Bicycle Mechanics - Suspension Fork Question...

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.




View Full Version : Suspension Fork Question...


Decatur_Tide
08-02-12, 09:12 AM
Right now I have a cheap Suntour threaded suspension fork with threaded headset. I would like to change over to a Rock Shox Recon Silver fork that is threadless with new threadless headset. Will this fit?

Here is a link to the new fork:http://www.pricepoint.com/detail/23553-315_ROC052_KIT-3-Parts-59-Forks/Accessories/RockShox-Recon-Silver-TK-Fork-2012-offerIN212MTF.htm?utm_source=MTBR&utm_medium=datafeed&utm_campaign=FTP.htm&zmam=30

Thanks for any help.

Chuck


DCB0
08-02-12, 09:48 AM
Maybe. What is the diameter of the steerer tube on your current bike? If you have a 1-1/8" headset (if th quill of your stem is 25.4mm diameter) then you can probably fit it if you get a new headset and stem.

However, if your bike came with a threaded headset then it is likely almost 20 years old (threaded headsets were almost completely gone from mountain bikes by the mid nineties) then it is likely a ~50mm or less travel fork. A newer fork will push the front end of you bike up an additional 2" which may impact the handling negatively.

Also, if your bike still has the original centre pull cantilever brakes, you will have to switch to v brakes or discs (which would also require a new front wheel) as you cannot mount a canti brake cable stop on the Rockshox fork. You will likely need new brake levers for either of these options, too.

I have to ask - what are you trying to accomplish with this? For a couple hundred dollars more you could get a whole new bike the same quality as what would have come with Suntour forks bak in the 90s. FOr the same price you could likely find something considerably better if you go for a used bike.

IMHO, this would not be as much an 'upgrade' as a 'waste of money.' If you current fork is completely buggered but the rest of the bike is immaculate, then a replacement rigid fork would be a better choice.

Decatur_Tide
08-02-12, 10:09 AM
Maybe. What is the diameter of the steerer tube on your current bike? If you have a 1-1/8" headset (if th quill of your stem is 25.4mm diameter) then you can probably fit it if you get a new headset and stem.

However, if your bike came with a threaded headset then it is likely almost 20 years old (threaded headsets were almost completely gone from mountain bikes by the mid nineties) then it is likely a ~50mm or less travel fork. A newer fork will push the front end of you bike up an additional 2" which may impact the handling negatively.

Also, if your bike still has the original centre pull cantilever brakes, you will have to switch to v brakes or discs (which would also require a new front wheel) as you cannot mount a canti brake cable stop on the Rockshox fork. You will likely need new brake levers for either of these options, too.

I have to ask - what are you trying to accomplish with this? For a couple hundred dollars more you could get a whole new bike the same quality as what would have come with Suntour forks bak in the 90s. FOr the same price you could likely find something considerably better if you go for a used bike.

IMHO, this would not be as much an 'upgrade' as a 'waste of money.' If you current fork is completely buggered but the rest of the bike is immaculate, then a replacement rigid fork would be a better choice.


It's a 2010 steel hardtail (comfort) bike that I am converting to a trail bike. Right now it does ok on the trails but was wanting a little more travel.
I've put a quill on it now that converts it to threadless for my new stem and handlebars. I'm thinking the quill was 25.4mm, bought it from Nashbar.
The brakes are linear pull right now so if the fork that I am looking at will fit, I can still use the brakes that I've got and could eventually upgrade to disc later on.


fietsbob
08-02-12, 11:06 AM
Right now I have a cheap Suntour threaded suspension fork with threaded headset.

Well, depends on measurements ,

A stem which is itself 1" in diameter is in a 9/8" steerer tube .

it is 1" ID, 1_1/8" OD

a Fork that has a 1" steerer tube has a 7/8" stem in it. AKA.. 22.2 ID, 25.4 OD.

Decatur_Tide
08-02-12, 11:14 AM
Well, depends on measurements ,

A stem which is itself 1" in diameter is in a 9/8" steerer tube .

it is 1" ID, 1_1/8" OD

a Fork that has a 1" steerer tube has a 7/8" stem in it. AKA.. 22.2 ID, 25.4 OD.

Thanks fietsbob, I think the steerer tube is 1 1/8" OD because I have a 25.4mm quill adapter inserted into it right now.

DCB0
08-02-12, 11:19 AM
It sounds like it should work.

I doubt there will be a very big difference in performance, though.

Decatur_Tide
08-02-12, 11:36 AM
It sounds like it should work.

I doubt there will be a very big difference in performance, though.

You're probably right DCBO, just going from 50mm to 100 mm travel to smooth things out a bit.

Thanks for your input.