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Motivation:
This answer says that installing a rigid fork on a frame, designed for a suspension, changes the geometry. Most answers to my question about rusted-out suspension recommend installing rigid suspension for riding in the rain and snow.

The question:
What changes to the feel of riding should I expect when changing a low to medium (80-100mm) travel suspension fork for a rigid fork? My bike is this one:

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Vorac
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    Assuming you find one with the same rake, I don't imagine the geometry would be any different between having a rigid fork, and having a suspension fork with the lock-out enabled. – Kibbee Dec 17 '12 at 14:28
  • @Kibbee, quite logical. I shall ride some with the fork locked, to get a feel of what it would be! – Vorac Dec 17 '12 at 14:50
  • A locked fork still has a bit of give, less than full travel, but usually it has some cushioning. It won't behave exactly like a rigid fork, but it will give you a bit better idea of what you're getting in to. Keep in mind, with less suspension, your tire pressure will have a bigger impact on the feel of your ride. – Benzo Dec 17 '12 at 15:33
  • That other answer is about putting a suspension fork on a bike not designed for suspension. – freiheit Dec 17 '12 at 17:50
  • @Kibbee - Suspension forks in lockout do so when at normal extension, no full compression- the axle to crown distance is larger than a traditional rigid fork, completely changing the bikes geometry. Have a look at the answer by Benzo – mattnz Dec 17 '12 at 20:14

2 Answers2

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Unless the correct fork is chosen , the bikes geometry will change. A rigid fork built for a bike designed for rigid forks has a smaller axle to crown measurement than a suspension fork. If your bike is designed for 100mm travel suspension, and you put "any old" rigid fork on, the front of you bike will be 100mm lower than it is now. Even if you correct this in the Steerer/stem/handlebars, this will be enough to upset the rake and therefore alter the handling of the bike. (refer @Benzo for the answer to this problem)

The bike will (should) be significantly lighter with the benefits that go with that.

If you are riding smooth pavement, the changes will be you feel more bumps, and need to use you arms to absorb and control the front of the bike if you hit small bumps in corners. Tyre choice and pressure becomes more important, as does attention to the surface ahead of you. The big gain is that you bike is more efficient - no soft squashy absorbing energy in the front end (even locked out suspension moves) - you will go faster.

Off road riding is a completely different ball game. If you are used to suspension and riding bumpy ground hard, you will need to change you style. Expect a few prangs along the way. When riding suspension, you weigh it in corners and let the shocks hold the front wheel on the ground over the bumps. Without suspension, the same technique will lead to the front wheel bouncing and loosing traction, with predictable consequences..... You need to learn to let your arms become the suspension, and your arms need to control the front wheel no only in direction, but "height" and "pressure on ground". The term "loose" takes in a new meaning. It requires more skill and concentration, and far more attention to detail than riding a suspension setup give, as well as being physically harder, but also in some ways, more rewarding.

mattnz
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  • I primarily ride a rigid 29er and can definitely attest that if you do off road riding, it will be much more work for your arms, shoulders, and upper back. This isn't a bad thing, just different. Certain features such as large roots and rock gardens can be a bit jarring compared to when using suspension. – Benzo Dec 18 '12 at 03:15
  • Soooo .... what parameters define the "correct fork"? Btw very insightful answer, thank you mattnz – Vorac Dec 18 '12 at 08:24
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    Arrhh, the million dollar question. Measure either the height of the bottom of the steerer tube to axle. The correct fork will be as close as possible to this measurement, for the same tire size. If you want to have a "play", you could consider a 29'er (700C) fork - in which case height of ground to bottom of steerer will need to be used (or simple math). If the wheel clears the downtube, and you don't mind different sized wheels, it might be an option worth considering. (29'ers are bigger wheels, meaning a standard 29'er fork will be quite close to the right geometry. – mattnz Dec 19 '12 at 04:46
  • Any valid reason for the down vote? Whats the objection to this answer? – mattnz Dec 20 '12 at 20:28
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Surly has suspension corrected forks for mountain bikes, try 1x1 fork for 26in or ogre or karate monkey for 29er. Check it out.

http://surlybikes.com/parts/category/forks

Benzo
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  • +1: Not really an answer to the question... But very valuable none the less – mattnz Dec 17 '12 at 20:17
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    "If you use a suspension corrected fork, the geometry won't change, so there won't be changes to the feel caused by geometry changes" is at least a partial answer to the question. – armb Feb 06 '13 at 14:06