Improving my Whyte PRST4.

I enjoyed my last trail ride up Great Hill on my Whyte PRST4, a full suspension mountain bike from 2004. A lot, however, has changed in bike design since those days and I was left wondering if the PRST4 could handle some of the trails which I routinely ride on more modern bikes. It only has 100 mm of suspension travel at each end but I noticed after my ride that I was only getting around two thirds of this travel.

I wasn’t getting anywhere near full travel.

I have a very similar bike in the form of a Whyte JW4 which has the same frame but a lower specification of components, including the shock absorbers. The PRST has Fox shox whilst the JW has XFusion. I set the pressures in the units to approximately match my body weight of 180 lbs at the rear and 75% of this figure at the front, so about 140 in psi (pounds per square inch). This seems to work fine on the XFusions and I get full travel on a big hit but it must be too much pressure for the Fox alternative. So before todays ride I reduced the pressures to 160 psi rear and 120 psi front and planned a trail ride to test things out.

We’d walked our dog, Freddie, along the canal bank at Adlington this morning and I was reminded of a trail which goes through some woodland towards a sand pit which is still producing sand. The start of the trail looked well used so I decided to ride it from the other end, then I could ride back with the help of gravity. I rode first through Duxbury Woods then started on the chosen trail. I don’t know if I’ve always ridden here earlier in the year but much of the trail was obscured by Himalayan Balsam which, in Britain, is a pernicious weed. It seeds so prolifically and is so tall that it blots out many kinds of vegetation, forming a monoculture. In addition there were so many fallen trees across the trail that I could only keep going for short distances each time. There was no point in trying to ride back down the trail so I changed my plan and climbed Healey Nab for its purpose built trails.

On the rest of the ride I put some effort in and unleashed the capabilities of a very unusual bike. According to the app. Strava I rode many segments, both climbs and descents, at a good speed. I even set some personal best times! The PRST4 was built at a time when light weight was a major consideration in bike design. It could be built as light as 10kg where a modern full suspension bike could easily weigh 15kg. I don’t know the weight of my bike, which I built up with whatever parts I had available but it’s certainly the lightest bike I own.

With less pressure in the shock absorbers I got to use all of the travel at the front but will reduce the pressure further at the rear. I found less of the jarring over rocks when under power and changed my technique to help further. By pulling back on the handlebars on rough climbs the front wheel skipped over rocks far better. I had a better ride than last time and think that if I ride Great Hill again on the PRST I’ll be in a much better position with the correct shock pressures and a little tweek to my riding technique.

Leave a Comment

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s