 9FS but decided the expense was unnecessary.

In the end I just changed the shifter to a Shimano LX and it's great. It was only £10 (England). The inner cable it came with is very good quality.

I tried it with a Short-cage 105 dérailleur which just about made the 32 cog. I eventually got a Nexave 600 rear dérailleur - a bit heavy but seamless shifting.

In all, super upgrades for very little cash.

I can attest to Nigel's bike handling and shifting very nice because I rode it at a meet recently. Shame it's so hard to get him to also part with cash for a beer too lol! :D

coolio 09-01-10 02:31 PM

What about this one?

http://www.rei.com/product/793371?pr...:referralID=NA

Dynocoaster 09-01-10 02:38 PM

on another thread someone mentioned that Yan is selling some FS with IGH for $200.

Dynocoaster 09-01-10 02:39 PM

http://www.bikeforums.net/showthread...mmend-a-folder

coolio 09-01-10 06:50 PM


Originally Posted by Dynocoaster (Post 11395044)
on another thread someone mentioned that Yan is selling some FS with IGH for $200.

That's great, but I'm not close to philly and it's looks like you're not either.

JosephLMonti 09-01-10 07:08 PM


Originally Posted by coolio (Post 11391409)
The rear derailleur is a "Juju" of some sort.

The JuJu line is "Sun Race's high end, competition level components..."

http://www.sunrace.com/en/about

mulleady 09-02-10 02:21 AM

I think a good derailleur is the cheapest option but if I was going to add a IGH then take a serious look at the Shimano Nexus 8. It must be cheaper now given the newer Alfine 8 from Shimano. An FS with a Nexus 8 would be quite a bike as the frame is actually a very nice one. Way better than other budget bikes unless you're a weight weenie. The hub would be great foe all-round riding and trails.

However, a short cage derailleur such as the Deore is a perfect budget solution and it transforms the FS. Downtube bikes are very nice with the exception of the Juju component. The newer Downtubes use Shimano now if I'm correct.


All times are GMT -6. The time now is 02:56 AM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.